WorldWideScience

Sample records for hvac in-duct ultraviolet

  1. Environmental Technology Verification: Biological Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Systems--American Ultraviolet Corporation, DC24-6-120 [EPA600etv08005

    Science.gov (United States)

    The Air Pollution Control Technology Verification Center (APCT Center) is operated by RTI International (RTI), in cooperation with EPA's National Risk Management Research Laboratory. The APCT Center conducts verifications of technologies that clean air in ventilation systems, inc...

  2. HVAC systems and equipment

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, S.T. (Linford Air and Refrigeration Company, Oakland, CA (US))

    1990-02-01

    The author discusses the section of the ASHRAE Standard 90.1-1989 which addresses HVAC systems and equipment. New features of HVAC systems mandatory general requirements are described. New prescriptive requirements are detailed.

  3. HVAC systems design handbook

    CERN Document Server

    Haines, Roger W

    2010-01-01

    Thoroughly updated with the latest codes, technologies, and practices, this all-in-one resource provides details, calculations, and specifications for designing efficient and effective residential, commercial, and industrial HVAC systems. HVAC Systems Design Handbook, Fifth Edition, features new information on energy conservation and computer usage for design and control, as well as the most recent International Code Council (ICC) Mechanical Code requirements. Detailed illustrations, tables, and essential HVAC equations are also included. This comprehensive guide contains everything you need to design, operate, and maintain peak-performing HVAC systems.

  4. Environmental Technology Verification: Supplement to Test/QA Plan for Biological and Aerosol Testing of General Ventilation Air Cleaners; Bioaerosol Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Air Cleaners

    Science.gov (United States)

    The Air Pollution Control Technology Verification Center has selected general ventilation air cleaners as a technology area. The Generic Verification Protocol for Biological and Aerosol Testing of General Ventilation Air Cleaners is on the Environmental Technology Verification we...

  5. HVAC retrofitting and remodeling

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.G. [Linford Co., Oakland, CA (United States)

    1996-03-01

    This article describes the pitfalls and problems as well as the benefits of updating a HVAC system. Failures and successes, and the lessons learned working in this dominant portion of the construction market are included as the author describes retrofit projects. The projects have ranged from total replacements in unoccupied buildings to updating systems in occupied buildings.

  6. HVAC system operation manual of IMEF

    International Nuclear Information System (INIS)

    Baek, Sang Yeol; Park, Dae Kyu; Ahn, Sang Bok; Ju, Yong Sun.

    1997-06-01

    This manual is operation procedures of the IMEF(Irradiated Material Examination Facility) HVAC(Heating, Ventilation and Air Conditioning) System. General operation procedures and test method of the IMEF HVAC system are described. The manual is as follows; 1. HVAC system operation manual 2. HVAC system management guide 3. HVAC system maintenance manual 4. HVAC system air velocity and flowrate measurement manual 5. HVAC system HEPA filter leak test manual 6. HVAC system charcoal filter leak test manual 7. HVAC system HEPA and charcoal filter exchange manual. (author). 8 tabs

  7. Efficient HVAC. New products

    International Nuclear Information System (INIS)

    2016-01-01

    Jung is responding to the challenge of energy efficiency, ease of operation and economic profitability in all of its solutions for the tertiary sector, whether for newly constructed buildings or refurbishments, for full management of the electrical system or the partial control of lighting, HVAC, mood settings, access control, etc., for the bedrooms or specