WorldWideScience

Sample records for dst ventilation system

  1. ALARACT Demonstration for Primary Ventilation Systems at the DST Tank Farms for the Interim Stabilization Project (Saltwell Pumping) [SEC 1 Thru 3

    International Nuclear Information System (INIS)

    STAM, E.C.

    2002-01-01

    A demonstration of As Low As Reasonably Achievable Control Technology (ALARACT) was performed for the existing Double Shell Tank (DST) farm primary ventilation systems in support of the Single Shell Tanks (SSTs) Interim Stabilization Project. The primary ventilation systems evaluated in this ALARACT are located at the 241-AW, AN, AP, and SY tank farms. Of these farms, only the AP and SY farms are scheduled to receive SST waste prior to new ventilation systems being installed at the farms. As a result, full evaluations were performed for the 241-AP and SY systems, whereas only partial evaluations were performed for the 241-AN and AW systems. The full evaluation included the evaluation of the stack sampling system, whereas the partial evaluation did not. Also, 241-AY and AZ are not scheduled to receive SST waste so they were both excluded completely from the evaluation. This ALARACT demonstration evaluated the ability of the abatement and control technologies in the DST ventilation systems identified above to function during SST waste transfers as part of the SST Interim Stabilization Project. Where available, field data (waste temperatures) gathered during actual saltwell pumping activities, were used to support this demonstration. Also used were other process data and equipment capacities associated with the system evaluation. Where actual field data were not available, conservative assumptions, based upon process knowledge and standard engineering calculation methodologies, were used. The DST ventilation systems were also evaluated for compliance against the technology standards identified in Washington Administrative Code (WAC) 246-247, Radioactive Air Emissions, as well as other governing codes and standards

  2. Ventilation systems

    International Nuclear Information System (INIS)

    Gossler

    1980-01-01

    The present paper deals with - controlled area ventilation systems - ventilation systems for switchgear-building and control-room - other ventilation systems for safety equipments - service systems for ventilation systems. (orig./RW)

  3. EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY FOR TOXICS (TBACT) DOUBLE SHELL TANK FARMS PRIMARY VENTILATION SYSTEMS SUPPORTING WASTE TRANSFER OPERATIONS

    International Nuclear Information System (INIS)

    Haas, C.C.; Kovach, J.L.; Kelly, S.E.; Turner, D.A.

    2010-01-01

    This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste through the DST storage system to the Waste Treatment and Immobilization Plant (WTP).

  4. EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY FOR TOXICS -TBACT- DOUBLE SHELL TANK FARMS PRIMARY VENTILATION SYSTEMS SUPPORTING WASTE TRANSFER OPERATIONS

    Energy Technology Data Exchange (ETDEWEB)

    HAAS CC; KOVACH JL; KELLY SE; TURNER DA

    2010-06-24

    This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste through the DST storage system to the Waste Treatment and Immobilizaiton Plant (WTP).

  5. EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY FOR TOXICS (TBACT) DOUBLE SHELL TANK FARMS PRIMARY VENTILATION SYSTEM SUPPORTING WASTE TRANSFER OPERATIONS

    Energy Technology Data Exchange (ETDEWEB)

    KELLY SE; HAASS CC; KOVACH JL; TURNER DA

    2010-06-03

    This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste throught the DST storage system to the Waste Treatment and Immobilization Plant (WTP).

  6. EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY FOR TOXICS (TBACT) DOUBLE SHELL TANK FARMS PRIMARY VENTILATION SYSTEM SUPPORTING WASTE TRANSFER OPERATIONS

    International Nuclear Information System (INIS)

    Kelly, S.E.; Haass, C.C.; Kovach, J.L.; Turner, D.A.

    2010-01-01

    This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste through out the DST storage system to the Waste Treatment and Immobilization Plant (WTP).

  7. 76 FR 32227 - DST Systems, Inc., Including On-Site Leased Workers From Comsys Information Technology Services...

    Science.gov (United States)

    2011-06-03

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,649; TA-W-74,649a] DST Systems... Kelly Services Kansas City, MO; DST Technologies, a Wholly Owned Subsidiary of DST Systems, Inc., Boston... November 5, 2010, applicable to workers of DST Systems, Inc., including on-site leased workers from Comsys...

  8. VENTILATION TECHNOLOGY SYSTEMS ANALYSIS

    Science.gov (United States)

    The report gives results of a project to develop a systems analysis of ventilation technology and provide a state-of-the-art assessment of ventilation and indoor air quality (IAQ) research needs. (NOTE: Ventilation technology is defined as the hardware necessary to bring outdoor ...

  9. Protective garment ventilation system

    Science.gov (United States)

    Lang, R. (Inventor)

    1970-01-01

    A method and apparatus for ventilating a protective garment, space suit system, and/or pressure suits to maintain a comfortable and nontoxic atmosphere within is described. The direction of flow of a ventilating and purging gas in portions of the garment may be reversed in order to compensate for changes in environment and activity of the wearer. The entire flow of the ventilating gas can also be directed first to the helmet associated with the garment.

  10. Ontogeny and Evolution Through the Lens of the Developmental Systems Theory (DST

    Directory of Open Access Journals (Sweden)

    Vicente Dressino

    2017-09-01

    Full Text Available The Developmental Systems Theory (DST intends to make a conceptual summary that links ontogenic development to evolution. This theory’s background may be found in the works of Waddington and Bertalanffy, who provided the foundations for the canalization of development and the biological systems theory, respectively. The aim of this work is to make a preliminary conceptual analysis of DST as a theoretical framework for developmental biology in particular and for evolutionary biology in general. For that purpose, we will take into account some of the concepts and proposals that constitute this framework, and we will work with secondary data obtained from the bibliography. We conclude that: 1. DST is able to argue against the gene centrist vision about the explanations that try to justify biological and evolutionary development; 2. DST argues coherently in favor of the role of Epigenetics in ontogeny and evolution; 3. In connection to that, the role of natural selection is restricted to a secondary plane; 4. DST proposes that the nature/nurture dichotomy must be overcome; and 5. DST constitutes a possible methodological research program composed of a series of not necessarily related hypothesis, theories, and methods that may be confirmed in a relatively independent manner from the rest of the theoretical network.

  11. Overall Subsurface Ventilation Systems

    International Nuclear Information System (INIS)

    Thomas, Edward G.

    2000-01-01

    The purpose of this analysis is to provide a conceptual design for the Subsurface Ventilation System and address the construction, emplacement, monitoring, backfill, and closure ventilation phases. The design will be based on the recently established program requirements for transitioning to the Site Recommendation (SR) design as outlined by ''Approach to Implementing the Site Recommendation Baseline'' (Stroupe 2000) and the Monitored Geologic Repository Project Description Document (CRWMS M and O 1999d) (MGR). This analysis will summarize the ventilation concepts that have developed from the incorporation of recent changes to the Technical Baseline and describe changes to the conceptual ventilation design that have resulted from the thermal management requirements. Ventilation concepts presented in the Viability Assessment Design (VA Design) that have not changed are identified and included. The objective of this analysis is to provide a basis for the System Description Document (SDD) Section 2 that provides input to the SR Consideration Report. The scope of the analysis includes the following tasks: (1) Determine the number of primary shafts based on the emplacement airflow rate required to meet thermal goals and (2) Determine conceptual airflow networks for major repository phases including: Construction; Emplacement; Monitoring; and Closure. In addition evaluate: (1) Radon mitigation concerns and options; (2) Monitoring and control requirement changes needed to meet current guidelines; and (3) The impact on the ventilation system of a radiological release due to a potential subsurface fire involving a waste package

  12. Work Plan for Updating Double Shell Tank (DST) Sub-System Specifications (TBR 120.020)

    International Nuclear Information System (INIS)

    GRENARD, C.E.

    1999-01-01

    The DST System stores waste from the processing of nuclear material at the Hanford Nuclear Reservation. The program to dispose of this waste has been divided into several phases with Phase 1 being the demonstration of the waste disposal technology by a private contractor. Subsystem specifications are being prepared providing requirements for the subsystems that are necessary for the continued safe storage of waste in the DST System and the removal of selected waste for processing by the privatized facility during Phase 1. This document provides the detailed plans for updating subsystem specifications developed during EY99

  13. Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Svendsen, Sv Aa Højgaard

    1999-01-01

    The note concerns ventilation in residential buildings. Describes components in ventilation systems, electric energy consumption and different ventilation systems with heat exchanger.......The note concerns ventilation in residential buildings. Describes components in ventilation systems, electric energy consumption and different ventilation systems with heat exchanger....

  14. How to Plan Ventilation Systems.

    Science.gov (United States)

    Clarke, John H.

    1963-01-01

    Ventilation systems for factory safety demand careful planning. The increased heat loads and new processes of industry have introduced complex ventilation problems in--(1) ventilation supply, (2) duct work design, (3) space requirements, (4) hood face velocities, (5) discharge stacks, and (6) building eddies. This article describes and diagrams…

  15. Emplacement ventilation system

    International Nuclear Information System (INIS)

    Vance, Robert W.

    2000-01-01

    This analysis updates design concepts for emplacement ventilation based upon the increased air flow required through the drift in the EDA II design (CRWMS M and O 1999a, Table O-6) and by current thermal modeling results compared to the VA design (DOE 1998, Section 4.2.4). It reviews the air pathway in the emplacement drift, describes three exhaust system options, discusses two air control options, and examines concepts for several system physical components including isolation doors, a portable shadow shield, and a partition in an exhaust main. The air path through the emplacement drift, itself, remains the same as described in the VA and EDA II design; that is, exhaust fans located on the surface pull air through an intake shaft into the subsurface repository. The ventilation air is distributed to the east and west mains by the cross-block drifts. From the mains, the air enters the emplacement drifts and flows to a central exhaust raise. The air then travels down an exhaust raise to the exhaust system

  16. Alternatives generation and analysis for double-shell tank primary ventilation systems emissions control and monitoring

    International Nuclear Information System (INIS)

    SEDERBURG, J.P.

    1999-01-01

    This AGA addresses the question: ''What equipment upgrades, operational changes, and/or other actions are required relative to the DST tanks farms' ventilation systems to support retrieval, staging (including feed sampling), and delivery of tank waste to the Phase I private contractor?'' Issues and options for the various components within the ventilation subsystem affect each other. Recommended design requirements are presented and the preferred alternatives are detailed

  17. Alternatives generation and analysis for double-shell tank primary ventilation systems emissions control and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    SEDERBURG, J.P.

    1999-09-30

    This AGA addresses the question: ''What equipment upgrades, operational changes, and/or other actions are required relative to the DST tanks farms' ventilation systems to support retrieval, staging (including feed sampling), and delivery of tank waste to the Phase I private contractor?'' Issues and options for the various components within the ventilation subsystem affect each other. Recommended design requirements are presented and the preferred alternatives are detailed.

  18. Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems

    OpenAIRE

    Sherman, Max H.

    2011-01-01

    Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outd...

  19. Subsurface Ventilation System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    Eric Loros

    2001-07-25

    The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

  20. Subsurface Ventilation System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-12

    The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

  1. Demand Controlled Ventilation in a Combined Ventilation and Radiator System

    OpenAIRE

    Hesaraki, Arefeh; Holmberg, Sture

    2013-01-01

    With growing concerns for efficient and sustainable energy treatment in buildings there is a need for balanced and intelligent ventilation solutions. This paper presents a strategy for demand controlled ventilation with ventilation radiators, a combined heating and ventilation system. The ventilation rate was decreased from normal requirements (per floor area) of 0.375 l·s-1·m-2 to 0.100 l·s-1·m-2 when the residence building was un-occupied. The energy saving potential due to decreased ventil...

  2. Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.; Walker, Iain S.

    2011-04-01

    Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outdoor pollutant levels are high, the importance of minimizing energy use particularly during times of peak electricity demand, and how the energy used to condition air as part of ventilation system operation changes with outdoor conditions. Dynamic control of ventilation systems can provide ventilation equivalent to or better than what is required by standards while minimizing energy costs and can also add value by shifting load during peak times and reducing intake of outdoor air contaminants. This article describes the logic that enables dynamic control of whole-house ventilation systems to meet the intent of ventilation standards and demonstrates the dynamic ventilation system control concept through simulations and field tests of the Residential Integrated Ventilation-Energy Controller (RIVEC).

  3. Ogaji, DST

    African Journals Online (AJOL)

    Ogaji, DST. Vol 8, No 1 (2006) - Articles Sexuality, Contraception And Unintended Pregnancy Among Female Student Nurses In Calabar, Nigeria Abstract PDF. ISSN: 0795-0268. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners ...

  4. Preoperational test report, vent building ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Vent Building Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides Heating, Ventilation, and Air Conditioning (HVAC) for the W-030 Ventilation Building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  5. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111.103-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Power ventilation systems except machinery space ventilation systems. Each power ventilation system must...

  6. STRONTIUM & TRANSURANIC (TRU) SEPARATION PROCESS IN THE DOUBLE SHELL TANK (DST) SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSON; SWANSON; BOECHLER

    2005-06-10

    The supernatants stored in tanks 241-AN-102 (AN-102) and 241-AN-107 (AN-107) contain soluble strontium-90 ({sup 90}Sr) and transuranic (TRU) elements that require removal prior to vitrification to comply with the Waste Treatment and Immobilization Plant (WTP) immobilized low-activity waste (ILAW) specification and with the 1997 agreement with the Nuclear Regulatory Commission on incidental waste. A precipitation process has been developed and tested with tank waste samples and simulants using strontium nitrate (Sr(NO{sub 3}){sub 2}) and sodium permanganate (NaMnO{sub 4}) to separate {sup 90}Sr and TRU from these wastes. This report evaluates removing Sr/TRU from AN-102 and AN-107 supernates in the DST system before delivery to the WTP. The in-tank precipitation is a direct alternative to the baseline WTP process, using the same chemical separations. Implementing the Sr/TRU separation in the DST system beginning in 2012 provides {approx}6 month schedule advantage to the overall mission, without impacting the mission end date or planned SST retrievals.

  7. The DST method for solar domestic hot water systems - Research and development for ISO and CEN standards

    NARCIS (Netherlands)

    Visser, H.; Ree, B.G.C. van der

    1996-01-01

    The Dynamic System Test (DST) method for performance characterization of solar domestic hot water (SDHW) systems has been the subject of international research for a number of years. At present, several countries are using the method and it is being standardized on international and European levels.

  8. Bridging the gap: Research and validation of the DST (Dynamic System Testing) performance test method for CE and ISO standards. Progress and preliminary results

    NARCIS (Netherlands)

    Naron, D.J.; Ree, B.G.C. van der; Rolloos, M.

    1998-01-01

    The Dynamic System Testing (DST) method is one of the methods chosen in the preliminary CEN/TC 312 European quality standards [1 ] to measure the energetic performance of Solar Domestic Hot Water (SDHW) systems. These European standards make a reference to the DST procedure as defined in the Draft

  9. 14 CFR 252.9 - Ventilation systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ventilation systems. 252.9 Section 252.9... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully functioning. Fully functioning for this purpose means operating so...

  10. Improvements of uranium mine ventilation system

    International Nuclear Information System (INIS)

    Liu Changrong; Zhou Xinghuo; Liu Zehua; Wang Zhiyong

    2007-01-01

    Ventilation has been proved to be a main method to eliminate radon and its daughters in uranium mines. According to the practical rectifications of uranium mine ventilation system, the improved measures are summarized. (authors)

  11. Architectural constructs of Ampex DST

    Science.gov (United States)

    Johnson, Clay

    1993-01-01

    The DST 800 automated library is a high performance, automated tape storage system, developed by AMPEX, providing mass storage to host systems. Physical Volume Manager (PVM) is a volume server which supports either a DST 800, DST 600 stand alone tape drive, or a combination of DST 800 and DST 600 subsystems. The objective of the PVM is to provide the foundation support to allow automated and operator assisted access to the DST cartridges with continuous operation. A second objective is to create a data base about the media, its location, and its usage so that the quality and utilization of the media on which specific data is recorded and the performance of the storage system may be managed. The DST tape drive architecture and media provides several unique functions that enhance the ability to achieve high media space utilization and fast access. Access times are enhanced through the implementation of multiple areas (called system zones) on the media where the media may be unloaded. This reduces positioning time in loading and unloading the cartridge. Access times are also reduced through high speed positioning in excess of 800 megabytes per second. A DST cartridge can be partitioned into fixed size units which can be reclaimed for rewriting without invalidating other recorded data on the tape cartridge. Most tape management systems achieve space reclamation by deleting an entire tape volume, then allowing users to request a 'scratch tape' or 'nonspecific' volume when they wish to record data to tape. Physical cartridge sizes of 25, 75, or 165 gigabytes will make this existing process inefficient or unusable. The DST cartridge partitioning capability provides an efficient mechanism for addressing the tape space utilization problem.

  12. Preoperational test report, primary ventilation system

    International Nuclear Information System (INIS)

    Clifton, F.T.

    1997-01-01

    This represents a preoperational test report for Primary Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space filtered venting of tanks AY101, AY102, AZ101, AZ102. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

  13. Preoperational test report, primary ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Primary Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space filtered venting of tanks AY101, AY102, AZ101, AZ102. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  14. A New DST-Belief Theoretic Project Selection Model for Multi-Criteria Decision Support System

    Science.gov (United States)

    Bakshi, Tuli; Sinharay, Arindam; Sarkar, Bijan; Sanyal, Subir Kumar

    2015-10-01

    Decision-making problem is co-related to quality and availability of the information. Innovative algorithms are proposed as a mathematical problem-solving technique to work in uncertainty-based decision science domain. Evidence-based theory of Dempster-Shafer (DST) is an effective mathematical tool to deal with uncertainty in the decision-making procedure. The current research exposition on new decision-making method based on DST of evidence, quantification evidence preference from different multiple criteria defined by belief function has been presented. They have developed a new framework that tackles the challenges and borne out of uncertainty both in criteria and in alternative levels. The proposed hybridized MCDM tool developed upon fuzzy domain uses plausibility and theory of belief function to construct decision on uncertain and imprecise information. The proposed method can be well fitted for real-life application. An illustrative example establishes the effectiveness of the aforesaid method.

  15. 46 CFR 153.312 - Ventilation system standards.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Ventilation system standards. 153.312 Section 153.312... Handling Space Ventilation § 153.312 Ventilation system standards. A cargo handling space ventilation system must meet the following: (a) A ventilation system exhaust duct must discharge no less than 10 m...

  16. A NEW EXHAUST VENTILATION SYSTEM DESIGN SOFTWARE

    Directory of Open Access Journals (Sweden)

    H. Asilian Mahabady

    2007-09-01

    Full Text Available A Microsoft Windows based ventilation software package is developed to reduce time-consuming and boring procedure of exhaust ventilation system design. This program Assure accurate and reliable air pollution control related calculations. Herein, package is tentatively named Exhaust Ventilation Design Software which is developed in VB6 programming environment. Most important features of Exhaust Ventilation Design Software that are ignored in formerly developed packages are Collector design and fan dimension data calculations. Automatic system balance is another feature of this package. Exhaust Ventilation Design Software algorithm for design is based on two methods: Balance by design (Static pressure balance and design by Blast gate. The most important section of software is a spreadsheet that is designed based on American Conference of Governmental Industrial Hygienists calculation sheets. Exhaust Ventilation Design Software is developed so that engineers familiar with American Conference of Governmental Industrial Hygienists datasheet can easily employ it for ventilation systems design. Other sections include Collector design section (settling chamber, cyclone, and packed tower, fan geometry and dimension data section, a unit converter section (that helps engineers to deal with units, a hood design section and a Persian HTML help. Psychometric correction is also considered in Exhaust Ventilation Design Software. In Exhaust Ventilation Design Software design process, efforts are focused on improving GUI (graphical user interface and use of programming standards in software design. Reliability of software has been evaluated and results show acceptable accuracy.

  17. Preoperational test report, primary ventilation condensate system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-01-29

    Preoperational test report for Primary Ventilation Condensate System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides a collection point for condensate generated by the W-030 primary vent offgas cooling system serving tanks AYIOI, AY102, AZIOI, AZI02. The system is located inside a shielded ventilation equipment cell and consists of a condensate seal pot, sampling features, a drain line to existing Catch Tank 241-AZ-151, and a cell sump jet pump. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  18. An intelligent control system for ventilators.

    Science.gov (United States)

    Wang, C S; Shaw, D; Jih, K S

    1998-10-01

    This study reports on a ventilator system that consists of several intelligent modules for controlling ventilator operation. These modules are software programs in two controllers. One controller is a personal computer used for diagnoses, determining settings and checking the effects of settings. The other controller is a single-chip microprocessor in a ventilator that controls the ventilator's settings in accordance with the computer settings. After setting up the system, an artificial lung model simulating a patient's lung is used to test the system. The result of test run indicated that it always responds to a patient's lung condition in a stable manner. Thus, the proposed system with its intelligent modules may assist clinicians in caring for patients and managing ventilator operation.

  19. Hybrid ventilation systems and high performance buildings

    Energy Technology Data Exchange (ETDEWEB)

    Utzinger, D.M. [Wisconsin Univ., Milwaukee, WI (United States). School of Architecture and Urban Planning

    2009-07-01

    This paper described hybrid ventilation design strategies and their impact on 3 high performance buildings located in southern Wisconsin. The Hybrid ventilation systems combined occupant controlled natural ventilation with mechanical ventilation systems. Natural ventilation was shown to provide adequate ventilation when appropriately designed. Proper control integration of natural ventilation into hybrid systems was shown to reduce energy consumption in high performance buildings. This paper also described the lessons learned from the 3 buildings. The author served as energy consultant on all three projects and had the responsibility of designing and integrating the natural ventilation systems into the HVAC control strategy. A post occupancy evaluation of building energy performance has provided learning material for architecture students. The 3 buildings included the Schlitz Audubon Nature Center completed in 2003; the Urban Ecology Center completed in 2004; and the Aldo Leopold Legacy Center completed in 2007. This paper included the size, measured energy utilization intensity and percentage of energy supplied by renewable solar power and bio-fuels on site for each building. 6 refs., 2 tabs., 6 figs.

  20. Hydrostatic Hyperbaric Chamber Ventilation System

    Science.gov (United States)

    Sarguisingh, Miriam J.

    2012-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy (HBOT) available in the developing world for the treatment of a variety of medical conditions. Specifically, HBOT is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. HBOT is simply too expensive and too dangerous to implement in the developing world using standard equipment. The HHC technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system to provide controlled pressurization and adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware

  1. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    Directory of Open Access Journals (Sweden)

    Yan Shi

    2014-01-01

    Full Text Available Volume controlled mechanical ventilation system is a typical time-delay system, which is applied to ventilate patients who cannot breathe adequately on their own. To illustrate the influences of key parameters of the ventilator on the dynamics of the ventilated respiratory system, this paper firstly derived a new mathematical model of the ventilation system; secondly, simulation and experimental results are compared to verify the mathematical model; lastly, the influences of key parameters of ventilator on the dynamics of the ventilated respiratory system are carried out. This study can be helpful in the VCV ventilation treatment and respiratory diagnostics.

  2. General design guide for ventilation systems for fuel reprocessing plants, September 1975

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    General safety, occupied area ventilation systems, process area ventilation systems, exhaust ventilation and filtration systems, ventilation system construction and layout ventilation system testing and monitoring, and the quality assurance program are discussed

  3. WASTE HANDLING BUILDING VENTILATION SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    P.A. Kumar

    2000-06-21

    The Waste Handling Building Ventilation System provides heating, ventilation, and air conditioning (HVAC) for the contaminated, potentially contaminated, and uncontaminated areas of the Monitored Geologic Repository's (MGR) Waste Handling Building (WHB). In the uncontaminated areas, the non-confinement area ventilation system maintains the proper environmental conditions for equipment operation and personnel comfort. In the contaminated and potentially contaminated areas, in addition to maintaining the proper environmental conditions for equipment operation and personnel comfort, the contamination confinement area ventilation system directs potentially contaminated air away from personnel in the WHB and confines the contamination within high-efficiency particulate air (HEPA) filtration units. The contamination confinement areas ventilation system creates airflow paths and pressure zones to minimize the potential for spreading contamination within the building. The contamination confinement ventilation system also protects the environment and the public by limiting airborne releases of radioactive or other hazardous contaminants from the WHB. The Waste Handling Building Ventilation System is designed to perform its safety functions under accident conditions and other Design Basis Events (DBEs) (such as earthquakes, tornadoes, fires, and loss of the primary electric power). Additional system design features (such as compartmentalization with independent subsystems) limit the potential for cross-contamination within the WHB. The system provides status of important system parameters and equipment operation, and provides audible and/or visual indication of off-normal conditions and equipment failures. The Waste Handling Building Ventilation System confines the radioactive and hazardous material within the building such that the release rates comply with regulatory limits. The system design, operations, and maintenance activities incorporate ALARA (as low as is

  4. NASA JPL Distributed Systems Technology (DST) Object-Oriented Component Approach for Software Inter-Operability and Reuse

    Science.gov (United States)

    Hall, Laverne; Hung, Chaw-Kwei; Lin, Imin

    2000-01-01

    The purpose of this paper is to provide a description of NASA JPL Distributed Systems Technology (DST) Section's object-oriented component approach to open inter-operable systems software development and software reuse. It will address what is meant by the terminology object component software, give an overview of the component-based development approach and how it relates to infrastructure support of software architectures and promotes reuse, enumerate on the benefits of this approach, and give examples of application prototypes demonstrating its usage and advantages. Utilization of the object-oriented component technology approach for system development and software reuse will apply to several areas within JPL, and possibly across other NASA Centers.

  5. Underground ventilation remote monitoring and control system

    International Nuclear Information System (INIS)

    Strever, M.T.; Wallace, K.G. Jr.; McDaniel, K.H.

    1995-01-01

    This paper presents the design and installation of an underground ventilation remote monitoring and control system at the Waste Isolation Pilot Plant. This facility is designed to demonstrate safe underground disposal of U.S. defense generated transuranic nuclear waste. To improve the operability of the ventilation system, an underground remote monitoring and control system was designed and installed. The system consists of 15 air velocity sensors and 8 differential pressure sensors strategically located throughout the underground facility providing real-time data regarding the status of the ventilation system. In addition, a control system was installed on the main underground air regulators. The regulator control system gives indication of the regulator position and can be controlled either locally or remotely. The sensor output is displayed locally and at a central surface location through the site-wide Central Monitoring System (CMS). The CMS operator can review all sensor data and can remotely operate the main underground regulators. Furthermore, the Virtual Address Extension (VAX) network allows the ventilation engineer to retrieve real-time ventilation data on his personal computer located in his workstation. This paper describes the types of sensors selected, the installation of the instrumentation, and the initial operation of the remote monitoring system

  6. 33 CFR 183.610 - Powered ventilation system.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Powered ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.610 Powered ventilation system... must: (1) Be open to the atmosphere, or (2) Be ventilated by an exhaust blower system. (b) Each exhaust...

  7. 46 CFR 153.310 - Ventilation system type.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Ventilation system type. 153.310 Section 153.310... Handling Space Ventilation § 153.310 Ventilation system type. A cargo handling space must have a permanent forced ventilation system of the exhaust type. ...

  8. 33 CFR 183.620 - Natural ventilation system.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Natural ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.620 Natural ventilation system. (a) Except for compartments open to the atmosphere, a natural ventilation system that meets the...

  9. Fires in large scale ventilation systems

    International Nuclear Information System (INIS)

    Gregory, W.S.; Martin, R.A.; White, B.W.; Nichols, B.D.; Smith, P.R.; Leslie, I.H.; Fenton, D.L.; Gunaji, M.V.; Blythe, J.P.

    1991-01-01

    This paper summarizes the experience gained simulating fires in large scale ventilation systems patterned after ventilation systems found in nuclear fuel cycle facilities. The series of experiments discussed included: (1) combustion aerosol loading of 0.61x0.61 m HEPA filters with the combustion products of two organic fuels, polystyrene and polymethylemethacrylate; (2) gas dynamic and heat transport through a large scale ventilation system consisting of a 0.61x0.61 m duct 90 m in length, with dampers, HEPA filters, blowers, etc.; (3) gas dynamic and simultaneous transport of heat and solid particulate (consisting of glass beads with a mean aerodynamic diameter of 10μ) through the large scale ventilation system; and (4) the transport of heat and soot, generated by kerosene pool fires, through the large scale ventilation system. The FIRAC computer code, designed to predict fire-induced transients in nuclear fuel cycle facility ventilation systems, was used to predict the results of experiments (2) through (4). In general, the results of the predictions were satisfactory. The code predictions for the gas dynamics, heat transport, and particulate transport and deposition were within 10% of the experimentally measured values. However, the code was less successful in predicting the amount of soot generation from kerosene pool fires, probably due to the fire module of the code being a one-dimensional zone model. The experiments revealed a complicated three-dimensional combustion pattern within the fire room of the ventilation system. Further refinement of the fire module within FIRAC is needed. (orig.)

  10. Preoperational test report, recirculation ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-11

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  11. Ventilation system for 99Mo production apparatus

    International Nuclear Information System (INIS)

    Izumo, Mishiroku; Okane, Shougo; Sorita, Takami; Aoyama, Saburou

    1978-04-01

    In production of 20 Ci 99 Mo from 235 U fission, about 120 Ci of radioiodine ( 131 I, 132 I, and 133 I) is involved. To remove airborne radioiodine from the exhaust air from production apparatus and minimize radioiodine release to the atmosphere, the ventilation system is equipped with 2 units of Model-FD charcoal filter (KI 3 -Impregnated charcoal 2 inch thick of Barnebey-Cheney Co.). From September 1976 to December 1977, 21 runs of 99 Mo production involving airborne radioiodine were carried out. The ventilation system was operated continuously for the whole 15 months period; variation in removal efficiency of airborne radioiodine from the exhaust air stream was observed. In the runs valuable experiences were gained in operation and maintenance of the ventilation system including activated charcoal filter and health-physics management of such facility. Following are the results: (1) Airborne radioiodine from 99 Mo production apparatus is reduced to 10 -3 % of the original quantity. (2) When the ventilation system is operated at a maximum air flow rate through the filter, the average efficiency during 15 months is over 98%. (3) Airborne radioiodine released from 99 Mo production apparatus to the ventilation system is less than 5% particulate iodine and alkyl iodines and more than 95% inorganic iodine. (4) Airborne radioiodine released from the stack is less than 28 μCi/run, which is below the limit in regulations on Radioisotope Production Laboratory. (auth.)

  12. Fire protection in ventilation systems and in case of fire operating ventilation systems

    International Nuclear Information System (INIS)

    Zitzelsberger, J.

    1983-01-01

    The fire risks in ventilation systems are discussed. It follows a survey of regulations on fire prevention and fire protection in ventilation systems and smoke and heat exhaust systems applicable to nuclear installations in the Federal Republic of Germany. Fire protection concepts for normal systems and for systems operating also in case of fire will be given. Several structural elements for fire protection in those systems will be illustrated with regard to recent research findings

  13. Project Design Concept - Primary Ventilation System

    International Nuclear Information System (INIS)

    MCGREW, D.L.

    2000-01-01

    Tank Farm Restoration and Safe Operation (TFRSO), Project W-3 14 was established to provide upgrades that would improve the reliability and extend the system life of portions of the waste transfer, electrical, ventilation, instrumentation and control systems for the Hanford Site Tank Farms. An assessment of the tank farm system was conducted and the results are documented in system assessment reports. Based on the deficiencies identified in the tank farm system assessment reports, and additional requirements analysis performed in support of the River Protection Project (RPP), an approved scope for the TFRSO effort was developed and documented in the Upgrade Scope Summary Report (USSR), WHC-SD-W314-RPT-003, Rev. 4. The USSR establishes the need for the upgrades and identifies the specific equipment to be addressed by this project. This Project Design Concept (PDC) is in support of the Phase 2 upgrades and provides an overall description of the operations concept for the W-314 Primary Ventilation Systems. Actual specifications, test requirements, and procedures are not included in this PDC. The PDC is a ''living'' document, which will be updated throughout the design development process to provide a progressively more detailed description of the W-314 Primary Ventilation Systems design. The Phase 2 upgrades to the Primary Ventilation Systems shall ensure that the applicable current requirements are met for: Regulatory Compliance; Safety; Mission Requirements; Reliability; and Operational Requirements

  14. Advanced design of local ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Kulmala, I. [VTT Manufacturing Technology, Espoo (Finland). Safety Technology

    1997-12-31

    Local ventilation is widely used in industry for controlling airborne contaminants. However, the present design practices of local ventilation systems are mainly based on empirical equations and do not take quantitatively into account the various factors affecting the performance of these systems. The aim of this study was to determine the applicability and limitations of more advanced fluid mechanical methods to the design and development of local ventilation systems. The most important factors affecting the performance of local ventilation systems were determined and their effect was studied in a systematic manner. The numerical calculations were made with the FLUENT computer code and they were verified by laboratory experiments, previous measurements or analytical solutions. The results proved that the numerical calculations can provide a realistic simulation of exhaust openings, effects of ambient air flows and wake regions. The experiences with the low-velocity local supply air showed that these systems can also be modelled fairly well. The results were used to improve the efficiency and thermal comfort of a local ventilation unit and to increase the effective control range of exhaust hoods. In the simulation of the interaction of a hot buoyant source and local exhaust, the predicted capture efficiencies were clearly higher than those observed experimentally. The deviations between measurements and non-isothermal flow calculations may have partly been caused by the inability to achieve grid independent solutions. CFD simulations is an advanced and flexible tool for designing and developing local ventilation. The simulations can provide insight into the time-averaged flow field which may assist us in understanding the observed phenomena and to explain experimental results. However, for successful calculations the applicability and limitations of the models must be known. (orig.) 78 refs.

  15. Discussion for management of ventilation system in uranium mines

    International Nuclear Information System (INIS)

    Li Xianjie; Ren Jianjun; Hu Penghua

    2014-01-01

    Radon exhaustion and ventilation are surely regarded as key links for safety production and radiation protection in underground uranium mines, and the crucial point to achieve safety production goals lies in timely and accurately adjusting and controlling of ventilation technical measures and ventilation system management with the changing operation conditions of mines. This paper proposes corresponding countermeasures based on the respectively systematical analysis of daily ventilation management, ventilation facilities and structures management, and ventilation system information management in uranium mines. Furthermore, standardized management approaches and suggestions are put forward to realize standardization of uranium mines' ventilation management and radon exhaustion technique. (authors)

  16. A hybrid energy efficient building ventilation system

    International Nuclear Information System (INIS)

    Calay, Rajnish Kaur; Wang, Wen Chung

    2013-01-01

    The present paper presents a high performance cooling/heating ventilation system using a rotary heat exchanger (RHE), together with a reverse-cycle heat pump (RCHP) that can be integrated with various heat sources. Energy consumption in the building sector is largely dominated by the energy consumed in maintaining comfortable conditions indoors. For example in many developed countries the building heating, ventilation and air conditioning (HVAC) systems consume up to 50% of the total energy consumed in buildings. Therefore energy efficient HVAC solutions in buildings are critical for realising CO 2 targets at local and global level. There are many heating/cooling concepts that rely upon renewable energy sources and/or use natural low temperature heat sources in the winter and heat sinks in the summer. In the proposed system, waste energy from the exhaust air stream is used to precondition the outdoor air before it is supplied into the building. The hybrid system provides heating in the winter and cooling in the summer without any need for additional heating or cooling devices as required in conventional systems. Its performance is better than a typical reheat or air conditioning system in providing the same indoor air quality (IAQ) levels. It is shown that an energy saving up to 60% (heat energy) is achieved by using the proposed hybrid system in building ventilation applications. -- Highlights: • Hybrid ventilation system: the hybrid ventilation system uses a rotating regenerator and a reversible heat pump. • Heat recovery: heat recovery from exhaust air stream by rotary wheel type heat exchanger. • Reversible cycle heat pump (RCHP): additional heating or cooling of the supply air is provided by the RCHP. • Energy efficiency: energy savings of up to 60% using the proposed system are achievable

  17. Dimensionless study on dynamics of pressure controlled mechanical ventilation system

    International Nuclear Information System (INIS)

    Shi, Yan; Niu, Jinglong; Cai, Maolin; Xu, Weiqing

    2015-01-01

    Dynamics of mechanical ventilation system can be referred in pulmonary diagnostics and treatments. In this paper, to conveniently grasp the essential characteristics of mechanical ventilation system, a dimensionless model of mechanical ventilation system is presented. For the validation of the mathematical model, a prototype mechanical ventilation system of a lung simulator is proposed. Through the simulation and experimental studies on the dimensionless dynamics of the mechanical ventilation system, firstly, the mathematical model is proved to be authentic and reliable. Secondly, the dimensionless dynamics of the mechanical ventilation system are obtained. Last, the influences of key parameters on the dimensionless dynamics of the mechanical ventilation system are illustrated. The study provides a novel method to study the dynamic of mechanical ventilation system, which can be referred in the respiratory diagnostics and treatment.

  18. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: General. 154.1200 Section... CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a...

  19. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: Standards. 154.1205... CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a...

  20. CLASSIFICATION OF THE MGR SUBSURFACE VENTILATION SYSTEM

    International Nuclear Information System (INIS)

    R.J. Garrett

    1999-01-01

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) subsurface ventilation system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P7 ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

  1. Ventilation systems in houses. Special issue; Woonhuisventilatie. Special

    Energy Technology Data Exchange (ETDEWEB)

    Op ' t Veld, P.; Van der Aa, A. [Cauberg-Huygen Raadgevend Ingenieurs, Rotterdam (Netherlands); Verschoor, M.J.E. [Afdeling Koudetechniek en Warmtepompen, TNO Milieu, Energie en Procesinnovatie TNO-MEP, Apeldoorn (Netherlands); Van Gulik, L.H. [Itho, Scheidam (Netherlands); Van der Mark, K.; Overman, P. [AGPO, Breda (Netherlands); Roemer, J.C.; Schuitema, R. [ECN Duurzame Energie in de Gebouwde Omgeving DEGO, Petten (Netherlands); Weterings, M. [GGD voor Rotterdam e.o., Rotterdam (Netherlands); Rosenmai, T.; Rasmussen, S. [Copenhagen Business School, Copenhagen (Denmark); Vollebregt, R. [Bureau Kent, Utrecht (Netherlands); Smeets, L.J.M. [Nederlandse onderneming voor energie en milieu Novem, Utrecht (Netherlands)

    2001-06-01

    In 10 articles attention is paid to several aspects with respect to ventilation of houses. This issue includes an overview of suppliers of high-efficiency heat recovering balanced ventilation systems.

  2. Project W-314 DST and DCRT instrument and control systems, initial assessment

    International Nuclear Information System (INIS)

    Acree, C.D.

    1996-01-01

    This report contains an assessment of the instrument and control systems in the Double Shell Tank Farms and the 244-A DCRT. The assessment report contains data from physical inspection activities and an overall engineering assessment of the instruments and control systems in use in the Double Shell Tanks

  3. PUREX exhaust ventilation system installation test report

    International Nuclear Information System (INIS)

    Blackaby, W.B.

    1997-01-01

    This Acceptance Test Report validates the testing performed, the exceptions logged and resolved and certifies this portion of the SAMCONS has met all design and test criteria to perform as an operational system. The proper installation of the PUREX exhaust ventilation system components and wiring was systematically evaluated by performance of this procedure. Proper operation of PUREX exhaust fan inlet, outlet, and vortex damper actuators and limit switches were verified, using special test equipment, to be correct and installed wiring connections were verified by operation of this equipment

  4. Double Shell Tank (DST) Monitor and Control Subsystem Definition Report

    International Nuclear Information System (INIS)

    BAFUS, R.R.

    2000-01-01

    The system description of the Double-Shell Tank (DST) Monitor and Control Subsystem establishes the system boundaries and describes the interface of the DST Monitor and Control Subsystem with new and existing systems that are required to accomplish the Waste Feed Delivery (WFD) mission

  5. Hybrid Ventilation with Innovative Heat Recovery—A System Analysis

    Directory of Open Access Journals (Sweden)

    Bengt Hellström

    2013-02-01

    Full Text Available One of the most important factors when low energy houses are built is to have good heat recovery on the ventilation system. However, standard ventilation units use a considerable amount of electricity. This article discusses the consequences on a system level of using hybrid ventilation with heat recovery. The simulation program TRNSYS was used in order to investigate a ventilation system with heat recovery. The system also includes a ground source storage and waste water heat recovery system. The result of the analysis shows that the annual energy gain from ground source storage is limited. However, this is partly a consequence of the fact that the well functioning hybrid ventilation system leaves little room for improvements. The analysis shows that the hybrid ventilation system has potential to be an attractive solution for low energy buildings with a very low need for electrical energy.

  6. Tracer gas evaluations of push-pull ventilation system performance.

    Science.gov (United States)

    Ojima, Jun

    2009-01-01

    A push-pull ventilation system is effective for hazardous material exhaustion. Although a push-pull ventilation system has advantages over a local exhaust hood, some laborious adjustments are required. The pertinence of the adjustments is uncertain because it is difficult to evaluate the performance of a push-pull ventilation system quantitatively. In this study, a measurement of the capture efficiency of a push-pull ventilation system was carried out by means of a tracer gas method. The capture efficiency decreased to 39.3-78.5% when blockage material, a dummy worker and a cross draft, were set in the ventilation zone, but the efficiency was 95.1-97.9% when the cross draft was stopped. The results suggest that the uniform flow of a push-pull ventilation system will detour a blockage and the performance of the system will not be reduced unless a cross draft disturbs the uniform flow.

  7. Position paper -- Tank ventilation system design air flow rates

    International Nuclear Information System (INIS)

    Goolsby, G.K.

    1995-01-01

    The purpose of this paper is to document a project position on required ventilation system design air flow rates for the waste storage tanks currently being designed by project W-236A, the Multi-Function Waste Tank Facility (MWTF). The Title 1 design primary tank heat removal system consists of two systems: a primary tank vapor space ventilation system; and an annulus ventilation system. At the conclusion of Title 1 design, air flow rates for the primary and annulus ventilation systems were 960 scfm and 4,400 scfm, respectively, per tank. These design flow rates were capable of removing 1,250,000 Btu/hr from each tank. However, recently completed and ongoing studies have resulted in a design change to reduce the extreme case heat load to 700,000 Btu/hr. This revision of the extreme case heat load, coupled with results of scale model evaporative testing performed by WHC Thermal Hydraulics, allow for a reduction of the design air flow rates for both primary and annulus ventilation systems. Based on the preceding discussion, ICF Kaiser Hanford Co. concludes that the design should incorporate the following design air flow rates: Primary ventilation system--500 scfm maximum and Annulus ventilation system--1,100 scfm maximum. In addition, the minimum air flow rates in the primary and annulus ventilation systems will be investigated during Title 2 design. The results of the Title 2 investigation will determine the range of available temperature control using variable air flows to both ventilation systems

  8. Performance potential of mechanical ventilation systems with minimized pressure loss

    DEFF Research Database (Denmark)

    Terkildsen, Søren; Svendsen, Svend

    2013-01-01

    In many locations mechanical ventilation has been the most widely used principle of ventilation over the last 50 years but the conventional system design must be revised to comply with future energy requirements. This paper examines the options and describes a concept for the design of mechanical....... This corresponds to 10-15% of the power consumption for conventional mechanical ventilation systems thus enabling the system to fulfil future energy requirements in buildings....... ventilation systems with minimal pressure loss and minimal energy use. This can provide comfort ventilation and avoid overheating through increased ventilation and night cooling. Based on this concept, a test system was designed for a fictive office building and its performance was documented using building...

  9. Advanced Controls for Residential Whole-House Ventilation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Turner, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    Whole-house ventilation systems are becoming commonplace in new construction, remodeling/renovation, and weatherization projects, driven by combinations of specific requirements for indoor air quality (IAQ), health and compliance with standards, such as ASHRAE 62.2. Ventilation systems incur an energy penalty on the home via fan power used to drive the airflow, and the additional space-conditioning load associated with heating or cooling the ventilation air. Finding a balance between IAQ and energy use is important if homes are to be adequately ventilated while not increasing the energy burden. This study used computer simulations to examine RIVEC the Residential Integrated Ventilation Controller - a prototype ventilation controller that aims to deliver whole-house ventilation rates that comply with ventilation standards, for the minimum use of energy. Four different whole-house ventilation systems were simulated, both with and without RIVEC, so that the energy and IAQ results could be compared. Simulations were conducted for 13 US climate zones, three house designs, and three envelope leakage values. The results showed that the RIVEC controller could typically return ventilation energy savings greater than 40percent without compromising long-term chronic or short-term acute exposures to relevant indoor contaminants. Critical and average peak power loads were also reduced as a consequence of using RIVEC.

  10. Mixing Ventilation System in a Single-Aisle Aircraft Cabin

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Zhang, Chen; Wojcik, Kamil

    2014-01-01

    and present a design procedure of the system. Finally, a personalised ventilation system will be described, which can be used together with the mixing ventilation system. The experiments are made in a full-scale, left side mock-up of a single-aisle (Boeing 737) cabin with four seats. The four passengers...

  11. Ventilation Systems Operating Experience Review for Fusion Applications

    International Nuclear Information System (INIS)

    Cadwallader, L.C.

    1999-01-01

    This report is a collection and review of system operation and failure experiences for air ventilation systems in nuclear facilities. These experiences are applicable for magnetic and inertial fusion facilities since air ventilation systems are support systems that can be considered generic to nuclear facilities. The report contains descriptions of ventilation system components, operating experiences with these systems, component failure rates, and component repair times. Since ventilation systems have a role in mitigating accident releases in nuclear facilities, these data are useful in safety analysis and risk assessment of public safety. An effort has also been given to identifying any safety issues with personnel operating or maintaining ventilation systems. Finally, the recommended failure data were compared to an independent data set to determine the accuracy of individual values. This comparison is useful for the International Energy Agency task on fusion component failure rate data collection

  12. Measure Guideline: Selecting Ventilation Systems for Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-02-01

    This document addresses adding -or improving - mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards. Advantages, disadvantages, and approximate costs of various system types are presented along with general guidelines for implementing the systems in homes. CARB intends for this document to be useful to decision makers and contractors implementing ventilation systems in homes. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors. It is the intent of this document to assist contractors in making more informed decisions when selecting systems. Ventilation is an integral part of a high-performance home. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability.

  13. USGS 1-min Dst index

    Science.gov (United States)

    Gannon, J.L.; Love, J.J.

    2011-01-01

    We produce a 1-min time resolution storm-time disturbance index, the USGS Dst, called Dst8507-4SM. This index is based on minute resolution horizontal magnetic field intensity from low-latitude observatories in Honolulu, Kakioka, San Juan and Hermanus, for the years 1985-2007. The method used to produce the index uses a combination of time- and frequency-domain techniques, which more clearly identifies and excises solar-quiet variation from the horizontal intensity time series of an individual station than the strictly time-domain method used in the Kyoto Dst index. The USGS 1-min Dst is compared against the Kyoto Dst, Kyoto Sym-H, and the USGS 1-h Dst (Dst5807-4SH). In a time series comparison, Sym-H is found to produce more extreme values during both sudden impulses and main phase maximum deviation, possibly due to the latitude of its contributing observatories. Both Kyoto indices are shown to have a peak in their distributions below zero, while the USGS indices have a peak near zero. The USGS 1-min Dst is shown to have the higher time resolution benefits of Sym-H, while using the more typical low-latitude observatories of Kyoto Dst. ?? 2010.

  14. Thermal analysis of a kitchen natural ventilation system with ...

    African Journals Online (AJOL)

    A numerical study was conducted to perform the design analysis of a novel kitchen natural ventilation system of Madirelo Hotel School. The analysis was performed by using Computational Fluid Dynamics to assess the performance of natural ventilation system. The design is expected to be energy efficient and cost effective ...

  15. Uncertainties in different level assessments of domestic ventilation systems

    NARCIS (Netherlands)

    Bokel, R.M.J.; Yang, Z.; Cauberg, J.J.M.

    2013-01-01

    In order to improve the quality of ventilation systems, assessments are widely used. In this paper, 3 main assessment levels are distinguished based on the number of ventilation systems to be assessed and the assessment objective. The main assessment levels distinguished in this paper are global

  16. An Overview of National Trends Related to Innovative Ventilation Systems

    DEFF Research Database (Denmark)

    Heijmans, Nicolas; Wouters, Peter; Heiselberg, Per

    2008-01-01

    This paper summarises the discussion related to innovative (ventilation) systems that took place at the AIVC workshop organised in Ghent, Belgium, in March 2008.......This paper summarises the discussion related to innovative (ventilation) systems that took place at the AIVC workshop organised in Ghent, Belgium, in March 2008....

  17. Fire protection countermeasures for containment ventilation systems

    International Nuclear Information System (INIS)

    Alvares, N.J.; Beason, D.G.; Bergman, W.; Ford, H.W.; Lipska, A.E.

    1980-01-01

    The goal of this project is to find countermeasures to protect HEPA filters in exit ventilation ducts from the heat and smoke generated by fire. Several methods for partially mitigating the smoke exposure to the HEPA filters were identified through testing and analysis. These independently involve controlling the fuel, controlling the fire, and intercepting the smoke aerosol prior to its sorption on the HEPA filter. Exit duct treatment of aerosols is not unusual in industrial applications and involves the use of scrubbers, prefilters, and inertial impaction, depending on the size, distribution, and concentration of the subject aerosol. However, when these unmodified techniques were applied to smoke aerosols from fires on materials, common to experimental laboratories of LLNL, it was found they offered minimal protection to the HEPA filters. Ultimately, a continuous, movable, high-efficiency prefilter using modified commercial equipment was designed. This technique is capable of protecting HEPA filters over the total duration of the test fires. The reason for success involved the modificaton of the prefiltration media. Commercially available filter media has a particle sorption efficiency that is inversely proportional to media strength. To achieve properties of both efficiency and strength, we laminated rolling filter media with the desired properties. It is not true that the use of rolling prefilters solely to protect HEPA filters from fire-generated smoke aerosols is cost effective in every type of containment system, especially if standard fire-protection systems are available in the space. But in areas of high fire risk, where the potential fuel load is large and ignition sources are plentiful, the complication of a rolling prefilter in exit ventilation ducts to protect HEPA filters from smoke aerosols is definitely justified

  18. Performance potential of mechanical ventilation systems with minimized pressure loss

    DEFF Research Database (Denmark)

    Terkildsen, Søren; Svendsen, Svend

    2013-01-01

    simulations that quantify fan power consumption, heating demand and indoor environmental conditions. The system was designed with minimal pressure loss in the duct system and heat exchanger. Also, it uses state-of-the-art components such as electrostatic precipitators, diffuse ceiling inlets and demand......In many locations mechanical ventilation has been the most widely used principle of ventilation over the last 50 years but the conventional system design must be revised to comply with future energy requirements. This paper examines the options and describes a concept for the design of mechanical...... ventilation systems with minimal pressure loss and minimal energy use. This can provide comfort ventilation and avoid overheating through increased ventilation and night cooling. Based on this concept, a test system was designed for a fictive office building and its performance was documented using building...

  19. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [Building Science Corporation, Somerville, MA (United States); Bergey, Daniel [Building Science Corporation, Somerville, MA (United States)

    2014-02-01

    In this project, Building America research team Building Science Corporation tested the effectiveness of ventilation systems at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. This was because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four system factor categories: balance, distribution, outside air source, and recirculation filtration. Recommended system factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  20. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bergey, Daniel [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-02-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. It was inferior because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  1. YMP Engineered Barrier Systems Scaled Ventilation Testing

    Energy Technology Data Exchange (ETDEWEB)

    S.D. Dunn; B. Lowry; B. Walsh; J.D. Mar; C. Howard; R. Johnston; T. Williams

    2002-11-22

    Yucca Mountain, approximately 100 miles northwest of Las Vegas, Nevada, has been selected as the site for the nation's first geologic repository for high level nuclear waste. The Yucca Mountain Project (YMP) is currently developing the design for the underground facilities. Ventilation is a key component of the design as a way to maintain the desired thermal conditions in the emplacement drifts prior to closure. As a means of determining the effects of continuous ventilation on heat removal from the emplacement drifts two series of scaled ventilation tests have been performed. Both test series were performed in the DOE/North Las Vegas Atlas facility. The tests provided scaled (nominally 25% of the full scale emplacement drift design) thermal and flow process data that will be used to validate YMP heat and mass transport codes. The Phase I Ventilation Test series evaluated the ability of ambient ventilation air to remove energy under varying flow and input power conditions. The Phase II Ventilation Test series evaluated the ability of pre-conditioned ventilation air to remove energy under varying flow, input temperature and moisture content, and simulated waste package input power conditions. Twenty-two distinct ventilation tests were run.

  2. Investigation of the ventilation performance of an integrated day lighting natural ventilation system

    International Nuclear Information System (INIS)

    Ahmed, S.; Abdul Rahman, S.; Ahmed, A.Z.

    2006-01-01

    Natural ventilation and daylighting are two passive strategies that can improve the indoor performance as well as reduce energy consumption in buildings. Both strategies when used appropriately, increase indoor quality and comport. In terms of energy costs, daylighting can significantly reduce artificial lighting as well as heat dissipated from the resulting fixtures while natural ventilation can minimize the need for air-conditioning. A study is currently being conducted to develop a system that integrates these two passive strategies, to be used specifically for buildings in Malaysia. The initial proposed integrated models are based on similar studies already conducted but with appropriate modifications for tropical climates. This paper will present some results of the ventilation performance of the proposed integrated system model, particularly the airflow distribution patterns and air speed, inside a naturally ventilated room. A CFD simulation software was used to investigate the optimum size of the integrated model with regards to interior ventilation performance. The simulations also included single sided and cross ventilated openings

  3. On analysis of operating efficiency of autonomous ventilation systems

    Directory of Open Access Journals (Sweden)

    Kostuganov Arman

    2017-01-01

    Full Text Available The paper deals with the causes and consequences of malfunctioning of natural and mechanical ventilation systems in civil buildings of Russia. Furthermore it gives their classification and analysis based on the literature review. On the basis of the analysis technical solutions for improving the efficiency of ventilation systems in civil buildings are summarized and the field of their application is specified. Among the offered technical solutions the use of autonomous ventilation systems with heat recovery is highlighted as one of the most promising and understudied. Besides it has a wide range of applications. The paper reviews and analyzes the main Russian and foreign designs of ventilation systems with heat recovery that are mostly used in practice. Three types of such systems: UVRK-50, Prana-150, ТеFо are chosen for consideration. The sequence of field tests of selected autonomous ventilation systems have been carried out in order to determine the actual air exchange and efficiency of heat recovery. The paper presents the processed results of the research on the basis of which advantages and disadvantages of the tested ventilation systems are identified and recommendations for engineering and manufacturing of new design models of autonomous ventilation systems with heat recovery are formulated.

  4. Control of ventilation system when changing of its topology

    International Nuclear Information System (INIS)

    Koketayev, A.I.

    2009-01-01

    The complex ventilation systems of modern coal and ore mines can be described by multidimensional and highly bound graphs. Because of changes in topology, it is very difficult to control ventilation systems in the event of emergency situations such as rock bumps, roof caving, sudden gas outburst, quicksand intrusion, or mine flooding. Special mathematical tools are needed to consider such changes and to determine the corresponding conditions of a mine's ventilation needs. This paper presented a system to simulate the behaviour of mine ventilation system. The system considered changes in topology as well as timely measures for support of necessary air quantity for safe conditions for miners in underground mine workings. The paper presented the details of the study with particular reference to the calculation of ventilation conditions; graphs and sub-graphs of the ventilation system; and corresponding equations. It was concluded that the simulated system would allow users to simulate the behaviour of the mine ventilation system when changing its topology in a timely manner and to take measures to control the required volume of air to ensure safe working conditions for underground miners. 3 refs., 1 fig.

  5. Constant depression fan system a novel glovebox ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Milliner, W.V. [AME plc., Aldermaston (United Kingdom)

    1995-02-01

    In a conventional glovebox ventilation system the depression within the glovebox under normal operation is controlled by instrumentation. In the event of a breach the pressure within the box rises to atmospheric pressure, this pressure rise is detected by instrumentation which in turn operates a quick opening damper in a high depression extract to achieve a 1 metre/sec (200 fpm) inflow through the breach, which can take up to 2 seconds to establish. This system, although widely used, suffers from two distinct drawbacks: It takes a finite time to achieve the containment velocity of 1 metre/sec. It relies upon instrumentation to achieve its objectives. A new glovebox ventilation system has been developed by AWE to overcome these drawbacks. This is the Constant Depression Fan System (CDFS) which is based on an extract fan with a flat characteristic. This achieves all the requirements for the ventilation of gloveboxes and has the advantages that: It has only one moving part - the extract fan. It requires NO INSTRUMENTATION to achieve its objectives. It achieves the containment velocity of 1 metre/sec in the shortest possible time - approximately 0.2 seconds - and tests have shown that containment is maintained under breach conditions. Thus the CDFS is SAFER, SIMPLER and MORE RELIABLE.

  6. Constant depression fan system a novel glovebox ventilation system

    International Nuclear Information System (INIS)

    Milliner, W.V.

    1995-01-01

    In a conventional glovebox ventilation system the depression within the glovebox under normal operation is controlled by instrumentation. In the event of a breach the pressure within the box rises to atmospheric pressure, this pressure rise is detected by instrumentation which in turn operates a quick opening damper in a high depression extract to achieve a 1 metre/sec (200 fpm) inflow through the breach, which can take up to 2 seconds to establish. This system, although widely used, suffers from two distinct drawbacks: It takes a finite time to achieve the containment velocity of 1 metre/sec. It relies upon instrumentation to achieve its objectives. A new glovebox ventilation system has been developed by AWE to overcome these drawbacks. This is the Constant Depression Fan System (CDFS) which is based on an extract fan with a flat characteristic. This achieves all the requirements for the ventilation of gloveboxes and has the advantages that: It has only one moving part - the extract fan. It requires NO INSTRUMENTATION to achieve its objectives. It achieves the containment velocity of 1 metre/sec in the shortest possible time - approximately 0.2 seconds - and tests have shown that containment is maintained under breach conditions. Thus the CDFS is SAFER, SIMPLER and MORE RELIABLE

  7. Measure Guideline: Selecting Ventilation Systems for Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2014-02-01

    This report, developed by Building America research team CARB, addresses adding or improving mechanical ventilation systems to existing homes. The goal of this report is to assist decision makers and contractors in making informed decisions when selecting ventilation systems for homes. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including examination of relevant codes and standards. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors.

  8. SUBSURFACE VOLATIZATION AND VENTILATION SYSTEM (SVVS) - INNOVATIVE TECHNOLOGY REPORT

    Science.gov (United States)

    This report summarizes the findings associated with a Demonstration Test of Environmental Improvement Technologies’ (EIT) Subsurface Volatilization and Ventilation System (SVVS) process. The technology was evaluated under the EPA Superfund Innovative Technology Evaluation (SITE) ...

  9. SITE TECHNOLOGY CAPSULE: SUBSURFACE VOLATILIZATION AND VENTILATION SYSTEM (SVVS)

    Science.gov (United States)

    The Subsurface Volatilization and Ventilation System is an integrated technology used for attacking all phases of volatile organic compound (VOC) contamination in soil and groundwater. The SVVS technology promotes insitu remediation of soil and groundwater contaminated with or-ga...

  10. Ventilation systems and components of nuclear power plants

    International Nuclear Information System (INIS)

    1997-01-01

    The most important radiation and nuclear safety requirements for the design and manufacture of nuclear power plant ventilation systems and components are presented in the guide. Also the regulatory activities of the Finnish Centre for Radiation and Nuclear Safety (STUK) as regards the ventilation systems and components are explained. Documents and data which shall be submitted to STUK during the various phases of the regulatory procedure relating to the design, construction, commissioning and operation of the nuclear power plants are presented. (13 refs.)

  11. Rising damp in building walls: the wall base ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, A.S.; Delgado, J.M.P.Q.; Freitas, V.P. de [Faculdade de Engenharia da Universidade do Porto, Laboratorio de Fisica das Construcoes (LFC), Departamento de Engenharia Civil, Porto (Portugal)

    2012-12-15

    This work intends to validate a new system for treating rising damp in historic buildings walls. The results of laboratory experiments show that an efficient way of treating rising damp is by ventilating the wall base, using the HUMIVENT technique. The analytical model presented describes very well the observed features of rising damp in walls, verified by laboratory tests, who contributed for a simple sizing of the wall base ventilation system that will be implemented in historic buildings. (orig.)

  12. Dependence of radon level on ventilation systems in residences

    International Nuclear Information System (INIS)

    Kokotti, H.

    1995-01-01

    The concentration of indoor radon and radon entry from soil into a house are expected to increase with increasing radon concentration in soil pores, and indoor radon concentration is expected to decrease with increasing ventilation rate. Depressurization, which can be caused by the stack effect, by wind and by unbalanced ventilation, creates different pressure conditions in a house and in the soil beneath it. To reveal the possible differences in radon removal and entry resulting from different ventilation systems, radon concentrations were determined in three similar slab-on-grade buildings provided with mechanical supply and exhaust ventilation, mechanical exhaust or natural ventilation. To limitate the effect of differences in soil parameters, the houses were constructed on the same gravel esker in Kuopio. Thus, the variation in radon entry as a result of different depressurisation of the houses (caused by unbalanced mechanical ventilation systems) could also be observed. In addition, the effect of pressurisation on living rooms could be determined in five slab-on-grade houses constructed on the same esker in Hollola. Mechanical supply and exhaust ventilation system controlled by measured indoor-outdoor pressure difference, was installed in the six houses. The seasonal variation with and without controlled pressure conditions were followed in a slab-on-grade house constructed on a gravel esker in Rekola. Long-term radon concentrations were observed to correlate negatively with air exchange rates. However, the removal effect of ventilation was found to be disturbed by negative pressure due to the stack effect and/or to unbalanced mechanical ventilation. (91 refs., 17 figs., 10 tabs.)

  13. The pit ventilation features and the design principle of ventilation system in trackless mining uranium mine

    International Nuclear Information System (INIS)

    Deng Wenhui; Zhou Xinghuo; Li Xianjie

    2001-01-01

    According to the pit arrangement features of trackless mining uranium mine, based on the fundamental of radon permeation and control, and analysis of radon pollution characteristics and radon education, the design principle of ventilation system in trackless mining uranium mine has been raised

  14. Hydrogen risk analysis for a generic nuclear containment ventilation system

    International Nuclear Information System (INIS)

    Xu, Z.; Jordan, T.

    2015-01-01

    Hydrogen safety issue in a ventilation system of a generic nuclear containment is studied. In accidental scenarios, a large amount of burnable gas mixture of hydrogen with certain amount of oxygen is released into the containment. In case of high containment pressure, the combustible mixture is further ventilated into the chambers and the piping of the containment ventilation system. The burnable even potentially detonable gas mixture could pose a risk to the structures of the system once being ignited unexpectedly. Therefore the main goal of the study is to apply the computational fluid dynamics (CFD) computer code - GASFLOW, to analyze the distribution of the hydrogen in the ventilation system, and to find how sensitive the mixture is to detonation in different scenarios. The CFD simulations manifest that a ventilation fan with sustained power supply can extinguish the hydrogen risk effectively. However in case of station blackout with loss of power supply to the fan, hydrogen/oxygen mixture could be accumulated in the ventilation system. A further study proves that steam injection could degrade the sensitivity of the hydrogen mixture significantly. (author)

  15. Operational models for forecasting Dst

    Science.gov (United States)

    Watanabe, S.; Sagawa, E.; Ohtaka, K.; Shimazu, H.

    We have constructed operational models for forecasting the geomagnetic storm index (Dst) two hours in advance from six parameters: the velocity and density of the solar wind, the magnitude of the interplanetary magnetic field (IMF), and the x, y, and z components of the IMF. Our models use an Elman-type neural network, and we forecast space weather by using real-time solar-wind data from the Advanced Composition Explorer spacecraft.The models have worked well since April of 1998 and the Dst values forecast using them have been made available to the public at http://www.crl.go.jp/uk/uk223/service/nnw/index.html. From February to October 1998 there were 11 storms with minimum Dst values below -80 nT, and for ten the difference between the forecast minimum Dst and the Dst calculated from data measured by ground stations was less than 23%.For the storm starting on 19 October, however, the difference was 40% because of the weak correlation between the ACE environment and the earth's environment during this event.The Dst depends on the orientation of the IMF relative to the solar magnetospheric x-y plane and seems to be relatively large when the y component of the IMF is positive and perhaps also when the x component is positive.

  16. Passive ventilation systems with heat recovery and night cooling

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Svendsen, Svend

    2008-01-01

    of Denmark. Through building integration in high performance offices the system is optimized to incorporate multiple functions like heating, cooling and ventilation, thus saving the expenses of separate cooling and heating systems. The simulation results are derived using the state-of-the-art building......In building design the requirements for energy consumption for ventilation, heating and cooling and the requirements for increasingly better indoor climate are two opposing factors. This paper presents the schematic layout and simulation results of an innovative multifunc-tional ventilation concept...... with little energy consumption and with satisfying indoor climate. The concept is based on using passive measures like stack and wind driven ventilation, effective night cooling and low pressure loss heat recovery using two fluid coupled water-to-air heat exchangers developed at the Technical University...

  17. Ventilation system in the RA reactor building - design specifications

    International Nuclear Information System (INIS)

    Badrljica, R.

    1984-09-01

    Protective role of the ventilation system of nuclear facilities involve construction of ventilation barriers which prevent release of radioactive particulates or gases, elimination od radioactive particulates and gases from the air which is released from contaminated zones into the reactor environment. Ventilation barriers are created by dividing the building into a number of ventilation zones with different sub pressure compared to the atmospheric pressure. The RA reactor building is divided into four ventilation zones. First zone is the zone of highest risk. It includes reactor core with horizontal experimental channels, underground rooms of the primary coolant system (D 2 O), helium system, hot cells and the space above the the reactor core. Second zone is the reactor hall and the room for irradiated fuel storage. The third zone includes corridors in the basement, ground floor and first floor where the probability of contamination is small. The fourth zone includes the annex where the contamination risk is low. There is no have natural air circulation in the reactor building. Ventilators for air input and outlet maintain the sub pressure in the building (pressure lower than the atmospheric pressure). This prevents release of radioactivity into the atmosphere [sr

  18. Preoperational test report, primary ventilation condenser cooling system

    International Nuclear Information System (INIS)

    Clifton, F.T.

    1997-01-01

    This represents the preoperational test report for the Primary Ventilation Condenser Cooling System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system uses a closed chilled water piping loop to provide offgas effluent cooling for tanks AY101, AY102, AZ1O1, AZ102; the offgas is cooled from a nominal 100 F to 40 F. Resulting condensation removes tritiated vapor from the exhaust stack stream. The piping system includes a package outdoor air-cooled water chiller with parallel redundant circulating pumps; the condenser coil is located inside a shielded ventilation equipment cell. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

  19. Optimized damper control of pressure and airflow in ventilation systems

    DEFF Research Database (Denmark)

    Koulani, Chrysanthi Sofia; Hviid, Christian Anker; Terkildsen, Søren

    2014-01-01

    Conventional control strategies in variable air volume (VAV) ventilation systems do not take fully into advantage the potential energy savings since the system operation is based on maintaining a constant static pressure (CSP) set point in the main duct irrespective of the actual pressure demand...... by using the Simulink programming tool which is addon software to MATLAB mathematical programming language. A model of a VAV ventilation system was created in Simulink based on the International Building Physics Toolbox (IBPT); the IBPT thermal zone was remodelled in order to calculate dynamically...... the airflow demand according to the zone air temperature. The performance of the Simulink model was evaluated based on the experimental setup of the ventilation system. The SPR control method established stable system operation and was proven efficient to maintain comfortable space conditions while reducing...

  20. Preoperational test report, primary ventilation condenser cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-10-29

    This represents the preoperational test report for the Primary Ventilation Condenser Cooling System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system uses a closed chilled water piping loop to provide offgas effluent cooling for tanks AY101, AY102, AZ1O1, AZ102; the offgas is cooled from a nominal 100 F to 40 F. Resulting condensation removes tritiated vapor from the exhaust stack stream. The piping system includes a package outdoor air-cooled water chiller with parallel redundant circulating pumps; the condenser coil is located inside a shielded ventilation equipment cell. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  1. Design of energy efficient ventilation and air-conditioning systems

    CERN Document Server

    Seppänen, Olli; Bertilsson, Thore; Maripuu, Mari-Liis; Lamy, Hervé; Vanden Borre, Alex

    2012-01-01

    This guidebook covers numerous system components of ventilation and air-conditioning systems and shows how they can be improved by applying the latest technology products. Special attention is paid to details, which are often overlooked in the daily design practice, resulting in poor performance of high quality products once they are installed in the building system.

  2. Basement depressurization using dwelling mechanical exhaust ventilation system

    International Nuclear Information System (INIS)

    Collignan, B.; O'Kelly, P.; Pilch, E.

    2004-01-01

    The mechanical ventilation exhaust system is commonly used in France to generate air renewal into building and especially into dwelling. It consists of a permanent mechanical air extraction from technical rooms (kitchen, bathrooms and toilets) using a unique fan connected to exhaust ducts. Natural air inlets in living room and bed rooms ensure an air flow from living spaces towards technical rooms. To fight against radon into building, the most recognised efficient technique is the Soil Depressurization System (S.D.S.) consisting in depressurizing the house basement. The aim of this study is to test the ability of the dwelling mechanical ventilation system to depressurize the basement in conjunction with air renewal of a house. For that purpose, a S.D.S. has been installed in an experimental house at CSTB during its construction. At first, tests undertaken with a variable velocity fan connected to the S.D.S. have characterised the permeability of the basement. It is shown that basement can be depressurized adequately with a relatively low air flow rate. At a second stage, S.D.S. has been connected to the exhaust ventilation fan used for the mechanical ventilation of the house. Results obtained show the ability of such ventilation system to generate sufficient depressurization in the basement and to ensure simultaneously adequate air change rate in the dwelling. (author)

  3. Argonne Fuel Cycle Facility ventilation system -- modeling and results

    International Nuclear Information System (INIS)

    Mohr, D.; Feldman, E.E.; Danielson, W.F.

    1995-01-01

    This paper describes an integrated study of the Argonne-West Fuel Cycle Facility (FCF) interconnected ventilation systems during various operations. Analyses and test results include first a nominal condition reflecting balanced pressures and flows followed by several infrequent and off-normal scenarios. This effort is the first study of the FCF ventilation systems as an integrated network wherein the hydraulic effects of all major air systems have been analyzed and tested. The FCF building consists of many interconnected regions in which nuclear fuel is handled, transported and reprocessed. The ventilation systems comprise a large number of ducts, fans, dampers, and filters which together must provide clean, properly conditioned air to the worker occupied spaces of the facility while preventing the spread of airborne radioactive materials to clean am-as or the atmosphere. This objective is achieved by keeping the FCF building at a partial vacuum in which the contaminated areas are kept at lower pressures than the other worker occupied spaces. The ventilation systems of FCF and the EBR-II reactor are analyzed as an integrated totality, as demonstrated. We then developed the network model shown in Fig. 2 for the TORAC code. The scope of this study was to assess the measured results from the acceptance/flow balancing testing and to predict the effects of power failures, hatch and door openings, single-failure faulted conditions, EBR-II isolation, and other infrequent operations. The studies show that the FCF ventilation systems am very controllable and remain stable following off-normal events. In addition, the FCF ventilation system complex is essentially immune to reverse flows and spread of contamination to clean areas during normal and off-normal operation

  4. Evaluation of a computerized system for mechanical ventilation of infants.

    Science.gov (United States)

    Tehrani, Fleur T; Abbasi, Soraya

    2009-04-01

    To evaluate a computerized system for mechanical ventilation of infants. FLEX is a computerized system that includes the features of a patented mode known as adaptive-support ventilation (ASV). In addition, it has many other features including adjustment of positive end-expiratory pressure (PEEP), fraction of inspired oxygen (F(IO2)), minute ventilation, and control of weaning. It is used as an open-loop decision support system or as a closed-loop technique. Blood gas and ventilation data were collected from 12 infants in the neonatal intensive care at baseline and at the next round of evaluation. This data were input to open-loop version of FLEX. The system recommendations were compared to clinical determinations. FLEX recommended values for ventilation were on the average within 25% and 16.5% of the measured values at baseline and at the next round of evaluation, respectively. For F(IO2) and PEEP, FLEX recommended values were in general agreement with the clinical settings. FLEX recommendations for weaning were the same as the clinical determinations 50% of the time at baseline and 55% of the time at the next round of evaluation. FLEX did not recommend weaning for infants with weak spontaneous breathing effort or those who showed signs of dyspnea. A computerized system for mechanical ventilation is evaluated for treatment of infants. The results of the study show that the system has good potential for use in neonatal ventilatory care. Further refinements can be made in the system for very low-birth-weight infants.

  5. Anaesthesia ventilators

    Science.gov (United States)

    Jain, Rajnish K; Swaminathan, Srinivasan

    2013-01-01

    Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bellows ventilators, ascending bellows design is safer than descending bellows. Piston ventilators have the advantage of delivering accurate tidal volume. They work with electricity as their driving force and do not require a driving gas. To enable improved patient safety, several modifications were done in circle system with the different types of anaesthesia ventilators. Fresh gas decoupling is a modification done in piston ventilators and in descending bellows ventilator to reduce th incidence of ventilator induced volutrauma. In addition to the conventional volume control mode, modern anaesthesia ventilators also provide newer modes of ventilation such as synchronised intermittent mandatory ventilation, pressure-control ventilation and pressure-support ventilation (PSV). PSV mode is particularly useful for patients maintained on spontaneous respiration with laryngeal mask airway. Along with the innumerable benefits provided by these machines, there are various inherent hazards associated with the use of the ventilators in the operating room. To use these workstations safely, it is important for every Anaesthesiologist to have a basic understanding of the mechanics of these ventilators and breathing circuits. PMID:24249886

  6. Anaesthesia ventilators

    OpenAIRE

    Jain, Rajnish K; Swaminathan, Srinivasan

    2013-01-01

    Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bello...

  7. Water spray ventilator system for continuous mining machines

    Science.gov (United States)

    Page, Steven J.; Mal, Thomas

    1995-01-01

    The invention relates to a water spray ventilator system mounted on a continuous mining machine to streamline airflow and provide effective face ventilation of both respirable dust and methane in underground coal mines. This system has two side spray nozzles mounted one on each side of the mining machine and six spray nozzles disposed on a manifold mounted to the underside of the machine boom. The six spray nozzles are angularly and laterally oriented on the manifold so as to provide non-overlapping spray patterns along the length of the cutter drum.

  8. 46 CFR 105.25-7 - Ventilation systems for cargo tank or pumping system compartment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation systems for cargo tank or pumping system... Requirements-When Cargo Tanks Are Installed Below Decks § 105.25-7 Ventilation systems for cargo tank or pumping system compartment. (a) Each compartment shall be provided with a mechanical exhaust system...

  9. Measured Air Distribution Effectiveness for Residential Mechanical Ventilation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max; Sherman, Max H.; Walker, Iain S.

    2008-05-01

    The purpose of ventilation is dilute or remove indoor contaminants that an occupant is exposed to. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. Most US homes have central HVAC systems, which tend to mix the air thus the indoor conditions between zones. Different types of ventilation systems will provide different amounts of exposure depending on the effectiveness of their air distribution systems and the location of sources and occupants. This paper will report on field measurements using a unique multi-tracer measurement system that has the capacity to measure not only the flow of outdoor air to each zone, but zone-to-zone transport. The paper will derive seven different metrics for the evaluation of air distribution. Measured data from two homes with different levels of natural infiltration will be used to evaluate these metrics for three different ASHRAE Standard 62.2 compliant ventilation systems. Such information can be used to determine the effectiveness of different systems so that appropriate adjustments can be made in residential ventilation standards such as ASHRAE Standard 62.2.

  10. Availability Analysis of the Ventilation Stack CAM Interlock System

    CERN Document Server

    Young, J

    2000-01-01

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies, and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability.

  11. Double-Shell Tank (DST) Maintenance and Recovery Subsystem Definition Report

    International Nuclear Information System (INIS)

    SMITH, E.A.

    2000-01-01

    The description of the Double-Shell Tank (DST) Maintenance and Recovery Subsystem presented in this document was developed to establish its boundaries. The DST Maintenance and Recovery Subsystem consists of new and existing equipment and facilities used to provide tank farm operators logistic support and problem resolution for the DST System during operations. This support will include evaluating equipment status, performing preventive and corrective maintenance, developing work packages, managing spares and consumables, supplying tooling, and training maintenance and operations personnel

  12. Field study of earth tempered swine ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Goetsch, W.D.; Peterson, W.H.; Muehling, A.J.

    1981-01-01

    Four earth-tube heat exchanger systems for heating and cooling the ventilation air for swine farrowing and nursery buildings were studied. Results show appreciable winter heating and summer cooling from the earth tubes with minimal variation in the temperature of the discharge air. 5 refs.

  13. DEMONSTRATION BULLETIN: SUBSURFACE VOLATILIZATION AND VENTILATION SYSTEM - BROWN & ROOT ENVIRONMENTAL

    Science.gov (United States)

    The Subsurface Volatilization and Ventilation System (SVVS*) is an in-situ vacuum extraction/air sparging and bioremediation technology for the treatment of subsurface organic contamination in soil and groundwater. The technology, developed by Billings and Associates, Inc., and o...

  14. Interaction of Air Flow in Complex Ventilation Systems

    Directory of Open Access Journals (Sweden)

    Zhorzh G. Levitskiy

    2013-01-01

    Full Text Available The article presents the results of study of interaction of air flow in complex ventilation systems. The study used Taylor and Maclaurin’s series and Lagrange formula to create the functional connections on estimation of the impact of changing aerodynamic parameters of one or several simultaneously working regulators on the air flow distribution in mines

  15. Heating, Ventilation and Air-Conditioning Systems, Part of Indoor Air Quality Design Tools for Schools

    Science.gov (United States)

    The main purposes of a Heating, Ventilation, and Air-Conditioning system are to help maintain good indoor air quality through adequate ventilation with filtration and provide thermal comfort. HVAC systems are among the largest energy consumers in schools.

  16. Technology Solutions Case Study: Selecting Ventilation Systems for Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-12-01

    In multifamily buildings, particularly in the Northeast, exhaust ventilation strategies are the norm as a means of meeting both local exhaust and whole-unit mechanical ventilation rates. The issue of where the "fresh" air is coming from is gaining significance as air-tightness standards for enclosures become more stringent, and the normal leakage paths through the building envelope disappear. Researchers from the Consortium for Advanced Residential Buildings (CARB) found that the majority of high performance, new construction, multifamily housing in the Northeast use one of four general strategies for ventilation: continuous exhaust only with no designated supply or make-up air source, continuous exhaust with ducted make-up air to apartments, continuous exhaust with supply through a make-up air device integral to the unit HVAC, and continuous exhaust with supply through a passive inlet device, such as a trickle vent. Insufficient information is available to designers on how these various systems are best applied. In this project, the CARB team evaluated the four different strategies for providing make-up air to multifamily residential buildings and developed guidelines to help contractors and building owners choose the best ventilation systems.

  17. Method to assess the performance of domestic ventilation systems considering the influence of uncertainties

    NARCIS (Netherlands)

    Yang, Z.

    2012-01-01

    The ventilation system plays an important role in the indoor environment of a domestic building. A ventilation system is normally designed based on the national or regional regulations. Although ventilation systems are designed based on the same design rules, performance deviations between different

  18. Exhaust, Dust Collection and Ventilation Systems. Module SH-44. Safety and Health.

    Science.gov (United States)

    Center for Occupational Research and Development, Inc., Waco, TX.

    This student module on exhaust, dust collection, and ventilation systems is one of 50 modules concerned with job safety and health. This module discusses the types of contaminants that can be controlled by ventilation, the types of ventilation systems, and the component parts of local exhaust systems. Following the introduction, 10 objectives…

  19. CLASSIFICATION OF THE MGR WASTE TREATMENT BUILDING VENTILATION SYSTEM

    International Nuclear Information System (INIS)

    S.E. Salzman

    1999-01-01

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) waste treatment building ventilation system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

  20. Bilevel vs ICU ventilators providing noninvasive ventilation: effect of system leaks: a COPD lung model comparison.

    Science.gov (United States)

    Ferreira, Juliana C; Chipman, Daniel W; Hill, Nicholas S; Kacmarek, Robert M

    2009-08-01

    Noninvasive positive-pressure ventilation (NPPV) modes are currently available on bilevel and ICU ventilators. However, little data comparing the performance of the NPPV modes on these ventilators are available. In an experimental bench study, the ability of nine ICU ventilators to function in the presence of leaks was compared with a bilevel ventilator using the IngMar ASL5000 lung simulator (IngMar Medical; Pittsburgh, PA) set at a compliance of 60 mL/cm H(2)O, an inspiratory resistance of 10 cm H(2)O/L/s, an expiratory resistance of 20 cm H(2)O/ L/s, and a respiratory rate of 15 breaths/min. All of the ventilators were set at 12 cm H(2)O pressure support and 5 cm H(2)O positive end-expiratory pressure. The data were collected at baseline and at three customized leaks. At baseline, all of the ventilators were able to deliver adequate tidal volumes, to maintain airway pressure, and to synchronize with the simulator, without missed efforts or auto-triggering. As the leak was increased, all of the ventilators (except the Vision [Respironics; Murrysville, PA] and Servo I [Maquet; Solna, Sweden]) needed adjustment of sensitivity or cycling criteria to maintain adequate ventilation, and some transitioned to backup ventilation. Significant differences in triggering and cycling were observed between the Servo I and the Vision ventilators. The Vision and Servo I were the only ventilators that required no adjustments as they adapted to increasing leaks. There were differences in performance between these two ventilators, although the clinical significance of these differences is unclear. Clinicians should be aware that in the presence of leaks, most ICU ventilators require adjustments to maintain an adequate tidal volume.

  1. Exposure of ventilation system cleaning workers to harmful microbiological agents.

    Science.gov (United States)

    Gołofit-Szymczak, Małgorzata; Ławniczek-Wałczyk, Anna; Górny, Rafał L

    2013-01-01

    Regular inspection of the cleanliness of the ventilation systems, as well as their periodic cleaning and disinfection, if necessary, are the main factors of the proper maintenance of each system. Performing maintenance operations on the ventilation system, workers are exposed to risk associated with the exposure to harmful biological agents. The aim of this study was to assess the employees' exposure to bioaerosols during maintenance work on ventilation systems. Bioaerosol measurements were carried out using a button sampler. The microbial particles were collected on gelatin filters. Settled-dust samples from the inner surface of the air ducts and filter-mat samples were selected for the microbiological analysis. In the collected air, dust and filter samples the concentration of bacteria and fungi were determined. Bacteria and fungi concentrations ranged between 3.6 x 10(2)-2.2 x 10(4) CFU/m3 and 4.7 x 10(2)-4.5 x 10(3) CFU/m3 at workplaces where the operations connected with mechanical ventilation cleaning were performed and 2.2 x 10(4)-1.2 x 10(5) CFU/m2 and 9.8 x 10(1)-2.5 x 10(2) CFU/m3 at workplaces where filter exchange was performed, respectively. The qualitative analysis of microorganisms isolated from the air in all studied workplaces revealed that the most prevalent bacteria belonged to Bacillus genus. The average concentrations of bacteria and fungi in filter-mat samples were 3.3 x 10(3) CFU/cm2 and 1.4 x 10(4) CFU/cm2, respectively. In settled-dust samples, average concentrations were 591 CFU/100 cm2 and 52 CFU/100 cm2, for bacteria and fungi respectively. Workers cleaning ventilation systems are exposed to harmful biological agents classified into risk groups, 1 and 2, according to their level of the risk of infection. The research conducted in the workplace can be the basis of risk assessment related to exposure to harmful biological agents during maintenance work in ventilation.

  2. 30 CFR 75.324 - Intentional changes in the ventilation system.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Intentional changes in the ventilation system... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.324 Intentional changes in the ventilation system. (a) A person designated by the operator shall supervise any...

  3. Design of multifunctional temperature controller for NPP ventilation system

    International Nuclear Information System (INIS)

    Xiao Xipeng; He Li; Yin Xiaolong; Gong Jianjun

    2014-01-01

    Based on full study on the original analog temperature controller of ventilation system in nuclear power plant, for the interface definition fixation, parameters preset as well as multiple output combination of the temperature controller circuit, a digital temperature circuit based on the front-end input conditioning module + multi channel ADC+STM32 architecture is proposed. The hardware structure and software process are described in details. The sampling data processing, phase-cut voltage output as well as control principle are focused, and some part of software program is presented. The experimental results show that the temperature controller can stably and reliably control the temperature of ventilation system and display digital parameters, and it can completely replace and upgrade the original analog controller. (authors)

  4. Evaluating Ventilation Systems for Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Arena, L.

    2013-02-01

    During the course of this project, an affordable and high performance ductwork system to directly address the problems of thermal losses, poor efficiency, and air leakage was designed. To save space and enable direct connections between different floors of the building, the ductwork system was designed in such a way that it occupied interior or exterior frame wall cavities. The ductwork system satisfied building regulations for structural support when bridging multiple floors, the spread of fire and smoke, and insulation to reduce the heat flow into or out of the building. Retrofits of urban residential buildings will be the main focus for the application of this ductwork system. Highly reflective foils and insulating materials were used to aid in the increase of the overall R-value of the ductwork itself and the wall assembly. It is expected that the proposed system will increase the efficiency of the HVAC system and the thermal resistance of the building envelope. The performance of the proposed ductwork design was numerically evaluated in a number of different ways. Our results indicate that the duct method is a very cost attractive alternative to the conventional method.

  5. Numerical simulation of volume-controlled mechanical ventilated respiratory system with 2 different lungs.

    Science.gov (United States)

    Shi, Yan; Zhang, Bolun; Cai, Maolin; Zhang, Xiaohua Douglas

    2017-09-01

    Mechanical ventilation is a key therapy for patients who cannot breathe adequately by themselves, and dynamics of mechanical ventilation system is of great significance for life support of patients. Recently, models of mechanical ventilated respiratory system with 1 lung are used to simulate the respiratory system of patients. However, humans have 2 lungs. When the respiratory characteristics of 2 lungs are different, a single-lung model cannot reflect real respiratory system. In this paper, to illustrate dynamic characteristics of mechanical ventilated respiratory system with 2 different lungs, we propose a mathematical model of mechanical ventilated respiratory system with 2 different lungs and conduct experiments to verify the model. Furthermore, we study the dynamics of mechanical ventilated respiratory system with 2 different lungs. This research study can be used for improving the efficiency and safety of volume-controlled mechanical ventilation system. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Indoor Chemistry: Materials, Ventilation Systems, and Occupant Activities

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, G.C.; Corsi, R.L.; Destaillats, H.; Nazaroff, W.W.; Wells, J.R.

    2006-05-01

    Chemical processes taking place in indoor environments can significantly alter the nature and concentrations of pollutants. Exposure to secondary contaminants generated in these reactions needs to be evaluated in association with many aspects of buildings to minimize their impact on occupant health and well-being. Focusing on indoor ozone chemistry, we describe alternatives for improving indoor air quality by controlling chemical changes related to building materials, ventilation systems, and occupant activities.

  7. Stochastic Prediction of Ventilation System Performance

    DEFF Research Database (Denmark)

    Haghighat, F.; Brohus, Henrik; Frier, Christian

    The paper briefly reviews the existing techniques for predicting the airflow rate due to the random nature of forcing functions, e.g. wind speed. The effort is to establish the relationship between the statistics of the output of a system and the statistics of the random input variables and param......The paper briefly reviews the existing techniques for predicting the airflow rate due to the random nature of forcing functions, e.g. wind speed. The effort is to establish the relationship between the statistics of the output of a system and the statistics of the random input variables...

  8. Double Shell Tank (DST) Transfer Pump Subsystem Specification

    International Nuclear Information System (INIS)

    GRAVES, C.E.

    2001-01-01

    This specification establishes the performance requirements and provides the references to the requisite codes and standards to be applied during the design of the Double-Shell Tank (DST) Transfer Pump Subsystem that supports the first phase of waste feed delivery (WFD). The DST Transfer Pump Subsystem consists of a pump for supernatant and/or slurry transfer for the DSTs that will be retrieved during the Phase 1 WFD operations. This system is used to transfer low-activity waste (LAW) and high-level waste (HLW) to designated DST staging tanks. It also will deliver blended LAW and HLW feed from these staging tanks to the River Protection Project (RPP) Waste Treatment Plant where it will be processed into an immobilized waste form. This specification is intended to be the basis for new projects/installations (W-521, etc.). This specification is not intended to retroactively affect previously established project design criteria without specific direction by the program

  9. Experimental Study of Air Distribution and Ventilation Effectiveness in a Room with a Combination of Different Mechanical Ventilation and Heating/Cooling Systems

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.; Simone, Angela; Krajcik, Michal

    2011-01-01

    Mixing and displacement ventilation are common systems in commercial buildings, while mixing ventilation is used in residential buildings. Displacement ventilation provides fresh air to the occupied zone in a more efficient way than mixing ventilation but it is important to know how well it works...... with a floor system for heating or cooling. Can, for example, a floor heating system warm up the supply air too fast and destroy the displacement effect? Will floor cooling, combined with displacement ventilation, result in too high a vertical temperature difference and too low a temperature at feet level......? The required amount of ventilation depends on the ventilation effectiveness. In standards, the recommended values for ventilation effectiveness depend on the position of the supply and exhaust device and on the difference between supply and room air temperature. Among others, for warm air heating...

  10. Modeling and Control of Livestock Ventilation Systems and Indoor Environments

    DEFF Research Database (Denmark)

    Wu, Zhuang; Heiselberg, Per; Stoustrup, Jakob

    2005-01-01

    and indoor environments with a major emphasis on the prediction of indoor horizontal variation of temperature and concentration adapted to the design of appropriate controlling strategy and control systems. The Linear Quadratic (LQ) optimal control method taking into account of the effect of necessary...... constraints and random disturbances is designed through system linearization. The well designed control systems are able to determine the demand ventilation rate and airflow pattern, improve and optimize the indoor Thermal Comfort (TC), Indoor Air Quality (IAQ) and energy use....

  11. Improving the effectiveness of boiler units with coal dust systems equipped with mill-ventilators

    Science.gov (United States)

    Elsukov, V. K.

    2007-09-01

    Problems pertinent to controlling the load of steam boilers and coal dust systems equipped with mill-ventilators are analyzed. A comprehensive set of patented technical solutions for these problems is presented. A formula for determining the ventilation output of mill-ventilators as a function of the fuel charge is proposed.

  12. Analysis of radon reduction and ventilation systems in uranium mines in China

    International Nuclear Information System (INIS)

    Hu Penghua; Li Xianjie

    2012-01-01

    Mine ventilation is the most important way of reducing radon in uranium mines. At present, the radon and radon progeny levels in Chinese uranium mines where the cut and fill stoping method is used are 3–5 times higher than those in foreign uranium mines, as there is not much difference in the investments for ventilation protection between Chinese uranium mines and international advanced uranium mines with compaction methodology. In this paper, through the analysis of radon reduction and ventilation systems in Chinese uranium mines and the comparison of advantages and disadvantages between a variety of ventilation systems in terms of radon control, the authors try to illustrate the reasons for the higher radon and radon progeny levels in Chinese uranium mines and put forward some problems in three areas, namely the theory of radon control and ventilation systems, radon reduction ventilation measures and ventilation management. For these problems, this paper puts forward some proposals regarding some aspects, such as strengthening scrutiny, verifying and monitoring the practical situation, making clear ventilation plans, strictly following the mining sequence, promoting training of ventilation staff, enhancing ventilation system management, developing radon reduction ventilation technology, purchasing ventilation equipment as soon as possible in the future, and so on.

  13. Analysis of radon reduction and ventilation systems in uranium mines in China.

    Science.gov (United States)

    Hu, Peng-hua; Li, Xian-jie

    2012-09-01

    Mine ventilation is the most important way of reducing radon in uranium mines. At present, the radon and radon progeny levels in Chinese uranium mines where the cut and fill stoping method is used are 3-5 times higher than those in foreign uranium mines, as there is not much difference in the investments for ventilation protection between Chinese uranium mines and international advanced uranium mines with compaction methodology. In this paper, through the analysis of radon reduction and ventilation systems in Chinese uranium mines and the comparison of advantages and disadvantages between a variety of ventilation systems in terms of radon control, the authors try to illustrate the reasons for the higher radon and radon progeny levels in Chinese uranium mines and put forward some problems in three areas, namely the theory of radon control and ventilation systems, radon reduction ventilation measures and ventilation management. For these problems, this paper puts forward some proposals regarding some aspects, such as strengthening scrutiny, verifying and monitoring the practical situation, making clear ventilation plans, strictly following the mining sequence, promoting training of ventilation staff, enhancing ventilation system management, developing radon reduction ventilation technology, purchasing ventilation equipment as soon as possible in the future, and so on.

  14. Controlled ventilation with the Mapleson D system A theoretical and experimental study.

    Science.gov (United States)

    Seeley, H F; Barnes, P K; Conway, C M

    1977-02-01

    A theoretical analysis has been performed to show the interrelationships between alveolar carbon dioxide concentration, carbon dioxide output, alveolar ventilation and fresh gas flow during controlled ventilation with the Mapleson D system. The model and forms of equation used have been substantiated by experiments in which dogs were ventilated through a coaxial version of the Mapleson D system at varying levels of fresh gas flow and alveolar ventilation. By assuming that man ventilated with this system behaves as does the dog, a nomogram has been produced to predict alveolar carbon dioxide concentrations at any levels of fresh gas flow and minute volume.

  15. Development of mechanical ventilation system with low energy consumption for renovation of buildings

    DEFF Research Database (Denmark)

    Terkildsen, Søren

    the performance of mechanical ventilation systems. The power consumption of mechanical ventilation depends on the flow rate, fan efficiency and pressure loss in the system. This thesis examines the options and develops a concept and components for the design of low-pressure mechanical ventilation. The hypothesis...... is that A new type of low-pressure mechanical ventilation with improved indoor environment and energy performance can be developed, by optimizing and redesigning each constituent element of conventional mechanical ventilation systems with respect to pressure and the development of new low-pressure components...... parts of a mechanical ventilation system and the parts that are critical for the hypothesis were identified. The system proposed consists of electrostatic precipitators for filtration, an “oversized” heat exchanger to reduce pressure loss and improve heat recovery efficiency, diffuse ceiling ventilation...

  16. A new positive pressure ventilation delivery system: its impact on lung ventilation studies that are technically inadequate or non diagnostic

    International Nuclear Information System (INIS)

    Bui, C.; Leiper, C.; Lee, K.; Saunders, C.; Dixson, H.; Elison, B.; Bennett, G.; Gibian, T.; Rutland, J.; Tse, V.; Elzein, H.; Babicheva, R.

    2000-01-01

    Full text: The objective of this study was to evaluate the efficacy and safety of an improved Positive Pressure Ventilation Delivery System (PVDS) in the investigation of Pulmonary Embolism (PE). The major component of PVDS is a commercially available, self-inflating 1.6L Hudson Resuscitator Bag, filled with either oxygen or air (if the patient has CO 2 retention), which is squeezed by the operator to push Technegas from the Technegas Generator Chamber to the patient via the Patient Administration Set synchronously with patient inspiration. 27 spontaneously breathing in-patients (12 males, 15 females, age range 64-89, 21 with chronic airflow limitation), whose conventional lung ventilation images were technically inadequate or non diagnostic, were re-scanned using PVDS within four days after the conventional ventilation study. Randomised blinded visual interpretation of conventional ventilation/perfusion scan vs. PVDS-assisted ventilation/perfusion scan was performed by consensus reading with two experienced observers. In conclusion PVDS was safe and well tolerated. PVDS improved the image quality of the lung ventilation scans in this cohort of patients. This technique has the potential to improve the accuracy of lung scanning in patients with severe lung disease. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  17. Energy requirements of a multi-sensor based demand control ventilation system in residential buildings

    Energy Technology Data Exchange (ETDEWEB)

    Chul Seong, Nam; Min Hong, Sung; Won Yoon, Dong [Kyoungwon University, Seoul (Korea, Republic of); Jun Moon, Hyeun [Dankook University, Yongin (Korea, Republic of); Augenbroe, Godfried [Georgia Institute of Technology, Atlanta (United States)

    2010-07-01

    Nowadays, people spend most of their time indoors. Therefore indoor air quality is of high importance and the building regulation in Korea was revised to apply 0.7 air change rate in residential apartment housing. However residents do not often operate mechanical ventilation systems mainly due to their utility cost. The aim of this paper is to present a demand control ventilation (DCV) system which implements ventilation strategies to meet the ventilation requirements. An evaluation was conducted on both conventional ventilation and sensor based DCV systems to compare their energy requirements. The study showed that the use of the DCV system results in a better indoor air quality and a lower energy consumption than conventional ventilation. This paper highlighted that the Korean ventilation regulation is not enough to control the CO2 concentration and that the use of the sensor-based DCV would result in a healthier and more comfortable indoor environment.

  18. Ventilation models

    Science.gov (United States)

    Skaaret, Eimund

    Calculation procedures, used in the design of ventilating systems, which are especially suited for displacement ventilation in addition to linking it to mixing ventilation, are addressed. The two zone flow model is considered and the steady state and transient solutions are addressed. Different methods of supplying air are discussed, and different types of air flow are considered: piston flow, plane flow and radial flow. An evaluation model for ventilation systems is presented.

  19. Ventilation System Type and the Resulting Classroom Temperature and Air Quality During Heating Season

    DEFF Research Database (Denmark)

    Gao, Jie; Wargocki, Pawel; Wang, Yi

    2014-01-01

    The present study investigated how different ventilation system types influence classroom temperature and air quality. Five classrooms were selected in the same school. They were ventilated by manually operable windows, manually operable windows with exhaust fan, automatically operable windows...... with and without exhaust fan and by mechanical ventilation system. Temperature, relative humidity, carbon dioxide (CO2) concentration and opening of windows were continuously monitored for one month during heating season in 2012. Classroom with manually operable windows had the highest carbon dioxide concentration...... levels so that the estimated ventilation rate was the lowest compared with the classrooms ventilated with other systems. Temperatures were slightly lower in classroom ventilated by manually operable windows with exhaust fan. Windows were opened seldom even in the classroom ventilated by manually operable...

  20. Technology Solutions Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    A. Rudd and D. Bergey

    2015-08-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs.

  1. HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT SEISMIC ANALYSIS IN SUPPORT OF INCREASED LIQUID LEVEL IN 241-AP TANK FARMS

    Energy Technology Data Exchange (ETDEWEB)

    MACKEY TC; ABBOTT FG; CARPENTER BG; RINKER MW

    2007-02-16

    The overall scope of the project is to complete an up-to-date comprehensive analysis of record of the DST System at Hanford. The "Double-Shell Tank (DST) Integrity Project - DST Thermal and Seismic Project" is in support of Tri-Party Agreement Milestone M-48-14.

  2. Pressure dynamic characteristics of pressure controlled ventilation system of a lung simulator.

    Science.gov (United States)

    Shi, Yan; Ren, Shuai; Cai, Maolin; Xu, Weiqing; Deng, Qiyou

    2014-01-01

    Mechanical ventilation is an important life support treatment of critically ill patients, and air pressure dynamics of human lung affect ventilation treatment effects. In this paper, in order to obtain the influences of seven key parameters of mechanical ventilation system on the pressure dynamics of human lung, firstly, mechanical ventilation system was considered as a pure pneumatic system, and then its mathematical model was set up. Furthermore, to verify the mathematical model, a prototype mechanical ventilation system of a lung simulator was proposed for experimental study. Last, simulation and experimental studies on the air flow dynamic of the mechanical ventilation system were done, and then the pressure dynamic characteristics of the mechanical system were obtained. The study can be referred to in the pulmonary diagnostics, treatment, and design of various medical devices or diagnostic systems.

  3. Availability Analysis of the Ventilation Stack CAM Interlock System

    International Nuclear Information System (INIS)

    YOUNG, J.

    2000-01-01

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability. Further, requiring an alarm to actuate upon CAM failure is not necessary to maintain the availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability. However, if CAM failures were only detected by the 92-day functional tests required in the Authorization Basis (AB), CAM availability would be much less than that credited in the safety analysis. Therefore it is recommended that the current surveillance practice of daily simple system checks, 30-day source checks and 92-day functional tests be continued in order to maintain CAM availability

  4. Co-occupant's exposure to exhaled pollutants with two types of personalized ventilation strategies under mixing and displacement ventilation systems.

    Science.gov (United States)

    Li, X; Niu, J; Gao, N

    2013-04-01

    Personalized ventilation (PV) system in conjunction with total ventilation system can provide cleaner inhaled air for the user. Concerns still exist about whether the normally protecting PV device, on the other hand, facilitates the dispersion of infectious agents generated by its user. In this article, two types of PV systems with upward supplied fresh air, namely a chair-based PV and one kind of desk-mounted PV systems, when combined with mixing ventilation (MV) and displacement ventilation (DV) systems, are investigated using simulation method with regard to their impacts on co-occupant's exposure to the exhaled droplet nuclei generated by the infected PV user. Simulation results of tracer gas and particles with aerodynamic diameter of 1, 5, and 10 μm from exhaled air show that, when only the infected person uses a PV, the different PV air supplying directions present very different impacts on the co-occupant's intake under DV, while no apparent differences can be observed under MV. The findings demonstrate that better inhaled air quality can always be achieved under DV when the adopted PV system can deliver conditioned fresh air in the same direction with the mainly upward airflow patterns of DV. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  5. Initial computer modeling of WIPP [Waste Isolation Pilot Plant] underground ventilation system, September 1985--March 1986

    International Nuclear Information System (INIS)

    Sethi, S.

    1986-11-01

    Provision of a good ventilation system has been and continues to be a major priority here of those responsible for its design, management, and operation. As an ongoing effort in this direction, development of computer simulated models for the system was initiated in September, 1985. It was decided to utilize Dravo's 'MINEVENT' computer program for this purpose. Accordingly, initial computer models of the mine's ventilation system have been developed for various modes of operation. Specifically, they include: Simulation of the current ventilation system, and Simulation of the designed ventilation system for modes: mine construction mode/shift, waste storage mode/shift, and air reversal mode. 5 figs

  6. Overall Ventilation System Flow Network Calculation for Site Recommendation

    International Nuclear Information System (INIS)

    Steinhoff, Jeff J.

    2001-01-01

    The scope of this calculation is to determine ventilation system resistances, pressure drops, airflows, and operating cost estimates for the Site Recommendation (SR) design as detailed in the ''Site Recommendation Subsurface Layout'' (BSC (Bechtel SAIC Company) 2001a). The statutory limit for emplacement of waste in Yucca Mountain is 70,000 metric tons of uranium (MTU) and is considered the base case for this report. The objective is to determine the overall repository system ventilation flow network for the monitoring phase during normal operations and to provide a basis for the system description document design descriptions. Any values derived from this calculation will not be used to support construction, fabrication, or procurement. The work scope is identified in the ''Technical Work Plan for Subsurface Design Section FY01 Work Activities'' (CRWMS M and O 2001, pp. 6 and 13). In accordance with the technical work plan this calculation was prepared in accordance with AP-3.12Q, ''Calculations'' and other procedures invoked by AP-3.12Q. It also incorporates the procedure AP-SI1.Q, ''Software Management''

  7. Dst Prediction Based on Solar Wind Parameters

    Directory of Open Access Journals (Sweden)

    Yoon-Kyung Park

    2009-12-01

    Full Text Available We reevaluate the Burton equation (Burton et al. 1975 of predicting Dst index using high quality hourly solar wind data supplied by the ACE satellite for the period from 1998 to 2006. Sixty magnetic storms with monotonously decreasing main phase are selected. In order to determine the injection term (Q and the decay time (tau of the equation, we examine the relationships between Dst* and VB_s, Delta Dst* and VB_s, and Delta Dst* and Dst* during the magnetic storms. For this analysis, we take into account one hour of the propagation time from the ACE satellite to the magnetopause, and a half hour of the response time of the magnetosphere/ring current to the solar wind forcing. The injection term is found to be Q({nT}/h=-3.56VB_s for VB_s>0.5mV/m and Q({nT}/h=0 for VB_s leq0.5mV/m. The tau (hour is estimated as 0.060 Dst* + 16.65 for Dst*>-175nT and 6.15 hours for Dst* leq -175nT. Based on these empirical relationships, we predict the 60 magnetic storms and find that the correlation coefficient between the observed and predicted Dst* is 0.88. To evaluate the performance of our prediction scheme, the 60 magnetic storms are predicted again using the models by Burton et al. (1975 and O'Brien & McPherron (2000a. The correlation coefficients thus obtained are 0.85, the same value for both of the two models. In this respect, our model is slightly improved over the other two models as far as the correlation coefficients is concerned. Particularly our model does a better job than the other two models in predicting intense magnetic storms (Dst* lesssim -200nT.

  8. Effects of types of ventilation system on indoor particle concentrations in residential buildings.

    Science.gov (United States)

    Park, J S; Jee, N-Y; Jeong, J-W

    2014-12-01

    The objective of this study was to quantify the influence of ventilation systems on indoor particle concentrations in residential buildings. Fifteen occupied, single-family apartments were selected from three sites. The three sites have three different ventilation systems: unbalanced mechanical ventilation, balanced mechanical ventilation, and natural ventilation. Field measurements were conducted between April and June 2012, when outdoor air temperatures were comfortable. Number concentrations of particles, PM2.5 and CO2 , were continuously measured both outdoors and indoors. In the apartments with natural ventilation, I/O ratios of particle number concentrations ranged from 0.56 to 0.72 for submicron particles, and from 0.25 to 0.60 for particles larger than 1.0 μm. The daily average indoor particle concentration decreased to 50% below the outdoor level for submicron particles and 25% below the outdoor level for fine particles, when the apartments were mechanically ventilated. The two mechanical ventilation systems reduced the I/O ratios by 26% for submicron particles and 65% for fine particles compared with the natural ventilation. These results showed that mechanical ventilation can reduce exposure to outdoor particles in residential buildings. Results of this study confirm that mechanical ventilation with filtration can significantly reduce indoor particle levels compared with natural ventilation. The I/O ratios of particles substantially varied at the naturally ventilated apartments because of the influence of variable window opening conditions and unsteadiness of wind flow on the penetration of outdoor air particles. For better prediction of the exposure to outdoor particles in naturally ventilated residential buildings, it is important to understand the penetration of outdoor particles with variable window opening conditions. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Industrial ventilation

    Science.gov (United States)

    Goodfellow, H. D.

    Industrial ventilation design methodology, using computers and using fluid dynamic models, is considered. It is noted that the design of a ventilation system must be incorporated into the plant design and layout at the earliest conceptual stage of the project. A checklist of activities concerning the methodology for the design of a ventilation system for a new facility is given. A flow diagram of the computer ventilation model shows a typical input, the initialization and iteration loop, and the output. The application of the fluid dynamic modeling techniques include external and internal flow fields, and individual sources of heat and contaminants. Major activities for a ventilation field test program are also addressed.

  10. Ventilation and air-conditioning system for PWR nuclear power plant

    International Nuclear Information System (INIS)

    Ohmoto, Kenji

    1987-01-01

    This report outlines the ventilation and air conditioning facilities for PWR nuclear power plant as well as design re-evaluation and optimization of ventilation and air-conditioning. The primary PWR installations are generally housed in the nuclear reactor building, auxiliary buildings and control building, which are equipped with their own ventilation and air-conditioning systems to serve for their specific purposes. A ventilation/air-conditioning system should be able to work effectively not only for maintaining the ordinary reactor operation but also for controlling the environmental temperature in the event of an accident. Designing of a ventilation/air-conditioning system relied on empirical data in the past, but currently it is performed based on information obtained from various analyses to optimize the system configuration and ventilation capacity. Design re-evaluation of ventilation/air-conditioning systems are conducted widely in various areas, aiming at the integration of safety systems, optimum combination of air-cooling and water-cooling systems, and optimization of the ventilation rate for controlling the concentrations of radioactive substances in the atmosphere in the facilities. It is pointed out that performance evaluation of ventilation/air-conditioning systems, which has been conducted rather macroscopically, should be carried out more in detal in the future to determine optimum air streams and temperature distribution. (Nogami, K.)

  11. An air-conditioning, ventilation and automatic ventilation monitoring and recording system constructed in an unsealed radioisotope laboratory. Energy-saving measures in Nagasaki University Radioisotope Center

    International Nuclear Information System (INIS)

    Takatsuji, Toshihiro; Yoshida, Masahiro; Takao, Hideaki; Okumura, Yutaka; Ooura, Tosinobu; Kotoura, Kazuki; Yamanaka, Yasushi; Yanagita, Hiroyoshi.

    1998-01-01

    We constructed an automatic operation system of air-conditioners and ventilators in a radiation controlled area to minimize electric consumption. The system operates the air-conditioner and the ventilator of each ventilation unit when someone is staying in rooms belonging to the unit based on information from an access control system to the controlled area and lighting switches in front of individual room. For understanding of operation conditions and confirmation of radioactive concentration in air lower than the legal limit at the ventilation stack, we also constructed an automatic ventilation monitoring and recording system, which makes complete operation records of each ventilator automatically. These systems enabled to achieve sharp energy-saving compatible with radiation protection. (author)

  12. An overview of the TA-55, Building PF-4 ventilation system

    International Nuclear Information System (INIS)

    1994-01-01

    An overview of the TA-55, Building PF-4 ventilation system is provided in the following sections. Included are descriptions of the zone configurations, equipment-performance criteria, ventilation support systems, and the ventilation-system evaluation criteria. Section 4.2.1.1 provides a brief discussion of the ventilation system function. Section 4.2.1.2 provides details on the overall system configuration. Details of system interfaces and support systems are provided in Section 4.2.1.3. Section 4.2.1.4 describes instrumentation and control needed to operate the ventilation system. Finally, Sections 4.2.1.5 and 4.2.1.6 describe system surveillance/maintenance and Technical Safety Requirements (TSR) Limitations, respectively. Note that the numerical parameters included in this description are considered nominal; set points and other specifications actually fall within operational bands

  13. An overview of the TA-55, Building PF-4 ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-02-22

    An overview of the TA-55, Building PF-4 ventilation system is provided in the following sections. Included are descriptions of the zone configurations, equipment-performance criteria, ventilation support systems, and the ventilation-system evaluation criteria. Section 4.2.1.1 provides a brief discussion of the ventilation system function. Section 4.2.1.2 provides details on the overall system configuration. Details of system interfaces and support systems are provided in Section 4.2.1.3. Section 4.2.1.4 describes instrumentation and control needed to operate the ventilation system. Finally, Sections 4.2.1.5 and 4.2.1.6 describe system surveillance/maintenance and Technical Safety Requirements (TSR) Limitations, respectively. Note that the numerical parameters included in this description are considered nominal; set points and other specifications actually fall within operational bands.

  14. Ventilation and air heating systems. 5. rev. and enlarged ed. Lueftung und Luftheizung

    Energy Technology Data Exchange (ETDEWEB)

    Ihle, C. (Bundesfachschule fuer Sanitaer-, Heizungs- und Klimatechnik, Karlsruhe (Germany))

    1991-01-01

    Higher demands on the air quality of flats, offices and assembly rooms make ventilation and air heating the subjects of increasing interest. Taking into account the ever more urgent need for energy conservation the book deals with all aspects of ventilation on the basis of the recent DIN standards, VDI sheets and regulations. It may be used as an instruction manual, professional reference book or as a guide to practice-oriented subject selection with a minimum of theoretical fundamentals. The book deals with ventilation and air heating systems, free ventilation, design fundamentals, exercised for ventilation and air heating systems, central and decentralized ventilation systems, practical examples, ducts and calculation of ducts, air distribution, fans, noise formation, noise pollution abatement and heat recovery. (BWI) With 472 figs., 91 tabs., 1 separate map.

  15. Applied patent RFID systems for building reacting HEPA air ventilation system in hospital operation rooms.

    Science.gov (United States)

    Lin, Jesun; Pai, Jar-Yuan; Chen, Chih-Cheng

    2012-12-01

    RFID technology, an automatic identification and data capture technology to provide identification, tracing, security and so on, was widely applied to healthcare industry in these years. Employing HEPA ventilation system in hospital is a way to ensure healthful indoor air quality to protect patients and healthcare workers against hospital-acquired infections. However, the system consumes lots of electricity which cost a lot. This study aims to apply the RFID technology to offer a unique medical staff and patient identification, and reacting HEPA air ventilation system in order to reduce the cost, save energy and prevent the prevalence of hospital-acquired infection. The system, reacting HEPA air ventilation system, contains RFID tags (for medical staffs and patients), sensor, and reacting system which receives the information regarding the number of medical staff and the status of the surgery, and controls the air volume of the HEPA air ventilation system accordingly. A pilot program was carried out in a unit of operation rooms of a medical center with 1,500 beds located in central Taiwan from Jan to Aug 2010. The results found the air ventilation system was able to function much more efficiently with less energy consumed. Furthermore, the indoor air quality could still keep qualified and hospital-acquired infection or other occupational diseases could be prevented.

  16. Interplanetary magnetic field and geomagnetic Dst variations.

    Science.gov (United States)

    Patel, V. L.; Desai, U. D.

    1973-01-01

    The interplanetary magnetic field has been shown to influence the ring current field represented by Dst. Explorer 28 hourly magnetic field observations have been used with the hourly Dst values. The moderate geomagnetic storms of 60 gammas and quiet-time fluctuations of 10 to 30 gammas are correlated with the north to south change of the interplanetary field component perpendicular to the ecliptic. This change in the interplanetary field occurs one to three hours earlier than the corresponding change in the Dst field.

  17. Effect of an automatic triggering and cycling system on comfort and patient-ventilator synchrony during pressure support ventilation.

    Science.gov (United States)

    Vasconcelos, Renata dos S; Melo, Luíz Henrique de P; Sales, Raquel P; Marinho, Liégina S; Deulefeu, Flávio C; Reis, Ricardo C; Alves-de-Almeida, Mirizana; Holanda, Marcelo A

    2013-01-01

    The digital Auto-Trak™ system is a technology capable of automatically adjusting the triggering and cycling mechanisms during pressure support ventilation (PSV). To compare Auto-Trak with conventional settings in terms of patient-ventilator synchrony and discomfort. Twelve healthy volunteers underwent PSV via the mouth by breathing through an endotracheal tube. In the conventional setting, a pressure support of 8 cm H2O with flow cycling (25% peak inspiratory flow) and a sensitivity of 1 cm H2O was adjusted. In Auto-Trak the triggering and cycling were automatically set. Discomfort, effort of breathing, and the asynchrony index (AI) were assessed. In a complementary bench study, the inspiratory and expiratory time delays were quantified for both settings in three mechanical models: 'normal', obstructive (COPD), and restrictive (ARDS), using the ASL 5000 simulator. In the volunteer study the AI and the discomfort scores did not differ statistically between the two settings. In the bench investigation the use of Auto-Trak was associated with a greater triggering delay in the COPD model and earlier expiratory cycling in the ARDS model but with no asynchronic events. Use of the Auto-Trak system during PSV showed similar results in comparison to the conventional adjustments with respect to patient-ventilator synchrony and discomfort in simulated conditions of invasive mechanical ventilation. Copyright © 2013 S. Karger AG, Basel.

  18. Functional Analysis for Double Shell Tank (DST) Subsystems

    Energy Technology Data Exchange (ETDEWEB)

    SMITH, D.F.

    2000-08-22

    This functional analysis identifies the hierarchy and describes the subsystem functions that support the Double-Shell Tank (DST) System described in HNF-SD-WM-TRD-007, System Specification for the Double-Shell Tank System. Because of the uncertainty associated with the need for upgrades of the existing catch tanks supporting the Waste Feed Delivery (WFD) mission, catch tank functions are not addressed in this document. The functions identified herein are applicable to the Phase 1 WFD mission only.

  19. Building America Case Study: Selecting Ventilation Systems for Existing Homes (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-12-01

    This document addresses adding -or improving - mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards. Advantages, disadvantages, and approximate costs of various system types are presented along with general guidelines for implementing the systems in homes. CARB intends for this document to be useful to decision makers and contractors implementing ventilation systems in homes. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors. It is the intent of this document to assist contractors in making more informed decisions when selecting systems. Ventilation is an integral part of a high-performance home. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability.

  20. Performance analysis of a new design of office diffuse ceiling ventilation system

    DEFF Research Database (Denmark)

    Fan, Jianhua; Hviid, Christian Anker; Yang, Honglu

    2013-01-01

    surface temperatures, pressure loss of the ceiling and ventilation effectiveness are measured for an air change rate of 3.5 h-1 and 5.1 h -1 respectively. A computational fluid dynamics model of the office with the diffuse ceiling ventilation system is built and validated by the full scale measurement....... The measurements of pressure loss across the ceiling show a low pressure drop between the plenum and the occupied zone. Ventilation effectiveness is measured to be close to 1 on average under the tested conditions. It is shown that the diffuse ceiling ventilation system is able to remove indoor pollutant...

  1. Performance analysis of ventilation systems with desiccant wheel cooling based on exergy destruction

    International Nuclear Information System (INIS)

    Tu, Rang; Liu, Xiao-Hua; Hwang, Yunho; Ma, Fei

    2016-01-01

    Highlights: • Ventilation systems with desiccant wheel were analyzed from exergy destruction. • Main performances influencing factors for ventilation systems are put forward. • Improved ventilation systems with lower exergy destruction are suggested. • Performances of heat pumps driven ventilation systems are greatly increased. - Abstract: This paper investigates the performances of ventilation systems with desiccant wheel cooling from the perspective of exergy destructions. Based on the inherent influencing factors for exergy destructions of heat and mass transfer and heat sources, provide guidelines for efficient system design. First, performances of a basic ventilation system are simulated, which is operated at high regeneration temperature and low coefficient of performance (COP). Then, exergy analysis of the basic ventilation system shows that exergy destructions mainly exist in the heat and mass transfer components and the heat source. The inherent influencing factors for the heat and mass transfer exergy destruction are heat and mass transfer capacities, which are related to over dehumidification of the desiccant wheel, and unmatched coefficients, which represent the uniformity of the temperature or humidity ratio differences fields for heat and mass transfer components. Based on these findings, two improved ventilation systems are suggested. For the first system, over dehumidification is avoided and unmatched coefficients for each component are reduced. With lower heat and mass transfer exergy destructions and lower regeneration temperature, COP and exergy efficiency of the first system are increased compared with the basic ventilation system. For the second system, a heat pump, which recovers heat from the process air to heat the regeneration air, is adopted to replace the electrical heater and cooling devices. The exergy destruction of the heat pump is considerably reduced as compared with heat source exergy destruction of the basic ventilation

  2. A new prototype of an electronic jet-ventilator and its humidification system

    Science.gov (United States)

    Kraincuk, Paul; Kepka, Anton; Ihra, Gerald; Schabernig, Christa; Aloy, Alexander

    1999-01-01

    Background: Adequate humidification in long-term jet ventilation is a critical aspect in terms of clinical safety. Aim: To assess a prototype of an electronic jet-ventilator and its humidification system. Methods: Forty patients with respiratory insufficiency were randomly allocated to one of four groups. The criterion for inclusion in this study was respiratory insufficiency exhibiting a Murray score above 2. The four groups of patients were ventilated with three different respirators and four different humidification systems. Patients in groups A and B received superimposed high-frequency jet ventilation (SHFJV) by an electronic jet-ventilator either with (group A) or without (group B) an additional humidification system. Patients in group C received high-frequency percussive ventilation (HFPV) by a pneumatic high-frequency respirator, using a hot water humidifier for warming and moistening the inspiration gas. Patients in group D received conventional mechanical ventilation using a standard intensive care unit respirator with a standard humidification system. SHFJV and HFPV were used for a period of 100 h (4days). Results: A significantly low inspiration gas temperature was noted in patients in group B, initially (27.2 ± 2.5°C) and after 2 days (28.0 ± 1.6°C) (P humidification associated with jet ventilation can be fully prevented by using this new jet-ventilator. These data were sustained by nondeteriorating MIS values at the end of the 4-day study period in groups A, C and D. PMID:11056732

  3. Experimental evaluation of the Skylab orbital workshop ventilation system concept

    Science.gov (United States)

    Allums, S. L.; Hastings, L. J.; Ralston, J. T.

    1972-01-01

    Extensive testing was conducted to evaluate the Orbital Workshop ventilation concept. Component tests were utilized to determine the relationship between operating characteristics at 1 and 0.34 atm. System tests were conducted at 1 atm within the Orbital Workshop full-scale mockup to assess delivered volumetric flow rate and compartment air velocities. Component tests with the Anemostat circular diffusers (plenum- and duct-mounted) demonstrated that the diffuser produced essentially equivalent airflow patterns and velocities in 1- and 0.34-atm environments. The tests also showed that the pressure drop across the diffuser could be scaled from 1 to 0.34 atm using the atmosphere pressure ratio. Fan tests indicated that the performance of a multiple, parallel-mounted fan cluster could be predicted by summing the single-fan flow rates at a given delta P.

  4. Effect of Room Ventilation Rates in Rodent Rooms with Direct-Exhaust IVC Systems.

    Science.gov (United States)

    Geertsema, Roger S; Lindsell, Claire E

    2015-09-01

    When IVC are directly exhausted from a rodent housing room, the air quality of the room can become independent of the intracage air quality and may reduce the need for high room ventilation rates. This study assessed the effect of decreasing the ventilation rate in rodent rooms using direct-exhaust IVC systems. The study was conducted over 16 wk and compared conditions in 8 rodent rooms that had ventilation rates of 5 to 6 air changes per hour (ACH) with those in rooms at 10 to 12 ACH. At the low ventilation rate, rooms had higher CO₂ concentrations, higher dew point temperature, and lower particulate levels and spent a greater percentage of time above the temperature set point than did rooms at the high rate. The levels of allergens and endotoxins in room air were the same regardless of the ventilation rate. Differences seen in parameters within cages at the 2 ventilation rates were operationally irrelevant. We detected no total volatile organic compounds in the room that were attributable to ammonia, regardless of the ventilation rate. Clearing the air of ethanol after a spill took longer at the low compared with high rate. However, ethanol clearance was faster at the low rate when the demand-control system was activated than at the high ventilation rate alone. Air quality in the room and in the cages were acceptable with room ventilation rates of 5 to 6 ACH in rodent rooms that use direct-exhaust IVC systems.

  5. KANGA(ROO): Handling the micro-DST of the BaBar Experiment with ROOT

    Energy Technology Data Exchange (ETDEWEB)

    Gowdy, Stephen J.

    2002-06-24

    A system based on ROOT for handling the micro-DST of the BABAR experiment is described. The purpose of the KANGA system is to have micro-DST data available in a format well suited for data distribution within a world-wide collaboration with many small sites. The design requirements, implementation and experience in practice after three years of data taking by the BABAR experiment are presented.

  6. Passive ventilation systems with heat recovery and night cooling

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Svendsen, Svend

    2008-01-01

    In building design the requirements for energy consumption for ventilation, heating and cooling and the requirements for increasingly better indoor climate are two opposing factors. This paper presents the schematic layout and simulation results of an innovative multifunc-tional ventilation conce...

  7. Analysis of the systems of ventilation of residential houses of Ukraine and Estonia

    Science.gov (United States)

    Savchenko, Olena; Zhelykh, Vasyl; Voll, Hendrik

    2017-12-01

    The most common ventilation system in residential buildings in Ukraine is natural ventilation. In recent years, due to increased tightness of structures, an increase in the content of synthetic finishing materials in them, the quality of microclimate parameters deteriorated. One of the measures to improve the parameters of indoor air in residential buildings is the use of mechanical inflow and exhaust ventilation system. In this article the regulatory documents concerning the design of ventilation systems in Ukraine and Estonia and the requirements for air exchange in residential buildings are considered. It is established that the existing normative documents in Ukraine are analogous to European norms, which allow design the system of ventilation of residential buildings according to European standards. However, the basis for the design of ventilation systems in Ukraine is the national standards, in which mechanical ventilation, unfortunately, is provided only for the design of high-rise buildings. To maintain acceptable microclimate parameters in residential buildings, it is advisable for designers to apply the requirements for designing ventilation systems in accordance with European standards.

  8. Analysis of the systems of ventilation of residential houses of Ukraine and Estonia

    Directory of Open Access Journals (Sweden)

    Savchenko Olena

    2017-12-01

    Full Text Available The most common ventilation system in residential buildings in Ukraine is natural ventilation. In recent years, due to increased tightness of structures, an increase in the content of synthetic finishing materials in them, the quality of microclimate parameters deteriorated. One of the measures to improve the parameters of indoor air in residential buildings is the use of mechanical inflow and exhaust ventilation system. In this article the regulatory documents concerning the design of ventilation systems in Ukraine and Estonia and the requirements for air exchange in residential buildings are considered. It is established that the existing normative documents in Ukraine are analogous to European norms, which allow design the system of ventilation of residential buildings according to European standards. However, the basis for the design of ventilation systems in Ukraine is the national standards, in which mechanical ventilation, unfortunately, is provided only for the design of high-rise buildings. To maintain acceptable microclimate parameters in residential buildings, it is advisable for designers to apply the requirements for designing ventilation systems in accordance with European standards.

  9. Computer-simulation study on fire behaviour in the ventilated cavity of ventilated façade systems

    Directory of Open Access Journals (Sweden)

    Giraldo María P.

    2013-11-01

    Full Text Available Fire spread through the façades is widely recognized as one of the fastest pathways of fire spreading in the buildings. Fire may spread through the façade in different ways depending on the type of façade system and on the elements and materials from which it is constructed. Ventilated façades are multilayer systems whose main feature is the creation of an air chamber of circulating air between the original building wall and the external cladding. The “chimney effect” in the air cavity is a mechanism that improves the façade's thermal behaviour and avoids the appearance of moisture from rain or condensation. However, in a event of fire, it may contribute to the quickest spreading of fire, representing a significant risk to the upper floors of a building. This study deals with some aspects of fire propagation through the ventilated cavity in ventilated façade systems. Also we review the provisions stipulated by the Spanish building code (Código Técnico de la Edificación, CTE [1] to avoid fire spread outside the building. The results highlight the importance of the use of proper fire barriers to ensure the compartmentalization of the ventilated cavity, as well as the use of non-combustible thermal insulation materials, among others. In addition, based on the results, it might be considered that the measures stipulated by the CTE are insufficient to limit the risks associated with this kind of façades systems. The study has been performed using field models of computational fluid-dynamics. In particular, the Fire Dynamics Simulator (FDS software has been used to numerically solve the mathematical integration models.

  10. A novel system solution for cooling and ventilation in office buildings

    DEFF Research Database (Denmark)

    Yu, Tao; Heiselberg, Per Kvols; Lei, Bo

    2015-01-01

    technologies and renewable energy sources have risen. Based on a literature review of natural ventilation, building thermal mass activation and diffuse ceiling ventilation, this paper proposes a new system solution combining these three technologies for cooling and ventilation in office buildings. This new...... solution has the special function of using natural ventilation all the year around without draught risk, even in very cold seasons. A case study of a typical office room using this solution and other traditional HVAC systems is carried out by energy simulation. The results show that there is a large energy...... saving potential using this solution compared with other systems. Energy saving potential for cooling occurs in summer, transitional seasons and part of winter, depending on the internal heat load level. Meanwhile, due to the large cooling potential of outside air in winter, the minimum ventilation rate...

  11. A summary of Nimbus-6 temperature retrieval accuracy statistics for DST-5 and DST-6

    Science.gov (United States)

    Hayden, C. M.

    1977-01-01

    Statistics compiled from Nimbus-6 temperature retrievals processed during the 18 August-4 September 1975 DST-5, and the 1 February-4 March 1976 DST-6 are addressed. All statistics were compiled from samples of colocated satellite sounding and radiosonde measurements. The colocation window is 222 km in space and 6 hours in time.

  12. Noxious gases in rabbit housing systems: effects of cross and longitudinal ventilation

    Directory of Open Access Journals (Sweden)

    Francesco da Borso

    2016-12-01

    Full Text Available Animal welfare is a matter of increasing interest due to ethical and economical worries regarding animal rights and the sustainability of meat production. Ammonia, carbon dioxide, and methane can be produced in the livestock buildings and, if not adequately controlled by ventilation, can be dangerous for animals and farmers. The aim of the present paper is to study the effects of different ventilation systems in rabbit buildings based on the temporal patterns and the spatial distribution of these noxious gases. The experimental measurements were conducted in two rabbit farms with genetically homogeneous animals subjected to the same diet. Two buildings with different forced ventilation layouts (cross ventilation - building A and longitudinal ventilation - building B were subjected to the monitoring of indoor environmental conditions (temperature, relative humidity, ammonia, carbon dioxide, methane over a whole year. In both the buildings, ventilation was adjusted automatically by means of electronic control units, which were controlled by temperature sensors, located at the centre of the buildings. Gas concentrations inside the buildings followed clearly defined sinusoidal patterns on a daily basis with the highest values reached in winter during the morning hours for ammonia and during the night hours for carbon dioxide and methane. In particular, ammonia revealed a maximum concentration of 30.7 mg m–3 in building A (cross ventilation and 12.9 mg m–3 in building B (longitudinal ventilation, whereas the minimum values were 6.0 and 4.2 mg m–3, in building A and B, respectively. As a consequence, daily mean concentrations of noxious gases, solely could not be considered representative of the actual conditions of air quality in the buildings. The airflow direction clearly influenced the spatial concentration of ammonia, which showed different patterns in the two buildings. In building A, the highest ammonia concentration was in a diffuse

  13. An Evaluation of a Proposed Ventilation System for Melbourne's CH2 Building

    Directory of Open Access Journals (Sweden)

    Lu Aye

    2012-11-01

    Full Text Available The understanding of ventilation requirements in commercial buildings has been significantly revised in the last 10-15 years. A link between health, productivity and increased fresh air use has been established by some research and this understanding underpins the ventilation philosophy adopted for the CH2 building. The ventilation system design for CH2 that has been evaluated in this paper envisages a mechanically driven system during the day, using the displacement technique to distribute filtered air. All introduced air will be drawn from outside and no recycling of air will occur. Natural ventilation will be employed at night using the stack effect, enhanced by turbine ventilators. This paper critiques the proposed ventilation system in the light of international experience and the particular conditions of the building's location. The evidence suggests that natural ventilation sometimes may be inadequate to achieve the desired objectives. Minimization of indoor pollutants, adequate filtration and high levels of ventilation should, however, ensure satisfactory air quality during occupied hours.

  14. TVENT: a computer program for analysis of tornado-induced transients in ventilation systems

    International Nuclear Information System (INIS)

    Duerre, K.H.; Andrae, R.W.; Gregory, W.S.

    1978-07-01

    The report describes TVENT, a portable FORTRAN computer program for predicting flows and pressures in a ventilation system subject to a tornado. The pressure and flow values calculated by TVENT can be used as a basis for structural analysis. TVENT is a one-dimensional, lumped-parameter model with incompressible flow augmented by fluid storage. The theoretical basis for the mathematical modeling and analysis is presented, and a description of the input for the computer code is provided. Modeling techniques specific to ventilation systems are described. Sample problems illustrate the use of TVENT in analyzing ventilation systems. Other sample problems illustrate modeling techniques used in reducing complex systems

  15. Computer modelling of an underground mine ventilation system

    International Nuclear Information System (INIS)

    1984-12-01

    The ability to control workplace short-lived radon daughter concentrations to appropriate levels is crucial to the underground mining of uranium ores. Recognizing that mine ventilation models can be used to design ventilation facilities in new mines and to evaluate proposed ventilation changes in existing mines the Atomic Energy Control Board (AECB) initiated this study to first investigate existing mine ventilation models and then develop a suitable model for use by AECB staff. At the start of the study, available literature on mine ventilation models, in partiuclar models suitable for the unique task of predicting radon daughter levels, were reviewed. While the details of the models varied, it was found that the basic calculation procedures used by the various models were similar. Consequently, a model developed at Queen's University that not only already incorporated most of the desired features but was also readily available, was selected for implementation. Subsequently, the Queen's computer program (actually two programs, one for mine ventilation and one to calculate radon daughter levels) was extended and tested. The following report provides the relevant documentation for setting up and running the models. The mathematical basis of the calculational procedures used in the models are also described

  16. Radon mitigation in schools utilising heating, ventilating and air conditioning systems

    International Nuclear Information System (INIS)

    Fisher, G.; Ligman, B.; Brennan, T.; Shaughnessy, R.; Turk, B.H.; Snead, B.

    1994-01-01

    As part of a continuing radon in schools technology development effort, EPA's School Evaluation Team has performed radon mitigation in schools by the method of ventilation/pressurisation control technology. Ventilation rates were increased, at a minimum, to meet the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) standard, Ventilation for Acceptable Indoor Air Quality (ASHRAE 62-1989). This paper presents the results and the preliminary evaluations which led to the team's decision to implement this technology. Factors considered include energy penalties, comfort, indoor air quality (IAQ), building shell tightness, and equipment costs. Cost benefit of heat recovery ventilation was also considered. Earlier results of the SEP team's efforts have indicated a severe ventilation problem within the schools of the United States. Two case studies are presented where HVAC technology was implemented for controlling radon concentrations. One involved the installation of a heat recovery ventilator to depressurise a crawl space and provide ventilation to the classrooms which previously had no mechanical ventilation. The other involved the restoration of a variable air volume system in a two-storey building. The HVAC system's controls were restored and modified to provide a constant building pressure differential to control the entry of radon. Pre-mitigation and post-mitigation indoor air pollutant measurements were taken, including radon, carbon dioxide (CO 2 ), particulates, and bio-aerosols. Long-term monitoring of radon, CO 2 , building pressure differentials, and indoor/outdoor temperature and relative humidity is presented. (author)

  17. Ventilating system for reprocessing of nuclear fuel rods

    International Nuclear Information System (INIS)

    Szulinski, M.J.

    1981-01-01

    In a nuclear facility such as a reprocessing plant for nuclear fuel rods, the central air cleaner discharging ventilating gas to the atmosphere must meet preselected standards not only as to the momentary concentration of radioactive components, but also as to total quantity per year. In order to comply more satisfactorily with such standards, reprocessing steps are conducted by remote control in a plurality of separate compartments. The air flow for each compartment is regulated so that the air inventory for each compartment has a slow turnover rate of more than a day but less than a year, which slow rate is conveniently designated as quasihermetic sealing. The air inventory in each such compartment is recirculated through a specialized processing unit adapted to cool and/or filter and/or otherwise process the gas. Stale air is withdrawn from such recirculating inventory and fresh air is injected (eg., By the less than perfect sealing of a compartment) into such recirculating inventory so that the air turnover rate is more than a day but less than a year. The amount of air directed through the manifold and duct system from the reprocessing units to the central air cleaner is less than in reprocessing plants of conventional design

  18. Comparison of Dst Forecast Models for Intense Geomagnetic Storms

    Science.gov (United States)

    Ji, Eun-Young; Moon, Y.-J.; Gopalswamy, N.; Lee, D.-H.

    2012-01-01

    We have compared six disturbance storm time (Dst) forecast models using 63 intense geomagnetic storms (Dst Dst data and the predicted Dst during the geomagnetic storm period as well as the difference of the value of minimum Dst (Delta Dst(sub min)) and the difference in the absolute value of Dst minimum time (Delta t(sub Dst)) between the observed and the predicted. As a result, we found that the model by Temerin and Li gives the best prediction for all parameters when all 63 events are considered. The model gives the average values: the linear correlation coefficient of 0.94, the RMS error of 14.8 nT, the Delta Dst(sub min) of 7.7 nT, and the absolute value of Delta t(sub Dst) of 1.5 hour. For further comparison, we classified the storm events into two groups according to the magnitude of Dst. We found that the model of Temerin and Lee is better than the other models for the events having 100 Dst Dst <= 200 nT.

  19. The special improvement scheme for ventilation system of Caotaobei uranium mine and its implementation effect

    International Nuclear Information System (INIS)

    Wu Jianming; Du Yuhai; Shi Zuyuan

    2011-01-01

    The status of mine development, ventilation system and ventilation management in Caotaobei uranium mine is introduced, and problems existing in the ventilation system are pointed out, including enter-air pollution, air leaking, large air resistance. The special improvement scheme involved with technique and management are proposed for problems. After implementation of the scheme, the effective utilization of air volume has been greatly enhanced, and the allocation of air volume is reasonable. The acceptability rate of radon and its daughter concentrations has risen from 12.5% before implementation of the scheme to 88.9%. (authors)

  20. Upgrade of a transverse ventilation system in a bi-directional tunnel

    Directory of Open Access Journals (Sweden)

    Vidmar Peter

    2012-01-01

    Full Text Available The Karavanke tunnel forms an important link between Slovenia and Austria. The almost 8 km long tunnel is operated with bi-directional traffic and does not have dedicated escape routes. Moreover, the ventilation in case of fire does not satisfy requirements of the EU Directive 2004/54/EC that specifies the minimum requirements for tunnels in the trans-European road network. The paper present results of the research conducted regarding the possibility of upgrade the existing system in order to reach the required level of safety at lower costs possible. It is shown that with simple but novel adaptations of the ventilation system, a sizeable increase in the overall level of safety can be achieved. The methodology applied is a combination of a simple pipe model for tunnel ventilation and for detailed fluid dynamics analysis the CFD model is used. The existing ventilation system that in fire ventilation extracts smoke from a single duct is replaced with the smoke extraction from both ducts applying four axial fans. The analysis is focused on air/smoke flow through the vents and ducts and on pressure drops calculated over the length of the ventilation duct and its influence on the total flow. The change of the flow condition also has influence on ventilation fan operation point that is investigated in the paper as well.

  1. Association of ventilation system type with SBS symptoms in office workers

    Energy Technology Data Exchange (ETDEWEB)

    Seppanen, Olli; Fisk, William J.

    2001-02-07

    This paper provides a review and synthesis of current knowledge about the associations of ventilation system types in office buildings with sick building syndrome symptoms and discusses potential explanations for the associations. Relative to natural ventilation, air conditioning, with or without humidification, was consistently associated with a statistically significant increase in the prevalence of one or more SBS symptoms. Prevalences were typically higher by approximately 30% to 200% in the air conditioned buildings. In two of three assessments from a single study, symptom prevalences were also significantly higher in air conditioned buildings than in buildings with simple mechanical ventilation and no humidification. In approximately half of assessments, SBS symptom prevalences were significantly higher in buildings with simple mechanical ventilation than in buildings with natural ventilation. Insufficient information was available for conclusions about the potential increased risk of SBS symptoms with humidification. The statistically significant associations of mechanical ventilation and air conditioning with SBS symptoms are much more frequent than expected from chance and also not likely to be a consequence of confounding by several potential personal, job, or building related confounders. The reasons for the increases in symptom prevalences with mechanical ventilation and particularly with air conditioning remain unclear. Multiple deficiencies in HVAC system design, construction, operation, or maintenance, including some which cause pollutant emissions from HVAC systems, may contribute to the increases in symptom prevalences.

  2. A simulation Model of the Reactor Hall Ventilation and air Conditioning Systems of ETRR-2

    International Nuclear Information System (INIS)

    Abd El-Rahman, M.F.

    2004-01-01

    Although the conceptual design for any system differs from one designer to another. each of them aims to achieve the function of the system required. the ventilation and air conditioning system of reactors hall is one of those systems that really differs but always dose its function for which it is designed. thus, ventilation and air conditioning in some reactor hall constitute only one system whereas in some other ones, they are separate systems. the Egypt Research Reactor-2 (ETRR-2)represents the second type. most studies conducted on ventilation and air conditioning simulation models either in traditional building or for research rectors show that those models were not designed similarly to the model of the hall of ETRR-2 in which ventilation and air conditioning constitute two separate systems.besides, those studies experimented on ventilation and air conditioning simulation models of reactor building predict the temperature and humidity inside these buildings at certain outside condition and it is difficult to predict when the outside conditions are changed . also those studies do not discuss the influences of reactor power changes. therefore, the present work deals with a computational study backed by infield experimental measurements of the performance of the ventilation and air conditioning systems of reactor hall during normal operation at different outside conditions as well as at different levels of reactor power

  3. Design of Mine Ventilators Monitoring System Based on Wireless Sensor Network

    Science.gov (United States)

    Fu, Sheng; Song, Haiqiang

    2012-05-01

    A monitoring system for a mine ventilator is designed based on ZigBee wireless sensor network technology in the paper. The system consists of a sink node, sensor nodes, industrial personal computer and several sensors. Sensor nodes communicate with the sink node through the ZigBee wireless sensor network. The sink node connects with the configuration software on the pc via serial port. The system can collect or calculate vibration, temperature, negative pressure, air volume and other information of the mine ventilator. Meanwhile the system accurately monitors operating condition of the ventilator through these parameters. Especially it provides the most original information for potential faults of the ventilator. Therefore, there is no doubt that it improves the efficiency of fault diagnosis.

  4. Design of Mine Ventilators Monitoring System Based on Wireless Sensor Network

    International Nuclear Information System (INIS)

    Fu Sheng; Song Haiqiang

    2012-01-01

    A monitoring system for a mine ventilator is designed based on ZigBee wireless sensor network technology in the paper. The system consists of a sink node, sensor nodes, industrial personal computer and several sensors. Sensor nodes communicate with the sink node through the ZigBee wireless sensor network. The sink node connects with the configuration software on the pc via serial port. The system can collect or calculate vibration, temperature, negative pressure, air volume and other information of the mine ventilator. Meanwhile the system accurately monitors operating condition of the ventilator through these parameters. Especially it provides the most original information for potential faults of the ventilator. Therefore, there is no doubt that it improves the efficiency of fault diagnosis.

  5. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: NEW CONDENSATOR, INC.--THE CONDENSATOR DIESEL ENGINE RETROFIT CRANKCASE VENTILATION SYSTEM

    Science.gov (United States)

    EPA's Environmental Technology Verification Program has tested New Condensator Inc.'s Condensator Diesel Engine Retrofit Crankcase Ventilation System. Brake specific fuel consumption (BSFC), the ratio of engine fuel consumption to the engine power output, was evaluated for engine...

  6. Study on pollution control in residential kitchen based on the push-pull ventilation system

    DEFF Research Database (Denmark)

    Zhou, Bin; Chen, Feng; Dong, Zhibo

    2016-01-01

    Highlights •The push-pull ventilation system is proposed to improve IAQ inside kitchen, where air is supplied through slot air curtain and then exhausted through range hood. •CO2 reduction efficiency with application of air curtain in experiment and simulation in breathing zone was 23.7% and 23.......1%, respectively. •By orthogonal method, the influence of factors on pollution control of the push-pull ventilation system was presented....

  7. Indoor temperatures for calculating room heat loss and heating capacity of radiant heating systems combined with mechanical ventilation systems

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Olesen, Bjarne W.; Fang, Lei

    2016-01-01

    In this study, a typical office room with a radiant heating system and a mechanical ventilation system was selected as the research subject. Indoor temperature formulas for calculating the room heat loss (including transmission heat loss and ventilation heat loss) and heating capacity of the hybrid...... for calculating ventilation heat loss and heating capacity of radiant heating systems combined with mechanical ventilation systems. (C) 2015 Elsevier B.V. All rights reserved....... change rates on the indoor temperatures were performed using the proposed model. When heated surface temperatures and air change rates were from 21.0 to 29.0 degrees C and from 0.5 to 4.0 h-1, the indoor temperatures for calculating the transmission heat loss and ventilation heat loss were between 20...

  8. Indoor radon in three similar two-story houses with different ventilation systems

    International Nuclear Information System (INIS)

    Kokotti, H.; Savolainen, T.; Raunemaa, T.; Kalliokoski, P.

    1989-01-01

    Radon levels were monitored in three similar two-story apartment houses which were located side by side on a gravel esker in eastern Finland. The houses differed only in regard to their ventilation systems which included the following: natural ventilation, mechanical exhaust, and complete mechanical ventilation. The study started immediately when the houses were finished and was continued for two years. Radon concentrations were highest (60-430 Bq/m 3 ) in the beginning of the study period before the tenants moved in. During the following spring and fall, average radon levels of the houses decreased below 100 Bq/m 3 . Radon concentrations varied within a wide range, from 20 to 230 Bq/m 3 , in the apartments. Among the houses, the highest concentrations were found in the house equipped with mechanical exhaust ventilation and the lowest in the house with both a mechanical supply and exhaust system. One reason for the decreasing levels of radon after a one-year occupancy was that the tenants increased the ventilation of their apartments. In the house with complete mechanical ventilation, the stability of ventilation also contributed to the decrease of the indoor radon level

  9. Use of perforated acoustic panels as supply air diffusers in diffuse ceiling ventilation systems

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Kazemi, Seyed Hossein; Ardkapan, Siamak Rahimi

    Ventilation is needed for diluting and removing the contaminants, odour and excess heat from the building interior. It is important that the inhabitants perceive the ventilated spaces as comfortable. Therefore, the supply air should reach all parts of the occupied zones. Troldtekt has been...... manufacturing perforated acoustic panels for the last 13 years. The panels can be used not only in applications related to acoustics but also as low pressure drop supply air diffusers, particularly in diffuse ceiling ventilation systems. The present study verifies on a theoretically level the performance...

  10. Change-over natural and mechanical ventilation system energy consumption in single-family buildings

    Science.gov (United States)

    Kostka, Maria; Szulgowska-Zgrzywa, Małgorzata

    2017-11-01

    The parameters of the outside air in Poland cause that in winter it is reasonable to use a mechanical ventilation equipped with a heat recovery exchanger. The time of spring, autumn, summer evenings and nights are often characterized by the parameters of the air, which allow for a natural ventilation and reduce the electricity consumption. The article presents the possibilities of energy consumption reduction for three energy standards of buildings located in Poland, ventilated by a change-over hybrid system. The analysis was prepared on the assumption that the air-to-water heat pump is the heat source for the buildings.

  11. Clinical assessment of a commercial delivery system for aerosol ventilation scanning by comparison with Krypton-81m

    International Nuclear Information System (INIS)

    Wollmer, P.; Eriksson, L.; Andersson, A.

    1985-01-01

    A commercial aerosol delivery system for ventilation scanning was evaluated in 23 patients with lung disease involving regional disturbances of ventilation. Ventilation scans obtained after inhalation of an aerosol labeled with In-113m were compared with Kr-81m ventilation scans. An indirect comparison was also made with a settling bag technique. There was close agreement between the aerosol and the Kr-81m ventilation scans in all of the patients. The aerosol outlined the ventilated parts of the lung adequately, and central deposition of particles was minimal. The penetration of the aerosol into the lung was higher with the delivery system that with a settling bag system. The aerosol delivery system appears suitable for clinical pulmonary ventilation scintigraphy

  12. Ventilation system type, classroom environmental quality and pupils' perceptions and symptoms

    DEFF Research Database (Denmark)

    Gao, Jie; Wargocki, Pawel; Wang, Yi

    2014-01-01

    -heating and heating seasons; CO2 concentration was used to estimate average classroom ventilation rates. At the end of each measuring period, the pupils were asked to report their perceptions of the indoor environment and their acute health-related symptoms. The classroom in which ventilation was achieved by manually...... opened in all four classrooms in the non-heating season but very seldom in the heating season. Automatic operation of the windows had a marked effect on CO2 concentration and classroom temperature in the heating season. Perceptions of the indoor environment were more positive in the classroom...... that was ventilated by automatically operable windows with an exhaust fan in operation: fewer symptoms were reported in this classroom compared with classrooms with other systems. Present results and approach can be used as the basis for rational selection of systems that ensure adequate classroom ventilation. © 2014...

  13. Ventilation systems as an effective tool for control of radon daughter concentration in mines

    International Nuclear Information System (INIS)

    Dory, A.B.

    1981-10-01

    Introduced with a brief discussion of the key role of ventilation in controlling mine atmospheres, the effects of the design of the ventilation system on the control of radon daughter concentrations are illustrated with specific reference to Alcan's Director Mine, St-Lawrence, Nfld. (This fluorspar mine was found to have high radon concentrations due to mine water bringing in dissolved radon.) After a discussion of the health physics history of the mine, the various phases of the ventilation system design and the general results are detailed. The author draws some conclusions having general application to the design of any mine with a radon or thoron daughter concentration. These include minimizing the 'age' of the air; the need for continuous ventilation in all areas; the value of remote control and monitoring; and the benefits of mine pressurization

  14. Ventilation patterns of the songbird lung/air sac system during different behaviors.

    Science.gov (United States)

    Mackelprang, Rebecca; Goller, Franz

    2013-10-01

    Unidirectional, continuous airflow through the avian lung is achieved through an elaborate air sac system with a sequential, posterior to anterior ventilation pattern. This classical model was established through various approaches spanning passively ventilated systems to mass spectrometry analysis of tracer gas flow into various air sacs during spontaneous breathing in restrained ducks. Information on flow patterns in other bird taxa is missing, and these techniques do not permit direct tests of whether the basic flow pattern can change during different behaviors. Here we use thermistors implanted into various locations of the respiratory system to detect small pulses of tracer gas (helium) to reconstruct airflow patterns in quietly breathing and behaving (calling, wing flapping) songbirds (zebra finch and yellow-headed blackbird). The results illustrate that the basic pattern of airflow in these two species is largely consistent with the model. However, two notable differences emerged. First, some tracer gas arrived in the anterior set of air sacs during the inspiration during which it was inhaled, suggesting a more rapid throughput through the lung than previously assumed. Second, differences in ventilation between the two anterior air sacs emerged during calling and wing flapping, indicating that adjustments in the flow pattern occur during dynamic behaviors. It is unclear whether this modulation in ventilation pattern is passive or active. This technique for studying ventilation patterns during dynamic behaviors proves useful for establishing detailed timing of airflow and modulation of ventilation in the avian respiratory system.

  15. A new system for continuous and remote monitoring of patients receiving home mechanical ventilation.

    Science.gov (United States)

    Battista, L

    2016-09-01

    Home mechanical ventilation is the treatment of patients with respiratory failure or insufficiency by means of a mechanical ventilator at a patient's home. In order to allow remote patient monitoring, several tele-monitoring systems have been introduced in the last few years. However, most of them usually do not allow real-time services, as they have their own proprietary communication protocol implemented and some ventilation parameters are not always measured. Moreover, they monitor only some breaths during the whole day, despite the fact that a patient's respiratory state may change continuously during the day. In order to reduce the above drawbacks, this work reports the development of a novel remote monitoring system for long-term, home-based ventilation therapy; the proposed system allows for continuous monitoring of the main physical quantities involved during home-care ventilation (e.g., differential pressure, volume, and air flow rate) and is developed in order to allow observations of different remote therapy units located in different places of a city, region, or country. The developed remote patient monitoring system is able to detect various clinical events (e.g., events of tube disconnection and sleep apnea events) and has been successfully tested by means of experimental tests carried out with pulmonary ventilators typically used to support sick patients.

  16. A new system for continuous and remote monitoring of patients receiving home mechanical ventilation

    Science.gov (United States)

    Battista, L.

    2016-09-01

    Home mechanical ventilation is the treatment of patients with respiratory failure or insufficiency by means of a mechanical ventilator at a patient's home. In order to allow remote patient monitoring, several tele-monitoring systems have been introduced in the last few years. However, most of them usually do not allow real-time services, as they have their own proprietary communication protocol implemented and some ventilation parameters are not always measured. Moreover, they monitor only some breaths during the whole day, despite the fact that a patient's respiratory state may change continuously during the day. In order to reduce the above drawbacks, this work reports the development of a novel remote monitoring system for long-term, home-based ventilation therapy; the proposed system allows for continuous monitoring of the main physical quantities involved during home-care ventilation (e.g., differential pressure, volume, and air flow rate) and is developed in order to allow observations of different remote therapy units located in different places of a city, region, or country. The developed remote patient monitoring system is able to detect various clinical events (e.g., events of tube disconnection and sleep apnea events) and has been successfully tested by means of experimental tests carried out with pulmonary ventilators typically used to support sick patients.

  17. Ventilation Model

    International Nuclear Information System (INIS)

    Yang, H.

    1999-01-01

    The purpose of this analysis and model report (AMR) for the Ventilation Model is to analyze the effects of pre-closure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts and provide heat removal data to support EBS design. It will also provide input data (initial conditions, and time varying boundary conditions) for the EBS post-closure performance assessment and the EBS Water Distribution and Removal Process Model. The objective of the analysis is to develop, describe, and apply calculation methods and models that can be used to predict thermal conditions within emplacement drifts under forced ventilation during the pre-closure period. The scope of this analysis includes: (1) Provide a general description of effects and heat transfer process of emplacement drift ventilation. (2) Develop a modeling approach to simulate the impacts of pre-closure ventilation on the thermal conditions in emplacement drifts. (3) Identify and document inputs to be used for modeling emplacement ventilation. (4) Perform calculations of temperatures and heat removal in the emplacement drift. (5) Address general considerations of the effect of water/moisture removal by ventilation on the repository thermal conditions. The numerical modeling in this document will be limited to heat-only modeling and calculations. Only a preliminary assessment of the heat/moisture ventilation effects and modeling method will be performed in this revision. Modeling of moisture effects on heat removal and emplacement drift temperature may be performed in the future

  18. Test Protocol for Room-to-Room Distribution of Outside Air by Residential Ventilation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Barley, C. D.; Anderson, R.; Hendron, B.; Hancock, E.

    2007-12-01

    This test and analysis protocol has been developed as a practical approach for measuring outside air distribution in homes. It has been used successfully in field tests and has led to significant insights on ventilation design issues. Performance advantages of more sophisticated ventilation systems over simpler, less-costly designs have been verified, and specific problems, such as airflow short-circuiting, have been identified.

  19. ASSESSMENT of POTENTIAL CARBON DIOXIDE-BASED DEMAND CONTROL VENTILATION SYSTEM PERFORMANCE in SINGLE ZONE SYSTEMS

    Science.gov (United States)

    2013-03-21

    requirements of a 400 m3 space in a multiuse facility in South Korea using two types of DCV systems—one CO2-based and the other uses a radio frequency...identification (RFID) device to detect zone occupancy 25 (Jeong et al., 2010). A dedicated outdoor air system supplies ventilation air to the zone...use a known control scheme (ASHRAE, 2010b). Carbon Dioxide Sensor Modeling Case Study 2 While the first case study examines a single multiuse

  20. VENTILATION NEEDS DURING CONSTRUCTION

    International Nuclear Information System (INIS)

    C.R. Gorrell

    1998-01-01

    The purpose of this analysis is to determine ventilation needs during construction and development of the subsurface repository and develop systems to satisfy those needs. For this analysis, construction is defined as pre-emplacement excavation and development is excavation that takes place simultaneously with emplacement. The three options presented in the ''Overall Development and Emplacement Ventilation Systems'' analysis (Reference 5.5) for development ventilation will be applied to construction ventilation in this analysis as well as adding new and updated ventilation factors to each option for both construction and development. The objective of this analysis is to develop a preferred ventilation system to support License Application Design. The scope of this analysis includes: (1) Description of ventilation conditions; (2) Ventilation factors (fire hazards, dust control, construction logistics, and monitoring and control systems); (3) Local ventilation alternatives; (4) Global ventilation options; and (5) Evaluation of options

  1. Performance evaluation of a novel personalized ventilation-personalized exhaust system for airborne infection control.

    Science.gov (United States)

    Yang, J; Sekhar, S C; Cheong, K W D; Raphael, B

    2015-04-01

    In the context of airborne infection control, it is critical that the ventilation system is able to extract the contaminated exhaled air within the shortest possible time. To minimize the spread of contaminated air exhaled by occupants efficiently, a novel personalized ventilation (PV)-personalized exhaust (PE) system has been developed, which aims to exhaust the exhaled air as much as possible from around the infected person (IP). The PV-PE system was studied experimentally for a particular healthcare setting based on a typical consultation room geometry and four different medical consultation positions of an IP and a healthy person (HP). Experiments using two types of tracer gases were conducted to evaluate two types of PE: Top-PE and Shoulder-PE under two different background ventilation systems: Mixing Ventilation and Displacement Ventilation. Personalized exposure effectiveness, intake fraction (iF) and exposure reduction (ε) were used as indices to evaluate the PV-PE system. The results show that the combined PV-PE system for the HP achieves the lowest intake fraction; and the use of PE system for the IP alone shows much better performance than using PV system for the HP alone. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Assessment of the impact of dipped guideways on urban rail transit systems: Ventilation and safety requirements

    Science.gov (United States)

    1982-01-01

    The ventilation and fire safety requirements for subway tunnels with dipped profiles between stations as compared to subway tunnels with level profiles were evaluated. This evaluation is based upon computer simulations of a train fire emergency condition. Each of the tunnel configurations evaluated was developed from characteristics that are representative of modern transit systems. The results of the study indicate that: (1) The level tunnel system required about 10% more station cooling than dipped tunnel systems in order to meet design requirements; and (2) The emergency ventilation requirements are greater with dipped tunnel systems than with level tunnel systems.

  3. Design Principles for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system -Hybrid Ventilation. ....... The hybrid ventilation concepts, design challenges and - principles are discussed and illustrated by four building examples....

  4. Monitoring and energetic performance of two similar semi-closed greenhouse ventilation systems

    International Nuclear Information System (INIS)

    Coomans, Mathias; Allaerts, Koen; Wittemans, Lieve; Pinxteren, Dave

    2013-01-01

    Highlights: • Measurements on two semi-closed greenhouses and two traditional open greenhouses. • Mechanical and natural ventilation for dehumidification and cooling. • Analyses and comparison of installation controls, indoor climate and energy flows. • Examination of air-to-air heat recuperation efficiency in ventilation unit. • Using the semi-closed systems amounted to energy savings of 13% and 28%. - Abstract: Horticulture is an energy intensive industry when dealing with cold climates such as Western Europe. High energy prices and on-going pressure from international competition are raising demand for energy efficient solutions. In search of reducing greenhouse energy consumption, this study investigates semi-closed systems combining controlled mechanical and natural ventilation with thermal screens. Ventilated greenhouse systems (semi-closed) have been implemented in the greenhouse compartments of two Belgian horticulture research facilities: the Research Station for Vegetable Production Sint-Katelijne-Waver (PSKW) and the Research Center Hoogstraten (PCH). Additionally, two reference compartments were included for comparison of the results. The greenhouses were part of a long-term monitoring campaign in which detailed measurements with a high time resolution were gathered by a central monitoring system. A large amount of data was processed and analysed, including outdoor and indoor climatic parameters, system controls and installation measurements. The ventilated greenhouses obtained energy savings of 13% and 28% for PSKW and PCH respectively, without substantial impact on crop production or indoor climate conditions when compared to the reference compartments. A considerable amount of heat was recovered by the heat recuperation stage in the ventilation unit of PCH, accounting for 12% of the total heat demand. In general, it was demonstrated that the greenhouse heat demand can be reduced significantly by controlled dehumidification with mechanical

  5. Design of the ventilation system of the nuclear facility(I). General requirements

    International Nuclear Information System (INIS)

    Lee, K. M.; Kang, I. S.; Bae, S. M.; Kim, T. K.; Kim, K. J.

    1998-03-01

    To assure that the operation of the nuclear ventilation system is effective and economic, the reasonable design of system is essential. As the nuclear ventilation system has to meet the particular conditions; to keep the rooms at an below atmospheric pressure at all times and, furthermore, to maintain frequent air circulation in the rooms, the system needs the big rotating machinery. Consequently, the construction cost and the operational cost of the ventilation system is very high. For maximum function with the minimum cost, areas are to be divided into several zones depending on the level of radioactivity and the once-through air flow in the shortest route should be adopted. The pressure difference between the zones and the number of air circulations per unit time in the rooms must be reasonable, thus, the venting air volume should be of minimum. (author). 19 refs., 7 tabs., 21 figs

  6. Real-time modelling of a ventilation system for a power plant simulator

    International Nuclear Information System (INIS)

    Kocher, P.; Welfonder, E.

    1992-01-01

    This paper describes how to simulate in real-time the ventilation system of a nuclear power plant. The simulation is made under difficult computing time conditions. The ventilation system program is part of a simulator which simulates the whole nuclear power plant process in realtime. Therefore the ventilation system is split up into several smaller units. For each of these process units a real-time module has been developed, being as simple as possible but nevertheless coming close enough to the real dynamic behaviour. After that the simple real-time modules are linked together to form the total dynamic model ''ventilation system''. The continuous dynamic model developed is numerically integrated by the Euler method. The stability of this explicit method is maintained by special modelling measures such as the increasing of too low flow resistances or the limitation of too high gain factors. At the end of the paper some curves, recorded at the simulator, illustrate the behaviour of the ventilation system in the case of an accident. (author)

  7. Evaluation of a positive ventilation delivery system (PVDS) in administering technegas to the noncompliant patient

    International Nuclear Information System (INIS)

    Cook, P.; Bedford, B.; Bell, A.; Lang, P.; Leiper, C.; Prouse, A.

    1998-01-01

    Full text: Certain groups of patients have been excluded from ventilation lung scanning due to their inability to comply with instruction. Tetley Manufacturing have recently developed a Positive Ventilation Delivery System (PVDS) which assists in delivering Technegas to patients who are unable to cooperate fully. The aim of this study is to evaluate the PVDS in the clinical setting. Fifteen frail aged and psychogeriatric patients (n=l 5), mean age 78 years (range 60-93), were ventilated with Technegas using the PVDS. The decision to ventilate the patient with the PVDS was based on an initial assessment of the patients ability to comply with instructions, or failure of the conventional ventilation method, to produce an adequate count rate. Technegas was prepared in the usual manner and then delivered to the patients lungs by squeezing a black anesthetic bag synchronously with the patients breathing, until a count rate of approximately 1000 counts/second was obtained. All patients achieved a satisfactory count rate, mean 1500 counts/second (range 900 to 2300), allowing adequate ventilation images to be obtained. Time to reach this count rate varied between patients, mean 130 seconds (range 40 to 300). The number of assisted breaths also varied, mean 9 (range 3-15). In addition, four patients who required a switch from the conventional method to the PVDS, increased their initial count rate from a mean 200 ± 8% counts/second to a mean of 1300 ± 29% counts/second. This was statistically significant at p = 0.006. Our initial results demonstrate the ability of the PVDS to facilitate ventilation imaging in noncompliant patients such as the frail aged and psychogeriatric. Ventilation times and amounts of radioisotope used were acceptable, economical and practical within a busy department

  8. Effectiveness of a personalized ventilation system in reducing personal exposure against directly released simulated cough droplets.

    Science.gov (United States)

    Pantelic, J; Tham, K W; Licina, D

    2015-12-01

    The inhalation intake fraction was used as an indicator to compare effects of desktop personalized ventilation and mixing ventilation on personal exposure to directly released simulated cough droplets. A cough machine was used to simulate cough release from the front, back, and side of a thermal manikin at distances between 1 and 4 m. Cough droplet concentration was measured with an aerosol spectrometer in the breathing zone of a thermal manikin. Particle image velocimetry was used to characterize the velocity field in the breathing zone. Desktop personalized ventilation substantially reduced the inhalation intake fraction compared to mixing ventilation for all investigated distances and orientations of the cough release. The results point out that the orientation between the cough source and the breathing zone of the exposed occupant is an important factor that substantially influences exposure. Exposure to cough droplets was reduced with increasing distance between cough source and exposed occupant. The results from this study show that an advanced air distribution system such as personalized ventilation reduces exposure to cough-released droplets better than commonly applied overhead mixing ventilation. This work can inform HVAC engineers about different aspects of air distribution systems’ performance and can serve as an aid in making critical design decisions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Reduction of nanoparticle exposure to welding aerosols by modification of the ventilation system in a workplace

    Science.gov (United States)

    Lee, Myong-Hwa; McClellan, William J.; Candela, Joe; Andrews, Dan; Biswas, Pratim

    2007-01-01

    Nanometer particle size distributions were measured in booths with two different ventilation patterns in an occupational environment with welding operations underway. The measurements were used to illustrate the impact of change of ventilation methods (existing - with ventilation ducts located at the top, modified - with ventilation ducts located below the weld bench) on the aerosol size distributions at different locations: close to the weld, in the vicinity of the welder's face, and in the exhaust duct. Particle number concentrations measured in the vicinity of the welder's face (mask) during a horizontal standard arc welding process in a booth with ventilation at the top was in the range of 7.78×105 particles cm-3 with a geometric mean size of 181 nm and geometric standard deviation of 1.8. This reduced to 1.48×104 particles cm-3 in the vicinity of the welder's face with the modified ventilation system. The clearance of the welding aerosol was also faster in the modified booth (6 min compared to 11 min in a conventional booth). Particles were collected in the booth for the various test conditions, and analyzed to determine their composition and morphology. The particles were composed of hazardous heavy metals such as manganese, chromium and nickel, and had varying morphologies.

  10. Reduction of nanoparticle exposure to welding aerosols by modification of the ventilation system in a workplace

    International Nuclear Information System (INIS)

    Lee, Myong-Hwa; McClellan, William J.; Candela, Joe; Andrews, Dan; Biswas, Pratim

    2007-01-01

    Nanometer particle size distributions were measured in booths with two different ventilation patterns in an occupational environment with welding operations underway. The measurements were used to illustrate the impact of change of ventilation methods (existing - with ventilation ducts located at the top, modified - with ventilation ducts located below the weld bench) on the aerosol size distributions at different locations: close to the weld, in the vicinity of the welder's face, and in the exhaust duct. Particle number concentrations measured in the vicinity of the welder's face (mask) during a horizontal standard arc welding process in a booth with ventilation at the top was in the range of 7.78x10 5 particles cm -3 with a geometric mean size of 181 nm and geometric standard deviation of 1.8. This reduced to 1.48x10 4 particles cm -3 in the vicinity of the welder's face with the modified ventilation system. The clearance of the welding aerosol was also faster in the modified booth (6 min compared to 11 min in a conventional booth). Particles were collected in the booth for the various test conditions, and analyzed to determine their composition and morphology. The particles were composed of hazardous heavy metals such as manganese, chromium and nickel, and had varying morphologies

  11. Dynamic Characteristics of Mechanical Ventilation System of Double Lungs with Bi-Level Positive Airway Pressure Model

    Directory of Open Access Journals (Sweden)

    Dongkai Shen

    2016-01-01

    Full Text Available In recent studies on the dynamic characteristics of ventilation system, it was considered that human had only one lung, and the coupling effect of double lungs on the air flow can not be illustrated, which has been in regard to be vital to life support of patients. In this article, to illustrate coupling effect of double lungs on flow dynamics of mechanical ventilation system, a mathematical model of a mechanical ventilation system, which consists of double lungs and a bi-level positive airway pressure (BIPAP controlled ventilator, was proposed. To verify the mathematical model, a prototype of BIPAP system with a double-lung simulators and a BIPAP ventilator was set up for experimental study. Lastly, the study on the influences of key parameters of BIPAP system on dynamic characteristics was carried out. The study can be referred to in the development of research on BIPAP ventilation treatment and real respiratory diagnostics.

  12. Software Verification and Validation Report for the 244-AR Vault Interim Stabilization Ventilation System

    International Nuclear Information System (INIS)

    YEH, T.

    2002-01-01

    This document reports on the analysis, testing and conclusions of the software verification and validation for the 244-AR Vault Interim Stabilization ventilation system. Automation control system will use the Allen-Bradley software tools for programming and programmable logic controller (PLC) configuration. The 244-AR Interim Stabilization Ventilation System will be used to control the release of radioactive particles to the environment in the containment tent, located inside the canyon of the 244-AR facility, and to assist the waste stabilization efforts. The HVAC equipment, ducts, instruments, PLC hardware, the ladder logic executable software (documented code), and message display terminal are considered part of the temporary ventilation system. The system consists of a supply air skid, temporary ductwork (to distribute airflow), and two skid-mounted, 500-cfm exhausters connected to the east filter building and the vessel vent system. The Interim Stabilization Ventilation System is a temporary, portable ventilation system consisting of supply side and exhaust side. Air is supplied to the containment tent from an air supply skid. This skid contains a constant speed fan, a pre-filter, an electric heating coil, a cooling coil, and a constant flow device (CFD). The CFD uses a passive component that allows a constant flow of air to pass through the device. Air is drawn out of the containment tent, cells, and tanks by two 500-cfm exhauster skids running in parallel. These skids are equipped with fans, filters, stack, stack monitoring instrumentation, and a PLC for control. The 500CFM exhaust skids were fabricated and tested previously for saltwell pumping activities. The objective of the temporary ventilation system is to maintain a higher pressure to the containment tent, relative to the canyon and cell areas, to prevent contaminants from reaching the containment tent

  13. Combining a building simulation with energy systems analysis to assess the benefits of natural ventilation

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg; Remmen, Arne

    2013-01-01

    This article shows the combination of a thermal air flow simulation program with an energy systems analysis model in order to assess the use of natural ventilation as a method for saving energy within residential buildings in large-scale scenarios. The aim is to show the benefits for utilizing...... natural airflow instead of active systems such as mechanical ventilation or air-conditioning in buildings where the indoor temperature is over the upper limit of the comfort range. The combination is done by introducing the energy saving output - calculated with a model of natural ventilation using...... a thermal air flow simulation program - Into the energy systems analysis model. Descriptions of the energy systems in two geographical locations, i.e. Mexico and Denmark, are set up as inputs. Then, the assessment is done by calculating the energy impacts as well as environmental benefits in the energy...

  14. Evaluation of AY/AZ tank farm ventilation system during aging waste retrieval operations

    International Nuclear Information System (INIS)

    Wong, J.J.; Waters, E.D.

    1995-01-01

    Waste Management is currently planning to demonstrate mobilization of radioactive waste sludges in Tank 101-AZ beginning in October 1991. The retrieval system being designed will utilize mixer pumps that generate high-velocity, high-volume submerged liquid jets to mobilize settled solids. There is concern that these jets may also generate radioactive aerosols, some of which may be carried into the tank Ventilation system. The purpose of this study is to determine if the current AY/AZ ventilation system or the proposed ventilation system upgrade (Project W-030) will provide adequate deentrainment of liquid and solid aerosols during mixer pump operations, or if the radioactive aerosols will overload the HEPA filters

  15. Procedures and Standards for Residential Ventilation System Commissioning: An Annotated Bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Stratton, J. Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wray, Craig P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-04-01

    Beginning with the 2008 version of Title 24, new homes in California must comply with ANSI/ASHRAE Standard 62.2-2007 requirements for residential ventilation. Where installed, the limited data available indicate that mechanical ventilation systems do not always perform optimally or even as many codes and forecasts predict. Commissioning such systems when they are installed or during subsequent building retrofits is a step towards eliminating deficiencies and optimizing the tradeoff between energy use and acceptable IAQ. Work funded by the California Energy Commission about a decade ago at Berkeley Lab documented procedures for residential commissioning, but did not focus on ventilation systems. Since then, standards and approaches for commissioning ventilation systems have been an active area of work in Europe. This report describes our efforts to collect new literature on commissioning procedures and to identify information that can be used to support the future development of residential-ventilation-specific procedures and standards. We recommend that a standardized commissioning process and a commissioning guide for practitioners be developed, along with a combined energy and IAQ benefit assessment standard and tool, and a diagnostic guide for estimating continuous pollutant emission rates of concern in residences (including a database that lists emission test data for commercially-available labeled products).

  16. The influence of an estimated energy saving due to natural ventilation on the Mexican energy system

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg

    2014-01-01

    This article shows the impacts of the extensive use of NV (natural ventilation) in the Mexican residential sector on the Mexican energy system. By integrating a thermal-airflow simulation programme with an energy systems analysis model, the impact on the Mexican energy system of replacing air...... conditioning, in particular, with natural ventilation to cool residential buildings is determined. It is shown that when, as in Mexico, there is a relatively simple connection between supply and electricity demand, NV creates savings which could be used to reduce either the fossil-fuel-based generation...

  17. Design and simulation of a new energy conscious system, (ventilation and thermal performance simulation)

    Energy Technology Data Exchange (ETDEWEB)

    Gadi, Mohamed B. [Nottingham Univ., School of the Built Environment, Nottingham (United Kingdom)

    2000-04-01

    This paper presents the results of simulating the ventilation and thermal performance of a new passive cooling and heating system. The new systems was integrated into the roof of a typical contemporary North African house, which was modelled and mounted inside a wind tunnel, for natural ventilation simulation. Thermal performance of the new systems was simulated using a new computer programme (BTS), developed by the author. Results are presented in terms of indoor temperature and CATD and HATD, which are newly introduced concepts in defining the building cooling and heating loads. (Author)

  18. A perfluorochemical loss/restoration (L/R) system for tidal liquid ventilation.

    Science.gov (United States)

    Libros, R; Philips, C M; Wolfson, M R; Shaffer, T H

    2000-01-01

    Tidal liquid ventilation is the transport of dissolved respiratory gases via volume exchange of perfluorochemical (PFC) liquid to and from the PFC-filled lung. All gas-liquid surface tension is eliminated, increasing compliance and providing lung protection due to lower inflation pressures. Tidal liquid ventilation is achieved by cycling fluid from a reservoir to and from the lung by a ventilator. Current approaches are microprocessor-based with feedback control. During inspiration, warmed oxygenated PFC liquid is pumped from a fluid reservoir/gas exchanger into the lung. PFC fluid is conserved by condensing (60-80% efficiency) vapor in the expired gas. A feedback-control system was developed to automatically replace PFC lost due to condenser inefficiency. This loss/restoration (L/R) system consists of a PFC-vapor thermal detector (+/- 2.5%), pneumatics, amplifiers, a gas flow detector (+/- 1%), a PFC pump (+/- 5%), and a controller. Gravimetric studies of perflubron loss from a flask due to evaporation were compared with experimental L/R results and found to be within +/- 1.4%. In addition, when L/R studies were conducted with a previously reported liquid ventilation system over a four-hour period, the L/R system maintained system perflubron volume to within +/- 1% of prime volume and 11.5% of replacement volume, and the difference between experimental PFC loss and that of the L/R system was 1.8 mL/hr. These studies suggest that the PFC L/R system may have significant economic (appropriate dosing for PFC loss) as well as physiologic (maintenance of PFC inventory in the lungs and liquid ventilator) impact on liquid ventilation procedures.

  19. Laboratory study of subjective perceptions to low temperature heating systems with exhaust ventilation in Nordic countries

    DEFF Research Database (Denmark)

    Jin, Quan; Simone, Angela; Olesen, Bjarne W.

    2017-01-01

    in Nordic countries for greater energy efficiency, this study focused on human subjects’ thermal sensation, thermal comfort, thermal acceptability, draft acceptability, and perceived air quality when three low-temperature heating systems were used: conventional radiator, ventilation radiator, or floor...... sensation and thermal comfort between the three heating systems. Ventilation radiator promised a comfortable indoor environment with a decreased water supply temperature and floor heating with exhaust ventilation can provide a basic thermal comfort level. Thermal acceptability and draft acceptability show...... variations in different heating systems. Gender has significant influences on thermal sensation, draft acceptability, and preference of clo values. Personal thermal preference is observed between males and females. The males prefer to dress lighter than the females, but both can get the same thermal comfort...

  20. Ventilation Transport Trade Study for Future Space Suit Life Support Systems

    Science.gov (United States)

    Kempf, Robert; Vogel, Matthew; Paul, Heather L.

    2008-01-01

    A new and advanced portable life support system (PLSS) for space suit surface exploration will require a durable, compact, and energy efficient system to transport the ventilation stream through the space suit. Current space suits used by NASA circulate the ventilation stream via a ball-bearing supported centrifugal fan. As NASA enters the design phase for the next generation PLSS, it is necessary to evaluate available technologies to determine what improvements can be made in mass, volume, power, and reliability for a ventilation transport system. Several air movement devices already designed for commercial, military, and space applications are optimized in these areas and could be adapted for EVA use. This paper summarizes the efforts to identify and compare the latest fan and bearing technologies to determine candidates for the next generation PLSS.

  1. Parameter estimation of an artificial respiratory system under mechanical ventilation following a noisy regime

    Directory of Open Access Journals (Sweden)

    Marcus Henrique Victor Júnior

    Full Text Available Abstract Introduction: This work concerns the assessment of a novel system for mechanical ventilation and a parameter estimation method in a bench test. The tested system was based on a commercial mechanical ventilator and a personal computer. A computational routine was developed do drive the mechanical ventilator and a parameter estimation method was utilized to estimate positive end-expiratory pressure, resistance and compliance of the artificial respiratory system. Methods The computational routine was responsible for establishing connections between devices and controlling them. Parameters such as tidal volume, respiratory rate and others can be set for standard and noisy ventilation regimes. Ventilation tests were performed directly varying parameters in the system. Readings from a calibrated measuring device were the basis for analysis. Adopting a first-order linear model, the parameters could be estimated and the outcomes statistically analysed. Results Data acquisition was effective in terms of sample frequency and low noise content. After filtering, cycle detection and estimation took place. Statistics of median, mean and standard deviation were calculated, showing consistent matching with adjusted values. Changes in positive end-expiratory pressure statistically imply changes in compliance, but not the opposite. Conclusion The developed system was satisfactory in terms of clinical parameters. Statistics exhibited consistent relations between adjusted and estimated values, besides precision of the measurements. The system is expected to be used in animals, with a view to better understand the benefits of noisy ventilation, by evaluating the estimated parameters and performing cross relations among blood gas, ultrasonography and electrical impedance tomography.

  2. A method for evaluating the problem complex of choosing the ventilation system for a new building

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Svendsen, Svend

    2007-01-01

    The application of a ventilation system in a new building is a multidimensional complex problem that involves quantifiable and non-quantifiable data like energy consump¬tion, indoor environment, building integration and architectural expression. This paper presents a structured method...... for evaluating the performance of a ventilation system in the design proces by treating quantifiable and non-quantifiable datasets together. The method is based on general morphological analysis and applies cross-consistency assessment for reducing the problem complex, thus treating the multi-dimensionality...

  3. : ventilators for noninvasive ventilation

    OpenAIRE

    Fauroux , Brigitte; Leroux , Karl; Desmarais , Gilbert; Isabey , Daniel; Clément , Annick; Lofaso , Frédéric; Louis , Bruno

    2008-01-01

    International audience; The aim of the present study was to evaluate the performance characteristics of all the ventilators proposed for home noninvasive positive-pressure ventilation in children in France. The ventilators (one volume-targeted, 12 pressure-targeted and four dual) were evaluated on a bench which simulated six different paediatric ventilatory patterns. For each ventilator, the quality of the inspiratory and expiratory trigger and the ability to reach and maintain the preset pre...

  4. Cleanup and Dismantling of Highly Contaminated Ventilation Systems Using Robotic Tools - 13162

    International Nuclear Information System (INIS)

    Chambon, Frederic; CIZEL, Jean-Pierre; Blanchard, Samuel

    2013-01-01

    The UP1 plant reprocessed nearly 20,000 tons of used natural uranium gas cooled reactor fuel coming from the first generation of civil nuclear reactors in France. Following operating incidents in the eighties, the ventilation system of the continuous dissolution line facility was shut down and replaced. Two types of remote controlled tool carriers were developed to perform the decontamination and dismantling operations of the highly contaminated ventilation duct network. The first one, a dedicated small robot, was designed from scratch to retrieve a thick powder deposit within a duct. The robot, managed and confined by two dedicated glove boxes, was equipped for intervention inside the ventilation duct and used for carrying various cleanup and inspection tools. The second type, consisting of robotic tools developed on the base of an industrial platform, was used for the clean-up and dismantling of the ventilation duct system. Depending on the type of work to be performed, on the shape constraints of the rooms and any equipment to be dismantled, different kinds of robotic tools were developed and installed on a Brokk 40 carrier. After more than ten years of ventilation duct D and D operations at the UP1 plant, a lot of experience was acquired about remote operations. The three main important lessons learned in terms of remote controlled operation are: characterizing the initial conditions as much as reasonably possible, performing non-radioactive full scale testing and making it as simple and modular as possible. (authors)

  5. Modification of the ventilation system at Waste Isolation Pilot Plant (WIPP)

    International Nuclear Information System (INIS)

    Sethi, S.C.

    1987-01-01

    The WIPP (Waste Isolation Pilot Plant) Project near Carlsbad, New Mexico, is a research and development project sponsored by the US Department of Energy, designed to demonstrate the safe disposal of radioactive waste. A mine (repository) is being developed 2,150 feet below the surface in a thick salt bed, which will serve as the disposal medium. The underground ventilation system for the WIPP project was originally designed based on a fixed project scope. The design criteria and ventilation requirements were developed for the performance of various activities as then envisioned towards the achievement of this goal. However, in light of new information and actual site-specific experience at WIPP leading to a clearer definition of the scope-related programs and activities, it was realized that the existing ventilation system may need to be modified

  6. Energy and exergy performance of residential heating systems with separate mechanical ventilation

    International Nuclear Information System (INIS)

    Zmeureanu, Radu; Yu Wu, Xin

    2007-01-01

    The paper brings new evidence on the impact of separate mechanical ventilation system on the annual energy and exergy performance of several design alternatives of residential heating systems, when they are designed for a house in Montreal. Mathematical models of residential heating, ventilation and domestic hot water (HVAC-DHW) systems, which are needed for this purpose, are developed and furthermore implemented in the Engineering Equation Solver (EES) environment. The Coefficient of Performance and the exergy efficiency are estimated as well as the entropy generation and exergy destruction of the overall system. The equivalent greenhouse gas emissions due to the on-site and off-site use of primary energy sources are also estimated. The addition of a mechanical ventilation system with heat recovery to any HVAC-DHW system discussed in the paper increases the energy efficiency; however, it decreases the exergy efficiency, which indicates a potential long-term damaging impact on the natural environment. Therefore, the use of a separate mechanical ventilation system in a house should be considered with caution, and recommended only when other means for controlling the indoor air quality cannot be applied

  7. Programmatic implementation of rapid DST for Mycobacterium tuberculosis in Peru.

    Science.gov (United States)

    Asencios, L; Yale, G; Yagui, M; Quispe, N; Taylor, A; Blaya, J; Contreras, C; Cegielski, P; Bayona, J; Bonilla, C; Shin, S

    2008-07-01

    Performance characteristics of novel rapid drug susceptibility tests (DST) for Mycobacterium tuberculosis may change when moving from research to implementation in actual public health practice. We describe the performance characteristics of a direct, rapid DST when implemented in Lima, Peru. A district laboratory validated conventional proportions and nitrate reductase methods. We collected data on samples submitted for DST from January 2005 to June 2007 and calculated frequency of testing and results, and median time to test results. A total of 4102 DSTs were performed by conventional DST and 895 by nitrate reductase. Results were obtained from 72.8% of samples by conventional DST and from 70.2% of those processed by Griess; respectively 26.4% and 31.5% were multidrug-resistant tuberculosis. The median time from sample collection to test result was 31 days for Griess vs. 99 days for conventional DST. Preliminary experience with the Griess method demonstrates favorable performance under program conditions.

  8. A DST Model of Multilingualism and the Role of Metalinguistic Awareness

    Science.gov (United States)

    Jessner, Ulrike

    2008-01-01

    This paper suggests that a dynamic systems theory (DST) provides an adequate conceptual metaphor for discussing multilingual development. Multilingual acquisition is a nonlinear and complex dynamic process depending on a number of interacting factors. Variability plays a crucial role in the multilingual system as it changes over time (Herdina &…

  9. Geomagnetic Dst index forecast based on IMF data only

    Directory of Open Access Journals (Sweden)

    G. Pallocchia

    2006-05-01

    Full Text Available In the past years several operational Dst forecasting algorithms, based on both IMF and solar wind plasma parameters, have been developed and used. We describe an Artificial Neural Network (ANN algorithm which calculates the Dst index on the basis of IMF data only and discuss its performance for several individual storms. Moreover, we briefly comment on the physical grounds which allow the Dst forecasting based on IMF only.

  10. Provisional hourly values of equatorial Dst for 1971

    Science.gov (United States)

    Sugiura, M.; Poros, D. J.

    1972-01-01

    Tables and plots of provisional hourly values of the equatorial Dst index for 1971 are given, a table of daily mean Dst values for 1971 is also provided. The base line values for the four observatories, Hermanus, Kakioka, Honolulu, and San Juan, were obtained from extrapolations using the coefficients for the secular variations determined for the previous years. Examining the Dst values for quiet days, the base lines so determined appear to be slightly low, so that the Dst index for quiet periods tends to be high.

  11. 46 CFR 108.437 - Pipe sizes and discharge rates for enclosed ventilation systems for rotating electrical equipment.

    Science.gov (United States)

    2010-10-01

    ... enclosed ventilation systems for rotating electrical equipment. (a) The minimum pipe size for the initial... 46 Shipping 4 2010-10-01 2010-10-01 false Pipe sizes and discharge rates for enclosed ventilation systems for rotating electrical equipment. 108.437 Section 108.437 Shipping COAST GUARD, DEPARTMENT OF...

  12. Parametric instabilities of rotor-support systems with application to industrial ventilators

    Science.gov (United States)

    Parszewski, Z.; Krodkiemski, T.; Marynowski, K.

    1980-01-01

    Rotor support systems interaction with parametric excitation is considered for both unequal principal shaft stiffness (generators) and offset disc rotors (ventilators). Instability regions and types of instability are computed in the first case, and parametric resonances in the second case. Computed and experimental results are compared for laboratory machine models. A field case study of parametric vibrations in industrial ventilators is reported. Computed parametric resonances are confirmed in field measurements, and some industrial failures are explained. Also the dynamic influence and gyroscopic effect of supporting structures are shown and computed.

  13. Diffuse ceiling ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen

    Diffuse ceiling ventilation is an innovative ventilation concept where the suspended ceiling serves as air diffuser to supply fresh air into the room. Compared with conventional ventilation systems, diffuse ceiling ventilation can significantly reduce or even eliminate draught risk due to the low...... momentum supply. In addition, this ventilation system uses a ceiling plenum to deliver air and requires less energy consumption for air transport than full-ducted systems. There is a growing interest in applying diffuse ceiling ventilation in offices and other commercial buildings due to the benefits from...... both thermal comfort and energy efficient aspects. The present study aims to characterize the air distribution and thermal comfort in the rooms with diffuse ceiling ventilation. Both the stand-alone ventilation system and its integration with a radiant ceiling system are investigated. This study also...

  14. Design, Implementation & Assessment of Local Exhaust Ventilation System and dust collectors for crushing unit

    Directory of Open Access Journals (Sweden)

    Farshid Ghorbani shahna

    2015-09-01

    Full Text Available Background & objective: Industrial ventilation systems and dust collectors are effective solutions to reduce particulate emissions in the workplace and environmental in mineral processes. In this study, Local Exhaust Ventilation System and dust collectors for control of emitted silica, coke, silicon carbide dusts from crushing unit was designed and evaluated. Methods: : Local Exhaust ventilation system based on standards and guides was designed and implemented after field study of the processes and sources of air pollutants. A set comprised of the four parallel cyclones (Stairmand model and a new design of the scrubber had been used for dust control. After set-up of systems, its effectiveness in reducing the exposure of workers in the workshops and dust collecting were assessed. Results: Test results were significant differences between the concentration of particles in both on and off the ventilation system revealed (P <0.05. The system has been implemented as means of personal exposure to pollutants and environmental emissions were reduced 93.01% and 64.64%, respectively. Also, alone and integrated collection efficiency of cyclone and scrubber, were 94.2%, 59.05% and 97.4%, respectively. The results show good agreement with the values of the parameters ventilation system was designed. Conclusion: Implementation of integrated dust collectors is a good option in industries that have the financial and technical constraints to improve change processes and devices. This method with attainment to health and environmental standards not only can be resolve of the pollution problems, but also will be economically justified of such projects with reduction of depreciation expense and dust recycling.

  15. Ventilator-Related Adverse Events: A Taxonomy and Findings From 3 Incident Reporting Systems

    Science.gov (United States)

    Pham, Julius Cuong; Williams, Tamara L; Sparnon, Erin M; Cillie, Tam K; Scharen, Hilda F; Marella, William M

    2016-01-01

    BACKGROUND: In 2009, researchers from Johns Hopkins University's Armstrong Institute for Patient Safety and Quality; public agencies, including the FDA; and private partners, including the Emergency Care Research Institute and the University HealthSystem Consortium (UHC) Safety Intelligence Patient Safety Organization, sought to form a public-private partnership for the promotion of patient safety (P5S) to advance patient safety through voluntary partnerships. The study objective was to test the concept of the P5S to advance our understanding of safety issues related to ventilator events, to develop a common classification system for categorizing adverse events related to mechanical ventilators, and to perform a comparison of adverse events across different adverse event reporting systems. METHODS: We performed a cross-sectional analysis of ventilator-related adverse events reported in 2012 from the following incident reporting systems: the Pennsylvania Patient Safety Authority's Patient Safety Reporting System, UHC's Safety Intelligence Patient Safety Organization database, and the FDA's Manufacturer and User Facility Device Experience database. Once each organization had its dataset of ventilator-related adverse events, reviewers read the narrative descriptions of each event and classified it according to the developed common taxonomy. RESULTS: A Pennsylvania Patient Safety Authority, FDA, and UHC search provided 252, 274, and 700 relevant reports, respectively. The 3 event types most commonly reported to the UHC and the Pennsylvania Patient Safety Authority's Patient Safety Reporting System databases were airway/breathing circuit issue, human factor issues, and ventilator malfunction events. The top 3 event types reported to the FDA were ventilator malfunction, power source issue, and alarm failure. CONCLUSIONS: Overall, we found that (1) through the development of a common taxonomy, adverse events from 3 reporting systems can be evaluated, (2) the types of

  16. Calculation notes in support of ammonia releases from waste tank ventilation systems

    International Nuclear Information System (INIS)

    Wojdac, L.F.

    1996-01-01

    Ammonia is generated in waste tanks via the degradation of nitrogen compounds. The ammonia is released from the liquids by a mechanism which is dependent on temperature, pH, ionic strength and ammonia concentration. The release of ammonia to the environment occurs via diffusion of ammonia through a stagnant air mass and into the ventilation system

  17. A method for evaluating the problem complex of choosing the ventilation system for a new building

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Svendsen, Svend

    2007-01-01

    The application of a ventilation system in a new building is a multidimensional complex problem that involves quantifiable and non-quantifiable data like energy consump¬tion, indoor environment, building integration and architectural expression. This paper presents a structured method for evaluat...

  18. Performance of Counter Flow Heat Recovery Ventilation Systems in Dwellings Considering the Influence of Uncertainties

    NARCIS (Netherlands)

    Yang, Z.; Cauberg, J.J.M.; Tenpierik, M.J.

    2012-01-01

    Both critical and optimistic claims have been made regarding the performance of heat recovery ventilation systems (HRVS) in dwellings. Such arguments are raised partly because two key aspects are not fully clarified, i.e. the performance criteria and the influence of uncertainties. In the current

  19. Measuring Airflow in Local Exhaust Ventilation Systems. Module 23. Vocational Education Training in Environmental Sciences.

    Science.gov (United States)

    Consumer Dynamics Inc., Rockville, MD.

    This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on measuring airflow in local exhaust ventilation systems. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) naming each…

  20. Ventilation system consequence calculations to support salt well pumping single-shell tank 241-A-101

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, G.W.

    1997-05-07

    This document presents the radiological dose and toxicological exposure calculations for an accident scenario involved with the ventilation system used to support salt well pumping single-shell tank 241-A-101. This tank has been listed on the Hydrogen Watch List.

  1. Ventilation system consequence calculations to support salt well pumping single-shell tank 241-A-101

    International Nuclear Information System (INIS)

    Ryan, G.W.

    1997-01-01

    This document presents the radiological dose and toxicological exposure calculations for an accident scenario involved with the ventilation system used to support salt well pumping single-shell tank 241-A-101. This tank has been listed on the Hydrogen Watch List

  2. Ventilation systems as an effective tool for control of radon daughter concentration in mines

    International Nuclear Information System (INIS)

    Dory, A.B.

    1981-10-01

    Experience in mines shows that a very high concentration of radon daughters builds up in an unventilated dead end heading. Even minimal air movement results in a drastic reduction in radon daughter concentration. Designing the ventilation system to provide an optimized flow of fresh air into the workplace results in acceptable climatic conditions and radon daughter levels. The example of the Director fluorospar mine in Newfoundland is used to illustrate the actual design and operation of a ventilation system that provided effective radon daughter control. It was found at this mine that the age of the air underground should be kept as low as possible; that no areas of the mine should be left unventilated unless they could be kept at negative pressure; that a comparatively simple remote control and monitoring system helped stabilize ventilation and detected upsets; that the ventilation system should operate continuously, even when the mine is shut down for short periods; and that pressurization of the mine seemed to inhibit radon influx

  3. Engineering task plan for tank farm ventilation strategy document preparation and maintenance

    International Nuclear Information System (INIS)

    VanderZanden, M.D.

    1994-01-01

    Active and passive systems provide ventilation for single shell tanks (SST), double shell tanks (DST), and doubly contained receiver tanks (DCRT). The systems perform or contribute to one or more of the following functions: maintain structural integrity (prevent overpressurization), confinement, cooling, vapor and gas removal, and leak detection. For certain tanks, ventilation also removes particles, in addition to vapors, to permit visual observation of the tank inner walls and waste surface. The function(s) performed are dependent on tank construction, watchlist classification, and tank contents. The function(s) should be maintained to support the TWRS mission. The tank farm mission is expected to extend to 2028, based on Tri-Party Agreement (TPA) milestone, M-50-00, for completion of waste pretreatment. Many systems are currently beyond service life expectations and continued operation will result in decreased reliability and increased maintenance. Therefore, the systems must be replaced or upgraded to ensure adequate reliability. Ventilation system upgrades are included in a capital Project W-314, Tank Farm Restoration and Safe Operations. The ventilation upgrades are expected to be completed by June 2002. The new ventilation systems will satisfy the required function(s) of the tanks and/or tank farms. However, interim component upgrades may be required to guarantee reliability of systems until the capital project is completed. Some upgrades originally identified in the project might more suitably be provided with non-project resources

  4. Positioning of sensors for control of ventilation systems in broiler houses: a case study

    Directory of Open Access Journals (Sweden)

    Thayla Morandi Ridolfi de Carvalho Curi

    Full Text Available ABSTRACT Ventilation systems are incorporated at intensive poultry farms to control environment conditions and thermal comfort of broilers. The ventilation system operates based on environmental data, particularly measured by sensors of temperature and relative humidity. Sensors are placed at different positions of the facility. Quality, number and positioning of the sensors are critical factors to achieve an efficient performance of the system. For this reason, a strategic positioning of the sensors associated to controllers could support the maintenance and management of the microclimate inside the facility. This research aims to identify the three most representative points for the positioning of sensors in order to support the ventilation system during the critical period from 12h00 to 15h00 on summer days. Temperature, relative humidity and wind speed were measured in four different tunnel ventilated barns at the final stage of the production cycle. The descriptive analysis was performed on these data. The Temperature and Humidity Index (THI was also calculated. Then, the geostatistical analysis of THI was performed by GS+ and the position of sensors was determined by ordinary kriging. The methodology was able to detect the most representative points for the positioning of sensors in a case study (southeastern Brazil. The results suggested that this strategic positioning would help controllers to obtain a better inference of the microclimate during the studied period (the hottest microclimate, considered critical in Brazil. In addition, these results allow developing a future road map for a decision support system based on 24 h monitoring of the ventilation systems in broiler houses.

  5. Dispersion of exhaled droplet nuclei in a two-bed hospital ward with three different ventilation systems

    DEFF Research Database (Denmark)

    Qian, H.; Li, Y.; Nielsen, Peter V.

    2006-01-01

    hospital ward with three ventilation systems, i.e. mixing, downward and displacement ventilation. Two life-size breathing thermal manikins were used to simulate a source patient and a receiving patient. The exhalation jet from a bed-lying manikin was visualized using smoke. N2O was used as tracer gas...... with displacement ventilation. This work is useful for identifying an appropriate ventilation method that can remove droplet nuclei more effectively and minimize the risk of cross-infections in a hospital ward environment....

  6. A novel fiber-optic measurement system for the evaluation of performances of neonatal pulmonary ventilators

    Science.gov (United States)

    Battista, L.; Scorza, A.; Botta, F.; Sciuto, S. A.

    2016-02-01

    Published standards for the performance evaluation of pulmonary ventilators are mainly directed to manufacturers rather than to end-users and often considered inadequate or not comprehensive. In order to contribute to overcome the problems above, a novel measurement system was proposed and tested with waveforms of mechanical ventilation by means of experimental trials carried out with infant ventilators typically used in neonatal intensive care units: the main quantities of mechanical ventilation in newborns are monitored, i.e. air flow rate, differential pressure and volume from infant ventilator are measured by means of two novel fiber-optic sensors (OFSs) developed and characterized by the authors, while temperature and relative humidity of air mass are obtained by two commercial transducers. The proposed fiber-optic sensors (flow sensor Q-OFS, pressure sensor P-OFS) showed measurement ranges of air flow and pressure typically encountered in neonatal mechanical ventilation, i.e. the air flow rate Q ranged from 3 l min-1 to 18 l min-1 (inspiratory) and from  -3 l min-1 to  -18 l min-1 (expiratory), the differential pressure ΔP ranged from  -15 cmH2O to 15 cmH2O. In each experimental trial carried out with different settings of the ventilator, outputs of the OFSs are compared with data from two reference sensors (reference flow sensor RF, reference pressure sensor RP) and results are found consistent: flow rate Q showed a maximum error between Q-OFS and RF up to 13 percent, with an output ratio Q RF/Q OFS of not more than 1.06  ±  0.09 (least square estimation, 95 percent confidence level, R 2 between 0.9822 and 0.9931). On the other hand the maximum error between P-OFS and RP on differential pressure ΔP was lower than 10 percent, with an output ratio ΔP RP/ΔP OFS between 0.977  ±  0.022 and 1.0  ±  0.8 (least square estimation, 95 percent confidence level, R 2 between 0.9864 and 0.9876). Despite the possible improvements

  7. A novel fiber-optic measurement system for the evaluation of performances of neonatal pulmonary ventilators

    International Nuclear Information System (INIS)

    Battista, L; Scorza, A; Botta, F; Sciuto, S A

    2016-01-01

    Published standards for the performance evaluation of pulmonary ventilators are mainly directed to manufacturers rather than to end-users and often considered inadequate or not comprehensive. In order to contribute to overcome the problems above, a novel measurement system was proposed and tested with waveforms of mechanical ventilation by means of experimental trials carried out with infant ventilators typically used in neonatal intensive care units: the main quantities of mechanical ventilation in newborns are monitored, i.e. air flow rate, differential pressure and volume from infant ventilator are measured by means of two novel fiber-optic sensors (OFSs) developed and characterized by the authors, while temperature and relative humidity of air mass are obtained by two commercial transducers. The proposed fiber-optic sensors (flow sensor Q-OFS, pressure sensor P-OFS) showed measurement ranges of air flow and pressure typically encountered in neonatal mechanical ventilation, i.e. the air flow rate Q ranged from 3 l min −1 to 18 l min −1 (inspiratory) and from  −3 l min −1 to  −18 l min −1 (expiratory), the differential pressure ΔP ranged from  −15 cmH 2 O to 15 cmH2O. In each experimental trial carried out with different settings of the ventilator, outputs of the OFSs are compared with data from two reference sensors (reference flow sensor RF, reference pressure sensor RP) and results are found consistent: flow rate Q showed a maximum error between Q-OFS and RF up to 13 percent, with an output ratio Q RF /Q OFS of not more than 1.06  ±  0.09 (least square estimation, 95 percent confidence level, R 2 between 0.9822 and 0.9931). On the other hand the maximum error between P-OFS and RP on differential pressure ΔP was lower than 10 percent, with an output ratio ΔP RP /ΔP OFS between 0.977  ±  0.022 and 1.0  ±  0.8 (least square estimation, 95 percent confidence level, R 2 between 0.9864 and 0.9876). Despite the

  8. Determination of respiratory system compliance during pressure support ventilation by small variations of pressure support.

    Science.gov (United States)

    Becher, Tobias; Schädler, Dirk; Rostalski, Philipp; Zick, Günther; Frerichs, Inéz; Weiler, Norbert

    2017-09-22

    In mechanically ventilated patients, measurement of respiratory system compliance (C rs ) is of high clinical interest. Spontaneous breathing activity during pressure support ventilation (PSV) can impede the correct assessment of C rs and also alter the true C rs by inducing lung recruitment. We describe a method for determination of C rs during PSV and assess its accuracy in a study on 20 mechanically ventilated patients. To assess C rs during pressure support ventilation (C rs,PSV ), we performed repeated changes in pressure support level by ± 2 cmH 2 O. C rs,PSV was calculated from the volume change induced by these changes in pressure support level, taking into account the inspiration time and the expiratory time constant. As reference methods, we used C rs , measured during volume controlled ventilation (C rs,VCV ). In a post-hoc analysis, we assessed C rs during the last 20% of the volume-controlled inflation (C rs,VCV20 ). Values were compared by linear regression and Bland-Altman methods comparison. Comparing C rs,PSV to the reference value C rs,VCV , we found a coefficient of determination (r 2 ) of 0.90, but a relatively high bias of - 7 ml/cm H 2 O (95% limits of agreement - 16.7 to + 2.7 ml/cmH 2 O). Comparison with C rs,VCV20 resulted in a negligible bias (- 1.3 ml/cmH 2 O, 95% limits of agreement - 13.9 to + 11.3) and r 2 of 0.81. We conclude that the novel method provides an estimate of end-inspiratory C rs during PSV. Despite its limited accuracy, it might be useful for non-invasive monitoring of C rs in patients undergoing pressure support ventilation.

  9. Mechanical Ventilation

    Science.gov (United States)

    ... ventilation is a life support treatment. A mechanical ventilator is a machine that helps people breathe when ... to breathe enough on their own. The mechanical ventilator is also called a ventilator , respirator, or breathing ...

  10. Natural ventilation systems to enhance sustainability in buildings: a review towards zero energy buildings in schools

    Science.gov (United States)

    Gil-Baez, Maite; Barrios-Padura, Ángela; Molina-Huelva, Marta; Chacartegui, Ricardo

    2017-11-01

    European regulations set the condition of Zero Energy Buildings for new buildings since 2020, with an intermediate milestone in 2018 for public buildings, in order to control greenhouse gases emissions control and climate change mitigation. Given that main fraction of energy consumption in buildings operation is due to HVAC systems, advances in its design and operation conditions are required. One key element for energy demand control is passive design of buildings. On this purpose, different recent studies and publications analyse natural ventilation systems potential to provide indoor air quality and comfort conditions minimizing electric power consumption. In these passive systems are of special relevance their capacities as passive cooling systems as well as air renovation systems, especially in high-density occupied spaces. With adequate designs, in warm/mild climates natural ventilation systems can be used along the whole year, maintaining indoor air quality and comfort conditions with small support of other heating/cooling systems. In this paper is analysed the state of the art of natural ventilation systems applied to high density occupied spaces with special focus on school buildings. The paper shows the potential and applicability of these systems for energy savings and discusses main criteria for their adequate integration in school building designs.

  11. Assessment of dynamic mechanical properties of the respiratory system during high-frequency oscillatory ventilation*.

    Science.gov (United States)

    Dellacà, Raffaele L; Zannin, Emanuela; Ventura, Maria L; Sancini, Giulio; Pedotti, Antonio; Tagliabue, Paolo; Miserocchi, Giuseppe

    2013-11-01

    1) To investigate the possibility of estimating respiratory system impedance (Zrs, forced oscillation technique) by using high-amplitude pressure oscillations delivered during high-frequency oscillatory ventilation; 2) to characterize the relationship between Zrs and continuous distending pressure during an increasing/decreasing continuous distending pressure trial; 3) to evaluate how the optimal continuous distending pressure identified by Zrs relates to the point of maximal curvature of the deflation limb of the quasi-static pressure-volume curve. Prospective laboratory animal investigation. Experimental medicine laboratory. Eight New Zealand rabbits. The rabbits were ventilated with high-frequency oscillatory ventilation. Zrs was measured while continuous distending pressure was increased and decreased between 2 and 26 cm H2O in 1-minute steps of 4 cm H2O. At each step, a low-amplitude (6 cm H2O) sinusoidal signal was alternated with a high-amplitude (18 cm H2O) asymmetric high-frequency oscillatory ventilation square pressure waveform. Pressure-volume curves were determined at the end of the continuous distending pressure trial. All measurements were repeated after bronchoalveolar lavage. Zrs was estimated from flow and pressure measured at the inlet of the tracheal tube and expressed as resistance (Rrs) and reactance (Xrs). Linear correlation between the values, measured by applying the small-amplitude sinusoidal signal and the ventilator waveform, was good for Xrs (r = 0.95 ± 0.04) but not for Rrs (r = 0.60 ± 0.34). Following lavage, the Xrs-continuous distending pressure curves presented a maximum on the deflation limb, identifying an optimal continuous distending pressure that was, on average, 1.1 ± 1.7 cm H2O below the point of maximal curvature of the deflation limb of the pressure-volume curves. Xrs can be accurately measured during high-frequency oscillatory ventilation without interrupting ventilation and/or connecting additional devices. An optimal

  12. Ventilator-derived dynamic respiratory system compliance: Comparison with static compliance in children.

    Science.gov (United States)

    Kaskinen, Anu K; Kirjavainen, Turkka; Rautiainen, Paula; Martelius, Laura; Andersson, Sture; Pitkänen, Olli M

    2018-02-01

    Measurement of dynamic lung compliance during breathing requires measurement of esophageal pressure, whereas static respiratory system compliance (Crs) method requires several airway occlusions. Despite their precision these compliance methods are cumbersome and not suitable for evaluation of pulmonary system in intensive care. The current ventilators display dynamic Crs, which, however, is seldom utilized in clinical practice. We studied the feasibility of ventilator-derived dynamic Crs measurement in pulmonary evaluation after congenital cardiac surgery in children. In 50 children static Crs was measured by double-occlusion technique, and compared with simultaneous ventilator-derived dynamic Crs values. The early postoperative dynamic and static Crs showed a correlation (r = 0.57, p static Crs was 48% higher than dynamic (p static Crs showed a negative correlation with radiographic lung edema scoring (r = -0.50, p = 0.0002). Thus ventilator-derived dynamic Crs seems less reliable in postoperative pulmonary evaluation than static Crs. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Energy Performance of a Novel System Combining Natural Ventilation with Diffuse Ceiling Inlet and Thermally Activated Building Systems (TABS)

    DEFF Research Database (Denmark)

    Yu, Tao

    . Both steady-state and dynamic measurements are carried out in the experimental chamber to investigate the energy performance of the system and the thermal comfort in the test room. Overall, this integrated system has high energy saving potential without any compromise of thermal comfort even in extreme...... and thermally activated building systems (TABS) for cooling and ventilation in future Danish office buildings. The new solution would have the special potential of using natural ventilation all year round even in the extremely cold seasons without any draught risk. The main focuses of this study are the energy...

  14. Special features of nuclear waste repository ventilation system VIS-A-VIS experiences at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Sethi, S.C.

    1991-01-01

    The paper presents an analysis and discussion of the underground ventilation system at the Waste Isolation Pilot Plant (WIPP). Particular emphasis is placed on specific repository-related requirements and the gradual evolution of engineering designs relative to the WIPP Project scope. The ventilation system for a nuclear waste facility similar to WIPP is designed to provide a suitable environment for personnel and equipment during normal activities. It is also designed to provide confinement and channeling of potential airborne radioactive material in the event of an accidental release. It is desirable to identify and design all parallel activities and the required process equipment prior to completion of the repository mine final design. Such factors as ventilation requirements, drift sizes, bulkhead sizes, and placement are dependent on these items. Mine creep closure properties must be factored into the mine and ventilation equipment design considerations. Effects of natural ventilation pressures deserve due consideration in the design. Mine ventilation requirements are dominated by the diesel equipment to be operated in the underground horizon. WIPP engineers have also found it extremely desirable to have automated real-time monitoring and control for the underground ventilation air. Final testing and balancing of the ventilation system is an extremely important startup requirement. 3 refs., 2 figs

  15. Definition and means of maintaining the ventilation system confinement portion of the PFP safety envelope

    Energy Technology Data Exchange (ETDEWEB)

    Dick, J.D.; Grover, G.A.; O`Brien, P.M., Fluor Daniel Hanford

    1997-03-05

    The Plutonium Finishing Plant Heating Ventilation and Cooling system provides for the confinement of radioactive releases to the environment and provides for the confinement of radioactive contamination within designated zones inside the facility. This document identifies the components and procedures necessary to ensure the HVAC system provides these functions. Appendices E through J provide a snapshot of non-safety class HVAC equipment and need not be updated when the remainder of the document and Appendices A through D are updated.

  16. Design and operating technique for ventilating system of irradiated materials examination facility

    International Nuclear Information System (INIS)

    Hwang, Yong Hwa; Hong, Kwon Pyo; Eom, Sung Ho

    1999-08-01

    Ventilation and air filtering system is installed at IMEF to maintain optimized operating condition of the facility by keeping different negative pressure condition depending on contamination level in the IMEF due to its treatment of radioactive materials. Inspection on each system, air flow measurement, filter leak test and other related test are periodically performed as the performance test for increasing operational efficiency and safety. (Author). 16 refs., 21 tabs., 9 figs

  17. Advanced Hybrid Spacesuit Concept Featuring Integrated Open Loop and Closed Loop Ventilation Systems

    Science.gov (United States)

    Daniel, Brian A.; Fitzpatrick, Garret R.; Gohmert, Dustin M.; Ybarra, Rick M.; Dub, Mark O.

    2013-01-01

    A document discusses the design and prototype of an advanced spacesuit concept that integrates the capability to function seamlessly with multiple ventilation system approaches. Traditionally, spacesuits are designed to operate both dependently and independently of a host vehicle environment control and life support system (ECLSS). Spacesuits that operate independent of vehicle-provided ECLSS services must do so with equipment selfcontained within or on the spacesuit. Suits that are dependent on vehicle-provided consumables must remain physically connected to and integrated with the vehicle to operate properly. This innovation is the design and prototype of a hybrid spacesuit approach that configures the spacesuit to seamlessly interface and integrate with either type of vehicular systems, while still maintaining the ability to function completely independent of the vehicle. An existing Advanced Crew Escape Suit (ACES) was utilized as the platform from which to develop the innovation. The ACES was retrofitted with selected components and one-off items to achieve the objective. The ventilation system concept was developed and prototyped/retrofitted to an existing ACES. Components were selected to provide suit connectors, hoses/umbilicals, internal breathing system ducting/ conduits, etc. The concept utilizes a lowpressure- drop, high-flow ventilation system that serves as a conduit from the vehicle supply into the suit, up through a neck seal, into the breathing helmet cavity, back down through the neck seal, out of the suit, and returned to the vehicle. The concept also utilizes a modified demand-based breathing system configured to function seamlessly with the low-pressure-drop closed-loop ventilation system.

  18. MODELLING AND SIMULATION OF A SINGLE-ZONE HEATING AND VENTILATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Mesut ŞENGİRGİN

    2005-03-01

    Full Text Available In this study, modelling and simulation results of a single-zone heating and ventilation system of a large office room are introduced. Heating system is controlled by an on-off controller. By considering the sinusoidal outdoor air tempareture variation and various outdoor/return air ratios as input parameters, dynamic behaviour of room air tempereture are investigated. For this purpose, MATLAB/Simulink code is used.

  19. Alternative ventilation system for operating theaters: parameter study and full-scale assessment of the performance of a local ventilation system

    NARCIS (Netherlands)

    J.G.H. Loogman; Dr. H.S.M. Kort; M.G.L.C. Loomans; I.M. de Visser

    2016-01-01

    A local operating theater ventilation device to specifically ventilate the wound area has been developed and investigated. The ventilation device is combined with a blanket which lies over the patient during the operation. Two configurations were studied: Configuration 1 where HEPA-filtered air was

  20. A novel simulator for mechanical ventilation in newborns: MEchatronic REspiratory System SImulator for Neonatal Applications.

    Science.gov (United States)

    Baldoli, Ilaria; Cuttano, Armando; Scaramuzzo, Rosa T; Tognarelli, Selene; Ciantelli, Massimiliano; Cecchi, Francesca; Gentile, Marzia; Sigali, Emilio; Laschi, Cecilia; Ghirri, Paolo; Menciassi, Arianna; Dario, Paolo; Boldrini, Antonio

    2015-08-01

    Respiratory problems are among the main causes of mortality for preterm newborns with pulmonary diseases; mechanical ventilation provides standard care, but long-term complications are still largely reported. In this framework, continuous medical education is mandatory to correctly manage assistance devices. However, commercially available neonatal respiratory simulators are rarely suitable for representing anatomical and physiological conditions; a step toward high-fidelity simulation, therefore, is essential for nurses and neonatologists to acquire the practice needed without any risk. An innovative multi-compartmental infant respirator simulator based on a five-lobe model was developed to reproduce different physio-pathological conditions in infants and to simulate many different kinds of clinical scenarios. The work consisted of three phases: (1) a theoretical study and modeling phase, (2) a prototyping phase, and (3) testing of the simulation software during training courses. The neonatal pulmonary simulator produced allows the replication and evaluation of different mechanical ventilation modalities in infants suffering from many different kinds of respiratory physio-pathological conditions. In particular, the system provides variable compliances for each lobe in an independent manner and different resistance levels for the airway branches; moreover, it allows the trainer to simulate both autonomous and mechanically assisted respiratory cycles in newborns. The developed and tested simulator is a significant contribution to the field of medical simulation in neonatology, as it makes it possible to choose the best ventilation strategy and to perform fully aware management of ventilation parameters. © IMechE 2015.

  1. Personalized ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor

    2004-01-01

    The thermal environment and air quality in buildings affects occupants' health, comfort and performance. The heating, ventilating and air-conditioning (HVAC) of buildings today is designed to provide a uniform room environment. However, large individual differences exist between occupants in regard...... microenvironment. Furthermore, HVAC systems should be designed to protect occupants from airborne transmission of infectious agents that may be present in exhaled air. Personalized ventilation is a new development in the field of HVAC and has the potential to fulfill the above requirements. This paper reviews...... existing knowledge on performance of personalized ventilation (PV) and on human response to it. The airflow interaction in the vicinity of the human body is analyzed and its impact on thermal comfort and inhaled air quality is discussed together with control strategies and the application of PV in practice...

  2. Performance of a demand controlled mechanical extract ventilation system for dwellings

    Directory of Open Access Journals (Sweden)

    I. Pollet

    2013-10-01

    Full Text Available The main aim of ventilation is to guarantee a good indoor air quality, related to the energy consumed for heating and fan(s. Active or passive heat recovery systems seem to focus on the reduction of heating consumption at the expense of fan electricity consumption and maintenance. In this study, demandcontrolled mechanical extract ventilation systems of Renson (DCV1 and DCV2, based on natural supply in the habitable rooms and mechanical extraction in the wet rooms (or even the bedrooms, was analysed for one year by means of multi-zone Contam simulations on a reference detached house and compared with standard MEV and mechanical extract ventilation systems with heat recovery (MVHR. To this end, IAQ, total energy consumption, CO2 emissions and total cost of the systems are determined. The results show that DCV systems with increased supply air flow rates or direct mechanical extract from bedrooms can significantly improve IAQ, while reducing total energy consumption compared to MEV. Applying DCV reduces primary heating energy consumption and yearly fan electricity consumption at most by 65% to 50% compared to MEV. Total operational energy costs and CO2 emissions of DCV are similar when compared to MVHR. Total costs of DCV systems over 15 years are smaller when compared to MVHR due to lower investment and maintenance costs.

  3. Energy saving effect of desiccant ventilation system using Wakkanai siliceous shale

    Science.gov (United States)

    Nabeshima, Yuki; Togawa, Jun-ya; Nagano, Katsunori; Kazuyo, Tsuzuki

    2017-10-01

    The nuclear power station accident resulting from the Great East Japan Earthquake disaster has resulted in a constrained electricity supply. However, in this Asian region there is high temperature and high humidity and consequently dehumidification process requires a huge amount of energy. This is the reason for the increasing energy consumption in the residential and commercial sectors. Accordingly, a high efficiency air-conditioning system is needed to be developed. The desiccant ventilation system is effective to reduce energy consumption for the dehumidification process. This system is capable of dehumidifying without dew condensing unlike a conventional air-conditioning system. Then we focused on Wakkanai Siliceous Shale (WSS) as a desiccant material to develop a new desiccant ventilation system. This is low priced, high performance, new type of thing. The aim of this study is to develop a desiccant ventilation unit using the WSS rotor which can be regenerated with low-temperature by numerical calculation. The results of performance prediction of the desiccant unit, indicate that it is possible to regenerate the WSS rotor at low-temperature of between 35 - 45 °C. In addition, we produced an actual measurement for the desiccant unit and air-conditioning unit. This air-conditioning system was capable to reduce roughly 40 % of input energy consumption.

  4. Designing, Constructing and Installing a Local Exhaust Ventilation System to Minimize Welders\\' Exposure to Welding Fumes

    Directory of Open Access Journals (Sweden)

    Sajad Zare

    2017-10-01

    Full Text Available Background & Aims of the Study: Welder’s exposure to welding fumes can cause occupational diseases. The current study sought to examine exposure to welding fumes among welders who work in the repair shop of Sarcheshmeh Copper Complex and design a local exhaust ventilation system to control exposure to welding fumes. Materials & Methods: This applied analytical study was conducted in the summer of 2016 among welders working in the repair shop of Sarcheshmeh Copper Complex. The study comprised three phases; in the first one, welders’ exposure to welding fumes was assessed at the beginning of the study. After that, a local exhaust ventilation system was designed and installed in the aforementioned repair shop. In the final stage, welders’ exposure to welding fumes was assessed again after installation of the ventilation system. The procedure recommended by NIOSH (method number 7300 was used for individual sampling of welders. Results: Based on the obtained findings, before installing the ventilation system, welding technicians were exposed to 0.3 mg/m3 of copper fumes and 0.04 mg/m3 of chromium fumes. Journeyman welders were also exposed to 2.16 mg/m3 of manganese fumes, while stellar welders were exposed to 6.9 mg/m3 of iron fumes. In the light of these measurements, a local exhaust ventilation system was designed and installed. Subsequently, measurement of exposure to welding fumes showed a significant reduction. That is, welding technicians were exposed to 0.17 mg/m3 and 0.015 mg/m3 of copper and chromium fumes respectively. Additionally, journeyman welders were exposed to 0.86 mg/m3 of manganese fumes, whereas stellar welders were exposed to 4.3 mg/m3 of iron fumes. Conclusions: A comparison of standard limits of exposure to welding fumes and the results obtained from measurements in sampling stations before and after the installation of the local exhaust ventilation system reveals that this controlling measure was very effective in the

  5. The DST group ionospheric sounder replacement for JORN

    Science.gov (United States)

    Harris, T. J.; Quinn, A. D.; Pederick, L. H.

    2016-06-01

    The Jindalee Over-the-horizon Radar Network (JORN) is an integral part of Australia's national defense capability. JORN uses a real-time ionospheric model as part of its operations. The primary source of data for this model is a set of 13 vertical-incidence sounders (VIS) scattered around the Australian coast and inland locations. These sounders are a mix of Lowell digisonde portable sounder (DPS)-1 and DPS-4. Both of these sounders, the DPS-1 in particular, are near the end of their maintainable life. A replacement for these aging sounders was required as part of the ongoing sustainment program for JORN. Over the last few years the High-Frequency Radar Branch (HFRB) of the Defence Science and Technology (DST) Group, Australian Department of Defence, has been developing its own sounders based on its successful radar hardware technology. The DST Group VIS solution known as PRIME (Portable Remote Ionospheric Monitoring Equipment) is a 100% duty cycle, continuous wave system that receives the returned ionospheric signal while it is still transmitting and operates the receiver in the near field of the transmitter. Of considerable importance to a successful VIS is the autoscaling software, which takes the ionogram data and produces an ionogram trace (group delay as a function of frequency), and from that produces a set of ionospheric parameters that represent the (bottomside) overhead electron density profile. HFRB has developed its own robust autoscaling software. The performance of DST Group's PRIME under a multitude of challenging ionospheric conditions has been studied. In December 2014, PRIME was trialed at a JORN VIS site collocated with the existing Lowell Digisonde DPS-1. This side-by-side testing determined that PRIME was fit for purpose. A summary of the results of this comparison and example PRIME output will be discussed. Note that this paper compares PRIME with the 25 year old Lowell Digisonde DPS-1, which is planned to be replaced. Our future plans include

  6. Control System Implementation and Follow-up within the Cooling and Ventilation Contracts for the LHC

    CERN Document Server

    Body, Y; Morodo, M C

    2001-01-01

    The control system implementation for the cooling and ventilation facilities connected to the LHC Project relies on the technical and human resources that are organised within large-size industrial contracts. Beside the technical aspects, the follow-up of the implementation activities in the framework of such contracts also involves a managerial effort in order to achieve a flexible and coherent control system. The purpose is to assure precise and reliable regulation together with accurate local and remote supervision in conformity with the operational requirements. These objectives can only be reached by a systematic approach that keeps the co-ordination between the in-house and external cross-disciplinary teams as well as the fulfilment of the validation procedures and the contractual formalities. The case that here illustrates this approach is the control system implementation for the heating, ventilation and air conditioning of the LHC surface buildings, which shall extend up to 2004.

  7. [Reducing the levels of formaldehyde exposure during a gross anatomy dissection course with a local ventilation system].

    Science.gov (United States)

    Kikuta, Akio; Yamato, Hiroshi; Kunugita, Naoki; Nakashima, Tamiji; Hayashi, Haruki

    2010-03-01

    Reducing the levels of formaldehyde (FA) exposure in gross anatomy laboratories has been urgently required. We improved the environment of our gross anatomy laboratory by changing the existing general ventilation to local ventilation. We developed a local ventilation apparatus (grid-type of hood with downward suction) that can be attached to an ordinary dissection table. Furthermore, in order to make this local ventilation apparatus an enclosure hood, the upper plate of the dissection table was surrounded by flexible vertical flanges. The apparatus works as an effective enclosure hood without interfering with students' practice of dissection. We installed 26 local ventilation apparatuses and connected them to the ventilation duct. The ventilation ducts were installed above the ceiling or along the pillars not to interfere with students' vision and movements in the room. Adopting the local ventilation system reduced dramatically the students' and lecturers' exposure to formaldehyde. The geometric mean formaldehyde concentration was 0.066 ppm in the anatomy laboratory in 2005. Since 2005, the new system has enabled us to comply with safety and health regulations and providing a smell- and irritant-free dissection room with an excellent environment for anatomy study.

  8. On the thermal interaction of building structure and heating and ventilation system

    Science.gov (United States)

    Hensen, Joannes Laurentius Maria

    Developments in the field of building performance evaluation tools for thermal interaction of building structure and heating and ventilating systems are described. The technique employed is computer simulation of the integrated dynamic system comprising the occupants, the building and its heating and ventilating system. Assessment criteria from a literature review in thermal comfort to examine acceptable fluctuations in indoor climate are defined. Building and plant energy simulation within the context of Computer Aided Building Design (CABD) is described. An exisiting energy simulation environment ESP(R) (Environmental Systems Performance (Research version)) is chosen. A fluid flow network simulation module is described. Extensions to ESP(R) to predict the dynamic behavior of the heating and ventilation system are described. The coupling of fluid flow, plant side energy and mass, and building side energy simulation into one integrated program is described. A multistage verification and validation methodology is demonstrated by examples addressing each successive step. Imaginary and real world cases are described to demonstrate application of the study in a modeling orientated and a building engineering context.

  9. Ventilation systems analysis during tornado conditions. Progress report, July--December 1975

    International Nuclear Information System (INIS)

    Gregory, W.S.; Duerre, K.H.; Bennett, G.A.

    1976-04-01

    A review of some existing digital simulations of fluid systems, a brief description of the proposed generalized computer code, a description of, and results from, two solution techniques, and a sample test case ventilation system are presented. The review of some fluid system simulations covers methods and techniques for development of a more general digital solution technique than the successive substitution method used in previous analyses. The structure and organization of the computer code under development is discussed. A section dealing with the development of a user-oriented input to the code is also presented. Two solution techniques suitable for solving the simultaneous nonlinear algebraic and differential equations are presented. One of the techniques is based upon a loop method and employs Newton's method for obtaining simultaneous iterative corrections for the solution. The second approach is based upon a node orientation and employs Cross' method to arrive at successive iterative corrections for the solution. Graphical results using both methods are presented. The results are essentially identical. A ''test-case'' ventilation system is introduced. The test-case ventilation system model was developed primarily for ''debugging'' the proposed generalized code. The test case is a simple yet realistic representation of the types of subsystems which could be encountered in nuclear facilities

  10. Clinical validation of the Deltatrac monitoring system in mechanically ventilated patients.

    Science.gov (United States)

    Tissot, S; Delafosse, B; Bertrand, O; Bouffard, Y; Viale, J P; Annat, G

    1995-02-01

    To evaluate a monitor of pulmonary gas exchange (Deltatrac, Datex) in a clinical setting. After in vitro evaluation, comparison over 2 min between VO2 and VCO2 values measured by the Deltatrac and the Douglas bag technique. Comparisons were also achieved over 8 h periods between the Deltatrac and a system using a mass-spectrometer. Polyvalent intensive care unit (ICU 15 beds) in a 1200 bed general hospital. Comparison with the Douglas bag technique in 10 patients undergoing controlled ventilation. Comparison with the mass-spectrometer system in 25 other patients undergoing controlled or pressure support ventilation. Compared to the results obtained by the Douglas bag technique, the bias (+/- 2 SD) for VO2 and VCO2 was -3.5 +/- 26.6 and 6.1 +/- 12.7 ml.min-1, respectively. By comparison with the mass-spectrometer system, the bias for VO2 and RQ was -5.8 +/- 16.0 ml.min-1 and 0.018 +/- 0.048, respectively. No drift between the two systems was observed over time. The Deltatrac appears suitable for VO2 and VCO2 measurements in ventilated patients and equivalent to a mass-spectrometer system for long term measurements.

  11. CSF 5-HIAA and DST non-suppression -independent biomarkers in suicide attempters?

    Science.gov (United States)

    Jokinen, Jussi; Mårtensson, Björn; Nordström, Anna-Lena; Nordström, Peter

    2008-01-01

    Two major biomarkers of suicidal behaviour; low 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid (CSF) and non-suppression in the dexamethasone suppression test (DST) have evidence for predictive power for suicide in mood disorders. Previous suicide attempt is the most robust clinical risk factor. To study the interrelationship of suicide risk factors: low CSF 5-HIAA and the DST non-suppression in mood disorder patients with and without an index suicide attempt. Fifty-eight hospitalised mood disorder patients (twenty-five with an index suicide attempt), who were not receiving any treatment with antidepressants, underwent lumbar puncture and DST. Plasma cortisol levels were determined from blood samples drawn the following day at 8:00 a.m., 4:00 p.m. and 11:00 p.m. and analysed in relation to CSF 5-HIAA. In the sample as a whole, the serum cortisol level at 4:00 p.m. showed a significant positive correlation to CSF 5-HIAA (r=0.3, pDST non-suppression are relatively independent biomarkers of suicide risk in suicide attempters. The interrelation of the two systems seems to be different in suicide attempters compared to depressed inpatients without suicide attempt.

  12. Design of the natural ventilation system for the new San Diego Children's Museum

    Energy Technology Data Exchange (ETDEWEB)

    Graca, G.C. [Natural Works Inc., CA (United States); Linden, P.F. [California Univ., San Diego, CA (United States). Dept. of Mechanical and Aerospace Engineering; Brook, M. [California Energy Commission, Sacramento, CA (United States)

    2005-07-01

    One of the unique features of the newly designed San Diego Children's museum is the solar chimney that is expected to promote buoyancy-driven flow that would come into the space through large, user-controlled roll up doors on the south facade. As part of a sustainable design choice, the proposed museum exhibition space will not have any mechanical heating or cooling systems. Indoor temperatures will be controlled using ventilation air using a variable air volume principle driven by wind and buoyancy. The ventilation system inserts fresh outside air at low levels and exhausts at higher levels achieving displacement ventilation. Particular attention was given to defining the shape of the outlet from the chimney in order to maximize wind-induced suction effects in the outlet surface. A building management system (BMS) and a control strategy were developed to optimize the performance of the building. The tools used in the analysis were a specifically designed weather analysis spreadsheet, EnergyPlus with COMIS and computational fluid dynamics. This study of the passive climate control system also involved an analysis of weather characteristics; analysis of the different glazing, chimney geometries and roof insulation; refining existing window opening geometry and positions; defining window opening control strategies. It was concluded that it is possible to improve the chimney performance by using a high level opening on the East side. Additional gains can be obtained by inserting a small opening facing North. 5 refs., 5 tabs., 10 figs.

  13. A versatile hydraulically operated respiratory servo system for ventilation and lung function testing.

    Science.gov (United States)

    Meyer, M; Slama, H

    1983-09-01

    A description is given of the design and performance of a microcomputer-controlled respiratory servo system that incorporates the characteristics of a mechanical ventilator and also allows the performance of a multitude of test procedures required for assessment of pulmonary function in paralyzed animals. The device consists of a hydraulically operated cylinder-piston assembly and solenoid valves that direct inspiratory and expiratory gas flow and also enable switching to different test gas sources. The system operates as a volume-flow-preset ventilator but may be switched to other operational cycling modes. Gas flow rates may be constant or variable. The system operates as an assister-controller and, combined with a gas analyzer, can function as a "demand" ventilator allowing for set-point control of end-tidal PCO2 and PO2. Complex breathing maneuvers for a variety of single- and multiple-breath lung function tests are automatically performed. Because of the flexibility in selection and timing of respiratory parameters, the system is particularly suitable for respiratory gas studies.

  14. Analysis of ventilation systems subjected to explosive transients: initial analysis and proposed approach

    International Nuclear Information System (INIS)

    Gregory, W.S.; Smith, P.R.; Bolstad, J.W.; Duerre, K.H.

    1979-08-01

    This report describes an initial study of explosive pressure transients and their propagation through ventilation systems. The objective of this study is to organize the required calculations into a computer code that is highly user-oriented and will predict explosive-induced gas dynamics within a ventilation system. The explosive process is subdivided into three regimes - deflagration, detonation, and transition from deflagration to detonation. Equations describing each process and suggested procedures for solving these equations are presented. The proposed organization of the explosion code capitalizes on the desirable aspects of the previously developed TVENT code, which predicts tornado-induced pressure transients within ventilation systems. The explosion code will include both near- and far-field analyses. The near-field analysis will use detailed models to describe the combustion process near the explosive event, and provide parametric driving potentials for flow in the regions that are removed from the explosive event (far-field). The far-field analysis will include the combustion wave as it propagates through the rest of the system

  15. Active Fault Tolerant Control of Livestock Stable Ventilation System

    DEFF Research Database (Denmark)

    Gholami, Mehdi

    2011-01-01

    degraded performance even in the faulty case. In this thesis, we have designed such controllers for climate control systems for livestock buildings in three steps: Deriving a model for the climate control system of a pig-stable. Designing a active fault diagnosis (AFD) algorithm for different kinds...... of the hybrid model are estimated by a recursive estimation algorithm, the Extended Kalman Filter (EKF), using experimental data which was provided by an equipped laboratory. Two methods for active fault diagnosis are proposed. The AFD methods excite the system by injecting a so-called excitation input. In both...... methods, the input is designed off-line based on a sensitivity analysis in order to improve the precision of estimation of parameters associated with faults. Two different algorithm, the EKF and a new adaptive filter, are used to estimate the parameters of the system. The fault is detected and isolated...

  16. Cost optimization for buildings with hybrid ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Kun; Lu, Yan

    2018-02-13

    A method including: computing a total cost for a first zone in a building, wherein the total cost is equal to an actual energy cost of the first zone plus a thermal discomfort cost of the first zone; and heuristically optimizing the total cost to identify temperature setpoints for a mechanical heating/cooling system and a start time and an end time of the mechanical heating/cooling system, based on external weather data and occupancy data of the first zone.

  17. Use of geostatistics on broiler production for evaluation of different minimum ventilation systems during brooding phase

    Directory of Open Access Journals (Sweden)

    Thayla Morandi Ridolfi de Carvalho

    2012-01-01

    Full Text Available The objective of this research was to evaluate different minimum ventilation systems, in relation to air quality and thermal comfort using geostatistics in brooding phase. The minimum ventilation systems were: Blue House I: exhaust fans + curtain management (end of the building; Blue House II: exhaust fans + side curtain management; and Dark House: exhaust fans + flag. The climate variables evaluated were: dry bulb temperature, relative humidity, air velocity, carbon dioxide and ammonia concentration, during winter time, at 9 a.m., in 80 equidistant points in brooding area. Data were evaluated by geostatistic technique. The results indicate that Wider broiler houses (above 15.0 m width present the greatest ammonia and humidity concentration. Blue House II present the best results in relation to air quality. However, none of the studied broiler houses present an ideal thermal comfort.

  18. Ventilator Data Extraction with a Video Display Image Capture and Processing System.

    Science.gov (United States)

    Wax, David B; Hill, Bryan; Levin, Matthew A

    2017-06-01

    Medical hardware and software device interoperability standards are not uniform. The result of this lack of standardization is that information available on clinical devices may not be readily or freely available for import into other systems for research, decision support, or other purposes. We developed a novel system to import discrete data from an anesthesia machine ventilator by capturing images of the graphical display screen and using image processing to extract the data with off-the-shelf hardware and open-source software. We were able to successfully capture and verify live ventilator data from anesthesia machines in multiple operating rooms and store the discrete data in a relational database at a substantially lower cost than vendor-sourced solutions.

  19. SIMULATION OF FREE CURRENT FLOWS IN BUOYANCY-DRIVEN VENTILATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    D. V. Abramkina

    2017-01-01

    Full Text Available Objectives. The aim of the study is to analyse the effect of the design and methods for heating the ventilation duct of a buoyancy- driven system on the formation of free convective air currents in it.Methods. The study of free convection under the conditions of interior problem was carried out using the CFD software, based on  the finite volume method with unstructured grid. Ansys Fluent software was used as a calculation tool in the study, due to its having a high convergence of numerical solutions offering full-scale  measurements of convective currents.To evaluate the reliability of  the results obtained, a validation procedure was carried out, allowing us to determine how accurately the selected conceptual model describes the investigated flow through a comparison of experimental and numerical data.Results. The results of numerical modelling of free convective currents occurring in the heated channel of the ventilation system of  the top floor of a multi-storey residential building are presented in  the article. In the course of the study, the air velocity at the entrance to the ventilation duct was found to depend on the calculated  temperature difference θ ˚C for various heating methods. A gradual  increase in the discrepancy between the numerical simulation and  experimental results is observed if the calculated temperature  difference > 20 ° C. This phenomenon is due to the fact that with  increased duct temperature, it is quite difficult to achieve even  heating under actual conditions; this is especially noticeable when  considering the variant when the vertical part of the vent duct and the take-off are both heated. The maximum deviation of the  results is 4.4%. The obtained velocity profiles in the calculated  sections indicate the impact of the ventilation take-off on the nature  of the air flow motion.Conclusion. One of the drawbacks of the existing systems of natural ventilation of residential

  20. Use of VOC sensors for air quality control of building ventilation systems

    OpenAIRE

    Großklos, M.

    2015-01-01

    Air quality control with VOC (volatile organic compound) sensors in residential buildings could increase user comfort by adapting to the actual contaminant level. Preliminary tests assessed the dynamics of VOC levels in single-family passive houses with a ventilation system. At normal and exceptional usages, sufficient signal variations were measured for air quality control. An air quality control was developed and tested in four single-family passive house dwellings to cont...

  1. Plan of action for quality improvement of ventilation systems; Actieplan Kwaliteitsverbetering Ventilatievoorzieningen

    Energy Technology Data Exchange (ETDEWEB)

    Atsma, J. [Ministerie van Infrastructuur en Milieu IenM, Den Haag (Netherlands); Calon, M. [Aedes vereniging van woningcorporaties, Den Haag (Netherlands); Schoorl, F.J. [Bond Nederlandse Architecten BNA, Amsterdam (Netherlands); Van Tuinen, J.L. [Bouwend Nederland, Zoetermeer (Netherlands); Bodewes, W.J. [Vereniging van Nederlandse projectontwikkeling Maatschappijen Neprom, Voorburg (Netherlands); Goossens, J.H. [Vereniging voor ontwikkelaars en bouwondernemers NVB, Voorburg (Netherlands); Polman, E.J.M. [Stichting Waarborgfonds Koopwoningen SWK, Rotterdam (Netherlands); Engels, M. [Uneto-VNI, Zoetermeer (Netherlands); Werner-van Beek, H. J. [VACpunt Wonen, Utrecht (Netherlands); Mulder, R.J. [Vereniging Eigen Huis VEH, Amersfoort (Netherlands); Rook, G. [Vereniging Leveranciers van Luchttechnische Apparaten VLA, Zoetermeer (Netherlands); Van Noord, P. [Woningborg, Gouda (Netherlands); Paping, R.H.M. [De Nederlandse Woonbond, Amsterdam (Netherlands)

    2012-06-15

    The action plan comprises the agreements made by the Ministry of Infrastructure and Environment and the Ministry of Internal Affairs in the Netherlands with representatives of building organizations to improve the quality of ventilation systems in newly built houses [Dutch] Het actieplan bevat de afspraken die het ministerie van Infrastructuur en Milieu en het ministerie van Binnenlandse Zaken met de bouwpartijen hebben gemaakt om de kwaliteit van de ventilatievoorzieningen van nieuwbouwwoningen te verbeteren.

  2. The effect of a personalized ventilation system on perceived air quality and SBS symptoms

    DEFF Research Database (Denmark)

    Kaczmarczyk, Jan; Zeng, Q.; Melikov, Arsen Krikor

    2002-01-01

    Perceived air quality, SBS symptoms and performance were studied with 30 human subjects. Experiments were performed in an office set-up with six workplaces, each equipped with a Personalized Ventilation System (PVS). Each PVS allowed the amount of supply air and its direction to be controlled...... condition in regard to perceived air quality, perception of freshness and intensity of SBS symptoms was when PVS supplied outdoor air at 20 deg.C. Perceived air quality in this case was significantly better (p...

  3. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    International Nuclear Information System (INIS)

    Sonnenthale, E.

    2001-01-01

    The purpose of this Analysis/Model Report (AMR) is to document the Near-Field Environment (NFE) and Unsaturated Zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrologic-chemical (THC) processes on unsaturated zone flow and transport. This is in accordance with the ''Technical Work Plan (TWP) for Unsaturated Zone Flow and Transport Process Model Report'', Addendum D, Attachment D-4 (Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) 2000 [1534471]) and ''Technical Work Plan for Nearfield Environment Thermal Analyses and Testing'' (CRWMS M and O 2000 [153309]). These models include the Drift Scale Test (DST) THC Model and several THC seepage models. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal loading conditions, and predict the chemistry of waters and gases entering potential waste-emplacement drifts. The intended use of this AMR is to provide input for the following: Performance Assessment (PA); Near-Field Environment (NFE) PMR; Abstraction of Drift-Scale Coupled Processes AMR (ANL-NBS-HS-000029); and UZ Flow and Transport Process Model Report (PMR). The work scope for this activity is presented in the TWPs cited above, and summarized as follows: Continue development of the repository drift-scale THC seepage model used in support of the TSPA in-drift geochemical model; incorporate heterogeneous fracture property realizations; study sensitivity of results to changes in input data and mineral assemblage; validate the DST model by comparison with field data; perform simulations to predict mineral dissolution and precipitation and their effects on fracture properties and chemistry of water (but not flow rates) that may seep into drifts; submit modeling results to the TDMS and document the models. The model development, input data, sensitivity and validation studies described in this AMR are

  4. Embedded Controller Design for Pig Stable Ventilation Systems

    DEFF Research Database (Denmark)

    Jessen, Jan Jacob

    present an early result for performing system identification for zone based climate dynamics, based on an idea of guaranteed internal flow directions. Paper 6 presents a verified stable distributed temperature controller for pig stables divided into zones. Paper 7 is an expanded journal version of paper 6......This thesis focuses on zone based climate control in pig stables and how to implement climate controllers in a new range of products. The presented controllers are based on simple models of climate dynamics and simple models of actuators. The implementation uses graphical point and click features...... from the Mathworks' range of products and automatic code generation. It is furthermore shown how to build new climate control systems based on cheap and readily available hardware and software. An early result for performing system identification for zone based climate dynamics is also presented...

  5. A knowledge- and model-based system for automated weaning from mechanical ventilation: technical description and first clinical application.

    Science.gov (United States)

    Schädler, Dirk; Mersmann, Stefan; Frerichs, Inéz; Elke, Gunnar; Semmel-Griebeler, Thomas; Noll, Oliver; Pulletz, Sven; Zick, Günther; David, Matthias; Heinrichs, Wolfgang; Scholz, Jens; Weiler, Norbert

    2014-10-01

    To describe the principles and the first clinical application of a novel prototype automated weaning system called Evita Weaning System (EWS). EWS allows an automated control of all ventilator settings in pressure controlled and pressure support mode with the aim of decreasing the respiratory load of mechanical ventilation. Respiratory load takes inspired fraction of oxygen, positive end-expiratory pressure, pressure amplitude and spontaneous breathing activity into account. Spontaneous breathing activity is assessed by the number of controlled breaths needed to maintain a predefined respiratory rate. EWS was implemented as a knowledge- and model-based system that autonomously and remotely controlled a mechanical ventilator (Evita 4, Dräger Medical, Lübeck, Germany). In a selected case study (n = 19 patients), ventilator settings chosen by the responsible physician were compared with the settings 10 min after the start of EWS and at the end of the study session. Neither unsafe ventilator settings nor failure of the system occurred. All patients were successfully transferred from controlled ventilation to assisted spontaneous breathing in a mean time of 37 ± 17 min (± SD). Early settings applied by the EWS did not significantly differ from the initial settings, except for the fraction of oxygen in inspired gas. During the later course, EWS significantly modified most of the ventilator settings and reduced the imposed respiratory load. A novel prototype automated weaning system was successfully developed. The first clinical application of EWS revealed that its operation was stable, safe ventilator settings were defined and the respiratory load of mechanical ventilation was decreased.

  6. How respiratory system mechanics may help in minimising ventilator-induced lung injury in ARDS patients.

    Science.gov (United States)

    Terragni, P P; Rosboch, G L; Lisi, A; Viale, A G; Ranieri, V M

    2003-08-01

    The main supportive therapy in acute respiratory distress syndrome patients is mechanical ventilation. As with any therapy, mechanical ventilation has side-effects, and may induce lung injury (ventilator-induced lung injury (VILI)/ventilator-associated lung injury). The mechanical factors responsible for VILI are thought to be related to tidal recruitment/derecruitment of previously collapsed alveoli and/or pulmonary overdistension. The volume/pressure (V/P) curve of the respiratory system in patients as well as in animal models of acute lung injury (ALI) has a characteristic sigmoid shape, with a lower inflection point (LIP) corresponding to the pressure/end-expiratory volume required to initiate recruitment of collapsed alveoli, and an upper inflection point (UIP) corresponding to the pressure/end inspiratory volume at which alveolar overdistension occurs. "Protective" ventilatory approaches have therefore set out to minimise mechanical injury by using the V/P curve to individualise positive end-expiratory pressure (PEEP) (PEEP above the LIP) and tidal volume (by setting end-inspiratory V/P below the UIP) since a large number of experimental studies correlate P/V curves to histological and biological manifestations of VILI and two randomised trials showed that protective ventilatory strategy individually tailored to the P/V curve minimised pulmonary and systemic inflammation and decreased mortality in patients with ALI. However, despite the fact that several studies have: 1) proposed new techniques to perform pressure/volume curves at the bedside, 2) confirmed that the lower inflection point and upper inflection point correspond to computed tomography scan evidence of atelectasis and overdistension, and 3) demonstrated the ability of the pressure/volume curve to estimate alveolar recruitment with positive end-expiratory pressure, no large studies have assessed whether such measurement can be performed in all intensive care units as a monitoring tool to orient

  7. Intelligent solar-powered automobile-ventilation system

    International Nuclear Information System (INIS)

    Huang, K. David; Tzeng, S.-C.; Ma Weiping; Wu Mingfung

    2005-01-01

    This study adopts airflow management technology to improve the local temperature distributions in an automobile to counteract the greenhouse effect. The automobile's temperature can be reduced to almost the outside temperature before the driver or passenger gets into the vehicle. When the engine is idling, the greenhouse-control system can be activated to remove the hot air from the car. An appropriate negative pressure is maintained to prevent stuffiness and save energy. The greenhouse-control system requires electrical power when the engine is idle, and a battery cannot supply sufficient power. An auxiliary solar-power supply can save energy and reduce the greenhouse effect of sunlight, while creating a comfortable traveling environment. It ensures that the engine is not overburdened and increases its service life, conserving energy, protecting the environment and improving comfort

  8. Correlation between germ and particle measurements for the qualification of ventilation systems in the OR

    Directory of Open Access Journals (Sweden)

    Bulitta Clemens

    2017-09-01

    Full Text Available Healthcare associated infections in surgical procedures have long been the focus of scientific research. In Germany, more than 225,000 patients suffer from such infections each year [1]. However, the reduction of the microbiological contamination is not only limited by cleaning and disinfecting measures. The choice of the ventilation system in the operating room or the type of the clothing of the personnel during the operation is also an important factor contributing to patient safety and infection control. Currently there are different approaches for assessing the hygienic situation in an operating room. In Germany, the air quality and cleanliness is evaluated by the DIN 1946-4: 2008-12 [2] and is based on the measurement of particles in the operating theatre. Other countries i.eSweden. focus on the biological contamination and use microbiological methods for the assessment and surveillance of the operating room ventilation (SIS-TS 39: 2015 [3].

  9. Numerical analysis of natural ventilation system in a studio apartment in Bangladesh

    Science.gov (United States)

    Kabir, K. M. Ariful; Hasan, Md. Rakibul; Khan, Md. Abdul Hakim

    2017-07-01

    The study of temperature and air flow for natural ventilation system has been investigated numerically. A finite element model for studio apartment was developed with the aim of achieving detail energy allocation in the real buildings during the transient process in the walls and internal air. A tool of computational fluid dynamics (CFD) is employed to assist the process. In the tropical regions most of the energy is consumed by the heating, cooling and ventilation appliances. Therefore, the optimize ventilation system will be a suitable and valid option for the saving of energy from the household sector to increase cooling performance and ensuring thermal comfort as well. A mathematical exploration is carried out on full scale dwelling and small scale model and indication is given on the relevance of such a comparison. Calculations are carried out with household heat sources for calm and windy period, but without any human. As expected, for windy periods, the wind is the main driving force behind the internal air flow. However, in calm periods for unsteady flow the internal airflow looks like more complexes through observation.

  10. Development of a research-oriented system for collecting mechanical ventilator waveform data.

    Science.gov (United States)

    Rehm, Gregory B; Kuhn, Brooks T; Delplanque, Jean-Pierre; Guo, Edward C; Lieng, Monica K; Nguyen, Jimmy; Anderson, Nicholas R; Adams, Jason Y

    2017-10-28

    Lack of access to high-frequency, high-volume patient-derived data, such as mechanical ventilator waveform data, has limited the secondary use of these data for research, quality improvement, and decision support. Existing methods for collecting these data are obtrusive, require high levels of technical expertise, and are often cost-prohibitive, limiting their use and scalability for research applications. We describe here the development of an unobtrusive, open-source, scalable, and user-friendly architecture for collecting, transmitting, and storing mechanical ventilator waveform data that is generalizable to other patient care devices. The system implements a software framework that automates and enforces end-to-end data collection and transmission. A web-based data management application facilitates nontechnical end users' abilities to manage data acquisition devices, mitigates data loss and misattribution, and automates data storage. Using this integrated system, we have been able to collect ventilator waveform data from >450 patients as part of an ongoing clinical study. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. High-efficiency ventilation and heating systems by means of solar air collectors for industry building refurbishment

    OpenAIRE

    Benoit Sicre; Patrick Baumann

    2015-01-01

    For the purpose of energy conservation, modern buildings are becoming more and more air-tight and generally rely on a mechanical ventilation system. According to the literature, solar air heating systems can contribute in a cost-effective way to the heating and ventilation of utility buildings. Especially cost-efficient, unglazed, façade-integrated solar air collectors seem to be an attractive new market for façade renovation. To demonstrate the technical feasibility of generating heating ene...

  12. Design Principles for Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system- Hybrid Ventilation....... The hybrid ventilation concepts, design challenges and principles are discussed and illustrated by four building examples....

  13. Numerical analysis of diffuse ceiling ventilation and its integration with a radiant ceiling system

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per Kvols; Chen, Qingyan

    2017-01-01

    A novel system combining diffuse ceiling ventilation and radiant ceiling was proposed recently, with the aim of providing energy efficient and comfort environment to office buildings. Designing of such a system is challenging because of complex interactions between the two subsystems and a large...... number of design parameters encountered in practice. This study aimed to develop a numerical model that can reliably predict the airflow and thermal performance of the integrated system during the design stage. The model was validated by experiments under different operating conditions. The validated...

  14. [A design of simple ventilator control system based on LabVIEW].

    Science.gov (United States)

    Pei, Baoqing; Xu, Shengwei; Li, Hui; Li, Deyu; Pei, Yidong; He, Haixing

    2011-01-01

    This paper designed a ventilator control system to control proportional valves and motors. It used LabVIEW to control the object mentioned above and design ,validate, evaluate arithmetic, and establish hardware in loop platform. There are two system' s hierarchies. The high layer was used to run non-real time program and the low layer was used to run real time program. The two layers communicated through TCP/IP net. The program can be divided into several modules, which can be expanded and maintained easily. And the harvest in the prototype designing can be seamlessly used to embedded products. From all above, this system was useful in employing OEM products.

  15. J-shape ventilation system for controlling high gas emission at fully mechanized sub-level caving face

    Energy Technology Data Exchange (ETDEWEB)

    Wang, K.; Yu, Q.; Miao, X. (and others) [CUMT, Xuzhou (China). School of Mineral and Safety Engineering

    2004-07-01

    Considering the practical condition of No. 5201 fully mechanized sub-level caving face in Wangzhuang Coal Mine of Lu'an Mining Group, and based on the successfully retaining of small section entry along gob side, a method of J-shape ventilation system and its regulating technology were put forward for controlling high gas emission at fully mechanized sub-level caving face. Essentially, the J-shape ventilation system has one intake and two returns for controlling high gas emission according to different gas sources using ventilation measure. Through practical application it is proved that local gas accumulation at coal face and its upper corner can be eliminated by adopting J-shape ventilation system, thus high-production and high-efficiency of fully mechanized sub-level caving face can be also realized. 6 refs., 6 figs., 1 tab.

  16. Evaluation of comfort level in desks equipped with two personalized ventilation systems in slightly warm environments

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, Eusebio Z.E. [Faculdade de Ciencias e Tecnologia - Universidade do Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Lucio, Manuela J.R. [Agrupamento Vertical Professor Paula Nogueira, R. Comunidade Lusiada, 8700-000 Olhao (Portugal); Rosa, Silvia P.; Custodio, Ana L.V.; Andrade, Renata L.; Meira, Maria J.P.A. [Faculdade de Ciencias do Mar e do Ambiente - Universidade do Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)

    2010-03-15

    In this work the comfort level, namely the thermal comfort, local thermal discomfort and air quality levels, in a classroom with desks equipped with two personalized ventilation systems, in slightly warm environments, is evaluated. A manikin, a ventilated classroom desk, two indoor climate analyzers, a multi-nodal human thermal comfort numerical model and a computational fluid dynamic numerical model, are used. The classroom desk, with double occupation capacity, is used by a student, located in the right side seat. Each personalized ventilation system is equipped with one air terminal device located above the desk writing area, in front to the trunk area, and an other located below the desk writing area, in front to the legs area. The thermal comfort level is evaluated by the developed multi-nodal human thermal comfort numerical model, using a PMV value, the local thermal discomfort level, namely the draught risk and the air velocity fluctuation equivalent frequencies, is evaluated by empirical models, while the air quality level and the detailed airflow around the manikin are evaluated by the computational fluid dynamic numerical model. In the experimental tests the mean air velocity and the turbulence intensity in the upper air terminal device are 3.5 m/s and 9.7%, while in the lower air terminal device are 2.6 m/s and 15.2%. The mean air temperature in the air terminal devices is around 28 C, while the mean radiant temperature in the occupation area, the mean air temperature far from the occupation area and the internal mean air relative humidity were, respectively, 28 C, 28 C and 50%. The air velocity and temperature around the occupant are measured around 15 human body sections. The actual personalized ventilation system, which promotes an ascendant airflow around the occupant with highest air renovation rate in the respiration area, promotes acceptable thermal comfort conditions and air quality in the respiration area in accord to the present standards. The

  17. Physicochemical Characterization of Nanoparticles from Indoor Ventilation Systems and Their Potential Health Impacts

    Science.gov (United States)

    Dalton, G.; Revkin, A. C.; Gruenspecht, H.; Ramanathan, V.; Brown, M. A.; Nagel, D. C.; Revkin, A. C.; Umo, N. S.; Oseghe, E. O.

    2016-12-01

    Indoor air pollution remains a major concern to humans considering that we spend about 90% of our daily lives indoors [1,2]. Air pollutants, which ranges from gases to aerosol particles, vary considerably from our homes, public/work places and confined environments such as cars. They can impact on our health depending on the nature and concentration of the pollutants as well as the duration of exposure [3,4]. Particulate matter (PM), which is one of the major air pollutant markers, is present indoors and can be circulated for days to months within a confined space by the ventilation systems. In this study, both physical and chemical compositional evaluation of PM2.5 - 10 was carried out and the recirculation model of these particulates is presented based on the study of some ventilation systems such as air conditioners, cooling vents, and fans. For the first time, it is shown that the compositional variability of PM does not just depend on the source or the ongoing activities in the confined space but also on the recirculation time. Mineral dust particles were found to be dominant, some mixed with organics and soot or BC particles; heavy metals such as lead (Pb), cadmium (Cd), nickel (Ni), iron (Fe) and others were also analysed from the collected PM. Ventilation systems trap these particulates and do recirculate them over time and this can increase their toxicities and influences their composition. From this study, it can be suggested that regular cleaning of ventilation systems and flushing closed spaces with fresh air may become the most effective ways of controlling the concentration of PM in closed spaces with ventilation units such as indoors and cars. [1] H. K. Lai, et al., Atmospheric Environment 38 (37)(2004). [2] N.E. Klepeis, et al., J. of Exposure Analysis and Environmental Epidemiology 11(2001). [3] N. Bruce, et al., Bul. of the World Health Organization, 78 (9)(2000). [4] K.A. Miller, et al, The New England Journal of Medicine 356 (2007).

  18. Inspiratory capacity at inflation hold in ventilated newborns: a surrogate measure for static compliance of the respiratory system.

    Science.gov (United States)

    Hentschel, Roland; Semar, Nicole; Guttmann, Josef

    2012-09-01

    To study appropriateness of respiratory system compliance calculation using an inflation hold and compare it with ventilator readouts of pressure and tidal volume as well as with measurement of compliance of the respiratory system with the single-breath-single-occlusion technique gained with a standard lung function measurement. Prospective clinical trial. Level III neonatal unit of a university hospital. Sixty-seven newborns, born prematurely or at term, ventilated for a variety of pathologic conditions. A standardized sigh maneuver with a predefined peak inspiratory pressure of 30 cm H2O, termed inspiratory capacity at inflation hold, was applied. Using tidal volume, exhaled from inspiratory pause down to ambient pressure, as displayed by the ventilator, and predefined peak inspiratory pressure, compliance at inspiratory capacity at inflation hold conditions could be calculated as well as ratio of tidal volume and ventilator pressure using tidal volume and differential pressure at baseline ventilator settings: peak inspiratory pressure minus positive end-expiratory pressure. For the whole cohort, the equation for the regression between tidal volume at inspiratory capacity at inflation hold and compliance of the respiratory system was: compliance of the respiratory system = 0.052 * tidal volume at inspiratory capacity at inflation hold - 0.113, and compliance at inspiratory capacity at inflation hold conditions was closely related to the standard lung function measurement method of compliance of the respiratory system (R = 0.958). In contrast, ratio of tidal volume and ventilator pressure per kilogram calculated from the ventilator readouts and displayed against compliance of the respiratory system per kilogram yielded a broad scatter throughout the whole range of compliance; both were only weakly correlated (R = 0.309) and also the regression line was significantly different from the line of identity (p respiratory system. After a standard sigh maneuver

  19. A static pressure reset control system with a new type of flow damper for use in low pressure ventilation systems

    DEFF Research Database (Denmark)

    Terkildsen, Søren; Svendsen, Svend

    2012-01-01

    The control strategy for mechanical ventilation systems has significant impact on the performance of the system, in terms of energy consumption and correct air distribution. This paper presents a static pressure reset control system employing a new type of flow damper with lower pressure loss...... for use in low pressure ventilation systems. The flow damper has a droplet shape that minimizes turbulence generation and the resulting pressure loss. The performance of the damper was examined by making measurements of pressure loss and airflow. These were used to determine the required pressure loss...... for operation and the airflow accuracy. Results were compared to similar tests carried out with conventional flat plate dampers. A static pressure reset control algorithm was programmed and analyzed on a test system consisting of three dampers, representing three office rooms. The comparison of the dampers...

  20. Parametric study on the advantages of weather-predicted control algorithm of free cooling ventilation system

    International Nuclear Information System (INIS)

    Medved, Sašo; Babnik, Miha; Vidrih, Boris; Arkar, Ciril

    2014-01-01

    Predicted climate changes and the increased intensity of urban heat islands, as well as population aging, will increase the energy demand for the cooling of buildings in the future. However, the energy demand for cooling can be efficiently reduced by low-exergy free-cooling systems, which use natural processes, like evaporative cooling or the environmental cold of ambient air during night-time ventilation for the cooling of buildings. Unlike mechanical cooling systems, the energy for the operation of free-cooling system is needed only for the transport of the cold from the environment into the building. Because the natural cold potential is time dependent, the efficiency of free-cooling systems could be improved by introducing a weather forecast into the algorithm for the controlling. In the article, a numerical algorithm for the optimization of the operation of free-cooling systems with night-time ventilation is presented and validated on a test cell with different thermal storage capacities and during different ambient conditions. As a case study, the advantage of weather-predicted controlling is presented for a summer week for typical office room. The results show the necessity of the weather-predicted controlling of free-cooling ventilation systems for achieving the highest overall energy efficiency of such systems in comparison to mechanical cooling, better indoor comfort conditions and a decrease in the primary energy needed for cooling of the buildings. - Highlights: • Energy demand for cooling will increase due to climate changes and urban heat island • Free cooling could significantly reduce energy demand for cooling of the buildings. • Free cooling is more effective if weather prediction is included in operation control. • Weather predicted free cooling operation algorithm was validated on test cell. • Advantages of free-cooling on mechanical cooling is shown with different indicators

  1. Numerical Study on Different Series Modes of Jet Fan in a Longitudinal Tunnel Ventilation System

    Directory of Open Access Journals (Sweden)

    Guihong Pei

    2014-01-01

    Full Text Available Efficient ventilation systems will contribute to maintaining air quality in the tunnel. In order to improve ventilation performance in normal traffic condition, the 3D tunnel models were established according to the original design for the tunnel located in central plains of China. Based on the commercial CFD software Fluent 6.3 and k-ε turbulence model, numerical simulations were carried out to study the patterns of jet flow and the optimization of fan combinations. It is found that the axial velocity profile obtained from numerical simulation agrees quite well with turbulent free jet theory although there is a little difference on the magnitude. The comparison of four combination modes under the condition of operating four fans indicates that the ventilation effectiveness is affected mainly by both the interval of adjacent groups of fans and the combination modes of operational fans. According to the simulation results, a novel combination mode which consists of a group double paralleled fans and two groups single fan is designed. The novel combination mode is regarded as the optimum combination mode with respect to maximizing air velocity in the tunnel. Compared to the traditional combination modes, it will increase the air velocity by 5.7%.

  2. Contribution to the study of hybrid ventilation system effectiveness in office and educational buildings; Contribution a l'etude de l'efficacite des systemes de ventilation hybride dans les batiments du secteur tertiaire

    Energy Technology Data Exchange (ETDEWEB)

    Cron, F.

    2004-06-15

    This study is part of the International Energy Agency Annex 35, 'Hybrid Ventilation in New and Retro-fitted Office Buildings', also called the HybVent Project. It presents the numerical analyses of a number of hybrid ventilation systems and their potential for several buildings in relation to local climate characteristics. The first part of this work reviews the state-of-the-art of existing ventilation systems and details the principles, expectations and features of hybrid ventilation systems. This first section also examines some examples of hybrid systems extracted from the collection of Annex 35 case studies. A comprehensive bibliography of numerical tools available for this type of analysis is given in the second section. The numerical models for building simulation and the object-oriented environment used to develop our simulation tool are presented in this section as well. Two single-zone studies undertaken in this project are reported in the third section. The first study concerns an experimental cell simulation. Numerical results are compared to experimental data to validate the use of the simulation tool developed. The second single-zone study predicts the potential of a specific hybrid ventilation system in a typical classroom, given climatic conditions. Finally, the last section presents a more complete study - a multi-zone study of the Tonga school, an Annex 35 case study located in Sweden. Three rooms were modelled initially to compare numerical results to experimental data and then to analyse the performance of the existing hybrid ventilation system and two other systems. This final study was completed for three European cities with very different climates. The overall analysis of the potential of the hybrid ventilation systems considered and the perspective for future work are outlined in the conclusion. (author)

  3. Evaluation of a Mapleson D CPAP system for weaning of mechanical ventilation in pediatric patients.

    Science.gov (United States)

    Palomero-Rodríguez, Miguel Angel; de Arteaga, Héctor Chozas; Báez, Yolanda Laporta; de Vicente Sánchez, Jesús; Carretero, Pascual Sanabria; Conde, Pilar Sánchez; Pérez Ferrer, Antonio

    2016-01-01

    Over the last years, we have used a flow-inflating bag circuit with a nasotracheal or nasopharyngeal tube as an interface to deliver effective CPAP support in infants ("Mapleson D CPAP system"). The primary goal of this study was to assess the usefulness of the "Mapleson D CPAP system" for weaning of mechanical ventilation (MV) in infants who received MV over 24 h. All infants who received MV for more than 24 h in the last year were enrolled in the study. Demographic data included age, gender, weight, and admission diagnosis. Heart rate, respiratory rate, blood pressure, and oxygen saturation were measured during MV, 2 h after the nasotracheal Mapleson D CPAP system and 2 h after extubation. Patients were classified into two groups: patients MV more than 48 h, and patients with MV fewer than 48 h. P Mapleson D CPAP system and 2 h after extubation and spontaneous ventilation with the nasopharyngeal Mapleson D CPAP system or with nasal prongs. The overall extubation failure rate was 26% (n = 13). Weight and age were significantly associated with extubation failure (P Mapleson D CPAP system, in our opinion, is a useful and safe alternative to more complex and expensive noninvasive CPAP and BiPAP weaning from MV in infants.

  4. Evaluation of local exhaust ventilation system performance for control of Fe2O3 dust at an iron making unit

    Directory of Open Access Journals (Sweden)

    Mahdi Jamshidi Rastani

    2016-06-01

    Full Text Available Introduction: Adherence to the design values and ventilation standards (VS after installing and also maintaining continuous work of ventilation system with maximum performance throughout its life are amongst the reasons of ventilation systems monitoring. Therefore, the aim of this study was to evaluate performance of local exhaust ventilation system for control of dust by measuring the operating parameters and also to compare it with ventilation standards (VS and design values. Material and Method: The present research is a descriptive and cross-sectional study, conducted in three sections of measuring, monitoring and evaluating the operating parameters on hoods, channels and fan of ventilation system based on the current status of the system, documentation (design, and recommended standards (VS. Static pressure, velocity pressure, surface area, and flow rate were measured based on the recommendations of various sources and ACGIH industrial ventilation manual, and the data were compared with the design and recommended values, using the SPSS software version 16.   Result: The results of paired sample t-test between flow rate and velocities of design and current status, showed significant differences in various parts. Accordingly, the results revealed a reduction of more than 50% in the design duct velocity compared to the current duct velocity, while design duct velocity is 1.3 more than the standard duct velocity of current status, and current duct velocity is about 65% of standard duct velocity. Conclusion: The reduction and nonconformity of the results of measurements of operating parameters (after a minimum of two decades with design and standard values are corroborant and sufficient reason for obstructions, abrasions, leaks, imbalance of system ducts and their inefficiency in some branches. Since there is no base line measurements for system (supposing that the system worked with maximum amounts of setup time, one of the reasons for these

  5. Evaluation of the Ventilation and Air Cleaning System Design Concepts for Safety Requirements during Fire Conditions in Nuclear Applications

    International Nuclear Information System (INIS)

    Rashad, S.; El-Fawal, M.; Kandil, M.

    2013-01-01

    The ventilation and air cleaning system in the nuclear or radiological installations is one of the essential nuclear safety concerns. It is responsible for confining the radioactive materials involved behind suitable barriers during normal and abnormal conditions. It must be designed to prevent the release of harmful products (radioactive gases, or airborne radioactive materials) from the system or facility, impacting the public or workers, and doing environmental damage. There are two important safety functions common to all ventilation and air cleaning system in nuclear facilities. They are: a) the requirements to maintain the pressure of the ventilated volume below that of surrounding, relatively non-active areas, in order to inhibit the spread of contamination during normal and abnormal conditions, and b) the need to treat the ventilated gas so as to minimize the release of any radioactive or toxic materials. Keeping the two important safety functions is achieved by applying the fire protection for the ventilation system to achieve safety and adequate protection in nuclear applications facilities during fire and accidental criticality conditions.The main purpose of this research is to assist ventilation engineers and experts in nuclear installations for safe operation and maintaining ventilation and air cleaning system during fire accident in nuclear facilities. The research focuses on fire prevention and protection of the ventilation systems in nuclear facilities. High-Efficiency particulate air (HEPA) filters are extremely susceptible to damage when exposed to the effects of fire, smoke, and water; it is the intent of this research to provide the designer with the experience gained over the years from hard lessons learned in protecting HEPA filters from fire. It describes briefly and evaluates the design safety features, constituents and working conditions of ventilation and air cleaning system in nuclear and radioactive industry.This paper provides and

  6. Emergency automatic commutation of the ventilation system of the RP-10 nuclear reactor

    International Nuclear Information System (INIS)

    Castillo, Walter; Corimanya, Mario; Ovalle, Edgar; Anaya, Olgger; Veramendi, Emilio

    2013-01-01

    The present paper summarizes the achievements in the design and implementation of a system for monitoring and automatic control of radioactive effluents from the chimney of the RP-10 reactor, using as hardware an Arduino UNO platform containing an ATMEGA 328 programmable micro controller to which has been added LCD screen to display the values, a keyboard and an EEPROM memory data, where the limit of the level of radiation is fixed. The radiation level in the air of the reactor hall, going up the chimney is counted by a radiation monitor called MAB1000, and data are supplied to the new system. When the radiation level is above the national and international standards, the new design makes work a relay, so that the ventilation system is automatically switched to operate in emergency condition, preventing the release of radioactive contaminants into the environment. After installing the new design, it was verified that removed by the radiation monitor MAB1000, value is identical to that shown in the new system. Additionally, the operation of the relay was tested successfully with radioactive sources to switch the ventilation system to the emergency condition. (authors).

  7. Individually ventilated cages impose cold stress on laboratory mice: a source of systemic experimental variability.

    Science.gov (United States)

    David, John M; Knowles, Scott; Lamkin, Donald M; Stout, David B

    2013-11-01

    Individual ventilated cages (IVC) are increasing in popularity. Although mice avoid IVC in preference testing, they show no aversion when provided additional nesting material or the cage is not ventilated. Given the high ventilation rate in IVC, we developed 3 hypotheses: that mice housed in IVC experience more cold stress than do mice housed in static cages; that IVC-induced cold stress affects the results of experiments using mice; and that, when provided shelters, mice behaviorally thermoregulate and thereby rescue the cold-stress effects of IVC. To test these hypotheses, we housed mice in IVC, IVC with shelters, and static cages maintained at 20 to 21 °C. We quantified the cold stress of each housing system on mice by assessing nonshivering thermogenesis and brown adipose vacuolation. To test housing effects in a common, murine model of human disease, we implanted mice with subcutaneous epidermoid carcinoma cells and quantified tumor growth, tumor metabolism, and adrenal weight. Mice housed in IVC had histologic signs of cold stress and significantly higher nonshivering thermogenesis, smaller subcutaneous tumors, lower tumor metabolism, and larger adrenal weights than did mice in static cages. Shelters rescued IVC-induced nonshivering thermogenesis, adrenal enlargement, and phenotype-dependent cold-mediated histologic changes in brown adipose tissue and tumor size. IVC impose chronic cold stress on mice, alter experimental results, and are a source of systemic confounders throughout rodent-dependent research. Allowing mice to exhibit behavioral thermoregulation through seeking shelter markedly rescues the experiment-altering effects of housing-imposed cold stress, improves physiologic uniformity, and increases experimental reproducibility across housing systems.

  8. Heat pipes as perspective base elements of heat recovery in heat supply and ventilating systems

    Directory of Open Access Journals (Sweden)

    Matveev Andrey

    2017-01-01

    Full Text Available Thermotechnical characteristics of heat pipes are considered as high-efficient heat-transfer devices, which can provide energy-saving technologies for heat supply and ventilating systems and for different branches of industry. Thermotechnical and working (”performance capability” characteristics of heat pipes are investigated. By ”performance capability” of heat pipes and heat-transfer devices on heat pipes we mean the system state, where it can perform set functions and keep parameter values (thermal power, conductivity, thermal resistance, heat-transfer coefficient, temperature level and differential, etc. within the regulations of standardized specifications. The article presents theoretical and experimental methods of «gaslock» length determination on noncondensable gases during long-lasting tests of ammonia heat pipes made of aluminum shape АS – КRА 7.5 – R1 (alloy АD – 31. The paper gives results of research of thermotechnical characteristics of heat pipes in horizontal and vertical states (separate and as a set part while using different systems of thermal insulation. The obtained results of thermotechnical and resource tests show the advantages of ammonia heat pipes as basic elements for heat exchanger design in heating and ventilation systems.

  9. Applications and Energy Consumption of Demand Controlled Ventilation Systems. Modelling, Simulation and Implementation of Modular Built Dynamical VAV Systems and Control Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Bjoern R.

    2002-07-01

    This thesis discusses many topics of heating and ventilation. This is because the ventilation system is an integrated part of its host building. The functionality and effectiveness of the ventilation system are very much dependent on the building's architectural design, its internal materials, its occupants, its air tightness characteristics and its placement in the terrain. Although this thesis emphasizes strongly on VAV (Variable Air Volume) systems and, in particular, modelling and simulation of such systems, it touches a range of important HVAC related issues. The scope is however, limited to the field of comfort ventilation. That is because ventilation in industrial environments often is subject to separate regulations, and requires other and specialized methods of design and evaluation of ventilation performance. The main objectives have been to: (1) Develop mathematical models for VAV components and systems. (2) Evaluate existing and develop new strategies for VAV demand controlled ventilation by system simulation. (3) Investigate the potential for saving energy and the impact on indoor climate. The development of mathematical models and simulation of VAV systems are given quite much attention compared to the other topics discussed.

  10. Duct corrosion in the ventilating air conditioning system for Main Control Room

    International Nuclear Information System (INIS)

    Yamada, Kohei; Kobayashi, Takashi; Minami, Akiko; Fukuba, Kazushi

    2014-01-01

    Higashidori Nuclear Power Station, start-of-operation in December 2005, is a relatively new plant. We decided to get original data of air duct condition to determine maintenance policy of air duct, because planned maintenance of air duct has never been done and the corrosion of air duct has occurred in other plant. In January 2014, we found a corrosion-hole at the downstream of the inlet damper in the ventilating air conditioning system for Main Control Room (MCR). We supposed that the cause of rapid corrosion is related to the characteristic environment of this site. (author)

  11. An assessment of a partial pit ventilation system to reduce emission under slatted floor

    DEFF Research Database (Denmark)

    Wu, Wentao; Zhang, Guoqiang; Bjerg, Bjarne Schmidt

    2012-01-01

    of measured and calculated removal ratios were found for most of cases. It was feasible to use RSM to predict the removal capability. The future research should focus on depicting the airflow patterns inside the pit by using scale model under well controlled laboratory conditions and generating benchmark data...... to validate and improve CFD methods. Unsteady CFD simulation using large eddy simulation could be conducted to make more precise predictions of removal capability of the partial pit ventilation system by considering the unsteady phenomena of gas emission....

  12. Control and prevention of ice formation and accretion on heat exchangers for ventilation systems

    DEFF Research Database (Denmark)

    Rahimi, Maral; Afshari, Alireza

    2015-01-01

    In cold climates, the application of mechanical ventilation systems with heat recovery like are airto-air exchangers is used for reducing energy consumption for heating buildings by transferring heat exhausted air to supply air. However, increase efficiency of heat exchanger results in lower...... exhaust air temperatures and Ice formation on heat exchanger fins, which can cause problem and is not favourable. Therefore, prevention and control of ice formation on heat exchangers is necessary. The existing methods are divided into two different methods: active and passive ice control methods...

  13. Displacement ventilation

    DEFF Research Database (Denmark)

    Kosonen, Risto; Melikov, Arsen Krikor; Mundt, Elisabeth

    The aim of this Guidebook is to give the state-of-the art knowledge of the displacement ventilation technology, and to simplify and improve the practical design procedure. The Guidebook discusses methods of total volume ventilation by mixing ventilation and displacement ventilation and it gives...... insights of the performance of the displacement ventilation. It also shows practical case studies in some typical applications and the latest research findings to create good local micro-climatic conditions....

  14. Noninvasive ventilation for acute respiratory distress in children with central nervous system disorders.

    Science.gov (United States)

    Falsaperla, Raffaele; Elli, Marco; Pavone, Piero; Isotta, Gentile; Lubrano, Riccardo

    2013-09-01

    Acute respiratory distress (ARD) is a relatively frequent occurrence in patients suffering from central nervous system disorders (CNSD) and moderate to severe mental retardation. Whenever conventional therapy is little effective, noninvasive mechanical ventilation (NIV) is the additional treatment in patients with diseases of the peripheral nervous system. However, NIV is traditionally little employed in the acute phase in patients suffering from CNSD. In the latter, either conventional therapy is maintained or invasive mechanical ventilation is instituted if the patient's condition worsens severely. To challenge the traditional view, we conducted the study to prove that NIV is both applicable and effective in the treatment of ARD also in children with moderate to severe mental retardation. We studied 44 children with ARD secondary to pneumonia and CNSD causing moderate to severe mental retardation. The children were divided in two groups. One group received conventional therapy and NIV, the other conventional therapy only, before being advanced to invasive ventilator support when nonresponding. On admission to hospital and one hour following admission we registered pH, PaCO(2), PaO2, A - a DO2 and the PaO2/FiO2 ratio. The mean hospital stay was also recorded. After one hour on NIV PaO2 and pH increased, PaCO(2) decreased, A - a DO2 and PaO2/FiO2 ratio improved. No changes in the above parameters were observed in children on conventional therapy only. Hospital stay was shorter when NIV was instituted. NIV is both applicable and beneficial in stabilizing blood gases, respiratory and cardiovascular parameters also in children with CNSD. Moreover its use shortens the hospital stay. © 2013 Elsevier Ltd. All rights reserved.

  15. Flow requirements and rebreathing during mechanically controlled ventilation in a T-piece (Mapleson E) system.

    Science.gov (United States)

    Hatch, D J; Yates, A P; Lindahl, S G

    1987-12-01

    The influence of fresh gas flow (FGF) setting on rebreathing was investigated in 15 infants and children (weight 3.5-21.8 kg) during balanced anaesthesia with mechanically controlled ventilation using a T-piece (Mapleson E) system and a Nuffield ventilator 200. Tidal volume (VT), minute volume (VE), maximal inspired (PICO2) and end-tidal (PE'CO2) carbon dioxide tensions and airway pressure were measured. VE, set to produce a PE'CO2 of about 4.5 kPa and measured at a high FGF (minimal rebreathing), was unchanged throughout the study and the regression equation for VE and weight was: VE (ml min-1) = 146 x kg + 482, r = 0.92. Measurements were then repeated at FGF:VE ratios reduced to 1.5 and 1.0. To achieve minimal rebreathing (PICO2 less than 0.5 kPa), FGF:VE ratios greater than 1.8 (range 1.8-4.9) had to be used. At FGF:VE ratios of 1.5, some alveolar rebreathing occurred, indicated by increased inspired (P less than 0.001) and end-tidal (P less than 0.001) carbon dioxide tensions. At FGF:VE ratios equal to 1.0, alveolar rebreathing was more pronounced and hypercapnoea occurred with a PE'CO2 (mean +/- 1 SD) of 5.89 +/- 0.53 kPa. At this FGF setting, change in I:E ratio from 1:2 to 1:1 did not influence the level of alveolar rebreathing. A minimal FGF (ml min-1) setting of 1.5 x VE (that is, 1.5 (146 x kg + 482), approximated to the expression (200 x kg + 1000) is recommended for controlled ventilation to avoid hypercapnoea when using the T-piece system in children weighing less than 20 kg.

  16. Comparison of a Constant Air Volume (CAV) and a Demand Controlled Ventilation (DCV) System in a Residential Building

    DEFF Research Database (Denmark)

    Mortensen, Dorthe Kragsig; Nielsen, Toke Rammer; Topp, Claus

    2008-01-01

    The aim of this paper was to compare the indoor climate and the energy performance of a Constant Air Volume (CAV) system of 0.5h-1 with a Demand Controlled Ventilation (DCV) system controlled by occupancy and relative humidity for a studio apartment. Furthermore the impact of building materials...... it was found that the energy consumption for heating and operating the ventilation system could be reduced by respectively 8.0% and 10.6 % in the case of DCV without negative impact on the indoor climate. Including the hygroscopic properties of the materials resulted in a reduction of the energy consumption...... for heating and operating the ventilation system by respectively 9.5% and 17.1 % in favour of the DCV system....

  17. Ventilation systems analysis during tornado conditions. Progress report, January--June 1975

    International Nuclear Information System (INIS)

    Bennett, G.A.; Gregory, W.S.; Smith, P.R.

    1975-11-01

    The principal concern of this investigation is to develop the capability to simulate the dynamic effects of a tornado depressurization on a ventilation system. The basic formulation and solution of the two-zone series model ventilation subsystem is based on lumped parameter component response equations, the isothermal compression of air, and the conservation of mass. Solutions based on these assumptions are also presented for the two-zone series model with natural bypass, the two-zone series model with recirculation, and the natural branching model. A parameter study is presented comparing the effects of changes in system resistance, system capacitance, and variable tornado depressurization rates. The adaptability of the basic formulation to adiabatic compression of air and the addition of duct resistance is examined. A quasi-steady formulation is introduced and preliminary considerations of the importance of inertia are presented. Preliminary conclusions in this area indicate that inertial effects can be neglected. For relatively long ducts slow shock development appears possible. Work on the effect of tornado depressurization rates as related to shock development and on the importance of inertia effects is continuing

  18. Exploration Mission Particulate Matter Filtration Technology Performance Testing in a Simulated Spacecraft Cabin Ventilation System

    Science.gov (United States)

    Agui, Juan H.; Vijayakumar, R.; Perry, Jay L.; Frederick, Kenneth R.; Mccormick, Robert M.

    2017-01-01

    Human deep space exploration missions will require advances in long-life, low maintenance airborne particulate matter filtration technology. As one of the National Aeronautics and Space Administrations (NASA) developments in this area, a prototype of a new regenerable, multi-stage particulate matter filtration technology was tested in an International Space Station (ISS) module simulation facility. As previously reported, the key features of the filter system include inertial and media filtration with regeneration and in-place media replacement techniques. The testing facility can simulate aspects of the cabin environment aboard the ISS and contains flight-like cabin ventilation system components. The filtration technology test article was installed at the inlet of the central ventilation system duct and instrumented to provide performance data under nominal flow conditions. In-place regeneration operations were also evaluated. The real-time data included pressure drop across the filter stages, process air flow rate, ambient pressure, humidity and temperature. In addition, two video cameras positioned at the filtration technology test articles inlet and outlet were used to capture the mechanical performance of the filter media indexing operation under varying air flow rates. Recent test results are presented and future design recommendations are discussed.

  19. Ventilation of uranium mines

    International Nuclear Information System (INIS)

    Francois, Y.; Pradel, J.; Zettwoog, P.; Dumas, M.

    1975-01-01

    In the first part of the paper the authors describe the ventilation of French mines in terms of the primary ventilation system, which brings the outside air close to the working places using the overall structure of the mine to form the airways, and the secondary ventilation system, which is for the distribution of the primary air or for the ventilation of the development drifts and blind tunnels. Brief mention is made of the French regulations on the ventilation of mines in general and uranium mines in particular. The authors describe the equipment used and discuss the installed capacities and air flow per man and per working place. The difficulties encountered in properly ventilating various types of working places are mentioned, such as sublevel development drifts, reinforced stopes, and storage chambers with an artificial crown. The second part of the paper is devoted to computer calculations of the primary ventilation system. It is explained why the Commissariat a l'energie atomique has found it necessary to make these calculations. Without restating the mathematical theories underlying the methods employed, the authors demonstrate how simple measuring instruments and a small-size computer can be used to solve the ventilation problems arising in French mines. Emphasis is given to the layout of the ventilation system and to air flow and negative pressure measurements at the base of the mine. The authors show how calculations can be applied to new heading operations, a change in resistance, the replacement or addition of a ventilator, and a new air inlet or outlet. The authors come to the conclusion that since ventilation is at present the most reliable way of avoiding the pollution of mines, a thorough knowledge of the capabilities in this respect can often help improve working conditions. Despite the progress made, however, constant surveillance of the ventilation systems in uranium mines by a separate team with no responsibility for production problems is

  20. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    Energy Technology Data Exchange (ETDEWEB)

    E. Gonnenthal; N. Spyoher

    2001-02-05

    The purpose of this Analysis/Model Report (AMR) is to document the Near-Field Environment (NFE) and Unsaturated Zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrologic-chemical (THC) processes on unsaturated zone flow and transport. This is in accordance with the ''Technical Work Plan (TWP) for Unsaturated Zone Flow and Transport Process Model Report'', Addendum D, Attachment D-4 (Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) 2000 [153447]) and ''Technical Work Plan for Nearfield Environment Thermal Analyses and Testing'' (CRWMS M and O 2000 [153309]). These models include the Drift Scale Test (DST) THC Model and several THC seepage models. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal loading conditions, and predict the chemistry of waters and gases entering potential waste-emplacement drifts. The intended use of this AMR is to provide input for the following: (1) Performance Assessment (PA); (2) Abstraction of Drift-Scale Coupled Processes AMR (ANL-NBS-HS-000029); (3) UZ Flow and Transport Process Model Report (PMR); and (4) Near-Field Environment (NFE) PMR. The work scope for this activity is presented in the TWPs cited above, and summarized as follows: continue development of the repository drift-scale THC seepage model used in support of the TSPA in-drift geochemical model; incorporate heterogeneous fracture property realizations; study sensitivity of results to changes in input data and mineral assemblage; validate the DST model by comparison with field data; perform simulations to predict mineral dissolution and precipitation and their effects on fracture properties and chemistry of water (but not flow rates) that may seep into drifts; submit modeling results to the TDMS and document the models. The model development, input data

  1. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping improves systemic and cerebral oxygenation in preterm lambs.

    Directory of Open Access Journals (Sweden)

    Graeme R Polglase

    Full Text Available As measurement of arterial oxygen saturation (SpO2 is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known.We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs.Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2 were measured continuously in apnoeic preterm lambs (126±1 day gestation. Positive pressure ventilation was initiated either 1 prior to umbilical cord clamping, or 2 after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping.Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping.The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  2. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping) improves systemic and cerebral oxygenation in preterm lambs.

    Science.gov (United States)

    Polglase, Graeme R; Dawson, Jennifer A; Kluckow, Martin; Gill, Andrew W; Davis, Peter G; Te Pas, Arjan B; Crossley, Kelly J; McDougall, Annie; Wallace, Euan M; Hooper, Stuart B

    2015-01-01

    As measurement of arterial oxygen saturation (SpO2) is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known. We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs. Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2) were measured continuously in apnoeic preterm lambs (126±1 day gestation). Positive pressure ventilation was initiated either 1) prior to umbilical cord clamping, or 2) after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping. Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping. The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  3. CSF 5-HIAA and DST non-suppression--orthogonal biologic risk factors for suicide in male mood disorder inpatients.

    Science.gov (United States)

    Jokinen, Jussi; Nordström, Anna-Lena; Nordström, Peter

    2009-01-30

    Two biomarkers of suicide risk; non-suppression in the dexamethasone suppression test (DST) and low 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid (CSF) have been reported to be predictors of suicide in mood disorders. The interrelation of the two systems seems to be different in suicide attempters compared with depressed inpatients who have not made a suicide attempt, indicating that the two biomarkers may be seen as independent. This investigation examined the interrelation of low CSF 5-HIAA and DST non-suppression in suicide victims with mood disorder. Fifty-eight mood disorder inpatients not receiving any treatment with antidepressants underwent lumbar puncture and the DST. Plasma cortisol levels at 8:00 a.m., 4:00 p.m. and 11:00 p.m. were analysed in relation to CSF 5-HIAA. All patients were followed up for causes of death and suicides were verified with death certificates. During follow-up (mean 21 years), 11 (19%) patients had committed suicide. In male suicide victims (n=6), the serum cortisol level at 4:00 p.m. showed a significant positive correlation with CSF 5-HIAA. Low CSF 5-HIAA predicted all early suicides (within 1 year), whereas all males who committed suicide after 1 year were DST non-suppressors. In female suicide victims (n=5), the post-DST serum cortisol did not correlate with CSF 5-HIAA. Low CSF 5-HIAA and DST non-suppression are orthogonal biologic risk factors for suicide in male mood disorder inpatients. CSF 5-HIAA is associated with short-term suicide risk; dysregulation of the hypothalamic-pituitary-adrenal axis seems to be a long-term suicide predictor.

  4. Multifamily Ventilation Retrofit Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, K.; Lstiburek, J.; Bergey, D.

    2012-12-01

    In multifamily buildings, central ventilation systems often have poor performance, overventilating some portions of the building (causing excess energy use), while simultaneously underventilating other portions (causing diminished indoor air quality). BSC and Innova Services Corporation performed a series of field tests at a mid-rise test building undergoing a major energy audit and retrofit, which included ventilation system upgrades.

  5. Nuclear power plant control room ventilation system design for meeting general criterion 19

    International Nuclear Information System (INIS)

    Murphy, K.G.; Campe, K.M.

    1975-01-01

    The requirement for protection of control room personnel against radiation is specified in General Design Criterion 19 of Appendix A, 10 CFR Part 50. The evaluation of a control room design, especially its emergency ventilation system, with respect to radiation protection primarily consists of determining the radiation doses to control room personnel under accident conditions. The accident dose assessment involves modeling and evaluation of radiological source terms, atmospheric transport of airborne activity, and protection features of the control room ventilation system. Some of the assumptions and conservatisms used in the dose analyses are based on the technical review experience of existing or proposed control room designs. A review of over 50 control room designs has revealed a great variety of design concepts, not all of which seem to have been based on radiation protection criteria. A summary of the basic control room protection requirements, design features, dose acceptance criteria, and an outline of the methods used by the Regulatory staff for accident dose evaluation are presented. (U.S.)

  6. Effect of central ventilation and air conditioner system on the concentration and health risk from airborne polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Lv, Jinze; Zhu, Lizhong

    2013-03-01

    Central ventilation and air conditioner systems are widely utilized nowadays in public places for air exchange and temperature control, which significantly influences the transfer of pollutants between indoors and outdoors. To study the effect of central ventilation and air conditioner systems on the concentration and health risk from airborne pollutants, a spatial and temporal survey was carried out using polycyclic aromatic hydrocarbons (PAHs) as agent pollutants. During the period when the central ventilation system operated without air conditioning (AC-off period), concentrations of 2-4 ring PAHs in the model supermarket were dominated by outdoor levels, due to the good linearity between indoor air and outdoor air (r(p) > 0.769, p ventilating like the model supermarket increased the potential health risks from low molecular weight PAHs. During the period when the central ventilation and air conditioner systems were working simultaneously (AC-on period), although the total levels of PAHs were increased, the concentrations and percentage of the particulate PAHs indoors declined significantly. The BaP equivalency (BaPeq) concentration indicated that utilization of air conditioning reduced the health risks from PAHs in the model supermarket.

  7. Evaluation of optimal dual axis concentrated photovoltaic thermal system with active ventilation using Frog Leap algorithm

    International Nuclear Information System (INIS)

    Gholami, H.; Sarwat, A.I.; Hosseinian, H.; Khalilnejad, A.

    2015-01-01

    Highlights: • Electro-thermal performance of open-loop controlled dual axis CPVT is investigated. • For using the absorbed heat, active ventilation with a heat storage tank is used. • Economic optimization of the system is performed, using Frog Leap algorithm. • Detailed model of all sections is simulated with their characteristics evaluation. • Triple-junction photovoltaic cells, which are the most recent technology, are used. - Abstract: In this study, design and optimization of a concentrated photovoltaic thermal (CPVT) system considering electrical, mechanical, and economical aspects is investigated. For this purpose, each section of the system is simulated in MATLAB, in detail. Triple-junction photovoltaic cells, which are the most recent technology, are used in this study. They are more efficient in comparison to conventional photovoltaic cells. Unlike ordinary procedures, in this work active ventilation is used for absorbing the thermal power of radiation, using heat storage tanks, which not only results in increasing the electrical efficiency of the system through decreasing the temperature, but also leads to storing and managing produced thermal energy and increasing the total efficiency of the system up to 85 percent. The operation of the CPVT system is investigated for total hours of the year, considering the needed thermal load, meteorological conditions, and hourly radiation of Khuznin, a city in Qazvin province, Iran. Finally, the collector used for this system is optimized economically, using frog leap algorithm, which resulted in the cost of 13.4 $/m 2 for a collector with the optimal distance between tubes of 6.34 cm.

  8. The LoTrach system: its role in the prevention of ventilator-associated pneumonia.

    Science.gov (United States)

    Fletcher, Andrew J W; Ruffell, Alison J; Young, Peter J

    2008-01-01

    To discuss the development of the LoTrach system in light of current evidence around the prevention of ventilator-associated pneumonia (VAP) and its practical application in the intensive care setting. VAP causes substantial morbidity and mortality in ventilated patients in the Intensive Care Unit (ICU), increases length of stay in ICU and is extremely costly. Strategies are needed to reduce the risk of VAP. We examine the need for an endotracheal tube (ETT) specifically designed for the critically-ill patient, the development of the LoTrach system from conception to production, and the role of the various components of the system in preventing VAP. Early issues in implementing this revolutionary equipment into ICU are explored and three case studies highlight advantages of this system. The LoTrach system has been designed to facilitate the provision of a number of evidence-based interventions that have been shown to reduce VAP. Pulmonary aspiration is ubiquitous with conventional cuffs but prevented by the cuff of the LoTrach system when held at a constant and safe pressure against the tracheal wall with a cuff pressure controller. Other aspects incorporated in the ETT are aimed at clearing the secretions from the subglottic space, preventing tube occlusion and accidental extubation, and avoiding damage to the airway. In this way the LoTrach system employs a multifactorial approach to the prevention of VAP and the cost savings from LoTrach rather than a standard ETT will be considerable because of an average 3 day reduction in ICU length of stay related to this. It thus has the potential to be a very useful tool in the ICU setting in the prevention of VAP.

  9. Influence of paravertebral miorelaxant on arbitrary maximal ventilation of respirators system at skilled sportsmen

    Directory of Open Access Journals (Sweden)

    Syshko D.V.

    2012-09-01

    Full Text Available The functional being of the respirator system of the skilled sportsmen, engaged in the greco-roman fight (n=22, heavy athletics (n=25 and football (n=24 before and after course of paravertebral miorelaxant, is studied. The course of paravertebral miorelaxant was the system of exercises in a water environment with the use of «noodle». The necessity of application of correction influences, for sportsmen, was conditioned by the presence of hypertonic of paravertebral muscles, registered through miotonometric. It is got, those parameters of arbitrary maximal ventilation of respirators system (MVR, after the course of paravertebral miorelaxant, changed depending on the orientation of the training process determined by the type of sport. It is certain, whatever the change of tone of paravertebral muscles renders the reliable changes in the structure of arbitrary MVL at footballers, for certain affects chronotropics to the component at heavy athletics and inotropics at the representatives of the greco-roman fight.

  10. Restoration of Secondary Containment in Double Shell Tank (DST) Pits

    International Nuclear Information System (INIS)

    SHEN, E.J.

    2000-01-01

    Cracks found in many of the double-shell tank (DST) pump and valve pits bring into question the ability of the pits to provide secondary containment and remain in compliance with State and Federal regulations. This study was commissioned to identify viable options for maintain/restoring secondary containment capability in these pits. The basis for this study is the decision analysis process which identifies the requirements to be met and the desired goals (decision criteria) that each option will be weighed against. A facilitated workshop was convened with individuals knowledgeable of Tank Farms Operations, engineering practices, and safety/environmental requirements. The outcome of this workshop was the validation or identification of the critical requirements, definition of the current problem, identification and weighting of the desired goals, baselining of the current repair methods, and identification of potential alternate solutions. The workshop was followed up with further investigations into the potential solutions that were identified in the workshop and through other efforts. These solutions are identified in the body of this report. Each of the potential solutions were screened against the list of requirements and only those meeting the requirements were considered viable options. To expand the field of viable options, hybrid concepts that combine the strongest features of different individual approaches were also examined. Several were identified. The decision analysis process then ranked each of the viable options against the weighted decision criteria, which resulted in a recommended solution. The recommended approach is based upon installing a sprayed on coating system

  11. Restoration of Secondary Containment in Double Shell Tank (DST) Pits

    Energy Technology Data Exchange (ETDEWEB)

    SHEN, E.J.

    2000-10-05

    Cracks found in many of the double-shell tank (DST) pump and valve pits bring into question the ability of the pits to provide secondary containment and remain in compliance with State and Federal regulations. This study was commissioned to identify viable options for maintain/restoring secondary containment capability in these pits. The basis for this study is the decision analysis process which identifies the requirements to be met and the desired goals (decision criteria) that each option will be weighed against. A facilitated workshop was convened with individuals knowledgeable of Tank Farms Operations, engineering practices, and safety/environmental requirements. The outcome of this workshop was the validation or identification of the critical requirements, definition of the current problem, identification and weighting of the desired goals, baselining of the current repair methods, and identification of potential alternate solutions. The workshop was followed up with further investigations into the potential solutions that were identified in the workshop and through other efforts. These solutions are identified in the body of this report. Each of the potential solutions were screened against the list of requirements and only those meeting the requirements were considered viable options. To expand the field of viable options, hybrid concepts that combine the strongest features of different individual approaches were also examined. Several were identified. The decision analysis process then ranked each of the viable options against the weighted decision criteria, which resulted in a recommended solution. The recommended approach is based upon installing a sprayed on coating system.

  12. An example of a component replacement when applying ASME N509 and ASME N510 to older ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Arndt, T.E. [Westinghouse Hanford Company, Richland, WA (United States)

    1995-02-01

    This paper presents an example of a component replacement (electric heater) when installed in an older ventilation system that was constructed before the issuance of ASME N509{sup 1} and N510{sup 2}. Many of the existing ventilation systems at the Hanford Site were designed, fabricated, and installed before the issuance of ASME N509{sup 1} and N510{sup 2}. Requiring the application of these codes to existing ventilation systems presents challenges to the engineer when design changes are needed. Although it may seem that the application of ASME N509{sup 1} or N510{sup 2} may be a hindrance at times, this does not need to occur. Proper preparation at the start of project or design modifications can minimize frustration to the engineer when it is judged that portions of ASME N509{sup 1} and N510{sup 2} do not apply in a particular application.

  13. Operation technology of the ventilation system of the radioactive waste treatment facility(II) - Design and operation note

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K. M.; Lee, B. C.; Bae, S. M. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-12-01

    As the radioactive waste treatment work, such as compaction and/or solidification of wastes, are done directly by the workers in the Radioactive Waste Treatment Facility, the reasonable design and operation of the ventilation system is essential. In this report, the design criteria and specification of the ventilation equipment, system operation method are described for the effective design and operation of ventilation system in the radioactive waste treatment facility. And the anti-vibration work which was done in the Radioactive Waste Treatment Facility in KAERI to reduce the effect of vibration due to the continuous operation of big rotational equipment, the intake fans and the exhaust fans, are described in the report. 11 refs., 10 figs., 12 tabs. (Author)

  14. HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT BUCKLING EVALUATION METHODS & RESULTS FOR THE PRIMARY TANKS

    Energy Technology Data Exchange (ETDEWEB)

    MACKEY TC; JOHNSON KI; DEIBLER JE; PILLI SP; RINKER MW; KARRI NK

    2007-02-14

    This report documents a detailed buckling evaluation of the primary tanks in the Hanford double-shell waste tanks (DSTs), which is part of a comprehensive structural review for the Double-Shell Tank Integrity Project. This work also provides information on tank integrity that specifically responds to concerns raised by the Office of Environment, Safety, and Health (ES&H) Oversight (EH-22) during a review of work performed on the double-shell tank farms and the operation of the aging waste facility (AWF) primary tank ventilation system. The current buckling review focuses on the following tasks: (1) Evaluate the potential for progressive I-bolt failure and the appropriateness of the safety factors that were used for evaluating local and global buckling. The analysis will specifically answer the following questions: (a) Can the EH-22 scenario develop if the vacuum is limited to -6.6-inch water gage (w.g.) by a relief valve? (b) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario can develop? (c) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario cannot develop? (2) Develop influence functions to estimate the axial stresses in the primary tanks for all reasonable combinations of tank loads, based on detailed finite element analysis. The analysis must account for the variation in design details and operating conditions between the different DSTs. The analysis must also address the imperfection sensitivity of the primary tank to buckling. (3) Perform a detailed buckling analysis to determine the maximum allowable differential pressure for each of the DST primary tanks at the current specified limits on waste temperature, height, and specific gravity. Based on the I-bolt loads analysis and the small deformations that are predicted at the unfactored limits on vacuum and axial loads, it is very unlikely that the EH-22 scenario (i.e., progressive I-bolt failure leading to global

  15. Assessment of the Economic and Environmental Impact of Double Glazed Façade Ventilation Systems in Mediterranean Climates

    Directory of Open Access Journals (Sweden)

    Pere Alavedra

    2013-09-01

    Full Text Available Free convection is the most often used method in order to reduce solar load gains on a building with double glazed façades (DGFs. However, depending on the climate factors, the thermal performance of a DGF may not be satisfactory and extra energy costs are required to obtain suitable comfort conditions inside the building. Forced ventilation systems are a feasible alternative to improve the thermal performance of a DGF in Mediterranean climates where large solar gains are a permanent condition throughout the year. In this paper the feasibility of using diverse forced ventilation methods in DGF is evaluated. In addition, an economical comparison between different mechanical ventilation systems was performed in order to demonstrate the viability of DGF forced ventilation. Moreover, an environmental study was carried out to prove the positive energetic balance on cooling loads between free and forced convection in DGF for Mediterranean climates. For this investigation, a CFD model was used to simulate the thermal conditions in a DGF for the different ventilation systems. Results obtained for heat flux, temperature and reductions in solar load gains were analyzed and applied for the economic and environmental research.

  16. Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

    Directory of Open Access Journals (Sweden)

    Rajagopalan Parameshwaran

    2008-01-01

    Full Text Available In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

  17. A study of energy use for ventilation and air-conditioning systems in Hong Kong

    Science.gov (United States)

    Yu, Chung Hoi Philip

    Most of the local modern buildings are high-rise with enclosed structure. Mechanical ventilation and air conditioning (MVAC) systems are installed for thermal comfort. Various types of MVAC systems found in Hong Kong were critically reviewed with comments on their characteristics in energy efficiency as well as application. The major design considerations were also discussed. Besides MVAC, other energy-consuming components in commercial buildings were also identified, such as lighting, lifts and escalators, office equipment, information technology facilities, etc. A practical approach has been adopted throughout this study in order that the end results will have pragmatic value to the heating, ventilating and air-conditioning (HVAC) industry in Hong Kong. Indoor Air Quality (IAQ) has become a major issue in commercial buildings worldwide including Hong Kong. Ventilation rate is no doubt a critical element in the design of HVAC systems, which can be realized more obviously in railway train compartments where the carbon dioxide level will be built up quickly when the compartments are crowded during rush hours. A study was carried out based on a simplified model using a train compartment that is equipped with an MVAC system. Overall Thermal Transfer Value (OTTV) is a single-value parameter for controlling building energy use and is relatively simple to implement legislatively. The local government has taken a first step in reacting to the worldwide concern of energy conservation and environmental protection since 1995. Different methods of OTTV calculation were studied and the computation results were compared. It gives a clear picture of the advantages and limitations for each method to the building designers. However, due to the limitations of using OTTV as the only parameter for building energy control, some new approaches to a total control of building energy use were discussed and they might be considered for future revision of the building energy codes in Hong

  18. Optimising ventilation-system design for a container-housed engine

    Energy Technology Data Exchange (ETDEWEB)

    Sala, J.M.; Eguia, J.; Flores, I. [Escuela Superior de Ingenieros Industriales de Bilbao, Universidad del Pais Vasco, Alameda de Urquijo, s/n 48013 Bilbao (Bizkaia) (Spain); Lopez-Gonzalez, L.M.; Ruiz de Adana, M. [Escuela Tecnica Superior de Ingenieria Industrial, Depto de Ingenieria Mecanica, Universidad de La Rioja, C/Luis de Ulloa, 20, E-26004 Logrono (La Rioja) (Spain); Miguez, J.L. [Universidad de Vigo, Escuela Tecnica Superior de Ingenieros Industriales, C/Lagoas-Marcosende, s/n 36200 Vigo (Pontevedra) (Spain)

    2006-10-15

    Containerised cogeneration sets, CCSs, are an efficient answer for remote developing regions which do not have alternative energy sources and for those applications requiring mobility and the quick installation of energy plants. Nevertheless, CCSs can present over-heating problems as a result of inefficient ventilation. The heat dissipated by each of the 28 elements under consideration in the engine compartment was assessed, together with the mass flow rate of air supplied to the cab and the air temperature at the inlet and outlet. A Computational Fluid Dynamics (CFD) model has been developed that allows for simulation of the parameters of velocity, temperature and pressure and for calculating the heat flows in a CCS with a reciprocating diesel engine, with an alternator power of 903kW. Predictions from this model have been contrasted with the experimental data obtained in a series of measurements. The CFD model has been used to analyse possible alternatives for improving the ventilation system. Besides the use of insulation to reduce the heat dissipated, other alternatives have been studied: e.g., improving the airflow by fitting a metal sheet as a deflector, or using a third fan. Of the three alternatives analysed, the company has decided to incorporate the simplest and cheapest, consisting in fitting a metal sheet around the alternator. (author)

  19. Comparison of two humidification systems for long-term noninvasive mechanical ventilation.

    Science.gov (United States)

    Nava, S; Cirio, S; Fanfulla, F; Carlucci, A; Navarra, A; Negri, A; Ceriana, P

    2008-08-01

    There is no consensus concerning the best system of humidification during long-term noninvasive mechanical ventilation (NIMV). In a technical pilot randomised crossover 12-month study, 16 patients with stable chronic hypercapnic respiratory failure received either heated humidification or heat and moisture exchanger. Compliance with long-term NIMV, airway symptoms, side-effects and number of severe acute pulmonary exacerbations requiring hospitalisation were recorded. Two patients died. Intention-to-treat statistical analysis was performed on 14 patients. No significant differences were observed in compliance with long-term NIMV, but 10 out of 14 patients decided to continue long-term NIMV with heated humidification at the end of the trial. The incidence of side-effects, except for dry throat (significantly more often present using heat and moisture exchanger), hospitalisations and pneumonia were not significantly different. In the present pilot study, the use heated humidification and heat and moisture exchanger showed similar tolerance and side-effects, but a higher number of patients decided to continue long-term noninvasive mechanical ventilation with heated humidification. Further larger studies are required in order to confirm these findings.

  20. Effect of a ceiling fan ventilation system on finishing young bulls' health, behaviour and growth performance.

    Science.gov (United States)

    Magrin, L; Brscic, M; Lora, I; Rumor, C; Tondello, L; Cozzi, G; Gottardo, F

    2017-06-01

    This research aimed at assessing the effects of a ceiling fan ventilation system on health, feeding, social behaviour and growth response of finishing young bulls fattened indoors during a mild summer season. A total of 69 Charolais young bulls were housed in six pens without any mechanical ventilation system (Control) and in six pens equipped with ceiling fans. The experimental period lasted 98 days from June until mid-September 2014. Four experimental days were considered in order to assess the effect of the ventilation system under two different microclimatic conditions: 2 alert days at monthly interval with temperature humidity index (THI) between 75 and 78, and 2 normal days with THI⩽74. Health and behaviour of the bulls were evaluated through 8-h observation sessions starting after morning feed delivery. The study was carried out during a rather cool summer with a climate average THI of 68.9 and 4 days with average THI>75. Despite these mild climate conditions, ceiling fans lowered litter moisture and acted as a preventive measure for bulls' dirtiness (odd ratio=47.9; 95% CI 19.6 to 117.4). The risk of abnormal breathing was increased for Control bulls (odd ratio=40.7; 95% CI 5.4 to 304.2). When exposed to alert THI conditions, respiration rate and panting scores increased and rumination duration dropped in Control bulls compared with bulls provided with a ceiling fan. During observations under alert THI, bulls spent less time eating, more time being inactive and consumed more water compared with normal THI conditions. Bulls' daily dry matter intake measured during the observation sessions decreased on alert compared with normal THI days (Pbehaviour (rumination, lying down and drinking water) and respiration rate, however. The lack of a significant improvement of bulls' growth response should not discourage beef farmers from using ceiling fans in indoor systems, considering the likely increase in frequency and intensity of heat waves in the planet

  1. A novel fuzzy logic inference system for decision support in weaning from mechanical ventilation.

    Science.gov (United States)

    Kilic, Yusuf Alper; Kilic, Ilke

    2010-12-01

    Weaning from mechanical ventilation represents one of the most challenging issues in management of critically ill patients. Currently used weaning predictors ignore many important dimensions of weaning outcome and have not been uniformly successful. A fuzzy logic inference system that uses nine variables, and five rule blocks within two layers, has been designed and implemented over mathematical simulations and random clinical scenarios, to compare its behavior and performance in predicting expert opinion with those for rapid shallow breathing index (RSBI), pressure time index and Jabour' weaning index. RSBI has failed to predict expert opinion in 52% of scenarios. Fuzzy logic inference system has shown the best discriminative power (ROC: 0.9288), and RSBI the worst (ROC: 0.6556) in predicting expert opinion. Fuzzy logic provides an approach which can handle multi-attribute decision making, and is a very powerful tool to overcome the weaknesses of currently used weaning predictors.

  2. VENTILATION MODEL

    International Nuclear Information System (INIS)

    V. Chipman

    2002-01-01

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their postclosure analyses

  3. Demand controlled ventilation; Behovsstyrt ventilasjon

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Henning Holm

    2006-07-01

    The terms CAV and VAV have been known terms for many years in the ventilation business. The terms are also included in building regulations, but the time is now right to focus on demand controlled ventilation (DCV). The new building regulations and the accompanying energy framework underline the need for a more nuanced thinking when it comes to controlling ventilation systems. Descriptions and further details of the ventilation systems are provided (ml)

  4. Evaluation of a Mapleson D CPAP system for weaning of mechanical ventilation in pediatric patients

    Directory of Open Access Journals (Sweden)

    Miguel Angel Palomero-Rodríguez

    2016-01-01

    Full Text Available Background: Over the last years, we have used a flow-inflating bag circuit with a nasotracheal or nasopharyngeal tube as an interface to deliver effective CPAP support in infants (“Mapleson D CPAP system”. The primary goal of this study was to assess the usefulness of the “Mapleson D CPAP system” for weaning of mechanical ventilation (MV in infants who received MV over 24 h. Materials and Methods: All infants who received MV for more than 24 h in the last year were enrolled in the study. Demographic data included age, gender, weight, and admission diagnosis. Heart rate, respiratory rate, blood pressure, and oxygen saturation were measured during MV, 2 h after the nasotracheal Mapleson D CPAP system and 2 h after extubation. Patients were classified into two groups: patients MV more than 48 h, and patients with MV fewer than 48 h. P < 0.05 was considered statistically significant. Results: A total of 50 children were enrolled in the study, with a median age was 34 ± 45 months (range, 1-59 months and median weight was 11.98 ± 9.31 kg (range, 1-48 kg. Median duration of MV was 480 h (range, 2-570. There were no significant differences in PaO 2 , PaCO 2 , and pH among MV, 2 h after the nasotracheal Mapleson D CPAP system and 2 h after extubation and spontaneous ventilation with the nasopharyngeal Mapleson D CPAP system or with nasal prongs. The overall extubation failure rate was 26% (n = 13. Weight and age were significantly associated with extubation failure (P < 0.05. Conclusions: The Mapleson D CPAP system, in our opinion, is a useful and safe alternative to more complex and expensive noninvasive CPAP and BiPAP weaning from MV in infants.

  5. Performance evaluation of the pilot-scale, double-shell tank ventilation system using simulated aerosol streams

    Energy Technology Data Exchange (ETDEWEB)

    Brouns, T.M.; Peterson, M.E.

    1989-12-01

    Radioactive waste slurries are currently being stored in underground tanks on the Hanford Site. The slurries that are being stored in the double-shell tanks (DSTs) are various mixtures of radioactive solids, liquids, and aqueous wastes. The tanks must be maintained at a negative pressure relative to atmospheric pressure to safeguard against pressurization and the subsequent leakage of entrained radioactive aerosols to the environment. A ventilation system must be capable of withdrawing the total volume of off gas generated from the tanks while maintaining the tanks at a negative pressure. Westinghouse Hanford Company (WHC) has identified a need to improve the efficiency of the ventilation system being used on the tank farms to meet the more restrictive release limits for radioactive isotopes. Kaiser Engineers Hanford Company (KEH) has been contracted by WHC to design the new ventilation system for the existing tank farms. WHC contracted the Pacific Northwest Laboratory (PNL) to fabricate and test the prototypic pilot-scale design prior to finalizing the design of the ventilation system. The PNL has conducted tests to determine (1) the effectiveness of the system for removal of vapors condensable at 35{degrees}F, (2) the effectiveness for removal of soluble and insoluble aerosols, and (3) the life span of the mist eliminators to be used in the new system. The results of extensive testing of the pilot-scale system with condensables and both soluble and insoluble aerosols are presented in this report. 7 refs., 25 figs., 8 tabs.

  6. Evaluation of a Shaker Dust Collector for Use in a Recirculating Ventilation System.

    Science.gov (United States)

    Peters, Thomas M; Sawvel, Russell A; Park, Jae Hong; Anthony, T Renée

    2015-01-01

    General ventilation with recirculated air may be cost-effective to control the concentration of low-toxicity, contaminants in workplaces with diffuse, dusty operations, such as in agriculture. Such systems are, however, rarely adopted with little evidence showing improved air quality and ability to operate under harsh conditions. The goal of this work was to examine the initial and long-term performance of a fabric-filter shaker dust collector (SDC) in laboratory tests and as deployed within a recirculating ventilation system in an agricultural building. In laboratory tests, collection efficiency and pressure drop were tracked over several filter loading cycles, and the recovery of filter capacity (pressure drop) from filter shaking was examined. Collection efficiencies of particles larger than 5 μm was high (>95%) even when the filter was pristine, showing effective collection of large particles that dominate inhalable concentrations typical of agricultural dusts. For respirable-sized particles, collection efficiencies were low when the filter was pristine (e.g., 27% for 1 μm) but much higher when a dust cake developed on the filter (>99% for all size particles), even after shaking (e.g., 90% for 1 μm). The first shake of a filter was observed to recovery a substantial fraction of filter capacity, with subsequent shakes providing little benefit. In field tests, the SDC performed effectively over a period of three months in winter when incorporated in a recirculating ventilation system of a swine farrowing room. Trends in collection efficiency and pressure drop with loading were similar to those observed in the laboratory with overall collection efficiencies high (>80%) when pressure drop exceeded 230 Pa, or 23% of the maximum loading recommended by the manufacturer. This work shows that the SDC can function effectively over the harsh winter in swine rearing operations. Together with findings of improved air quality in the farrowing room reported in a

  7. Natural Ventilation in Atria

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per; Hendriksen, Ole Juhl

    This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions....

  8. Development of a Defense Meteorological Satellite Program (DMSP) F-15 Disturbance Storm-Time (Dst) Index

    National Research Council Canada - National Science Library

    Bono, James M

    2005-01-01

    .... An accurate, real-time Disturbance storm-time (Dst) index would be a primary input into current and future space weather models The Dst index is a measure of geomagnetic activity used to assess the severity of magnetic storms...

  9. Design of Energy Efficient Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The focus in the development has for both systems been to minimise energy consumption while maintaining a comfortable and healthy indoor environment. The natural next step in this development is to develop ventilation concepts that utilises and combines the best features from each system......[Mechanical and natural ventilation] into a new type of ventilation system- Hybrid Ventilation....

  10. Experimental Study of an Integrated System with Diffuse Ceiling Ventilation and Thermally Activated Building Constructions

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per

    of thermal comfort and energy performance. 20 cases with different boundary conditions are conducted varying on climate condition heat load. TABS water temperature and flow rate with or without diffuse ceiling. The energy evaluation includes energy balance of test room and cooling or heating capacity of TABS....... And the thermal comfort is analyzed by draught rate vertical temperature gradient and radiant temperature asymmetry. Finally the effect of plenum and diffuse ceiling is discussed. This report mainly focuses on the experiment results and discussions. Therefore, some details about the measurement are not presented......The experiments are carried out in a climate chamber located at the Department of Civil Engineering Aalborg University. The objective of the experiments is to evaluate the performance of the system combining diffuse ceiling ventilation and thermally activated building construction (TABS) in terms...

  11. New counter flow heat exchanger designed for ventilation systems in cold climates

    DEFF Research Database (Denmark)

    Kragh, Jesper; Rose, Jørgen; Nielsen, Toke Rammer

    2007-01-01

    In cold climates, mechanical ventilation systems with highly efficient heat recovery will experience problems with condensing water from the extracted humid indoor air. If the condensed water changes to ice in the heat exchanger, the airflow rate will quickly fall due to the increasing pressure...... of the developed beat exchanger are low pressure loss, cheap materials and a simple construction. The disadvantage is that the exchanger is big compared with other heat exchangers. In this paper, the new heat exchanger's efficiency is calculated theoretically and measured experimentally. The experiment shows...... drop. Preheating the inlet air (outdoor air) to a temperature above 0 degrees C before it enters the exchanger is one solution often used to solve the problem, however, this method reduces the energy saving potential significantly. To minimize the energy cost, a more efficient way to solve the freezing...

  12. Microclimate measuring and fluid‑dynamic simulation in an industrial broiler house: testing of an experimental ventilation system.

    Science.gov (United States)

    Bianchi, Biagio; Giametta, Ferruccio; La Fianza, Giovanna; Gentile, Andrea; Catalano, Pasquale

    2015-01-01

    The environment in the broiler house is a combination of physical and biological factors generating a complex dynamic system of interactions between birds, husbandry system, light, temperature, and the aerial environment. Ventilation plays a key role in this scenario. It is pivotal to remove carbon dioxide and water vapor from the air of the hen house. Adequate ventilation rates provide the most effective method of controlling temperature within the hen house. They allow for controlling the relative humidity and can play a key role in alleviating the negative effects of high stocking density and of wet litter. In the present study the results of experimental tests performed in a breeding broiler farm are shown. In particular the efficiency of a semi transversal ventilation system was studied against the use of a pure transversal one. In order to verify the efficiency of the systems, fluid dynamic simulations were carried out using the software Comsol multiphysics. The results of this study show that a correct architectural and structural design of the building must be supported by a design of the ventilation system able to maintain the environmental parameters within the limits of the thermo‑neutral and welfare conditions and to achieve the highest levels of productivity.

  13. Physiologic effects of an ambulatory ventilation system in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Porszasz, Janos; Cao, Robert; Morishige, Richard; van Eykern, Leo A; Stenzler, Alex; Casaburi, Richard

    2013-08-01

    Exercise intolerance limits the ability of patients with chronic obstructive pulmonary disease (COPD) to perform daily living activities. Noninvasive ventilation reduces dyspnea and improves exercise performance, but current systems are unsuitable for ambulatory use. In patients with COPD experiencing exercise-induced desaturation, we evaluated improvements in exercise tolerance facilitated by a wearable, 1-lb, noninvasive open ventilation (NIOV) system featuring a nasal pillow interface during constant work rate (CWR) cycle ergometer exercise and associated effects on dyspnea, respiratory muscle activation, and pulmonary gas exchange efficiency. Fifteen men with COPD (FEV₁ = 32.2 ± 12.0% predicted; FEV₁/FVC = 31.6 ± 7.1%; exercise oxygen saturation as measured by pulse oximetry [Spo₂] = 86.5 ± 2.9%) participated. After incremental testing establishing peak work rate, subjects completed three visits in which they performed CWR exercise to tolerance at 80% peak work rate: (1) unencumbered breathing room air, (2) using NIOV+compressed air, (3) using NIOV+compressed O₂, or (4) using O₂ via nasal cannula. Assessments included exercise duration, surface inspiratory muscle EMG, Spo₂, transcutaneous Pco₂, and Borg dyspnea scores. Exercise endurance was 17.6 ± 5.7 minutes using NIOV+O₂, greatly prolonged compared with unencumbered (5.6 ± 1.9 min), nasal O₂ (11.4 ± 6.8 min), and NIOV+Air (6.3 ± 4.1 min). Isotime Spo₂ was higher and intercostal, scalene, and diaphragmatic EMG activity was reduced using NIOV+O₂ compared with unencumbered, nasal O₂, and NIOV+Air, signifying respiratory muscle unloading. Isotime dyspnea reduction correlated with isotime EMG reduction (r = 0.42, P = 0.0053). There were no significant differences in isotime VD/VT or transcutaneous Pco₂ among treatments. NIOV+O₂ yielded substantial exercise endurance improvements accompanied by respiratory muscle unloading and dyspnea reductions in patients with severe hypoxemic

  14. Impact of ventilation systems and energy savings in a building on the mechanisms governing the indoor radon activity concentration.

    Science.gov (United States)

    Collignan, Bernard; Powaga, Emilie

    2017-11-23

    For a given radon potential in the ground and a given building, the parameters affecting the indoor radon activity concentration (IRnAC) are indoor depressurization of a building and its air change rate. These parameters depend mainly on the building characteristics, such as airtightness, and on the nature and performances of the ventilation system. This study involves a numerical sensitivity assessment of the indoor environmental conditions on the IRnAC in buildings. A numerical ventilation model has been adapted to take into account the effects of variations in the indoor environmental conditions (depressurization and air change rate) on the radon entry rate and on the IRnAC. In the context of the development of a policy to reduce energy consumption in a building, the results obtained showed that IRnAC could be strongly affected by variations in the air permeability of the building associated with the ventilation regime. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Interim Manual for the DST: Decoding Skills Test.

    Science.gov (United States)

    Richardson, Ellis; And Others

    The Decoding Skills Test (DST) was developed to provide a detailed measurement of decoding skills which could be used in research on developmental dyslexia. Another purpose of the test is to provide a diagnostic-prescriptive instrument to be used in the evaluation of, and program planning for, children needing remedial reading. The test is…

  16. Is the Dst Index Sufficient to Define All Geospace Storms?

    Science.gov (United States)

    Borovsky, Joseph E.; Shprits, Yuri Y.

    2017-11-01

    The purpose of this commentary is (1) to raise awareness about some shortcomings of the use of the Dst index to identify storms, to gauge storm intensity, and to represent storm time space-weather phenomena and (2) to initiate discussions about different types of storms and about improved identifiers for different types of storms.

  17. A DST Sponsored Workshop on Methods in Behavioural Ecology ...

    Indian Academy of Sciences (India)

    A DST Sponsored Workshop on Methods in. Behavioural Ecology. Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, India. 15-29 January 2006. Aimed at Young Teachers and Senior Research Students The course will cover lectures on several aspects of Behavioral ecology including, ...

  18. Double Shell Tanks (DST) and Waste Feed Delivery Project Management Quality Affecting Procedures Management Plan

    International Nuclear Information System (INIS)

    LUND, D.P.

    2000-01-01

    The purpose of the Double Shell Tanks (DST) and Waste Feed Delivery (WFD) Management Assessment Plan is to define how management assessments within DST h WFD will be conducted. The plan as written currently includes only WFD Project assessment topics. Other DST and WFD group assessment topics will be added in future revisions

  19. Building a Comprehensive System of Services to Support Adults Living with Long-Term Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    David Leasa

    2016-01-01

    Full Text Available Background. Increasing numbers of individuals require long-term mechanical ventilation (LTMV in the community. In the South West Local Health Integration Network (LHIN in Ontario, multiple organizations have come together to design, build, and operate a system to serve adults living with LTMV. Objective. The goal was to develop an integrated approach to meet the health and supportive care needs of adults living with LTMV. Methods. The project was undertaken in three phases: System Design, Implementation Planning, and Implementation. Results. There are both qualitative and quantitative evidences that a multiorganizational system of care is now operational and functioning in a way that previously did not exist. An Oversight Committee and an Operations Management Committee currently support the system of services. A Memorandum of Understanding has been signed by the participating organizations. There is case-based evidence that hospital admissions are being avoided, transitions in care are being thoughtfully planned and executed collaboratively among service providers, and new roles and responsibilities are being accepted within the overall system of care. Conclusion. Addressing the complex and variable needs of adults living with LTMV requires a systems response involving the full continuum of care.

  20. Ventilation of nuclear power plants

    International Nuclear Information System (INIS)

    Madoyan, A.A.; Vlasik, V.F.

    1984-01-01

    Foundations and calculation methods of ventilation of rooms with different degree of heat and gas release with the change of operation mode of NPP main equipment, as well as problems of NPP site and adjoining area aerodynamics, have been presented. Systems of air ventilation and conditioning, cooling equipment, are considered. The main points of designing are described and determination of economic efficiency of the ventilation systems are made. Technical characteristics of the ventilators, conditioners, filters and air heaters used, are presented. Organization of adjustment, tests, operation and maintenance of the ventilation systems of NPP with RBMK and WWER-type reactors, is described

  1. Evaluation of waste temperatures in AWF tanks for bypass mode operation of the 702-AZ ventilation system (Project W-030)

    International Nuclear Information System (INIS)

    Sathyanarayana, K.

    1997-01-01

    This report describes the results of thermal hydraulic analysis performed to provide data in support of Project W-030 to startup new 702-AZ Primary Ventilation System. During the startup of W-030 system, the ventilation system will be operating in bypass mode. In bypass made of operation, the system is capable of supplying 1000 cfm total flow for all four AWF doubleshell tanks. The design of the W-030 system is based on the assumption that both the recirculation loop of the primary ventilation system and the secondary ventilation which provides cooling would be operating. However, during the startup neither the recirculation system nor the secondary ventilation system will be operating. A minimum flow of 100 cfm is required to prevent any flammable gas associated risk. The remaining 600 cfm flow can be divided among the four tanks as necessary to keep the peak sludge temperatures below the operating temperature limit. For the purpose of determining the minimum flow required for cooling each tank, the thermal hydraulic analysis is performed to predict the peak sludge temperatures in AY/AZ tanks under different ventilation flows. The heat load for AZ farm tanks is taken from characterization reports and for the AY farm tanks, the heat load was estimated by thermal analysis using the measured waste temperatures and the waste liquid evaporation rates. The tank 241-AZ-101 and the tank 241-AZ-102 have heat loads of 241,600 and 199,500 Btu/hr respectively. The tank 241-AY-101 and tank 241-AY-102 have heat loads of 41,000 and 33,000 Btu/hr respectively. Using the ambient meteorological conditions of temperature and relative humidity for the air and tank, some soil surface and the sludge levels reported in recent documents, the peak sludge and supernatant temperatures were predicted for various primary ventilation flows ranging from 100 to 400 cfm for AZ tanks and 100 and 150 cfm for AY tanks. The results of these thermal hydraulic analyses are presented. Based on the

  2. Demand control on room level of the supply air temperature in an air heating and ventilation system

    DEFF Research Database (Denmark)

    Polak, Joanna; Afshari, Alireza; Bergsøe, Niels Christian

    2017-01-01

    The aim of this study was to investigate a new strategy for control of supply air temperature in an integrated air heating and ventilation system. The new strategy enables demand control of supply air temperature in individual rooms. The study is based on detailed dynamic simulations of a combined...

  3. JACoW Virtual control commissioning for a large critical ventilation system: The CMS cavern use case

    CERN Document Server

    Booth, William; Bradu, Benjamin; Sourisseau, Samuel

    2018-01-01

    The current cavern ventilation control system of the CMS experiment at CERN is based on components which are already obsolete: the SCADA system, or close to the end of life: the PLCs. The control system is going to be upgraded during the LHC Long Shutdown 2 (2019-2020) and will be based on the CERN industrial control standard: UNICOS employing WinCC OA as SCADA and Schneider PLCs. Due to the critical nature of the CMS ventilation installation and the short allowed downtime, the approach was to design an environment based on the virtual commissioning of the new control. This solution uses a first principles model of the ventilation system to simulate the real process. The model was developed with the modelling and simulation software EcosimPro. In addition, the current control application of the cavern ventilation will also be re-engineered as it is not completely satisfactory in some transients where many sequences are performed manually and some pressure fluctuations observed could potentially cause issues t...

  4. Experimental study on the dynamic performance of a novel system combining natural ventilation with diffuse ceiling inlet and TABS

    DEFF Research Database (Denmark)

    Yu, Tao; Heiselberg, Per Kvols; Lei, Bo

    2016-01-01

    Highlights • Dynamic experiments are performed to study energy performance of a new HVAC system. • Designed control strategies show good utilization of natural ventilation cooling. • TABS work well with the diffuse ceiling in the dynamic measurements. • No local thermal comfort problem is found...

  5. Ontology for Life-Cycle Modeling of Heating, Ventilating, and Air Conditioning (HVAC) Systems: Experimental Applications Using Revit

    Science.gov (United States)

    2012-03-01

    Center, Construction Engineering Research Laboratory (ERDC-CERL) has developed a core life- cycle building information model ( BIM ) based on three...was to promote consistency and quality of content created for Building Information Models ( BIMs ) across various disciplines. The HVAC MVD was...MVD. 15. SUBJECT TERMS building information modeling ( BIM ), ontology, Army facilities, heating, ventilating, and air-conditioning (HVAC) systems

  6. Experimental Investigation of Convective Heat Transfer during Night Cooling with Different Ventilation Systems and Surface Emissivities

    DEFF Research Database (Denmark)

    Le Dreau, Jerome; Heiselberg, Per; Jensen, Rasmus Lund

    2013-01-01

    Night-time ventilation is a promising approach to reduce the energy needed for cooling buildings without reducing thermal comfort. Nevertheless actual building simulation tools have showed their limits in predicting accurately the efficiency of night-time ventilation, mainly due to inappropriate...

  7. Non-invasive mechanical ventilation: the benefits of the BiPAP system.

    Science.gov (United States)

    Teba, L; Marks, P; Benzo, R

    1996-01-01

    Many of the complications with endotracheal intubation and invasive mechanical ventilation can be avoided with the use of non-invasive mechanical ventilation (NIMV). This technique has been especially successful in treating patients with acute respiratory failure (ARF). NIMV improves gas exchange, avoids complications caused by endotracheal intubation, and allows patients to talk and take medications orally. This article reviews our experiences treating 27 patients with ARF with a BiPAP (bi-level positive airway pressure) ventilator. This is a portable unit which allows for selection of different modes of ventilation and adjustment of inspiratory and expiratory pressures. Non-invasive mechanical ventilation should be considered in patients presenting with ARF who are hemodynamically stable and in whom spontaneous breathing is preserved.

  8. A study on the evaluation of ventilation system suitable for outside air cooling applied in large data center for energy conservation

    International Nuclear Information System (INIS)

    Kwon, Yong Il

    2016-01-01

    In developed countries, expansion of communication technology has resulted in continual increase in the construction of data centers with high-density cooling loads. Throughout a year, IT equipment installed in a data center generates large and constant cooling load. As a result, data centers may be consuming an ever-growing amount of energy. The cooling system utilizing the energy of outside air is applied universally to reduce data center energy consumption. The application of the cooling system to the outdoor air cooling system of a data center considers that temperature efficiency and ventilation performance vary depending on the type of ventilation system. The displacement and mixed ventilation method can be applied generally to a data center. The efficiency of a ventilation system depends on inside temperature or contaminant concentrations in room and outlets. This study thus aims to evaluate the ventilation performance that varies according to type of ventilation system installed in the data center. Ventilation efficiency is assessed by applying the concept of total air age and considers the fresh air ratio and age of return air. Further, temperature efficiency gained by utilizing temperature difference is used to assess causes for changes in ventilation performance.

  9. A study on the evaluation of ventilation system suitable for outside air cooling applied in large data center for energy conservation

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Yong Il [Shinhan University, Euijungbu (Korea, Republic of)

    2016-05-15

    In developed countries, expansion of communication technology has resulted in continual increase in the construction of data centers with high-density cooling loads. Throughout a year, IT equipment installed in a data center generates large and constant cooling load. As a result, data centers may be consuming an ever-growing amount of energy. The cooling system utilizing the energy of outside air is applied universally to reduce data center energy consumption. The application of the cooling system to the outdoor air cooling system of a data center considers that temperature efficiency and ventilation performance vary depending on the type of ventilation system. The displacement and mixed ventilation method can be applied generally to a data center. The efficiency of a ventilation system depends on inside temperature or contaminant concentrations in room and outlets. This study thus aims to evaluate the ventilation performance that varies according to type of ventilation system installed in the data center. Ventilation efficiency is assessed by applying the concept of total air age and considers the fresh air ratio and age of return air. Further, temperature efficiency gained by utilizing temperature difference is used to assess causes for changes in ventilation performance.

  10. Ventilating Air-Conditioner

    Science.gov (United States)

    Dinh, Khanh

    1994-01-01

    Air-conditioner provides ventilation designed to be used alone or incorporated into cooling or heating system operates efficiently only by recirculating stale air within building. Energy needed to operate overall ventilating cooling or heating system slightly greater than operating nonventilating cooling or heating system. Helps to preserve energy efficiency while satisfying need for increased forced ventilation to prevent accumulation of undesired gases like radon and formaldehyde. Provides fresh treated air to variety of confined spaces: hospital surgeries, laboratories, clean rooms, and printing shops and other places where solvents used. In mobile homes and portable classrooms, eliminates irritant chemicals exuded by carpets, panels, and other materials, ensuring healthy indoor environment for occupants.

  11. Fiber Bragg Grating Measuring System for Simultaneous Monitoring of Temperature and Humidity in Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    Carlo Massaroni

    2017-04-01

    Full Text Available During mechanical ventilation, the humidification of the dry air delivered by the mechanical ventilator is recommended. Among several solutions, heated wire humidifiers (HWHs have gained large acceptance to be used in this field. The aim of this work is to fabricate a measuring system based on fiber Bragg grating (FBG for the simultaneous monitoring of gas relative humidity (RH and temperature, intended to be used for providing feedback to the HWHs’ control. This solution can be implemented using an array of two FBGs having a different center wavelength. Regarding RH monitoring, three sensors have been fabricated by coating an FBG with two different moisture-sensitive and biocompatible materials: the first two sensors were fabricated by coating the grating with a 3 mm × 3 mm layer of agar and agarose; to investigate the influence of the coating thickness to the sensor response, a third sensor was developed with a 5 mm × 5 mm layer of agar. The sensors have been assessed in a wide range of RH (up to 95% during both an ascending and a subsequent descending phase. Only the response of the 3 mm × 3 mm-coated sensors were fast enough to follow the RH changes, showing a mean sensitivity of about 0.14 nm/% (agar-coated and 0.12 nm/% (agarose-coated. The hysteresis error was about <10% in the two sensors. The contribution of temperature changes on these RH sensors was negligible. The temperature measurement was performed by a commercial FBG insensitive to RH changes. The small size of these FBG-based sensors, the use of biocompatible polymers, and the possibility to measure both temperature and RH by using the same fiber optic embedding an array of two FBGs make intriguing the use of this solution for application in the control of HWHs.

  12. Uncertainties in the measured quantities of water leaving waste Tank 241-C-106 via the ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Minteer, D.J.

    1995-01-23

    The purpose of this analysis is to estimate the uncertainty in the measured quantity of water which typically leaves Tank 241-C-106 via the ventilation system each month. Such measurements are essential for heat removal estimation and tank liquid level verification purposes. The uncertainty associated with the current, infrequent, manual method of measurement (involves various psychrometric and pressure measurements) is suspected to be unreasonably high. Thus, the possible reduction of this uncertainty using a continuous, automated method of measurement will also be estimated. There are three major conclusions as a result of this analysis: (1) the uncertainties associated with the current (infrequent, manual) method of measuring the water which typically leaves Tank 241-C-106 per month via the ventilation system are indeed quite high (80% to 120%); (2) given the current psychrometric and pressure measurement methods and any tank which loses considerable moisture through active ventilation, such as Tank 241-C-106, significant quantities of liquid can actually leak from the tank before a leak can be positively identified via liquid level measurement; (3) using improved (continuous, automated) methods of taking the psychrometric and pressure measurements, the uncertainty in the measured quantity of water leaving Tank 241-C-106 via the ventilation system can be reduced by approximately an order of magnitude.

  13. Uncertainties in the measured quantities of water leaving waste Tank 241-C-106 via the ventilation system

    International Nuclear Information System (INIS)

    Minteer, D.J.

    1995-01-01

    The purpose of this analysis is to estimate the uncertainty in the measured quantity of water which typically leaves Tank 241-C-106 via the ventilation system each month. Such measurements are essential for heat removal estimation and tank liquid level verification purposes. The uncertainty associated with the current, infrequent, manual method of measurement (involves various psychrometric and pressure measurements) is suspected to be unreasonably high. Thus, the possible reduction of this uncertainty using a continuous, automated method of measurement will also be estimated. There are three major conclusions as a result of this analysis: (1) the uncertainties associated with the current (infrequent, manual) method of measuring the water which typically leaves Tank 241-C-106 per month via the ventilation system are indeed quite high (80% to 120%); (2) given the current psychrometric and pressure measurement methods and any tank which loses considerable moisture through active ventilation, such as Tank 241-C-106, significant quantities of liquid can actually leak from the tank before a leak can be positively identified via liquid level measurement; (3) using improved (continuous, automated) methods of taking the psychrometric and pressure measurements, the uncertainty in the measured quantity of water leaving Tank 241-C-106 via the ventilation system can be reduced by approximately an order of magnitude

  14. Design Procedure for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per; Tjelflaat, Per Olaf

    Mechanical and natural ventilation systems have developed separately during many years. The natural next step in this development is development of ventilation concepts that utilises and combines the best features from each system into a new type of ventilation system - Hybrid Ventilation....... Buildings with hybrid ventilation often include other sustainable technologies and an energy optimisation requires an integrated approach in the design of the building and its mechanical systems. Therefore, the hybrid ventilation design procedure differs from the design procedure for conventional HVAC....... The first ideas on a design procedure for hybrid ventilation is presented and the different types of design methods, that is needed in different phases of the design process, is discussed....

  15. Definition and means of maintaining the supply ventilation system seismic shutdown portion of the PFP safety envelope. Revision 2

    International Nuclear Information System (INIS)

    Keck, R.D.

    1995-01-01

    This report describes the modifications to the ventilation system for the Plutonium Finishing Plant. Topics discussed in this report include; system functional requirements, evaluations of equipment, a list of drawings showing the safety envelope boundaries; list of safety envelope equipment, functional requirements for individual safety envelope equipment, and a list of the operational, maintenance and surveillance procedures necessary to operate and maintain the system equipment

  16. Ventilation and Heart Rate Monitoring in Drivers using a Contactless Electrical Bioimpedance System

    Science.gov (United States)

    Macías, R.; García, M. A.; Ramos, J.; Bragós, R.; Fernández, M.

    2013-04-01

    Nowadays, the road safety is one of the most important priorities in the automotive industry. Many times, this safety is jeopardized because of driving under inappropriate states, e.g. drowsiness, drugs and/or alcohol. Therefore several systems for monitoring the behavior of subjects during driving are researched. In this paper, a device based on a contactless electrical bioimpedance system is shown. Using the four-wire technique, this system is capable of obtaining the heart rate and the ventilation of the driver through multiple textile electrodes. These textile electrodes are placed on the car seat and the steering wheel. Moreover, it is also reported several measurements done in a controlled environment, i.e. a test room where there are no artifacts due to the car vibrations or the road state. In the mentioned measurements, the system response can be observed depending on several parameters such as the placement of the electrodes or the number of clothing layers worn by the driver.

  17. Ventilation and Heart Rate Monitoring in Drivers using a Contactless Electrical Bioimpedance System

    International Nuclear Information System (INIS)

    Macías, R; García, M A; Ramos, J; Bragós, R; Fernández, M

    2013-01-01

    Nowadays, the road safety is one of the most important priorities in the automotive industry. Many times, this safety is jeopardized because of driving under inappropriate states, e.g. drowsiness, drugs and/or alcohol. Therefore several systems for monitoring the behavior of subjects during driving are researched. In this paper, a device based on a contactless electrical bioimpedance system is shown. Using the four-wire technique, this system is capable of obtaining the heart rate and the ventilation of the driver through multiple textile electrodes. These textile electrodes are placed on the car seat and the steering wheel. Moreover, it is also reported several measurements done in a controlled environment, i.e. a test room where there are no artifacts due to the car vibrations or the road state. In the mentioned measurements, the system response can be observed depending on several parameters such as the placement of the electrodes or the number of clothing layers worn by the driver.

  18. Ventilation systems analysis during tornado conditions. Progress report, October 1, 1976--April 30, 1977

    International Nuclear Information System (INIS)

    Gregory, W.S.; Andrae, R.W.; Duerre, K.H.; Dove, R.C.

    1977-10-01

    A computer code, TVENT, has been developed to predict the tornado-induced pressures and flows within an arbitrary nuclear facility ventilation system. Operational experience with TVENT in analyzing an ERDA facility has resulted in code modifications. Several architectural firms have agreed to use TVENT to analyze their designs. They will provide us with comments on the code and user's manual to make them more useful. Our investigation of the feasibility of scale model analysis to provide additional comparative data and preliminary results is presented. Preliminary calculations indicate that a distorted model would be necessary. Distortion of the Reynolds number relating the model to the prototype appears to be the most practical approach. The Idaho Chemical Processing Plant (ICPP) atmospheric protection system was analyzed using TVENT, and the results are presented. They were found to be in close agreement with the real system under steady-state conditions. For a tornado at the exhaust stack, TVENT predicted a flow increase of 70 percent through the system's HEPA filters

  19. Modelica Library for Building Heating, Ventilation and Air-Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wetter, Michael

    2009-06-17

    This paper presents a freely available Modelica library for building heating, ventilation and air conditioning systems. The library is based on the Modelica.Fluid library. It has been developed to support research and development of integrated building energy and control systems. The primary applications are controls design, energy analysis and model-based operation. The library contains dynamic and steady-state component models that are applicable for analyzing fast transients when designing control algorithms and for conducting annual simulations when assessing energy performance. For most models, dimensional analysis is used to compute the performance for operating points that differ from nominal conditions. This allows parameterizing models in the absence of detailed geometrical information which is often impractical to obtain during the conceptual design phase of building systems. In the first part of this paper, the library architecture and the main classes are described. In the second part, an example is presented in which we implemented a model of a hydronic heating system with thermostatic radiator valves and thermal energy storage.

  20. Mine ventilation engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hall, C.J.

    1981-01-01

    This book on mine ventilation covers psychometrics, airflow through roadways and ducts, natural ventilation, fans, instruments, ventilation surveys, auxiliary ventilation, air quality, and planning and economics.

  1. The effects of individually ventilated cages on the respiratory systems of male and female Wistar rats from birth until adulthood

    Science.gov (United States)

    Marchesi, Guilherme D’Aprile; de Fatima Soto, Sônia; de Castro, Isac; Rodrigues, Thiago Guimarães; Moriya, Henrique Takachi; de Almeida, Francine Maria; Pazetti, Rogerio; Heimann, Joel Claudio; Furukawa, Luzia Naôko Shinohara

    2017-01-01

    OBJECTIVE: To evaluate the respiratory systems of male and female rats maintained in individually ventilated cages (IVCs) from birth until adulthood. METHODS: Female Wistar rats were housed in individually ventilated cages or conventional cages (CCs) and mated with male Wistar rats. After birth and weaning, the male offspring were separated from the females and kept in cages of the same type until 12 weeks of age. RESULTS: The level of food consumption was lower in male offspring (IVC=171.7±9; CC=193.1±20) than in female offspring (IVC=100.6±7; CC=123.4±0.4), whereas the water intake was higher in female offspring (IVC=149.8±11; CC=99.2±0) than in male offspring (IVC=302.5±25; CC=249.7±22) at 11 weeks of age when housed in IVCs. The cage temperature was higher in individually ventilated cages than in conventional cages for both male (IVCs=25.9±0.5; CCs=22.95±0.3) and female (IVCs=26.2±0.3; CCs=23.1±0.3) offspring. The respiratory resistance (IVC=68.8±2.8; CC=50.6±3.0) and elastance (IVC=42.0±3.9; CC=32.4±2.0) at 300 µm/kg were higher in the female offspring housed in ventilated cages. The ciliary beat values were lower in both the male (IVCs=13.4±0.2; CC=15±0.4) and female (IVC=13.5±0.4; CC=15.9±0.6) offspring housed in individually ventilated cages than in those housed in conventional cages. The total cell (IVC=117.5±9.7; CC=285.0±22.8), neutrophil (IVC=13.1±4.8; CC=75.6±4.1) and macrophage (IVC=95.2±11.8; CC=170.0±18.8) counts in the bronchoalveolar lavage fluid were lower in the female offspring housed in individually ventilated cages than in those housed in conventional cages. CONCLUSIONS: The environmental conditions that exist in individually ventilated cages should be considered when interpreting the results of studies involving laboratory animals. In this study, we observed gender dimorphism in both the water consumption and respiratory mechanics of rats kept in ventilated cages. PMID:28355363

  2. Respiratory symptoms, perceived air quality and physiological signs in elementary school pupils in relation to displacement and mixing ventilation system: an intervention study.

    Science.gov (United States)

    Norbäck, D; Wieslander, G; Zhang, X; Zhao, Z

    2011-10-01

    Schools may be poorly ventilated and may contain furry pet allergens, particles and microorganisms. We studied health effects when changing from mixing ceiling ventilation to two types of displacement ventilation, front ventilation system (FVS) and floor master system (FMS). The study included pupils in three elementary school classes (N = 61), all with floor heating. One class received blinded interventions; the two others were unchanged (controls). Ventilation flow and supply air temperature was kept constant. The medical investigation included tear film stability (BUT), nasal patency and a questionnaire containing rating scales. When changing from mixing ventilation to FVS, the pupils (N = 26) perceived better air quality (P = 0.006) and less dyspnoea (P = 0.007) as compared to controls (N = 35), and BUT was improved (P = 0.03). At desk level, mean CO(2) was reduced from 867 to 655 ppm. Formaldehyde and viable bacteria were numerically lower, while total bacteria and molds were higher with displacement ventilation. There was no difference in symptoms or signs when changing from FVS to FMS. Cat (Der p1), dog (Can f1) and horse allergen (Equ cx) were common in air at all conditions. In conclusion, displacement ventilation may have certain positive health effects among pupils, as compared to conventional mixing ceiling systems. Displacement ventilation may be a suitable ventilation principle for achieving good indoor environment in classrooms. The type of supply air diffuser does not seem to be of major importance. The combination of floor heating and displacement ventilation can be a useful way of avoiding the previously described problem of thermal discomfort. © 2011 John Wiley & Sons A/S.

  3. A static pressure reset control system with a new type of flow damper for use in low pressure ventilation systems

    DEFF Research Database (Denmark)

    Terkildsen, Søren; Svendsen, Svend

    2012-01-01

    The control strategy for mechanical ventilation systems has significant impact on the performance of the system, in terms of energy consumption and correct air distribution. This paper presents a static pressure reset control system employing a new type of flow damper with lower pressure loss...... shows that the droplet shaped damper resulted in an airflow of 234 L/s at 30 Pa pressure loss, more than twice the airflow past a flat-plate damper at the same pressure loss (114 L/s). Also the droplet shaped damper could operate precisely down to 5 Pa pressure loss. The programmed control algorithm...... significant fan power saving compared to a fixed static pressure control. A maximum static pressure of 15 Pa is a reduction of more than 50% compared to flat-plate dampers that required at least 30 Pa to operate precisely; this is expected to yield fan energy savings in practice....

  4. Subjective Evaluation of the Microenvironment Generated by a Hospital Bed with Localized Ventilation System

    DEFF Research Database (Denmark)

    Kehayova, Nushka; Bolashikov, Zhecho Dimitrov; Melikov, Arsen Krikor

    2016-01-01

    A novel method for local hospital bed ventilation, called HBIVCU (Hospital Bed with Integrated Ventilation and Cleansing Unit), was studied in a human subject experiment. The goal of this study was to identify human response to the microenvironment generated by a hospital bed with installed HBIVCU...... and to compare with human response to the micro-environment at a hospital bed without local ventilation. 32 participants took part in two experimental conditions - hospital bed with and without installed HBIVCU. Subject’s votes on the bed microenvironment were collected via standardized questionnaires...

  5. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    Energy Technology Data Exchange (ETDEWEB)

    P. Dixon

    2004-04-05

    The purpose of this Model Report (REV02) is to document the unsaturated zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrological-chemical (THC) processes on UZ flow and transport. This Model Report has been developed in accordance with the ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (Bechtel SAIC Company, LLC (BSC) 2002 [160819]). The technical work plan (TWP) describes planning information pertaining to the technical scope, content, and management of this Model Report in Section 1.12, Work Package AUZM08, ''Coupled Effects on Flow and Seepage''. The plan for validation of the models documented in this Model Report is given in Attachment I, Model Validation Plans, Section I-3-4, of the TWP. Except for variations in acceptance criteria (Section 4.2), there were no deviations from this TWP. This report was developed in accordance with AP-SIII.10Q, ''Models''. This Model Report documents the THC Seepage Model and the Drift Scale Test (DST) THC Model. The THC Seepage Model is a drift-scale process model for predicting the composition of gas and water that could enter waste emplacement drifts and the effects of mineral alteration on flow in rocks surrounding drifts. The DST THC model is a drift-scale process model relying on the same conceptual model and much of the same input data (i.e., physical, hydrological, thermodynamic, and kinetic) as the THC Seepage Model. The DST THC Model is the primary method for validating the THC Seepage Model. The DST THC Model compares predicted water and gas compositions, as well as mineral alteration patterns, with observed data from the DST. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal-loading conditions, and predict the evolution of mineral alteration and fluid chemistry around potential waste emplacement drifts. The

  6. Demand Controlled Ventilation and Classroom Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling.

  7. Demand controlled ventilation and classroom ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-06

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling.

  8. Measurement of HVAC system performance and local ventilation using passive perfluorocarbon tracer technology

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, R.N.; Goodrich, R.W.

    1995-06-01

    In April of 1993, two (2) perfluorocarbon tracer (PFT) ventilation/indoor air quality assessment tests were performed in the Gleeson Hall building of the SUNY Farmingdale campus. The building was being modified, in part, as a result of significant occupant complaints of perceived poor air quality. The four story building had a basement first floor with air supplied normally by an HVAC system labelled as AC1. During this study, AC1 was inoperational and the basement interior rooms (walls) were primarily gone; the other three floors were still being used for classes. It is possible that a sense of poor air quality may have been perceived by first-floor occupants because they were working in the basement, but this issue could not be addressed. The second floor had two (2) lecture halls--Rm 202 (handled by AC4) and Rm 204 (handled by AC5); the balance of the second floor interior rooms and corridors was split between two other air handling systems, AC2 for the west side of the building and AC3 for the east side. The remaining 3rd and 4th floors were also split about evenly between AC2 and AC3. The perimeter rooms, equipped with wall units having their own outside air (OA) source plus centralized return air (RA) bypasses, were not included in this testing which was restricted to the basement floor (1st floor) and the four operating air handling systems, AC2 to AC5, during Test 1 and only AC2 to AC5 during Test 2. Two types of tests were performed using the full suite of 5 PFT types available. The first test was designed to measure the infiltration, exfiltration, and air exchange between the 5 AC zones above and the second test used the 5th tracer, which had been in the basement, as a distributed source throughout the four other zones to act as a surrogate pollutant source. This report provides final conclusions of both tests and suggestions regarding its usefulness in similar building ventilation and indoor air quality assessments.

  9. Displacement Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    Displacement ventilation is an interesting new type of air distribution principle which should be considered in connection with design of comfort ventilation in both smal1 and large spaces. Research activities on displacement ventilation are large all over the world and new knowledge of design...... methods appears continuously. This book gives an easy introduction to the basis of displacement ventilation and the chapters are written in the order which is used in a design procedure. The main text is extended by five appendices which show some of the new research activities taking place at Aalborg...

  10. Silver zeolite antimicrobial activity in aluminium heating, ventilation and air conditioning system ducts.

    Science.gov (United States)

    Rizzetto, R; Mansi, A; Panatto, D; Rizzitelli, E; Tinteri, C; Sasso, T; Gasparini, R; Crovari, P

    2008-03-01

    Air pollution in confined environments is a serious health problem, in that most people spend long periods indoors (in homes, offices, classrooms etc.). Some people (children, the elderly, heart disease patients, asthmatic or allergic subjects) are at greater risk because of their conditions of frailty. The growing use of air-conditioning systems in many public and private buildings aggravates this health risk, especially when these systems are not correctly installed or regularly serviced. The aim of our study was to verify the capacity of Ag+ ions to stop the growth of bacteria and moulds inside the ducts of Heating, Ventilation and Air Conditioning system ducts (HVAC) systems when these ducts were lined with active Ag+ ions zeolite-coated panels. A Y-shaped HVAC model with two branches was used; one branch was made of traditional galvanized iron, as was the whole system, while the other was lined with active Ag+ zeolite-coated polyurethane panels. During the test, samples of dust present inside both ducts were collected and seeded in liquid and solid media to detect bacteria and moulds. The presence of bacteria was also sought in the air emerging from the outlets of both ducts. Tests made on samples of particulate collected from the two different ducts revealed a lower total bacterial load in the samples collected from the Ag+ zeolite-coated duct than in the samples from the traditional Zn galvanized duct. In addition, the values of bacterial load found in the air emerging from the Ag+ ions zeolite-lined duct were 5 times lower than those found in the air from the traditional galvanized iron duct. The utilization of Ag+ zeolite-coated panels in air-conditioning systems could improve the quality of the emerging air in comparison with traditional installations in galvanized iron. This innovation could prove particularly advantageous in the event of accidents during the installation of air-conditioning systems or of contaminated aerosols coming from outside.

  11. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per; Nielsen, Peter V.

    2014-01-01

    As a novel air distribution system, diffuse ceiling ventilation combines the suspended acoustic ceiling with ventilation supply. Due to the low-impulse supply from the large ceiling area, the system does not generate draught when supplying cold air. However, heat sources play an important role...... on thermal comfort in the occupant zone. Another characteristic of this system is its lower pressure drop compared with conventional ventilation systems, which reduces the noise problem and, at the same time, the energy consumption of the fan can be reduced. This review is based on a number of experimental...... and numerical studies on diffuse ceiling ventilation. Performance in terms of thermal comfort, air quality, pressure drop as well as radiant cooling potential are examined. Finally, a discussion on the proper design of the suspended ceiling and plenum to achieve a uniform air distribution and surface...

  12. [Hygienic Inspections of Ventilation Systems Under Resting Conditions (According to DIN 1946-4:1999-03) - A Retrospective Assessment].

    Science.gov (United States)

    Friedrich, Lena; Boeckelmann, Irina

    2018-01-11

    Hygienic and microbiologically sterile air quality is essential for successful guideline-based work in operating theatres. To ensure clean air and to reduce contamination during surgery, ventilation systems are indispensable. Ventilation systems should be especially designed to keep the number of particles and germs under statutory limits. Therefore, they must be operated to recognised standards of good practice and be periodically inspected and maintained. The objective of this study was to prove, through the analysis of observation outside surgery time (rest condition), the effects of ventilation systems on air quality in a medical facility. Measurements were taken in 34 operating theatres annually over a period of ten years outside surgery time (resting condition) but with the air ventilation system operating under full load. 29 operating theatres were provided with laminar air flow and five theatres with turbulent air flow systems. In each operating theatre, air cleanliness was analysed by measuring the amount of airborne particles and airborne germs. Measuring points were determined 10 mm beneath the supply-air ceiling in the centre of the operating theatre and at one position outside the supply-air ceiling. The number of airborne particles at the supply-air ceiling was between 0/m³ and 4,441/m³ of air and, as such, the limiting factor was never exceeded. However, airborne germ measurements of between 0 CFU/m³ and 200 CFU/m³ (CFU: colony forming units) demonstrated that the limiting factor for this criterion was exceeded in 10.9% of occasions. In general, the values in the middle of the room were higher than at the supply-air ceiling. There were significant differences (p < 0.001) between the values at the supply-air ceiling, the surgery table and the values outside the supply-air ceiling. The results show the positive impact of ventilation systems on the air cleanliness in operating theatres. However, laminar airflow systems seem to create cleaner

  13. High frequency mechanical ventilation affects respiratory system mechanics differently in C57BL/6J and BALB/c adult mice.

    Science.gov (United States)

    Hadden, Hélène

    2013-01-15

    We tested the hypothesis that high frequency ventilation affects respiratory system mechanical functions in C57BL/6J and BALB/c mice. We measured respiratory mechanics by the forced oscillation technique over 1h in anesthetized, intubated, ventilated BALB/c and C57BL/6J male mice. We did not detect any change in airway resistance, Rn, tissue damping, G, tissue elastance, H and hysteresivity, eta in BALB/c mice during 1h of ventilation at 150 or at 450 breaths/min; nor did we find a difference between BALB/c mice ventilated at 150 breaths/min compared with 450 breaths/min. Among C57BL/6J mice, except for H, all parameters remained unchanged over 1h of ventilation in mice ventilated at 150 breaths/min. However, after 10 and 30 min of ventilation at 450 breaths/min, Rn, and respiratory system compliance were lower, and eta was higher, than their starting value. We conclude that high frequency mechanical ventilation affects respiratory system mechanics differently in C57BL/6J and BALB/c adult mice. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Reducing Mortality from Terrorist Releases of Chemical and Biological Agents: I. Filtration for Ventilation Systems in Commercial Building

    Energy Technology Data Exchange (ETDEWEB)

    Thatcher, Tracy L.; Daisey, Joan M.

    1999-09-01

    There is growing concern about potential terrorist attacks involving releases of chemical and/or biological (CB) agents, such as sarin or anthrax, in and around buildings. For an external release, the CB agent can enter the building through the air intakes of a building's mechanical ventilation system and by infiltration through the building envelope. For an interior release in a single room, the mechanical ventilation system, which often recirculates some fraction of the air within a building, may distribute the released CB agent throughout the building. For both cases, installing building systems that remove chemical and biological agents may be the most effective way to protect building occupants. Filtration systems installed in the heating, ventilating and air-conditioning (HVAC) systems of buildings can significantly reduce exposures of building occupants in the event of a release, whether the release is outdoors or indoors. Reduced exposures can reduce the number of deaths from a terrorist attack. The purpose of this report is to provide information and examples of the design of filtration systems to help building engineers retrofit HVAC systems. The report also provides background information on the physical nature of CB agents and brief overviews of the basic principles of particle and vapor filtration.

  15. Techno-economic evaluation of a ventilation system assisted with exhaust air heat recovery, electrical heater and solar energy

    OpenAIRE

    Özyoğurtçu, Gamze; Mobedi, Moghtada; Özerdem, Barış

    2014-01-01

    The energy consumed to condition fresh air is considerable, particularly for the buildings such as cinema, theatre or gymnasium saloons. The aim of the present study is to design a ventilation system assisted with exhaust air heat recovery unit, electrical heater and stored solar energy, then to make an economical analysis based on life cycle cost (LCC) to find out its payback period. The system is able to recover thermal energy of exhaust air, store solar energy during the sunlight period an...

  16. Effectiveness of a personalized ventilation system in reducing personal exposure against directly released simulated cough droplets

    DEFF Research Database (Denmark)

    Pantelic, J.; Tham, K. W.; Licina, Dusan

    2015-01-01

    The inhalation intake fraction was used as an indicator to compare effects of desktop personalized ventilation and mixing ventilation on personal exposure to directly released simulated cough droplets. A cough machine was used to simulate cough release from the front, back, and side of a thermal...... manikin at distances between 1 and 4m. Cough droplet concentration was measured with an aerosol spectrometer in the breathing zone of a thermal manikin. Particle image velocimetry was used to characterize the velocity field in the breathing zone. Desktop personalized ventilation substantially reduced...... the inhalation intake fraction compared to mixing ventilation for all investigated distances and orientations of the cough release. The results point out that the orientation between the cough source and the breathing zone of the exposed occupant is an important factor that substantially influences exposure...

  17. A CNC Sheetmetal Fabrication System for Production of Ships Ventilation Components and Flatwork

    National Research Council Canada - National Science Library

    Galie, Thomas R; Blais, David R

    1981-01-01

    .... By utilizing computer graphics technology and Computer Numeric Control (CNC) machine tools, it is possible to reduce the manhours required for fabrication of ventilation and flatwork by as much as 40 percent...

  18. Use of Disinfectants and Sanitizers in Heating, Ventilation, Air Conditioning, and Refrigeration Systems

    Science.gov (United States)

    This letter is to brings attention several concerns that the Agency has regarding the use of sanitizer and/or disinfectant products, and other types of antimicrobial products, to treat the surfaces of heating, ventilation

  19. Mathematical model and minimal measurement system for optimal control of heated humidifiers in neonatal ventilation.

    Science.gov (United States)

    Verta, Antonella; Schena, Emiliano; Silvestri, Sergio

    2010-06-01

    The control of thermo-hygrometric conditions of gas delivered in neonatal mechanical ventilation appears to be a particularly difficult task, mainly due to the vast number of parameters to be monitored and the control strategies of heated humidifiers to be adopted. In the present paper, we describe the heat and fluid exchange occurring in a heated humidifier in mathematical terms; we analyze the sensitivity of the relative humidity of outlet gas as a function of thermo-hygrometric and fluid-dynamic parameters of delivered gas; we propose a control strategy that will enable the stability of outlet gas thermo-hygrometric conditions. The mathematical model is represented by a hyper-surface containing the functional relations between the input variables, which must be measured, and the output variables, which have to remain constant. Model sensitivity analysis shows that heated humidifier efficacy and stability of outlet gas thermo-hygrometric conditions are principally influenced by four parameters: liquid surface temperature, gas flow rate, inlet gas temperature and inlet gas relative humidity. The theoretical model has been experimentally validated in typical working conditions of neonatal applications. The control strategy has been implemented by a minimal measurement system composed of three thermometers, a humidity sensor, and a flow rate sensor, and based on the theoretical model. Outlet relative humidity, contained in the range 90+/-4% and 94+/-4%, corresponding with temperature variations in the range 28+/-2 degrees C and 38+/-2 degrees C respectively, has been obtained in the whole flow rate range typical of neonatal ventilation from 1 to 10 L/min. We conclude that in order to obtain the stability of the thermo-hygrometric conditions of the delivered gas mixture: (a) a control strategy with a more complex measurement system must be implemented (i.e. providing more input variables); (b) and the gas may also need to be pre-warmed before entering the humidifying

  20. Concentration Distribution in a Mixing Ventilated Room

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Pedersen, D.N.; Nielsen, Peter V.

    2001-01-01

    Today there is an increasing focus on the importance of a proper ventilation system to obtain good working conditions in the term of air and thermal quality to ensure high productivity. Different ventilation principles are used, e.g., mixing ventilation and displacement ventilation. In order to e...

  1. Combined effects of leaks, respiratory system properties and upper airway patency on the performance of home ventilators: a bench study.

    Science.gov (United States)

    Zhu, Kaixian; Rabec, Claudio; Gonzalez-Bermejo, Jésus; Hardy, Sébastien; Aouf, Sami; Escourrou, Pierre; Roisman, Gabriel

    2017-11-21

    Combined effects of leaks, mechanical property of respiratory system and upper airway (UA) patency on patient-ventilator synchrony (PVA) and the level of clinically "tolerable" leaks are not well established in home ventilators. We comparatively assessed on a bench model, the highest leak level tolerated without inducing significant asynchrony ("critical leak") in three home ventilators (Astral 150, Trilogy 100 and Vivo 60; noted as A150, T100 and V60 respectively) subjected to three simulated diseased respiratory conditions: chronic obstructive pulmonary disease (COPD), obesity hypoventilation (OHS) and neuromuscular disorders (NMD), with both open and closed UA. Also, total leak values in the device reports were compared to the bench-measured values. With open UA, all ventilators were able to avoid asynchrony up to a 30 L/min leak and even to 55 L/min in some cases. UA closure and respiratory diseases especially OHS influenced PVA. With closed UA, the critical leak of A150 and T100 remained higher than 55 L/min in COPD and OHS, while for V60 decreased to 41 and 33 L/min respectively. In NMD with closed UA, only T100 reached a high critical leak of 69 L/min. Besides, inspiratory trigger sensitivity change was often necessary to avoid PVA. Home ventilators were able to avoid PVA in high-level leak conditions. However, asynchrony appeared in cases of abnormal mechanical properties of respiratory system or closed UA. In case of closed UA, the EPAP should be adjusted prior to the inspiratory trigger. Not applicable.

  2. Assessment of an automated surveillance system for detection of initial ventilator-associated events.

    Science.gov (United States)

    Nuckchady, Dooshanveer; Heckman, Michael G; Diehl, Nancy N; Creech, Tara; Carey, Darlene; Domnick, Robert; Hellinger, Walter C

    2015-10-01

    Surveillance for initial ventilator-associated events (VAEs) was automated and compared with nonautomated review of episodes of mechanical ventilation. Sensitivity, specificity, positive predictive value, and negative predictive value of automated surveillance were very high (>93%), and automated surveillance reduced the time spent on detection of VAEs by >90%. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  3. Plasma injection events at synchronous orbit related to positive Dst

    Science.gov (United States)

    Arnoldy, R. L.; Moore, T. E.; Akasofu, S.-I.

    1982-01-01

    AST 6 spacecraft synchronous orbit measurements are compared with space and ground data in a study of plasma effects related to SI and SC magnetic perturbations. It is found that synchronous orbit plasma injections related to the sudden phenomena are similar to those associated with substorms, although the former occur at all local times. The synchronous orbit plasma injections are interpreted as the co-location of particle boundaries on an inward propagating front and the compression magnetic pulse associated with SI and SC events is seen as responsible for the co-location of the boundaries and their inward propagation. The positive Dst magnetic pulse plays a role similar to that of the magnetic tail reconfiguration pulse associated with substorms, and evidence is shown that positive Dst enhances magnetospheric convection independently of interplanetary magnetic field direction

  4. The role of ventilation and HVAC systems for human health in nonindustrial indoor environments. A supplementary review by EUROVEN group

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Sundell, Jan; Bischof, W.

    2002-01-01

    ; 108 peer-reviewed papers have been reviewed among which 74 supported or refuted the hypotheses. The group concluded that increasing outdoor air supply rates is necessary for dilution/removal of pollutants generated indoors (including allergens), and that improper design, functioning and maintenance...... of ventilation and air-conditioning systems, as well as their intermittent operation, may be potential reasons for health problems of people staying indoors....... with increased productivity, and that air-conditioning systems may increase the risk of sick building syndrome (SBS) symptoms. Taking these findings into account, the group has elaborated 35 hypotheses on the role of ventilation ahd HVAC systems in nonindustrial indoor environments with regard to human health...

  5. EXPLORATION WELL TEST CASE HISTORY CONFIRMS IMPORTANCE OF DST

    OpenAIRE

    Dario Damjanić

    2009-01-01

    Drill stem testing of the exploration well consisted of two flow and two pressure build-up periods. Gas was obtained. Modified isochronal test was used during testing the well after completion. Except gas, small quantity of condensate and traces of oil and water were obtained. Both pressure build-up analyses showed that formation permeability is low. DST pressure build-up analysis showed that wellbore damage is present. This was proved later, when acid treatment was performed, by which skin w...

  6. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per Kvols

    -cooling period and night cooling potential. The investment cost of this ventilation system is about 5-10% lower than the conventional ones, because the acoustic ceiling could be directly applied as air diffuser and the use of plenum to distribute air reduces the cost of ductwork. There is a growing interest...... in applying diffuse ceiling ventilation in offices and other commercial buildings because of the benefits from both thermal comfort and energy efficiency aspects. The design guide introduces the principle and key characteristics of room air distribution with diffuse ceiling ventilation and the design...

  7. Behovstyret ventilation

    DEFF Research Database (Denmark)

    Afshari, Alireza; Heiselberg, Per; Reinhold, Claus

    2010-01-01

    I en nylig afsluttet undersøgelse er der udført en række målinger på otte udvalgte børneinstitutioner. Fire af disse med mekanisk ventilation og fire med naturlig ventilation. Formålet er at udvide den erfaringsbaserede viden om funktionen af naturlige og mekaniske ventilationsløsninger i...

  8. Ventilation Effectiveness

    DEFF Research Database (Denmark)

    Mundt, M.; Mathisen, H. M.; Moser, M.

    Improving the ventilation effectiveness allows the indoor air quality to be significantly enhanced without the need for higher air changes in the building, thereby avoiding the higher costs and energy consumption associated with increasing the ventilation rates. This Guidebook provides easy-to-un...

  9. Demonstration of the Performance of an Air-Type Photovoltaic Thermal (PVT System Coupled with a Heat-Recovery Ventilator

    Directory of Open Access Journals (Sweden)

    Jin-Hee Kim

    2016-09-01

    Full Text Available A heat-recovery ventilator (HRV effectively conducts ventilation by recovering waste heat from indoors to outdoors during heating periods. However, dew condensation associated with the HRV system may arise due to the difference between the indoor temperature and the very low outdoor temperature in winter, and this can decrease the heat exchange efficiency. These problems can be solved by the pre-heating of the incoming air, but additional energy is required when pursuing such a strategy. On the other hand, an air-type photovoltaic thermal (PVT system produces electricity and thermal energy simultaneously using air as the heat transfer medium. Moreover, the heated air from the air-type PVT system can be connected to the HRV to pre-heat the supply air instead of taking in the cold outdoor air. Thus, the ventilation efficiency can be improved and the problems arising during the heating period can be resolved. Consequentially, the heating energy required in a building can be reduced, with additional electricity acquired as well. In this paper, the performance of an air-type PVT system coupled with an HRV is assessed. To do this, air-type PVT collectors operating at 1 kWp were installed in an experimental house and coupled to an HRV system. Thermal performance and heating energy required during the winter season were analyzed experimentally. Furthermore, the electrical performances of the air-type PVT system with and without ventilation at the back side of the PV during the summer season were analyzed.

  10. DETERMINATION OF THE ZONE ENDANGERED BY METHANE EXPLOSION IN GOAF WITH CAVING OF LONGWALLS VENTILATED ON „Y” SYSTEM

    Directory of Open Access Journals (Sweden)

    Jarosław BRODNY

    2016-10-01

    Full Text Available One of the most dangerous and most commonly present risks in hard coal mines is methane hazard. During exploitation by longwall system with caving, methane is emitted to mine heading from the mined coal and coal left in a pile. A large amount of methane also flows from neighboring seams through cracks and fissures formed in rock mass. In a case of accumulation of explosive methane concentration in goaf zone and with appropriate oxygen concentration and occur-rence of initials (e.g. spark or endogenous fire, it may come to the explosion of this gas. In the paper there are present-ed results of numerical analysis of mixture of air and methane streams flow through the real heading system of a mine, characterized by high methane hazard. The aim of the studies was to analyze the ventilation system of considered head-ing system and determination of braking zones in goaf zone, in which dangerous and explosive concertation of methane can occur with sufficient oxygen concentration equal to at least 12%. Determination of position of these zones is neces-sary for the selection of appropriate parameters of the ventilation system to ensure safety of the crew. Analysis of the scale of methane hazard allows to select such a ventilation system of exploitation and neighboring headings that ensures chemical composition of mining atmosphere required by regulation, and required efficiency of methane drainage. The obtained results clearly show that numerical methods, combined with the results of tests in real conditions can be suc-cessfully used for the analysis of variants of processes related to ventilation of underground mining, and also in the anal-ysis of emergency states.

  11. Design and Integrate Improved Systems for Nuclear Facility Ventilation and Exhaust Operations

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-04-15

    Objective: The objective of this R&D project would complete the development of three new systems and integrate them into a single experimental effort. However, each of the three systems has stand-alone applicability across the DOE complex. At US DOE nuclear facilities, indoor air is filtered and ventilated for human occupancy, and exhaust air to the outdoor environment must be regulated and monitored. At least three technical standards address these functions, and the Los Alamos National Laboratory would complete an experimental facility to answer at least three questions: (1) Can the drag coefficient of a new Los Alamos air mixer be reduced for better operation in nuclear facility exhaust stacks? (2) Is it possible to verify the accuracy of a new dilution method for HEPA filter test facilities? (3) Is there a performance-based air flow metric (volumetric flow or mass flow) for operating HEPA filters? In summary, the three new systems are: a mixer, a diluter and a performance-based metric, respectively. The results of this project would be applicable to at least four technical standards: ANSI N13.1 Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities; ASTM F1471 Standard Test Method for Air Cleaning Performance of a High-Efficiency Particulate Air Filter System, ASME N511: In-Service Testing of Nuclear Air Treatment, Heating, Ventilating, and Air-Conditioning Systems, and ASME AG-1: Code On Nuclear Air And Gas Treatment. All of the three proposed new systems must be combined into a single experimental device (i.e. to develop a new function of the Los Alamos aerosol wind tunnel). Technical Approach: The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally (2006) designed to evaluate small air samplers (cf. US EPA 40 CFR 53.42). In 2009, the tunnel was modified for exhaust stack verifications per the ANSI N13.1 standard. In 2010, modifications were started on the

  12. DST non-suppression predicts suicide after attempted suicide.

    Science.gov (United States)

    Jokinen, Jussi; Carlborg, Andreas; Mårtensson, Björn; Forslund, Kaj; Nordström, Anna-Lena; Nordström, Peter

    2007-04-15

    Most prospective studies of HPA axis have found that non-suppressors in the dexamethasone suppression test (DST) are more likely to commit suicide during the follow-up. Attempted suicide is a strong clinical predictor of suicide. The aim of this study was to assess the predictive value of DST for suicide in a group of depressed inpatients with and without an index suicide attempt. Historical cohort of 382 psychiatric inpatients with mood disorder admitted to the department of Psychiatry at the Karolinska University Hospital between 1980 and 2000 were submitted to the DST and followed up for causes of death. During the follow-up (mean 18 years), 36 suicides (9.4%) occurred, 20 of these were non-suppressors and 16 were suppressors. There was no statistically significant difference in suicide risk between the suppressors and non-suppressors for the sample as a whole. An index suicide attempt predicted suicide. In suicide attempters with mood disorder, the non-suppressor status was significantly associated with suicide indicating that HPA axis hyperactivity is a risk factor for suicide in this group. The dexamethasone suppression test may be a useful predictor within this population.

  13. Ventilative Cooling

    DEFF Research Database (Denmark)

    Heiselberg, Per Kvols; Kolokotroni, Maria

    This report, by venticool, summarises the outcome of the work of the initial working phase of IEA ECB Annex 62 Ventilative Cooling and is based on the findings in the participating countries. It presents a summary of the first official Annex 62 report that describes the state-of-the-art of ventil......This report, by venticool, summarises the outcome of the work of the initial working phase of IEA ECB Annex 62 Ventilative Cooling and is based on the findings in the participating countries. It presents a summary of the first official Annex 62 report that describes the state......-of-the-art of ventilative cooling potentials and limitations, its consideration in current energy performance regulations, available building components and control strategies and analysis methods and tools. In addition, the report provides twenty six examples of operational buildings using ventilative cooling ranging from...

  14. Research on frequency conversion technology of metro station's ventilation and air-conditioning system

    International Nuclear Information System (INIS)

    Yang, Zhao; Yu, Zhuangzhuang; Yu, Longqing; Ma, Feng

    2014-01-01

    Ventilation and air-conditioning system (VAC) is the most energy-saving potential system in the metro. This paper analyzes the passenger traffic, air-conditioning load and station air supply on the initial, recent and long-term phase of metro station. And it proposes that it is necessary to run chilled-water pumps, air handing unit (AHU) fans and back/exhaust fans with frequency conversion technology (FCT). Then it uses the thermodynamic method to analyze the impact of running chilled-water pumps with FCT. The results show that running chilled-water pumps with FCT can reduce the total power consumption of system, although increases chiller energy consumption. Then the temperature and velocity fields of the platform and station hall are simulated by CFD software according to the variable air volume. And the results show that under the condition of running the VAC system with FCT, temperature and velocity fields distribution are both in the comfortable range. Finally, by taking a typical summer day for example, this paper analyzes the energy savings of chilled-water pumps, AHU fans and back/exhaust fans on the initial, recent and long-term phase, and the calculation results show that the respective total energy savings are 1103.4 kWh, 1064.3 kWh and 926.2 kWh, and the respective total power saving ratio is 73.4%, 71.2% and 59.5%. - Highlights: •Use the FCT to reduce energy consumption of metro VAC is necessary and possible. •Analyze the influence of running the chilled-water pumps with FCT. •Results show that variable air volume of station public area is feasible. •Calculations indicate that energy-saving effect of using the FCT is considerable

  15. Lung deposition and systemic bioavailability of different aerosol devices with and without humidification in mechanically ventilated patients.

    Science.gov (United States)

    Moustafa, Islam O F; Ali, Mohammed R A-A; Al Hallag, Moataz; Rabea, Hoda; Fink, James B; Dailey, Patricia; Abdelrahim, Mohamed E A

    During mechanical ventilation medical aerosol delivery has been reported to be upto two fold greater with dry inhaled gas than with heated humidity. Urine levels at 0.5 h post dose (URSAL0.5%) has been confirmed as an index of lung deposition and 24 h (URSAL24%) as index of systemic absorption. Our aim was to determine the effect of humidification and aerosol device type on drug delivery to ventilated patients using urine levels. In a randomized crossover design, 36 (18female) mechanically ventilated patients were assigned to one of three groups. Groups 1 and 2 received 5000 μg salbutamol using vibrating mesh (VM) and jet nebulizers (JN), respectively, while group 3 received 1600 μg (16 puffs) of salbutamol via metered dose inhaler with AeroChamber Vent (MDI-AV). All devices were placed in the inspiratory limb of ventilator downstream from the humidifier. Each subject received aerosol with and without humidity at >24 h intervals with >12 h washout periods between salbutamol doses. Patients voided urine 15 min before each study dose and urine samples were collected at 0.5 h post dosing and pooled for the next 24 h. The MDI-AV and VM resulted in a higher percentage of urinary salbutamol levels compared to the JN (p < 0.05). Urine levels were similar between humidity and dry conditions. Our findings suggest that in-vitro reports overestimate the impact of dry vs. heated humidified conditions on the delivery of aerosol during invasive mechanical ventilation. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Total System Performance Assessment- License Appication Design Selection (LADS) Phase 1 Analysis for Post-Closure Ventilation (Design Alternative 3)

    Energy Technology Data Exchange (ETDEWEB)

    N. Erb

    1999-06-21

    The objective of this report is to evaluate the effect of potential changes to the TSPA-VA base case design on long-term repository performance. The design changes that are evaluated in this report include two configurations for post-closure ventilation. bow tie and open loop (Design Alternative 3 or D3). The following paragraphs briefly describe the motivation for evaluating post-closure ventilation. The bow tie configuration for post closure ventilation has been identified as a design alternative to the TSPA-VA base case model (CRWMS M&O, 1998a) that may provide improved performance by reducing the temperature and relative humidity within the waste package drifts. The bow tie configuration for post-closure ventilation is a closed-loop design. In this design. cross drifts are placed in pairs with each drift angling up on opposite sides of the repository. From the side, the cross drifts and side drifts form the shape of a bow tie. Movement of air through the system is driven by convective heating from the waste packages in the cross drifts. The open loop configuration is also being considered for its potential to improve post-closure performance of the repository. As with the bow tie configuration, the open loop is designed to decrease temperature and relative humidity within the waste package drifts. For the open loop configuration, air is drawn into the drifts from outside the mountain. The configuration for the repository with open-loop ventilation is similar to the base case repository design with a few added shafts to increase air flow through the drifts. This report documents the modeling assumptions and calculations conducted to evaluate the long-term performance of Design Alternative 3. The performance measure for this evaluation is dose rate. Results are presented that compare the dose-rate time histories with the new design alternatives to that for the TSPA-VA base case calculation (CRWMS M&O, 1998a).

  17. Inverse Modeling of Respiratory System during Noninvasive Ventilation by Maximum Likelihood Estimation

    Directory of Open Access Journals (Sweden)

    Esra Saatci

    2010-01-01

    Full Text Available We propose a procedure to estimate the model parameters of presented nonlinear Resistance-Capacitance (RC and the widely used linear Resistance-Inductance-Capacitance (RIC models of the respiratory system by Maximum Likelihood Estimator (MLE. The measurement noise is assumed to be Generalized Gaussian Distributed (GGD, and the variance and the shape factor of the measurement noise are estimated by MLE and Kurtosis method, respectively. The performance of the MLE algorithm is also demonstrated by the Cramer-Rao Lower Bound (CRLB with artificially produced respiratory signals. Airway flow, mask pressure, and lung volume are measured from patients with Chronic Obstructive Pulmonary Disease (COPD under the noninvasive ventilation and from healthy subjects. Simulations show that respiratory signals from healthy subjects are better represented by the RIC model compared to the nonlinear RC model. On the other hand, the Patient group respiratory signals are fitted to the nonlinear RC model with lower measurement noise variance, better converged measurement noise shape factor, and model parameter tracks. Also, it is observed that for the Patient group the shape factor of the measurement noise converges to values between 1 and 2 whereas for the Control group shape factor values are estimated in the super-Gaussian area.

  18. Assessing the capacity of the healthcare system to use additional mechanical ventilators during a large-scale public health emergency (PHE)

    Science.gov (United States)

    Ajao, Adebola; Nystrom, Scott V.; Koonin, Lisa M.; Patel, Anita; Howell, David R.; Baccam, Prasith; Lant, Tim; Malatino, Eileen; Chamberlin, Margaret; Meltzer, Martin I.

    2015-01-01

    A large-scale Public Health Emergency (PHE), like a severe influenza pandemic can generate large numbers of critically ill patients in a short time. We modeled the number of mechanical ventilators that could be used in addition to the number of hospital-based ventilators currently in use. We identified key components of the healthcare system needed to deliver ventilation therapy, quantified the maximum number of additional ventilators that each key component could support at various capacity levels (i.e. conventional, contingency and crisis) and determined the constraining key component at each capacity level. Our study results showed that U.S. hospitals could absorb between 26,200 and 56,300 additional ventilators at the peak of a national influenza pandemic outbreak with robust pre-pandemic planning. This methodology could be adapted by emergency planners to determine stockpiling goals for critical resources or identify alternatives to manage overwhelming critical care need. PMID:26450633

  19. Effects of Open and Closed Suctioning Systems on Pain in Newborns Treated with Mechanical Ventilation.

    Science.gov (United States)

    Acikgoz, Ayfer; Yildiz, Suzan

    2015-10-01

    This experimental study was conducted to compare the effects of open and closed suctioning systems on pain in newborns receiving ventilation support. The study sample consisted of 42 babies (23 female, 16 male) hospitalized in the unit between December 2010 and December 2011 who met the selection criteria established for the study. Using the random sampling method, 20 of the babies were included in the closed suctioning system group and the remaining 22 were analyzed in the open suctioning system group. The data collection tools of the study were intervention monitoring form, data collection form, and documentation of the personal information on the babies; and the Neonatal Pain, Agitation, and Sedation Scale (N-PASS) evaluated the babies' pain responses. The data were evaluated using SPSS 15 software. Most neonates were born preterm (≤37 weeks' gestation at birth; 69% [n = 29]). The mean (SD) birth weight, gestational age, and intensive care unit stay were 1.82 kg (1.1 kg), 31.9 (5.3) weeks, and 25.3 (2.9) calendar days, respectively. Results of the study revealed no statistically significant difference between the open suctioning and closed suctioning groups (p = .194). However, the N-PASS pain scores obtained before and during the suctioning processes were significantly different (p pain during the suctioning process, according to N-PASS scores, and although not significant statistically, the level of pain felt during open suctioning was observed to be slightly higher compared with closed suctioning. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

  20. Realization of PLC to the Variable Frequency Speed Regulation System of Mine Local Ventilator based on RS-485 Communication

    Science.gov (United States)

    Ma, Kai; Li, Jian; Yun, Yichong

    2018-03-01

    The article first introduces the merits of serial communication in the PLC to the variable frequency speed regulation system of mine local ventilator, and then sets up a hardware application development platform of PLC and inverter based on RS-485 communication technology, next presents communication initialization of the PLC and Inverter. Finally according to the control requirements, PLC send run operation & monitoring instruction to Inverter, realizes the serial communication control between the PLC and Inverter.

  1. A Study on The Development of Local Exhaust Ventilation System (LEV’s) for Installation of Laser Cutting Machine

    Science.gov (United States)

    Harun, S. I.; Idris, S. R. A.; Tamar Jaya, N.

    2017-09-01

    Local exhaust ventilation (LEV) is an engineering system frequently used in the workplace to protect operators from hazardous substances. The objective of this project is design and fabricate the ventilation system as installation for chamber room of laser cutting machine and to stimulate the air flow inside chamber room of laser cutting machine with the ventilation system that designed. LEV’s fabricated with rated voltage D.C 10.8V and 1.5 ampere. Its capacity 600 ml, continuously use limit approximately 12-15 minute, overall length LEV’s fabricated is 966 mm with net weight 0.88 kg and maximum airflow is 1.3 meter cubic per minute. Stimulate the air flow inside chamber room of laser cutting machine with the ventilation system that designed and fabricated overall result get 2 main gas vapor which air and carbon dioxide. For air gas which experimented by using anemometer, general duct velocity that produce is same with other gas produce, carbon dioxide which 5 m/s until 10 m/s. Overall result for 5 m/s and 10 m/s as minimum and maximum duct velocity produce for both air and carbon dioxide. The air gas flow velocity that captured by LEV’s fabricated, 3.998 m/s average velocity captured from 5 m/s duct velocity which it efficiency of 79.960% and 7.667 m/s average velocity captured from 10 m/s duct velocity with efficiency of 76.665%. For carbon dioxide gas flow velocity that captured by LEV’s fabricated, 3.674 m/s average velocity captured from 5 m/s duct velocity which it efficiency of 73.480% and 8.255 m/s average velocity captured from 10 m/s duct velocity with efficiency of 82.545%.

  2. Fire, safety and ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Hindle, D.

    1999-02-01

    Correct ventilation in tunnel environments is vital for the comfort and safety of the people passing through. This article gives details of products from several manufacturers of safety rescue and fire fighting equipment, fire and fume detection equipment, special fire resistant materials, fire resistant hydraulic oils and fire dampers, and ventilation systems. Company addresses and fax numbers are supplied. 4 refs., 5 tabs., 10 photos.

  3. DNA accumulation on ventilation system filters in university buildings in Singapore.

    Science.gov (United States)

    Luhung, Irvan; Wu, Yan; Xu, Siyu; Yamamoto, Naomichi; Chang, Victor Wei-Chung; Nazaroff, William W

    2017-01-01

    Biological particles deposit on air handling system filters as they process air. This study reports and interprets abundance and diversity information regarding biomass accumulation on ordinarily used filters acquired from several locations in a university environment. DNA-based analysis was applied both to quantify (via DNA fluorometry and qPCR) and to characterize (via high-throughput sequencing) the microbial material on filters, which mainly processed recirculated indoor air. Results were interpreted in relation to building occupancy and ventilation system operational parameters. Based on accumulated biomass, average DNA concentrations per AHU filter surface area across nine indoor locations after twelve weeks of filter use were in the respective ranges 1.1 to 41 ng per cm2 for total DNA, 0.02 to 3.3 ng per cm2 for bacterial DNA and 0.2 to 2.0 ng DNA per cm2 for fungal DNA. The most abundant genera detected on the AHU filter samples were Clostridium, Streptophyta, Bacillus, Acinetobacter and Ktedonobacter for bacteria and Aspergillus, Cladosporium, Nigrospora, Rigidoporus and Lentinus for fungi. Conditional indoor airborne DNA concentrations (median (range)) were estimated to be 13 (2.6-107) pg/m3 for total DNA, 0.4 (0.05-8.4) pg/m3 for bacterial DNA and 2.3 (1.0-5.1) pg/m3 for fungal DNA. Conditional airborne concentrations and the relative abundances of selected groups of genera correlate well with occupancy level. Bacterial DNA was found to be more responsive than fungal DNA to differences in occupancy level and indoor environmental conditions.

  4. DNA accumulation on ventilation system filters in university buildings in Singapore.

    Directory of Open Access Journals (Sweden)

    Irvan Luhung

    Full Text Available Biological particles deposit on air handling system filters as they process air. This study reports and interprets abundance and diversity information regarding biomass accumulation on ordinarily used filters acquired from several locations in a university environment.DNA-based analysis was applied both to quantify (via DNA fluorometry and qPCR and to characterize (via high-throughput sequencing the microbial material on filters, which mainly processed recirculated indoor air. Results were interpreted in relation to building occupancy and ventilation system operational parameters.Based on accumulated biomass, average DNA concentrations per AHU filter surface area across nine indoor locations after twelve weeks of filter use were in the respective ranges 1.1 to 41 ng per cm2 for total DNA, 0.02 to 3.3 ng per cm2 for bacterial DNA and 0.2 to 2.0 ng DNA per cm2 for fungal DNA. The most abundant genera detected on the AHU filter samples were Clostridium, Streptophyta, Bacillus, Acinetobacter and Ktedonobacter for bacteria and Aspergillus, Cladosporium, Nigrospora, Rigidoporus and Lentinus for fungi. Conditional indoor airborne DNA concentrations (median (range were estimated to be 13 (2.6-107 pg/m3 for total DNA, 0.4 (0.05-8.4 pg/m3 for bacterial DNA and 2.3 (1.0-5.1 pg/m3 for fungal DNA.Conditional airborne concentrations and the relative abundances of selected groups of genera correlate well with occupancy level. Bacterial DNA was found to be more responsive than fungal DNA to differences in occupancy level and indoor environmental conditions.

  5. 2008 GEM Modeling Challenge: Metrics Study of the Dst Index in Physics-Based Magnetosphere and Ring Current Models and in Statistical and Analytic Specifications

    Science.gov (United States)

    Rastaetter, L.; Kuznetsova, M.; Hesse, M.; Pulkkinen, A.; Glocer, A.; Yu, Y.; Meng, X.; Raeder, J.; Wiltberger, M.; Welling, D.; hide

    2011-01-01

    In this paper the metrics-based results of the Dst part of the 2008-2009 GEM Metrics Challenge are reported. The Metrics Challenge asked modelers to submit results for 4 geomagnetic storm events and 5 different types of observations that can be modeled by statistical or climatological or physics-based (e.g. MHD) models of the magnetosphere-ionosphere system. We present the results of over 25 model settings that were run at the Community Coordinated Modeling Center (CCMC) and at the institutions of various modelers for these events. To measure the performance of each of the models against the observations we use comparisons of one-hour averaged model data with the Dst index issued by the World Data Center for Geomagnetism, Kyoto, Japan, and direct comparison of one-minute model data with the one-minute Dst index calculated by the United States Geologic Survey (USGS).

  6. COST EFFECTIVE VOC EMISSION CONTROL STARTEGIES FOR MILITARY, AEROSPACE,AND INDUSTRIAL PAINT SPRAY BOOTH OPERATIONS: COMBINING IMPROVED VENTILATION SYSTEMS WITH INNOVATIVE, LOW COST EMISSION CONTROL TECHNOLOGIES

    Science.gov (United States)

    The paper describes a full-scale demonstration program in which several paint booths were modified for recirculation ventilation; the booth exhaust streams are vented to an innovative volatile organic compound (VOC) emission control system having extremely low operating costs. ...

  7. Newer nonconventional modes of mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Preet Mohinder Singh

    2014-01-01

    Full Text Available The conventional modes of ventilation suffer many limitations. Although they are popularly used and are well-understood, often they fail to match the patient-based requirements. Over the years, many small modifications in ventilators have been incorporated to improve patient outcome. The ventilators of newer generation respond to patient′s demands by additional feedback systems. In this review, we discuss the popular newer modes of ventilation that have been accepted in to clinical practice. Various intensive care units over the world have found these modes to improve patient ventilator synchrony, decrease ventilator days and improve patient safety. The various modes discusses in this review are: Dual control modes (volume assured pressure support, volume support, Adaptive support ventilation, proportional assist ventilation, mandatory minute ventilation, Bi-level airway pressure release ventilation, (BiPAP, neurally adjusted ventilatory assist and NeoGanesh. Their working principles with their advantages and clinical limitations are discussed in brief.

  8. A Study on the Optimal Duration of Daylight Saving Time (DST in Korea

    Directory of Open Access Journals (Sweden)

    Byeong-Hee Mihn

    2009-09-01

    Full Text Available Daylight saving time aims at spending effective daylight in summer season. Korea had enforced daylight saving time twelve times from 1948 to 1988. Since 1988, it is not executed, but it is recently discussed the resumption of DST. In this paper, we investigate the trend of DST in other countries, review the history of DST in Korea, and suggest the optimal DST duration in terms of astronomical aspects (times of sunrise and sunset. We find that the starting day of DST in Korea is apt for the second Sunday in Mayor the second Sunday in April according to the time of sunrise or to the difference between Korean standard meridian and observer`s, respectively. We also discuss time friction that might be caused by time difference between DST and Korea Standard Time (KST.

  9. Response of Preterm Infants to 2 Noninvasive Ventilatory Support Systems: Nasal CPAP and Nasal Intermittent Positive-Pressure Ventilation.

    Science.gov (United States)

    Silveira, Carmen Salum Thomé; Leonardi, Kamila Maia; Melo, Ana Paula Carvalho Freire; Zaia, José Eduardo; Brunherotti, Marisa Afonso Andrade

    2015-12-01

    Noninvasive ventilation (NIV) in preterm infants is currently applied using intermittent positive pressure (2 positive-pressure levels) or in a conventional manner (one pressure level). However, there are no studies in the literature comparing the chances of failure of these NIV methods. The aim of this study was to evaluate the occurrence of failure of 2 noninvasive ventilatory support systems in preterm neonates over a period of 48 h. A randomized, prospective, clinical study was conducted on 80 newborns (gestational age Ventilatory support failure was observed in 25 (62.5%) newborns treated with nasal CPAP and in 12 (30%) newborns treated with NIPPV, indicating an association between NIV failure and the absence of intermittent positive pressure (odds ratio [OR] 1.22, P newborns receiving nasal CPAP and 12.5% (OR 0.14) receiving NIPPV required invasive mechanical ventilation. Ventilatory support failure was significantly more frequent when nasal CPAP was used. Copyright © 2015 by Daedalus Enterprises.

  10. Probabilistic Analysis Methods for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Brohus, Henrik; Frier, Christian; Heiselberg, Per

    This paper discusses a general approach for the application of probabilistic analysis methods in the design of ventilation systems. The aims and scope of probabilistic versus deterministic methods are addressed with special emphasis on hybrid ventilation systems. A preliminary application...

  11. Descriptions and diagrams of the primary and annulus ventilation systems of the double-shell tank farms as of January 1988

    International Nuclear Information System (INIS)

    Blackman, A.E.; Waters, E.D.

    1994-01-01

    This document is a compilation of information describing the ventilation systems of the Double-Shell Tank farms (214-AN, -AP, -AW, -AW, -AY, -AZ, and -SY). A general description of the primary tank and annulus ventilation systems is given along with specific information on the high efficiency particulate air (HEPA) filters, condensers, preheaters, exhaust fans, and piping. This information is considered to be current as of January 1988. 38 refs, 20 figs, 30 tabs

  12. Development and evaluation of a ceiling ventilation system enhanced by solar photovoltaic thermal collectors and phase change materials

    International Nuclear Information System (INIS)

    Lin, Wenye; Ma, Zhenjun; Sohel, M. Imroz; Cooper, Paul

    2014-01-01

    Highlights: • A novel ceiling ventilation system enhanced by PVT and PCMs was proposed. • PCM was used to increase the local thermal mass and to serve as a storage unit. • The proposed system can enhance indoor thermal comfort in winter and summer. - Abstract: This paper presents the development and performance evaluation of a novel ceiling ventilation system integrated with solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs). The PVT collectors are used to generate electricity and provide low grade heating and cooling energy for buildings by using winter daytime solar radiation and summer night-time sky radiative cooling, respectively. The PCM is integrated into the building ceiling as a part of the ceiling insulation and at the same time, as a centralized thermal energy storage to temporally store low grade energy collected from the PVT collectors. The performance of the proposed system was numerically evaluated based on a Solar Decathlon house using TRNSYS. The results showed that, in winter conditions, the proposed PVT–PCM integrated ventilation system can significantly improve the indoor thermal comfort of passive buildings without using air-conditioning systems with a maximum air temperature rise of 23.1 °C from the PVT collectors. Compared with the system using PCM but without using PVT collectors, the coefficient of thermal comfort enhancement in the kitchen, dining room and living room of the case building studied using the proposed system improved from almost zero to 0.9823 while the coefficient of thermal comfort enhancement in the study room improved from 0.0060 to 0.9921. In summer conditions, the proposed system can also enhance indoor thermal comfort through night-time sky radiative cooling

  13. Radiological and toxicological analyses of tank 241-AY-102 and tank 241-C-106 ventilation systems

    International Nuclear Information System (INIS)

    Himes, D.A.

    1998-01-01

    The high heat content solids contained in Tank 241-C-106 are to be removed and transferred to Tank 241-AY-102 by sluicing operations, to be authorized under project W320. While sluicing operations are underway, the state of these tanks will be transformed from unagitated to agitated. This means that the partition fraction which describes the aerosol content of the head space will increase from IE-10 to IE-8 (see WHC-SD-WM-CN062, Rev. 2 for discussion of partition fractions). The head spare will become much more loaded with suspended material. Furthermore, the nature of this suspended material can change significantly: sluicing could bring up radioactive solids which normally would lay under many meters of liquid supernate. It is assumed that the headspace and filter aerosols in Tank 241-AY-102 are a 90/10 liquid/solid split. It is further assumed that the sluicing line, the headspace in Tank 241-C-106, and the filters on Tank 241-C-106 contain aerosols which are a 67/33 liquid/solid split. The bases of these assumptions are discussed in Section 3.0. These waste compositions (referred to as mitigated compositions) were used in Attachments 1 through 4 to calculate survey meter exposure rates per liter of inventory in the various system components. Three accident scenarios are evaluated: a high temperature event which melts or burns the HEPA filters and causes releases from other system components; an overpressure event which crushes and blows out the HEPA filters and causes releases from other system components; and an unfiltered release of tank headspace air. The initiating event for the high temperature release is a fire caused by a heater malfunction inside the exhaust dust or a fire outside the duct. The initiating event for the overpressure event could be a steam bump which over pressurizes the tank and leads to a blowout of the HEPA filters in the ventilation system. The catastrophic destruction of the HEPA filters would release a fraction of the accumulated

  14. Radiological and toxicological analyses of tank 241-AY-102 and tank 241-C-106 ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Himes, D.A.

    1998-08-11

    The high heat content solids contained in Tank 241-C-106 are to be removed and transferred to Tank 241-AY-102 by sluicing operations, to be authorized under project W320. While sluicing operations are underway, the state of these tanks will be transformed from unagitated to agitated. This means that the partition fraction which describes the aerosol content of the head space will increase from IE-10 to IE-8 (see WHC-SD-WM-CN062, Rev. 2 for discussion of partition fractions). The head spare will become much more loaded with suspended material. Furthermore, the nature of this suspended material can change significantly: sluicing could bring up radioactive solids which normally would lay under many meters of liquid supernate. It is assumed that the headspace and filter aerosols in Tank 241-AY-102 are a 90/10 liquid/solid split. It is further assumed that the sluicing line, the headspace in Tank 241-C-106, and the filters on Tank 241-C-106 contain aerosols which are a 67/33 liquid/solid split. The bases of these assumptions are discussed in Section 3.0. These waste compositions (referred to as mitigated compositions) were used in Attachments 1 through 4 to calculate survey meter exposure rates per liter of inventory in the various system components. Three accident scenarios are evaluated: a high temperature event which melts or burns the HEPA filters and causes releases from other system components; an overpressure event which crushes and blows out the HEPA filters and causes releases from other system components; and an unfiltered release of tank headspace air. The initiating event for the high temperature release is a fire caused by a heater malfunction inside the exhaust dust or a fire outside the duct. The initiating event for the overpressure event could be a steam bump which over pressurizes the tank and leads to a blowout of the HEPA filters in the ventilation system. The catastrophic destruction of the HEPA filters would release a fraction of the accumulated

  15. Performance evaluation of ventilation radiators

    International Nuclear Information System (INIS)

    Myhren, Jonn Are; Holmberg, Sture

    2013-01-01

    A ventilation radiator is a combined ventilation and heat emission unit currently of interest due to its potential for increasing energy efficiency in exhaust-ventilated buildings with warm water heating. This paper presents results of performance tests of several ventilation radiator models conducted under controlled laboratory conditions. The purpose of the study was to validate results achieved by Computational Fluid Dynamics (CFD) in an earlier study and identify possible improvements in the performance of such systems. The main focus was on heat transfer from internal convection fins, but comfort and health aspects related to ventilation rates and air temperatures were also considered. The general results from the CFD simulations were confirmed; the heat output of ventilation radiators may be improved by at least 20% without sacrificing ventilation efficiency or thermal comfort. Improved thermal efficiency of ventilation radiators allows a lower supply water temperature and energy savings both for heating up and distribution of warm water in heat pumps or district heating systems. A secondary benefit is that a high ventilation rate can be maintained all year around without risk for cold draught. -- Highlights: ► Low temperature heat emitters are currently of interest due to their potential for increasing energy efficiency. ► A ventilation radiator is a combined ventilation and heat emission unit which can be adapted to low temperature heating systems. ► We examine how ventilation radiators can be made to be more efficient in terms of energy consumption and thermal comfort. ► Current work focuses on heat transfer mechanisms and convection fin configuration of ventilation radiators

  16. Acetylcholinesterase activity in the brain of dystonia musculorum (Dst(dt-J)) mutant mice.

    Science.gov (United States)

    Clément, C; Lalonde, R; Strazielle, C

    2012-01-01

    The dystonia musculorum (Dst(dt-J)) mutant mouse suffers from severe motor coordination deficits, characterized, among various symptoms, by a spastic ataxia and dystonic movements, indicating central defects in motor structures in addition to dystrophy of peripheral sensory tracts and partial degeneration of spinocerebellar tracts. Neurochemical alterations, notably in dopaminergic and noradrenergic systems, were previously observed in basal ganglia and cerebellum. A quantitative histochemical cartography of brain acetylcholinesterase activity in Dst(dt-J) mutants, in comparison with controls, revealed increases in the neostriatum, the habenula-interpeduncular pathway, the cholinergic pedunculopontine nucleus and its target structures, the thalamus, major regions of the basal ganglia, such as substantia nigra, ventral tegmental area, globus pallidum, and subthalamic nucleus, as well as in associated extrapyramidal regions, such as red nucleus, brainstem reticular formation, and superior colliculus. These acetylcholinesterase changes may play a role in motor deficits, particularly the dystonic symptomatology observed in the mutation. Copyright © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  17. Improving the energy and IAQ performance of ventilation systems in Dutch dwellings

    NARCIS (Netherlands)

    Holsteijn, R.C.A. van; Li, W.L.; Valk, H.J.J.; Kornaat, W.

    2016-01-01

    MONICAIR - MONItoring & Control of Air quality in Individual Rooms - is a pre-competitive field research project of a broad consortium of Dutch ventilation unit manufacturers and research institutes, supported by the Dutch government. The first aim of the project is to investigate and compare the

  18. DCT/DST-based transform coding for intra prediction in image/video coding.

    Science.gov (United States)

    Saxena, Ankur; Fernandes, Felix C

    2013-10-01

    In this paper, we present a DCT/DST based transform scheme that applies either the conventional DCT or type-7 DST for all the video-coding intra-prediction modes: vertical, horizontal, and oblique. Our approach is applicable to any block-based intra prediction scheme in a codec that employs transforms along the horizontal and vertical direction separably. Previously, Han, Saxena, and Rose showed that for the intra-predicted residuals of horizontal and vertical modes, the DST is the optimal transform with performance close to the KLT. Here, we prove that this is indeed the case for the other oblique modes. The optimal choice of using DCT or DST is based on intra-prediction modes and requires no additional signaling information or rate-distortion search. The DCT/DST scheme presented in this paper was adopted in the HEVC standardization in March 2011. Further simplifications, especially to reduce implementation complexity, which remove the mode-dependency between DCT and DST, and simply always use DST for the 4 × 4 intra luma blocks, were adopted in the HEVC standard in July 2012. Simulation results conducted for the DCT/DST algorithm are shown in the reference software for the ongoing HEVC standardization. Our results show that the DCT/DST scheme provides significant BD-rate improvement over the conventional DCT based scheme for intra prediction in video sequences.

  19. Ventilation and air conditioning systems in maritime productions units; Panorama dos sistemas de VAC em unidades maritimas de producao

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, Fernando Pedrosa; Sztajnbok, Ernani Luis [PETROBRAS, Rio de Janeiro, RJ (Brazil); Padua, Carlos Eduardo Dantas de; Passos, Alfredo Silveira [DUOVAC Engenharia Ltda. (Brazil)

    2004-07-01

    In an Offshore Stationary Production Unit (SPU), the adequate project of the Ventilation and Air Conditioning (VAC) System is not only a thermal comfort requirement but part of the essential safety services of the installation and complement for area classification requirements associated with electrical equipment. The VAC installations are sometimes the object of complaints by onboard team. Problems such as unsatisfactory system performance, high noise levels in the accommodation quarters, offices and other areas and the discomfort caused by unbalanced ventilation and air conditioning systems, are some of the most frequent complaints. Air Conditioning systems are classified as Direct and Indirect Expansion. Decentralized systems with Indirect Expansion has been adopted in PETROBRAS projects. This conception is not used in VAC Systems for platforms installed in North Sea, where the use of Centralized Systems with Direct Expansion are more common. The objective of this work is to compare the VAC conception projects, analyzing their advantages and disadvantages . The evaluation of VAC System in PETROBRAS project, and their steps in SPU development, is also scope of this paper. (author)

  20. Ventilator-dependent children and the health services system. Unmet needs and coordination of care.

    Science.gov (United States)

    Hefner, Jennifer L; Tsai, Wan Chong

    2013-10-01

    Children dependent on mechanical ventilation are a vulnerable population by virtue of their chronic disability and are therefore at increased risk for health disparities and access barriers. The present study is the first, to our knowledge, to conduct a large-scale survey of caregivers of ventilator-dependent children to develop a comprehensive socio-demographic profile. To describe the demographic and health status profile of ventilator-dependent children, to identify the types of unmet needs families caring for a child on a ventilator face, and to determine the correlates of access to care coordination. A survey was administered to 122 parents whose children attended a pediatric home ventilator clinic at a large tertiary Midwestern medical center (84% of the clinic population). Half of the patient population had severe functional limitations, and 70% had one or more comorbidities. One quarter of caregivers reported current financial struggles, and 16% screened positive for a probable depressive disorder. More than half of families reported unmet needs for care, most frequently therapeutic services and skilled nursing care. Of those reporting an unmet need for skilled nursing care, lack of adequate staffing was the main barrier (71.1%). Financial struggles and a probable caregiver depressive disorder were significantly associated with an unmet need for care coordination. This is the first large-scale quantitative study to investigate the themes of unmet need and care coordination within this vulnerable population. The results suggest these families face barriers accessing therapeutic and skilled nursing services, and caregiver mental health and financial struggles may be important points of intervention for service providers through the inclusion of multidisciplinary care teams and the strengthening of social services referral networks.

  1. Pleth variability index and respiratory system compliance to direct PEEP settings in mechanically ventilated patients, an exploratory study.

    Science.gov (United States)

    Zhou, Jing; Han, Yi

    2016-01-01

    To analyze the ability of pleth variability index (PVI) and respiratory system compliance (RSC) on evaluating the hemodynamic and respiratory effects of positive end expiratory pressure (PEEP), then to direct PEEP settings in mechanically ventilated critical patients. We studied 22 mechanically ventilated critical patients in the intensive care unit. Patients were monitored with classical monitor and a pulse co-oximeter, with pulse sensors attached to patients' index fingers. Hemodynamic data [heart rate (HR), perfusion index (PI), PVI, central venous pressure (CVP), mean arterial pressure (MAP), peripheral blood oxygen saturation (SPO2), peripheral blood oxygen content (SPOC) and peripheral blood hemoglobin (SPHB)] as well as the respiratory data [respiratory rate (RR), tidal volume (VT), RSC and controlled airway pressure] were recorded for 15 min each at 3 different levels of PEEP (0, 5 and 10 cmH2O). Different levels of PEEP (0, 5 and 10 cmH2O) had no obvious effect on RR, HR, MAP, SPO2 and SPOC. However, 10 cmH2O PEEP induced significant hemodynamic disturbances, including decreases of PI, and increases of both PVI and CVP. Meanwhile, 5 cmH2O PEEP induced no significant changes on hemodynamics such as CVP, PI and PVI, but improved the RSC. RSC and PVI may be useful in detecting the hemodynamic and respiratory effects of PEEP, thus may help clinicians individualize PEEP settings in mechanically ventilated patients.

  2. Evaluation of simplified ventilation system with direct air supply through the facade in a school in a cold climate

    Energy Technology Data Exchange (ETDEWEB)

    Mysen, M. [Norwegian Building Research Institute, Blindern, Oslo (Norway); Department of Energy and Process Technology, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Schild, P. G.; Hellstrand, V.; Thunshelle, K. [Norwegian Building Research Institute, Blindern, Oslo (Norway)

    2004-07-01

    Many educational buildings in industrialised countries have poor indoor climate, according to today's knowledge about the impact of indoor climate on well-being and productivity. Budget restrictions and practical limitations such as lack of space for central air handling units and ventilation ducts, have motivated the application of simplified ventilation systems in some schools, such as taking unconditioned supply air directly from the facade. One such school was recently evaluated in Norway. On cold days, thermal comfort in the classroom deteriorated due to cold down draught from the supply outlet. In addition, moist and fertile conditions for microbiological growth were observed in the air supply ductwork. On the other hand the same pupils are more satisfied with the school and have less sick building syndrome (SBS) symptoms during winter than summer. An improved control strategy with a temperature-compensated CO{sub 2} set-point for controlling the air flow is suggested. This could improve thermal comfort and reduce energy use without compromising perceived air quality (PAQ) during cold weather. Furthermore it could improve indoor air quality (IAQ) during warm weather with only a slight increase of energy use. Further evaluation of an improved solution is needed before such a ventilation concept can be recommended in cold climates. (author)

  3. Role of ventilation systems in the prevention of hospital infection; Innai kansen boshi ni okeru kanki system no yakuwari

    Energy Technology Data Exchange (ETDEWEB)

    Ayliffe, G.

    1996-05-05

    This paper investigates and considers the actual state of hospital infection. The 80% or more of surgical wound infection is self-infection, for which the factor is the microorganisms that exist in a surgical wound at the completion of an operation. Airborne infection is generally due to staphylococcus aureus. There rarely is a bacteria carrier, and the germ is dispersed from him in some instances. Staphylococcus epidermis sticks to prosthesis, propagates and causes wound infection in rare occasions. Clostridium perfringens and escherichia coli also sometimes cause self-infection from wound. An ordinary plenum ventilation system is less effective for the prevention of wound infection. A remarkable example for reduction in infection is the employment of an ultra clean air system in joint replacement operations, showing reduction in joint septicemic infection from 1.5 to 0.3%. A vertical air flow system may be effectively employed in an operation room for the purpose of improving the air stream. No interrelation exists between the total number of indoor bacteria and infection without staphylococcus aureus. A person infected by methicillin-resistant staphylococcus has to be isolated into a unit. 13 refs., 1 fig., 1 tab.

  4. Variable Ventilation Improved Respiratory System Mechanics and Ameliorated Pulmonary Damage in a Rat Model of Lung Ischemia-Reperfusion.

    Science.gov (United States)

    Soluri-Martins, André; Moraes, Lillian; Santos, Raquel S; Santos, Cintia L; Huhle, Robert; Capelozzi, Vera L; Pelosi, Paolo; Silva, Pedro L; de Abreu, Marcelo Gama; Rocco, Patricia R M

    2017-01-01

    Lung ischemia-reperfusion injury remains a major complication after lung transplantation. Variable ventilation (VV) has been shown to improve respiratory function and reduce pulmonary histological damage compared to protective volume-controlled ventilation (VCV) in different models of lung injury induced by endotoxin, surfactant depletion by saline lavage, and hydrochloric acid. However, no study has compared the biological impact of VV vs. VCV in lung ischemia-reperfusion injury, which has a complex pathophysiology different from that of other experimental models. Thirty-six animals were randomly assigned to one of two groups: (1) ischemia-reperfusion (IR), in which the left pulmonary hilum was completely occluded and released after 30 min; and (2) Sham, in which animals underwent the same surgical manipulation but without hilar clamping. Immediately after surgery, the left (IR-injured) and right (contralateral) lungs from 6 animals per group were removed, and served as non-ventilated group (NV) for molecular biology analysis. IR and Sham groups were further randomized to one of two ventilation strategies: VCV ( n = 6/group) [tidal volume (V T ) = 6 mL/kg, positive end-expiratory pressure (PEEP) = 2 cmH 2 O, fraction of inspired oxygen (FiO 2 ) = 0.4]; or VV, which was applied on a breath-to-breath basis as a sequence of randomly generated V T values ( n = 1200; mean V T = 6 mL/kg), with a 30% coefficient of variation. After 5 min of ventilation and at the end of a 2-h period (Final), respiratory system mechanics and arterial blood gases were measured. At Final, lungs were removed for histological and molecular biology analyses. Respiratory system elastance and alveolar collapse were lower in VCV than VV (mean ± SD, VCV 3.6 ± 1.3 cmH 2 0/ml and 2.0 ± 0.8 cmH 2 0/ml, p = 0.005; median [interquartile range], VCV 20.4% [7.9-33.1] and VV 5.4% [3.1-8.8], p = 0.04, respectively). In left lungs of IR animals, VCV increased the expression of interleukin-6 and

  5. The dexametazone suppression test (DST) for diagnosing of depression syndrome

    International Nuclear Information System (INIS)

    Rejopachi P, L.A.

    1984-09-01

    The dexametazone suppression test (DST) is a very valuable neuroendocrin assay as auxiliar method for diagnosing the depression. The serum cortisol levels of 20 patients of the Hospital de Salud Mental and of a control group were determined by radio-immunoassay technique. Normal concentration was defined as 5 micrograms per deciliter. Among depressed patients the average value was 9.8865 micro-grams per deciliter; having the test a 85% of positiveness. Among the control group the average value found was 1.167 micro-grams per deciliter, with a 20% of positiveness for the test. (author)

  6. "Fighting the system": Families caring for ventilator-dependent children and adults with complex health care needs at home

    Directory of Open Access Journals (Sweden)

    Nielsen Erik W

    2011-07-01

    Full Text Available Abstract Background An increasing number of individuals with complex health care needs now receive life-long and life-prolonging ventilatory support at home. Family members often take on the role of primary caregivers. The aim of this study was to explore the experiences of families giving advanced care to family members dependent on home mechanical ventilation. Methods Using qualitative research methods, a Grounded Theory influenced approach was used to explore the families' experiences. A total of 15 family members with 11 ventilator-dependent individuals (three children and eight adults were recruited for 10 in-depth interviews. Results The core category, "fighting the system," became the central theme as family members were asked to describe their experiences. In addition, we identified three subcategories, "lack of competence and continuity", "being indispensable" and "worth fighting for". This study revealed no major differences in the families' experiences that were dependent on whether the ventilator-dependent individual was a child or an adult. Conclusions These findings show that there is a large gap between family members' expectations and what the community health care services are able to provide, even when almost unlimited resources are available. A number of measures are needed to reduce the burden on these family members and to make hospital care at home possible. In the future, the gap between what the health care can potentially provide and what they can provide in real life will rapidly increase. New proposals to limit the extremely costly provision of home mechanical ventilation in Norway will trigger new ethical dilemmas that should be studied further.

  7. Measured performance of filtration and ventilation systems for fine and ultrafine particles and ozone in an unoccupied modern California house

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Black, Douglas R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-12-01

    This study evaluated nine ventilation and filtration systems in an unoccupied 2006 house located 250m downwind of the I-80 freeway in Sacramento, California. Systems were evaluated for reducing indoor concentrations of outdoor particles in summer and fall/winter, ozone in summer, and particles from stir-fry cooking. Air exchange rate was measured continuously. Energy use was estimated for year-round operation in California. Exhaust ventilation without enhanced filtration produced indoor PM2.5 that was 70% lower than outdoors. Supply ventilation with MERV13 filtration provided slightly less protection whereas supply MERV16 filtration reduced PM2.55 by 97-98% relative to outdoors. Supply filtration systems used little energy but provided no benefits for indoor-generated particles. Systems with MERV13-16 filters in the recirculating heating and cooling unit (FAU) operating continuously or 20 min/h reduced PM2.5 by 93-98%. Across all systems, removal percentages were higher for ultrafine particles and lower for black carbon, relative to PM2.5. Indoor ozone was 3-4% of outdoors for all systems except an electronic air cleaner that produced ozone. Filtration via the FAU or portable filtration units lowered PM2.5 by 25-75% when operated over the hour following cooking. The energy for year-round operation of FAU filtration with an efficient blower motor was estimated at 600 kWh/year.

  8. Mechanical ventilation in neurosurgical patients

    Directory of Open Access Journals (Sweden)

    Keshav Goyal

    2013-01-01

    Full Text Available Mechanical ventilation significantly affects cerebral oxygenation and cerebral blood flow through changes in arterial carbon dioxide levels. Neurosurgical patients might require mechanical ventilation for correction and maintenance of changes in the pulmonary system that occur either due to neurosurgical pathology or following surgery during the acute phase. This review discusses the basics of mechanical ventilation relevant to the neurosurgeon in the day-to-day management of neurosurgical patient requiring artificial support of the respiration.

  9. Auxiliary mine ventilation manual

    International Nuclear Information System (INIS)

    Workplace Safety North

    2010-01-01

    An adequate ventilation system is needed for air quality and handling in a mine and is comprised of many different pieces of equipment for removing contaminated air and supplying fresh air and thereby provide a satisfactory working environment. This manual highlights auxiliary ventilation systems made up of small fans, ducts, tubes, air movers, deflectors and additional air flow controls which distribute fresh air delivered by the primary system to all areas. A review of auxiliary ventilation is provided. Design, operation and management issues are discussed and guidelines are furnished. This manual is limited to underground hard rock operations and does not address directly other, specific auxiliary systems, either in underground coal mines or uranium mines.

  10. Ventilation distribution and small airway function in patients with systemic sclerosis

    Directory of Open Access Journals (Sweden)

    B.R.A. Silva

    2017-05-01

    Full Text Available Background: Despite the importance of traditional pulmonary function tests (PFTs in managing systemic sclerosis (SSc, many patients with pulmonary disease diagnosed by computed tomography (CT present with normal PFTs. Objective: To evaluate the efficacy of the nitrogen single-breath washout (N2SBW test in diagnosing SSc and to correlate N2SBW parameters with the PFT indexes used in the follow-up of these patients, clinical data, and CT findings. Methods: Cross-sectional study in which 52 consecutive SSc patients were subjected to spirometry, body plethysmography, analysis of the diffusing capacity for carbon monoxide (DLCO, analysis of respiratory muscle strength, N2SBW testing, and CT analysis. Results: Twenty-eight patients had a forced vital capacity (FVC that was 120% of the predicted value, while 15 patients had a closing volume/vital capacity (CV/VC that was >120% of the predicted value. A significant difference in Phase III slopeN2SBW was observed when the patients with predominant traction bronchiectasis and honeycombing were compared to the patients with other CT patterns (p < 0.0001. The Phase III slopeN2SBW was correlated with FVC (rs = −0.845, p < 0.0001 and DLCO (rs = −0.600, p < 0.0001, and the CV/VC was correlated with FVC (rs = −0.460, p = 0.0006 and residual volume/total lung capacity (rs = 0.328, p = 0.017. Conclusion: Ventilation heterogeneity is a frequent finding in SSc patients that is associated with restrictive damage, changes in pulmonary diffusion, and CT patterns. In addition, approximately one-third of the patients presented with findings that were compatible with small airway disease. Keywords: Systemic sclerosis, Respiratory function tests, Nitrogen single-breath washout test

  11. Building ventilation, state of the art, prospective

    International Nuclear Information System (INIS)

    1995-10-01

    This conference is composed of 21 communications and 21 posters in the domain of building ventilation and indoor air quality; the main themes are: indoor air quality assessment and optimization; performance enhancement and optimization of ventilation systems and equipment; ventilation systems for renovated and rehabilitated buildings; French and European regulations, standardizations and certifications; experimental and numerical simulation studies concerning ventilation systems, air flow, temperature distribution, air quality, radon decontamination, thermal comfort and acoustic levels in buildings

  12. HANFORD DOUBLE-SHELL TANK (DST) THERMAL and SEISMIC PROJECT-BUCKLING EVALUATION METHODS and RESULTS FOR THE PRIMARY TANKS

    International Nuclear Information System (INIS)

    Mackey, T.C.; Johnson, K.I.; Deibler, J.E.; Pilli, S.P.; Rinker, M.W.; Karri, N.K.

    2007-01-01

    This report documents a detailed buckling evaluation of the primary tanks in the Hanford double-shell waste tanks (DSTs), which is part of a comprehensive structural review for the Double-Shell Tank Integrity Project. This work also provides information on tank integrity that specifically responds to concerns raised by the Office of Environment, Safety, and Health (ES and H) Oversight (EH-22) during a review of work performed on the double-shell tank farms and the operation of the aging waste facility (AWF) primary tank ventilation system. The current buckling review focuses on the following tasks: (1) Evaluate the potential for progressive I-bolt failure and the appropriateness of the safety factors that were used for evaluating local and global buckling. The analysis will specifically answer the following questions: (a) Can the EH-22 scenario develop if the vacuum is limited to -6.6-inch water gage (w.g.) by a relief valve? (b) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario can develop? (c) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario cannot develop? (2) Develop influence functions to estimate the axial stresses in the primary tanks for all reasonable combinations of tank loads, based on detailed finite element analysis. The analysis must account for the variation in design details and operating conditions between the different DSTs. The analysis must also address the imperfection sensitivity of the primary tank to buckling. (3) Perform a detailed buckling analysis to determine the maximum allowable differential pressure for each of the DST primary tanks at the current specified limits on waste temperature, height, and specific gravity. Based on the I-bolt loads analysis and the small deformations that are predicted at the unfactored limits on vacuum and axial loads, it is very unlikely that the EH-22 scenario (i.e., progressive I-bolt failure leading to

  13. Assessing the Capacity of the US Health Care System to Use Additional Mechanical Ventilators During a Large-Scale Public Health Emergency.

    Science.gov (United States)

    Ajao, Adebola; Nystrom, Scott V; Koonin, Lisa M; Patel, Anita; Howell, David R; Baccam, Prasith; Lant, Tim; Malatino, Eileen; Chamberlin, Margaret; Meltzer, Martin I

    2015-12-01

    A large-scale public health emergency, such as a severe influenza pandemic, can generate large numbers of critically ill patients in a short time. We modeled the number of mechanical ventilators that could be used in addition to the number of hospital-based ventilators currently in use. We identified key components of the health care system needed to deliver ventilation therapy, quantified the maximum number of additional ventilators that each key component could support at various capacity levels (ie, conventional, contingency, and crisis), and determined the constraining key component at each capacity level. Our study results showed that US hospitals could absorb between 26,200 and 56,300 additional ventilators at the peak of a national influenza pandemic outbreak with robust pre-pandemic planning. The current US health care system may have limited capacity to use additional mechanical ventilators during a large-scale public health emergency. Emergency planners need to understand their health care systems' capability to absorb additional resources and expand care. This methodology could be adapted by emergency planners to determine stockpiling goals for critical resources or to identify alternatives to manage overwhelming critical care need.

  14. Assessment of ventilation system for centralized storage of spent radiation sources

    International Nuclear Information System (INIS)

    Soroka, Yu.N.; Udod, E.V.

    2014-01-01

    The hazards associated with treatment spent radiation sources in the centralized storage facility under construction in the Chernobyl exclusion zone are analysis. Models are proposed to calculate possible situations of contamination with radionuclides in centralized storage rooms. The required ventilation rate is calculated for areas where sources containing 60 Co; 90 Sr, 137 Cs, 226 Ra, 238 Pu, 239 Pu and 241 Am radionuclides are supposed to be treated

  15. The School Advanced Ventilation Engineering Software (SAVES)

    Science.gov (United States)

    The School Advanced Ventilation Engineering Software (SAVES) package is a tool to help school designers assess the potential financial payback and indoor humidity control benefits of Energy Recovery Ventilation (ERV) systems for school applications.

  16. Demonstration test on the safety of a cell ventilation system during a hypothetical explosive burning in a fuel reprocessing plant

    International Nuclear Information System (INIS)

    Suzuki, Motoe; Nishio, Gunji; Takada, Junichi; Tsukamoto, Michio; Koike, Tadao

    1993-01-01

    To demonstrate the safety of an air ventilation system of cells in a fuel reprocessing plant under a postulated explosive burning caused by solvent fire or by thermal decomposition of nitrated solvent, four types of demonstration tests have been conducted using a large-scale facility simulating a cell ventilation system of an actual reprocessing plant, thus revealing effective mitigation by cell and duct structures on the pressure and temperature pulses generated by explosive burning. In boilover burning tests, solvent fire in a model cell was observed with various sizes of burning surface area as a main parameter, and analysis was performed on the factors dominating the magnitude of boilover burning, revealing that the magnitude strongly depends on accumulated amounts and their ratio of oxygen and solvent vapor present in the cell. In deflagration tests, solid rocket fuel was burned in the cell to simulate the explosive source. The generated pressure and temperature pulses were effectively declined by the cell and duct structures and the integrity of the ventilation system was kept. In blower tests, a centrifugal turbo blower was imposed by a lump of air with a larger flow rate than the rated one by about six times to observe the transient response of the blower fan and motor. It was found that integrity of the blower was kept. In pressure transient tests, compressed air was blown into the cell to induce a mild transient state of fluid dynamics inside the facility, and a variety of data were successfully obtained to be used for the verification and improvement of a computer code. In all the tests, transient overloading of gas caused no damage on HEPA filters, and overloading on the blower motor was avoided either by the slipping of transmission belt or by the acceleration of blower fan rotation during peak flow. (author)

  17. ELECTROCHEMICAL STUDIES OF CARBON STEEL CORROSION IN HANFORD DOUBLE SHELL TANK (DST) WASTE

    Energy Technology Data Exchange (ETDEWEB)

    DUNCAN, J.B.; WINDISCH, C.F.

    2006-10-13

    This paper reports on the electrochemical scans for the supernatant of Hanford double-shell tank (DST) 241-SY-102 and the electrochemical scans for the bottom saltcake layer for Hanford DST 241-AZ-102. It further reports on the development of electrochemical test cells adapted to both sample volume and hot cell constraints.

  18. Ventilation with heat recovery

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Svendsen, Svend

    2005-01-01

    This paper presents the experiences from the use of ventilation with heat recovery in several experimental single-family houses developed and built within the last four years to meet the new Danish energy requirements of 2005. Included are descriptions of the ventilation system components...... and the main functional demands as well as measurements of the thermal efficiency, electricity consumptions and building air tightness. The paper addresses the aspects of minimizing the heat loss from the duct system and the heat recovery unit (when placed in an unheated attic space) in order to obtain...

  19. DST Indices - Reflection Variations in the Magnetospheric Tail Current and Field-aligned Currents in the Magnetosphere

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The file is comprised of monthly DST indices. These indices are derived from a network of eight stations in the equatorial latitudes. Hourly DST indices provide an...

  20. Lecture Notes on Mixing Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    The main task of the ventilation system or the air-conditioning system is to supply· and remove air and airborne materials and to supply or remove heat from a room. The necessary level of fresh air will be supplied to· a room by a ventilation system, and heat from equipment or solar radiation can...... be removed by an air-conditioning system. An industrial ventilation system may both take care of the occupants' comfort and the industrial processes in the area....

  1. Thermal plumes in ventilated rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    1990-01-01

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects. Free...... to be the only possible approach to obtain the volume flow in: thermal plumes in ventilated rooms....

  2. Mixing Ventilation

    DEFF Research Database (Denmark)

    Kandzia, Claudia; Kosonen, Risto; Melikov, Arsen Krikor

    In this guidebook most of the known and used in practice methods for achieving mixing air distribution are discussed. Mixing ventilation has been applied to many different spaces providing fresh air and thermal comfort to the occupants. Today, a design engineer can choose from large selection...

  3. Displacement Ventilation

    DEFF Research Database (Denmark)

    Bjørn, Erik; Mattsson, Magnus; Sandberg, Mats

    Full-scale experiments were made in a displacement ventilated room with two breathing thermal manikins to study the effect of movements and breathing on the vertical contaminant distribution, and on the personal exposure of occupants. Concentrations were measured with tracer gas equipment...

  4. HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT ESTABLISHMENT OF METHODOLOGY FOR TIME DOMAIN SOIL STRUCTURE INTERACTION ANALYSIS OF HANFORD DST

    Energy Technology Data Exchange (ETDEWEB)

    MACKEY, T.C.

    2006-03-14

    M&D Professional Services, Inc. (M&D) is under subcontract to Pacific Northwest National Laboratories (PNNL) to perform seismic analysis of the Hanford Site Double-Shell Tanks (DSTs) in support of a project entitled ''Double-Shell Tank DSV Integrity Project-DST Thermal and Seismic Analyses''. The overall scope of the project is to complete an up-to-date comprehensive analysis of record of the DST System at Hanford in support of Tri-Party Agreement Milestone M-48-14. The thermal and operating loads analysis of the DSTs is documented in Rinker et al. (2004). The work statement provided to M&D (PNNL 2003) required that the seismic analysis of the DST assess the impacts of potentially non-conservative assumptions in previous analyses and account for the additional soil mass due to the as-found soil density increase, the effects of material degradation, additional thermal profiles applied to the full structure including the soil-structure response with the footings, the non-rigid (low frequency) response of the tank roof, the asymmetric seismic-induced soil loading, the structural discontinuity between the concrete tank wall and the support footing and the sloshing of the tank waste. The seismic analysis considers the interaction of the tank with the surrounding soil, and the effects of the primary tank contents. The DST and the surrounding soil are modeled as a system of finite elements. The depth and width of the soil incorporated into the analysis model are sufficient to obtain appropriately accurate analytical results. The analyses required to support the work statement differ from previous analysis of the DSTs in that the soil-structure interaction (SSI) model includes several (nonlinear) contact surfaces in the tank structure, and the contained waste must be modeled explicitly in order to capture the fluid-structure interaction behavior between the primary tank and contained waste. Soil-structure interaction analyses are traditionally solved in

  5. Low-Flow Extracorporeal Carbon Dioxide Removal Using the Hemolung Respiratory Dialysis System® to Facilitate Lung-Protective Mechanical Ventilation in Acute Respiratory Distress Syndrome.

    Science.gov (United States)

    Akkanti, Bindu; Rajagopal, Keshava; Patel, Kirti P; Aravind, Sangeeta; Nunez-Centanu, Emmanuel; Hussain, Rahat; Shabari, Farshad Raissi; Hofstetter, Wayne L; Vaporciyan, Ara A; Banjac, Igor S; Kar, Biswajit; Gregoric, Igor D; Loyalka, Pranav

    2017-06-01

    Extracorporeal carbon dioxide removal (ECCO 2 R) permits reductions in alveolar ventilation requirements that the lungs would otherwise have to provide. This concept was applied to a case of hypercapnia refractory to high-level invasive mechanical ventilator support. We present a case of an 18-year-old man who developed post-pneumonectomy acute respiratory distress syndrome (ARDS) after resection of a mediastinal germ cell tumor involving the left lung hilum. Hypercapnia and hypoxemia persisted despite ventilator support even at traumatic levels. ECCO 2 R using a miniaturized system was instituted and provided effective carbon dioxide elimination. This facilitated establishment of lung-protective ventilator settings and lung function recovery. Extracorporeal lung support increasingly is being applied to treat ARDS. However, conventional extracorporeal membrane oxygenation (ECMO) generally involves using large cannulae capable of carrying high flow rates. A subset of patients with ARDS has mixed hypercapnia and hypoxemia despite high-level ventilator support. In the absence of profound hypoxemia, ECCO 2 R may be used to reduce ventilator support requirements to lung-protective levels, while avoiding risks associated with conventional ECMO.

  6. Effect of car speed on amount of air supplied by ventilation system to the space of car cabin

    Science.gov (United States)

    Fišer, Jan; Pokorný, Jan

    2014-03-01

    The amount of air supplied by ventilation system (HVAC system) of a car into a cabin is one of the main parameters for the correct simulation and prediction of a car cabin heat load. This amount is not based only on the current setting of the HVAC system, but also on the actual operating conditions and speed of the car. The authors therefore carried out experiments in the cabin of a passenger car in real traffic, while observing the amount of air on the speed of the car and setting of flap in mixing chamber. In a subsequent analysis the authors defined dependence of the airflow rate supplied by HVAC system on the speed of the car. Obtained empirical formulas were then used as a part of the code which calculates the data for the HVAC boundary conditions in the simulation of the car cabin environment.

  7. Evaluation of a Mapleson D CPAP system for weaning of mechanical ventilation in pediatric patients

    OpenAIRE

    Miguel Angel Palomero-Rodríguez; Héctor Chozas de Arteaga; Yolanda Laporta Báez; Jesús de Vicente Sánchez; Pascual Sanabria Carretero; Pilar Sánchez Conde; Antonio Pérez Ferrer

    2016-01-01

    Background: Over the last years, we have used a flow-inflating bag circuit with a nasotracheal or nasopharyngeal tube as an interface to deliver effective CPAP support in infants (“Mapleson D CPAP system”). The primary goal of this study was to assess the usefulness of the “Mapleson D CPAP system” for weaning of mechanical ventilation (MV) in infants who received MV over 24 h. Materials and Methods: All infants who received MV for more than 24 h in the last year were enrolled in the study. De...

  8. Commercial aircraft as a source of automated meteorological data for GATE and DST

    Science.gov (United States)

    Julian, P. R.; Steinberg, R.

    1975-01-01

    Specially-equipped wide-body commercial aircraft which are flying tropical and Southern Hemispheric routes are providing a new and unique source of meteorological data with a 100 km spatial resolution. Data have been gathered for the GATE, and the planning for a similar effort for the DST is in progress. These aircraft not only provide synoptic data in critical areas devoid of conventional data, but are, in effect, meteorological research platforms that can provide valuable information on mesoscale phenomena. By 1976 it is anticipated that there will be over 80 such aircraft flying global routes. These specially-equipped jets could also be effectively used for EGGE by providing the nucleus of a supplementary observing system for gathering world-wide meteorological data.

  9. Mine Ventilation System Variable Resistance Regulate Air Quantity Economy and Its Impacts on Artisanal Mine in Ivory Coast

    Directory of Open Access Journals (Sweden)

    Kouame Kouame Arthur Joseph

    2016-01-01

    Full Text Available The artisanal gold mining is one of the major illegal activities in Ivory Coast. Thousands of indigents and foreigners including men, women and children are involved in this dangerous activity. Contracting contagious diseases such as HIV/AIDS and multiple lung diseases are commonplace on the artisanal mining sites due to air pollution. For this reason, the differential analysis, research mine ventilation system by changing the working windage adjustment for air flow of the economy, identifies factors, obtained discriminant variable resistance air volume control economic quantitative criteria for underground actual situation of joint variable resistance method and economic variable resistance than the concept of the development of effective mine ventilation system to improve air quantity adjusting rheostat economical way. The findings of this study can help lead to better safety practices in mining in order to improve the health and safety of the miners who are involved in artisanal mining activities in Ivory Coast and other mining sites over the world.

  10. Flow-field characteristics of high-temperature annular buoyant jets and their development laws influenced by ventilation system.

    Science.gov (United States)

    Wang, Yi; Huang, Yanqiu; Liu, Jiaping; Wang, Hai; Liu, Qiuhan

    2013-01-01

    The flow-field characteristics of high-temperature annular buoyant jets as well as the development laws influenced by ventilation system were studied using numerical methods to eliminate the pollutants effectively in this paper. The development laws of high-temperature annular buoyant jets were analyzed and compared with previous studies, including radial velocity distribution, axial velocity and temperature decay, reattachment position, cross-section diameter, volumetric flow rate, and velocity field characteristics with different pressures at the exhaust hood inlet. The results showed that when the ratio of outer diameter to inner diameter of the annulus was smaller than 5/2, the flow-field characteristics had significant difference compared to circular buoyant jets with the same outer diameter. For similar diameter ratios, reattachment in this paper occurred further downstream in contrast to previous study. Besides, the development laws of volumetric flow rate and cross-section diameter were given with different initial parameters. In addition, through analyzing air distribution characteristics under the coupling effect of high-temperature annular buoyant jets and ventilation system, it could be found that the position where maximum axial velocity occurred was changing gradually when the pressure at the exhaust hood inlet changed from 0 Pa to -5 Pa.

  11. A Study on a Control Method with a Ventilation Requirement of a VAV System in Multi-Zone

    Directory of Open Access Journals (Sweden)

    Hyo-Jun Kim

    2017-11-01

    Full Text Available The objective of this study was to propose a control method with a ventilation requirement of variable air volume (VAV system in multi-zone. In order to control the VAV system inmulti-zone, it is essential to control the terminal unit installed in each zone. A VAV terminal unit with conventional control method using a fixed minimum air flow can cause indoor air quality (IAQ issues depending on the variation in the number of occupants. This research proposes a control method with a ventilation requirement of the VAV terminal unit and AHU inmulti-zone. The integrated control method with an air flow increase model in the VAV terminal unit, AHU, and outdoor air intake rate increase model in the AHU was based on the indoor CO2 concentration. The conventional and proposed control algorithms were compared through a TRNSYS simulation program. The proposed VAV terminal unit control method satisfies all the conditions of indoor temperature, IAQ, and stratification. An energy comparison with the conventional control method showed that the method satisfies not only the indoor thermal comfort, IAQ, and stratification issue, but also reduces the energy consumption.

  12. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per Kvols

    -cooling period and night cooling potential. The investment cost of this ventilation system is about 5-10% lower than the conventional ones, because the acoustic ceiling could be directly applied as air diffuser and the use of plenum to distribute air reduces the cost of ductwork. There is a growing interest...... and manufacturers and the users of diffuse ceiling technology. The design guide introduces the principle and key characteristics of room air distribution with diffuse ceiling ventilation. It provides an overview of potential benefit and limitations of this technology. The benefits include high thermal comfort, high...

  13. CFD and Ventilation Research

    DEFF Research Database (Denmark)

    Li, Y.; Nielsen, Peter V.

    2011-01-01

    of scientific research and engineering development of complex air distribution and ventilation systems in buildings. This review discusses the major and specific challenges of CFD in terms of turbulence modelling, numerical approximation, and boundary conditions relevant to building ventilation. We emphasize......There has been a rapid growth of scientific literature on the application of computational fluid dynamics (CFD) in the research of ventilation and indoor air science. With a 1000–10,000 times increase in computer hardware capability in the past 20 years, CFD has become an integral part...... the growing need for CFD verification and validation, suggest on-going needs for analytical and experimental methods to support the numerical solutions, and discuss the growing capacity of CFD in opening up new research areas. We suggest that CFD has not become a replacement for experiment and theoretical...

  14. Discrimination between patients with melancholic depression and healthy controls: comparison between 24-h cortisol profiles, the DST and the Dex/CRH test.

    Science.gov (United States)

    Paslakis, Georgios; Krumm, Bertram; Gilles, Maria; Schweiger, Ulrich; Heuser, Isabella; Richter, Inga; Deuschle, Michael

    2011-06-01

    Diurnal (24-h) cortisol profiles were compared to DST and Dex/CRH test outcomes with regard to their discriminative power in depressive disorder. With regard to several statistical measures (effect sizes, area under the curve) we found 24-h cortisol profiles to better discriminate between healthy controls and inpatients with the melancholic subtype of depression compared to the DST and Dex/CRH test. In search of a shortened time interval we found the 2-h time window 1000-1200 h of the cortisol profile to be the one with the highest sensitivity (83.3%) and specificity (87.9%). The specificity of the DST was 93.3% and somewhat higher than that of the cortisol profiles and the Dex/CRH test (87.9% and 78.8.%, respectively). However, the sensitivity of the DST was very low (30.8%), in fact similar to that of the Dex/CRH test (30.8%), but much lower than that of the 1000-1200 h interval (83.3%). The assessment of cortisol in plasma is an easy to perform, cost-saving method for the evaluation of the HPA system activity, which may have a series of clinical and scientific implications for the depressive disorder. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Ventilation in Commercial and Residential Buildings

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    A number of areas have to be considered in connection with indoor air quality and ventilation. The selection of ventilation principle and components in the ventilation system will have influence on the indoor air quality and this subject will be discussed on the following pages. The main object o...

  16. Subjective study of thermal acceptability of novel enhanced displacement ventilation system and implication of occupants' personal control

    DEFF Research Database (Denmark)

    Sun, Weimeng; Cheong, K.W.D.; Melikov, Arsen Krikor

    2012-01-01

    A novel air distribution principle of cooler air near the floor level being propelled upward via four fans mounted at each corner of a chair was developed to enhance the performance of conventional displacement ventilation (DV) system. Experiments were conducted in a well-controlled climate chamber...... and the implication of personal usage pattern of the enhanced DV system were studied. The results revealed that at the ambient temperature of 26 °C, subjects preferred higher air movement and were satisfied with the cooling provided by the fans. However, the subjects felt cooler at the waists at room air temperatures...... of 22 and 24 °C when the fans were in operation. It was also found that the Whole Body Thermal Sensation (WBTS) reported by the subjects was correlated with the Local Thermal Sensation (LTS) at the waist, the arms, the calf and the feet when the novel DV system was employed. An expression which allows...

  17. Measure Guideline: Ventilation Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Springer, D.; Dakin, B.; German, A.

    2012-04-01

    The purpose of this measure guideline on ventilation cooling is to provide information on a cost-effective solution for reducing cooling system energy and demand in homes located in hot-dry and cold-dry climates. This guideline provides a prescriptive approach that outlines qualification criteria, selection considerations, and design and installation procedures.

  18. Low velocity floor level displacement ventilation systems: Technology assessment. Sistemi di distribuzione dell'aria a pavimento a bassa velocita': Vecchie e nuove conoscenze

    Energy Technology Data Exchange (ETDEWEB)

    Borjesson, J.A.; Bertomeu, L.; Marchetti, F.

    1992-12-01

    Although the concept of floor level air displacement ventilation is not in fact truly innovative given that it has already been tried during the 1980's, this paper shows that the combination of the advantageous natural cooling air circulation dynamics inherent in this method, combined with modern air diffusion equipment, offers interesting opportunities for energy conservation. The thermodynamics/air flow analysis indicates that from 20 to 40% energy savings can be obtained, in addition to reduced ventilation system operating times, with the effective application of low velocity floor level displacement air distribution systems as compared with conventional ventilation systems using the air mixing concept. It is shown how this innovative air cooling/recirculation technique is particularly suitable for conditions characterized by high air infiltration, high heating load and low indoor air pollution.

  19. Radioaerosol ventilation imaging in ventilator-dependent patients. Technical considerations

    International Nuclear Information System (INIS)

    Vezina, W.; Chamberlain, M.; Vinitski, S.; King, M.; Nicholson, R.; Morgan, W.K.

    1985-01-01

    The differentiation of pulmonary embolism (PE) from regional ventilatory abnormalities accompanied by reduced perfusion requires contemporary perfusion and ventilation studies. Distinguishing these conditions in ventilator-dependent patients is aided by administering a Tc-99m aerosol to characterize regional ventilation, and by performing a conventional Tc-99m MAA perfusion study. The technique uses a simple in-house constructed apparatus. Simple photographic techniques suffice, but computer subtraction of perfusion from the combined perfusion-ventilation image renders interpretation easier if aerosol administration follows perfusion imaging. Multiple defects can be examined in a single study. Excluding normal or near-normal perfusion studies, PE was thought to be present in eight of 16 patients after perfusion imaging alone, but in only one of eight after added aerosol imaging. Angiography confirmed the diagnosis in that patient. Of the eight patients who had abnormal perfusion but were thought unlikely to have PE from the perfusion study alone, two had normal ventilation, and subsequently were shown to have PE by angiography. Because angiography was only performed on patients who were thought to have a high probability of PE on sequential perfusion-ventilation imaging, the true incidence of PE may have been higher. Aerosol ventilation imaging is a useful adjunct to perfusion imaging in patients on ventilators. It requires an efficient delivery system, particularly if aerosol administration follows perfusion imaging, as it does in this study

  20. Extension of the Dermal Sensitisation Threshold (DST) approach to incorporate chemicals classified as reactive.

    Science.gov (United States)

    Safford, Robert J; Api, Anne Marie; Roberts, David W; Lalko, Jon F

    2015-08-01

    The evaluation of chemicals for their skin sensitising potential is an essential step in ensuring the safety of ingredients in consumer products. Similar to the Threshold of Toxicological Concern, the Dermal Sensitisation Threshold (DST) has been demonstrated to provide effective risk assessments for skin sensitisation in cases where human exposure is low. The DST was originally developed based on a Local Lymph Node Assay (LLNA) dataset and applied to chemicals that were not considered to be directly reactive to skin proteins, and unlikely to initiate the first mechanistic steps leading to the induction of sensitisation. Here we have extended the DST concept to protein reactive chemicals. A probabilistic assessment of the original DST dataset was conducted and a threshold of 64 μg/cm(2) was derived. In our accompanying publication, a set of structural chemistry based rules was developed to proactively identify highly reactive and potentially highly potent materials which should be excluded from the DST approach. The DST and rule set were benchmarked against a test set of chemicals with LLNA/human data. It is concluded that by combining the reactive DST with knowledge of chemistry a threshold can be established below which there is no appreciable risk of sensitisation for protein-reactive chemicals. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Influence of bronchial diameter change on the airflow dynamics based on a pressure-controlled ventilation system.

    Science.gov (United States)

    Ren, Shuai; Cai, Maolin; Shi, Yan; Xu, Weiqing; Zhang, Xiaohua Douglas

    2018-03-01

    Bronchial diameter is a key parameter that affects the respiratory treatment of mechanically ventilated patients. In this paper, to reveal the influence of bronchial diameter on the airflow dynamics of pressure-controlled mechanically ventilated patients, a new respiratory system model is presented that combines multigeneration airways with lungs. Furthermore, experiments and simulation studies to verify the model are performed. Finally, through the simulation study, it can be determined that in airway generations 2 to 7, when the diameter is reduced to half of the original value, the maximum air pressure (maximum air pressure in lungs) decreases by nearly 16%, the maximum flow decreases by nearly 30%, and the total airway pressure loss (sum of each generation pressure drop) is more than 5 times the original value. Moreover, in airway generations 8 to 16, with increasing diameter, the maximum air pressure, maximum flow, and total airway pressure loss remain almost constant. When the diameter is reduced to half of the original value, the maximum air pressure decreases by 3%, the maximum flow decreases by nearly 5%, and the total airway pressure loss increases by 200%. The study creates a foundation for improvement in respiratory disease diagnosis and treatment. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Transmission of Mycobacterium chimaera from Heater–Cooler Units during Cardiac Surgery despite an Ultraclean Air Ventilation System

    Science.gov (United States)

    Sommerstein, Rami; Rüegg, Christian; Kohler, Philipp; Bloemberg, Guido; Kuster, Stefan P.

    2016-01-01

    Heater–cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices. PMID:27070958

  3. Transmission of Mycobacterium chimaera from Heater-Cooler Units during Cardiac Surgery despite an Ultraclean Air Ventilation System.

    Science.gov (United States)

    Sommerstein, Rami; Rüegg, Christian; Kohler, Philipp; Bloemberg, Guido; Kuster, Stefan P; Sax, Hugo

    2016-06-01

    Heater-cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices.

  4. Development of energy economic ventilation system with heat recovery in dwellings; Udvikling af energioekonomisk ventilationsloesning med varmegenvinding til boliger

    Energy Technology Data Exchange (ETDEWEB)

    Drivsholm, C.; Olsen, Hans; Groenborg Larsen, C.; Jensen, John Steen; Rammer Nielsen, T.; Kragh, J.; Svendsen, Svend

    2005-07-01

    This report describes and documents the development of a counter flow heat exchanger with efficiency of approximately 90% and a highly efficient axial fan both developed for small mechanical ventilation systems for use in single family houses. The report also treats problems concerning condensation and ice formation in efficient counter flow heat exchangers. The influence of condensate and ice is investigated by measurements on an efficient heat exchanger and different strategies for de-icing are tested. A computer program is developed to calculate how condensation and frost influence the heat exchange under stationary conditions. In the project a counter flow heat exchanger of aluminium is developed with a calculated efficiency of approximately 90%. The heat exchanger is hereby legal for ventilation of more than one fire section. CAD drawings of the exchanger are coded to a CNC milling machine and two cylinders (a positive and a negative mould) are produced. The joints of the heat exchanger are glued and placed in a protecting aluminium frame. (BA)

  5. Understanding mechanical ventilators.

    Science.gov (United States)

    Chatburn, Robert L

    2010-12-01

    The respiratory care academic community has not yet adopted a standardized system for classifying and describing modes of ventilation. As a result, there is enough confusion that patient care, clinician education and even ventilator sales are all put at risk. This article summarizes a ventilator mode taxonomy that has been extensively published over the last 15 years. Specifically, the classification system has three components: a description of the control variables within breath; a description of the sequence of mandatory and spontaneous breaths; and a specification for the targeting scheme. This three-level specification provides scalability of detail to make the mode description appropriate for the particular need. At the bedside, we need only refer to a mode briefly using the first or perhaps first and second components. To distinguish between similar modes and brand names, we would need to include all components. This taxonomy uses the equation of motion for the respiratory system as the underlying theoretical framework. All terms relevant to describing modes of mechanical ventilation are defined in an extensive appendix.

  6. Installation system for ceramic self-ventilated roofs and facades called: SKIN-KER; Sistema para la instalacion de cubiertas y fachadas ceramicas autoventiladas denominado: SKIN-KER

    Energy Technology Data Exchange (ETDEWEB)

    Puerta Lopez, A.; Casanova Ramon-Borja, A.

    2012-07-01

    The Company Tejas Borja S.A.U. has been awarded by the Spanish Ceramic and Glass Society with the 2012 Golden Alfa Pize for its research in the development of an installation system that creates a self-ventilated roof with modified red body porcelain tiles, and make it extended to a ventilated facade, allowing the entire house wrap with the same quality and aesthetics. The article describes the various stages of the project design both of individual components as well as verification by simulations and lab testing of the different elements of the system and auxiliary materials involved in the installation. (Author)

  7. Heat Exchanger/Humidifier Trade Study and Conceptual Design for the Constellation Space Suit Portable Life Support System Ventilation Subsystem

    Science.gov (United States)

    Paul, Heather L.; Sompayrac, Robert; Conger, Bruce; Chamberlain, Mateo

    2009-01-01

    As development of the Constellation Space Suit Element progresses, designing the most effective and efficient life support systems is critical. The baseline schematic analysis for the Portable Life Support System (PLSS) indicates that the ventilation loop will need some method of heat exchange and humidification prior to entering the helmet. A trade study was initiated to identify the challenges associated with conditioning the spacesuit breathing gas stream for temperature and water vapor control, to survey technological literature and resources on heat exchanger and humidifiers to provide solutions to the problems of conditioning the spacesuit breathing gas stream, and to propose potential candidate technologies to perform the heat exchanger and humidifier functions. This paper summarizes the results of this trade study and also describes the conceptual designs that NASA developed to address these issues.

  8. Thermal comfort and indoor air quality in rooms with integrated personalized ventilation and under-floor air distribution systems

    DEFF Research Database (Denmark)

    Li, Ruixin; Sekhar ., S. C.; Melikov, Arsen Krikor

    2011-01-01

    subjects were collected. The experiments were performed at various combinations of room air and PV air temperatures. The results reveal improved overall thermal sensation and decrease of cold feet complaints, as well as improved inhaled air quality (including perceived air quality) with PV....... The integrated PV-UFAD system, when operated at relatively high temperature of the air supplied from the UFAD system, provided comfortable cooling of the facial region, improved inhaled air quality, and decreased the risk of "cold feet," which is often reported in rooms with UFAD alone. This article explores......-UFAD in comparison with the reference case of UFAD alone or mixing ventilation with a ceiling supply diffuser. Increase of predicted draft rating with the decrease of the local thermal sensation at the feet was identified. The manikin-based equivalent temperature determined for the face was positively correlated...

  9. Purge ventilation operability

    International Nuclear Information System (INIS)

    Marella, J.R.

    1995-01-01

    A determination of minimum requirements for purge exhaust ventilation system operability has been performed. HLWE and HLW Regulatory Program personnel have evaluated the various scenarios of equipment conditions and HLWE has developed the requirements for purge exhaust systems. This report is provided to document operability requirements to assist Tank Farm personnel to determine whether a system is operable/inoperable and to define required compensatory actions

  10. Evaluation and comparison of tropical analyses during DST-5 and DST-6

    Science.gov (United States)

    Sadler, J. C.

    1980-01-01

    Data systems tests were conducted to assess the adequacy of the global data base for numerical analysis and forecasting and in the process to determine the impact of meteorological satellite data. The results of these tests indicate that the satellite data impact is model and season dependent but definitely dependent on the method of data assimilation and the numerical model used to produce the analyses or initial conditions.

  11. GTP-W - the ventilation planning module of the GTP system; GTP-W - Das wettertechnische Planungsmodul des GTP-Systems

    Energy Technology Data Exchange (ETDEWEB)

    Langefeld, O. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Bergbau; Guder, R. [Deutsche Steinkohle AG, Herne (Germany); Reinartz, A. [XGraphic Ingenieurgesellschaft mbH, Aachen (Germany); Huenefeld, R. [Technische Hochschule Aachen (Germany). Lehrstuhl und Inst. fuer Bergwerks- und Huettenmaschinenkunde

    2001-11-08

    The geometrical technical planning at the DSK consists of several calculation modules and a graphic module as well as the material and information management. This has already been described in detail in this publication. The ventilation planning module (GTP-W) is a further module in this planning system. The individual partial modules Ventilation network planning with the applications 'lod roadway network/mine layout' and 'network planning', 'positioning of ventilation equipment and symbols', the 'main ventilation manual and the fire upthrust calculation' are described. Inter alia the graphic plan compilation and the differences from the predecessor system GRUBE-W are highlighted. The series of publications concerning geometrical technical planning is thus completed for the time being. The module for support technology still in the introductory and development phase will be described later. (orig.) [German] Die Geometrisch-Technische-Planung bei der DSK besteht aus einigen Berechnungs- und einem graphischen Modul sowie dem Material- und Informationsmanagement. Hierueber wurde an dieser Stelle bereits ausfuehrlich berichtet. Das wettertechnische Planungsmodul (GTP-W) ist ein weiterer Baustein in diesem Planungssystem. Beschrieben werden die einzelnen Teilmodule Wetternetzplanung mit den Anwendungen 'Streckennetz/Grubengebaeude laden' und 'Netzplanung', 'Positionierung von wettertechnischen Betriebsmitteln und Symbolen', das 'Hauptwetterbuch' und die 'Brandauftriebsberechnung'. Herausgestellt werden unter anderem die graphische Planerstellung und die Unterschiede zum Vorlaeufersystem GRUBE-W. Damit ist die Veroeffentlichungsreihe ueber die Geometrisch-Technische-Planung zunaechst beendet. Das noch in der Einfuehrungs- und Entwicklungsphase befindliche Modul zur Ausbautechnik wird spaeter vorgestellt. (orig.)

  12. Decommissioning of Active Ventilation Systems in a Nuclear R and D Facility to Prepare for Building Demolition (Whiteshell Laboratories Decommissioning Project, Canada) - 13073

    International Nuclear Information System (INIS)

    Wilcox, Brian; May, Doug; Howlett, Don; Bilinsky, Dennis

    2013-01-01

    Whiteshell Laboratories (WL) is a nuclear research establishment owned by the Canadian government and operated by Atomic Energy of Canada Limited (AECL) since the early 1960's. WL is currently under a decommissioning license and the mandate is to remediate the nuclear legacy liabilities in a safe and cost effective manner. The WL Project is the first major nuclear decommissioning project in Canada. A major initiative underway is to decommission and demolish the main R and D Laboratory complex. The Building 300 R and D complex was constructed to accommodate laboratories and offices which were mainly used for research and development associated with organic-cooled reactors, nuclear fuel waste management, reactor safety, advanced fuel cycles and other applications of nuclear energy. Building 300 is a three storey structure of approximately 16,000 m 2 . In order to proceed with building demolition, the contaminated systems inside the building have to be characterized, removed, and the waste managed. There is a significant focus on volume reduction of radioactive waste for the WL project. The active ventilation system is one of the significant contaminated systems in Building 300 that requires decommissioning and removal. The active ventilation system was designed to manage hazardous fumes and radioactivity from ventilation devices (e.g., fume hoods, snorkels and glove boxes) and to prevent the escape of airborne hazardous material outside of the laboratory boundary in the event of an upset condition. The system includes over 200 ventilation devices and 32 active exhaust fan units and high efficiency particulate air (HEPA) filters. The strategy to remove the ventilation system was to work from the laboratory end back to the fan/filter system. Each ventilation duct was radiologically characterized. Fogging was used to minimize loose contamination. Sections of the duct were removed by various cutting methods and bagged for temporary storage prior to disposition

  13. Short-term airing by natural ventilation

    DEFF Research Database (Denmark)

    Perino, Marco; Heiselberg, Per

    2009-01-01

    The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. This kind of system frequently integrates...... that was aimed at developing and validating numerical models for the analysis of buoyancy driven single-sided natural ventilation systems. Once validated, these models can be used to optimize control strategies in order to achieve satisfactory indoor comfort conditions and IAQ....... traditional mechanical ventilation components with natural ventilation devices, such as motorized windows and louvers. Among the various ventilation strategies that are currently available, buoyancy driven single-sided natural ventilation has proved to be very effective and can provide high air change rates...

  14. Human versus Computer Controlled Selection of Ventilator Settings: An Evaluation of Adaptive Support Ventilation and Mid-Frequency Ventilation

    Directory of Open Access Journals (Sweden)

    Eduardo Mireles-Cabodevila

    2012-01-01

    Full Text Available Background. There are modes of mechanical ventilation that can select ventilator settings with computer controlled algorithms (targeting schemes. Two examples are adaptive support ventilation (ASV and mid-frequency ventilation (MFV. We studied how different clinician-chosen ventilator settings are from these computer algorithms under different scenarios. Methods. A survey of critical care clinicians provided reference ventilator settings for a 70 kg paralyzed patient in five clinical/physiological scenarios. The survey-derived values for minute ventilation and minute alveolar ventilation were used as goals for ASV and MFV, respectively. A lung simulator programmed with each scenario’s respiratory system characteristics was ventilated using the clinician, ASV, and MFV settings. Results. Tidal volumes ranged from 6.1 to 8.3 mL/kg for the clinician, 6.7 to 11.9 mL/kg for ASV, and 3.5 to 9.9 mL/kg for MFV. Inspiratory pressures were lower for ASV and MFV. Clinician-selected tidal volumes were similar to the ASV settings for all scenarios except for asthma, in which the tidal volumes were larger for ASV and MFV. MFV delivered the same alveolar minute ventilation with higher end expiratory and lower end inspiratory volumes. Conclusions. There are differences and similarities among initial ventilator settings selected by humans and computers for various clinical scenarios. The ventilation outcomes are the result of the lung physiological characteristics and their interaction with the targeting scheme.

  15. Comparison of indoor air distribution and thermal environment for different combinations of radiant heating systems with mechanical ventilation systems

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Fang, Lei; Olesen, Bjarne W.

    2018-01-01

    ) and mixing ventilation (MV) or displacement ventilation (DV) when the supply air temperature ranged from 15.0°C to 19.0°C. The results showed that the temperature effectiveness values were 1.05–1.16 and 0.95–1.02 for MV+ FH and MV+ CH, respectively, and they were 0.78–0.91 and 0.51–0.67 for DV + FH and DV......, and DV +CH had the smallest values. In addition, the vertical air temperature differences for MV+ FH and MV+CH were all within the comfort zone according to ISO 7730, but exceeded the comfort zone for DV + FH and DV +CH when the supply air temperature was less than 17°C and 19°C, respectively. The air...

  16. Comparison of the Mapleson C system and adult and paediatric self-inflating bags for delivering guideline-consistent ventilation during simulated adult cardiopulmonary resuscitation.

    Science.gov (United States)

    Sherren, P B; Lewinsohn, A; Jovaisa, T; Wijayatilake, D S

    2011-07-01

    There is a discrepancy between resuscitation teaching and witnessed clinical practice. Furthermore, deleterious outcomes are associated with hyperventilation. We therefore conducted a manikin-based study of a simulated cardiac arrest to evaluate the ability of three ventilating devices to provide guideline-consistent ventilation. Mean (SD) minute ventilation was reduced with the paediatric self-inflating bag (7.0 (3.2) l.min⁻¹) compared with the Mapleson C system (9.8 (3.5) l.min⁻¹) and adult self-inflating bag (9.7 (4.2) l.min⁻¹ ; p = 0.003). Tidal volume was also lower with the paediatric self-inflating bag (391 (52) ml) compared with the others (582 (87) ml and 625 (103) ml, respectively; p < 0.001), as was peak airway pressure (14.5 (5.2) cmH₂O vs 20.7 (9.0) cmH₂O and 30.3 (11.4) cmH₂O, respectively; p < 0.001). Participants hyperventilated patients' lungs in simulated cardiac arrest with all three devices. The paediatric self-inflating bag delivered the most guideline-consistent ventilation. Its use in adult cardiopulmonary resuscitation may ensure delivery of more guideline-consistent ventilation in patients with tracheal intubation. © 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.

  17. Removal of Particles from the Supply Air of Ventilation Systems Avoiding the Formation of Sensory Pollution Source

    DEFF Research Database (Denmark)

    Bekö, Gabriel

    2008-01-01

    with filtration. Finally, an experiment was designed to test the effect of different particle filters, activated carbon filters and their combinations on the perceived air quality after several months of continuous use. A commercially available HVAC filter that has low emissions of pollutants, even after...... an important role. Sensory pollutants emitted from used filters can have significant adverse impact on occupant performance. Therefore, removal of particles from the supply air of ventilation systems without the subsequent emission of pollutants into the airstream seems to be essential. Correct maintenance...... substantial time in service, would mean a step forward towards finding an engineering solution to the problem. Additional measurements examined the effect of different pressure sensing techniques and several modifications of an air handling unit on the accuracy of the measurements of pressure drop over...

  18. Experimental analysis of an air-to-air heat recovery unit for balanced ventilation systems in residential buildings

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, Jose; Diz, Ruben; Uhia, Francisco J.; Dopazo, Alberto; Ferro, Jose M. [Area de Maquinas y Motores Termicos, E.T.S. de Ingenieros Industriales, University of Vigo, Campus Lagoas-Marcosende No. 9, 36310 Vigo (Spain)

    2011-01-15

    This paper deals with the experimental analysis of an air-to-air heat recovery unit equipped with a sensible polymer plate heat exchanger (PHE) for balanced ventilation systems in residential buildings. The PHE is arranged in parallel triangular ducts. An experimental facility was designed to reproduce the typical outdoor and exhaust air conditions with regard to temperature and humidity. The unit was tested under balanced operation conditions, as commonly used in practice. A set of tests was conducted under the reference operating conditions to evaluate the PHE performance. Afterwards, an experimental parametric analysis was conducted to investigate the influence of changing the operating conditions on the PHE performance. Experiments were carried out varying the inlet fresh air temperature, the exhaust air relative humidity and the air flow rate. The experimental results are shown and discussed in this paper. (author)

  19. Evaluation of Heating, Ventilation, and Air conditioning (HVAC System Performance in an Administrative Building in Tehran (Iran

    Directory of Open Access Journals (Sweden)

    H. Mari Oriyad

    2014-09-01

    Full Text Available Introduction: One of the factors influencing on indoor air quality of the buildings is performance of HVAC (heating, ventilation, and air conditioning systems. These systems supply clean and odorless air, with temperature, humidity, and air velocity within comfort ranges for the residents. The aim of this study was to evaluate performance HVAC system in an administrative building in Tehran. .Material and Method: A questionnaire, developed in their research was used to assess the building occupants’ perception about the performance of HVAC system. To evaluate the performance of HVAC systems, air velocities were measured in the diffusers using a thermal anemometer. Moreover, CO2 concentration, air temperature and relative humidity were measured in the whole floors of the building. Air distribution inside the building was evaluated using smoke test. .Results: Most of the studied people complained about the direction of airflow, thermal conditions and cigarette odor. The highest level of carbon dioxide was measured at 930 ppm inside the restaurant. The maximum and minimum air temperatures and relative humidity were measured 28.3-13.8° C and 28.4-23% respectively. Smoke test showed that the air distribution/direction wasn’t suitable in one third of air diffusers. .Conclusion: Improper air distribution / direction was the main problem with the studied HVAC system which could be corrected by adjusting and balancing of the system.

  20. The dex/CRH test--is it better than the DST?

    Science.gov (United States)

    Watson, Stuart; Gallagher, Peter; Smith, Margaret S; Ferrier, I Nicol; Young, Allan H

    2006-08-01

    The dexamethasone suppression test (DST), frequently abnormal in mood disorder patients, is considered to measure glucocorticoid receptor-mediated negative feedback. We examined the hypothesis that the, apparently more sensitive, dexamethasone/corticotrophin-releasing-hormone (dex/CRH) test unveils subtle hypothalamic-pituitary-adrenal axis disturbance not detected by the DST in 82 patients with mood disorders and 28 controls. There was a close correlation between the cortisol responses on the two tests (r(s)=0.73, pDST (p=0.031). The sensitivity of delta cortisol (from the dex/CRH) was 61.9% and the specificity 71.4%. The sensitivity of 1500 h cortisol (the DST) was 66.6% and the specificity was 47.6%. This suggests that the two tests measure common pathology but that the dex/CRH test has better diagnostic utility.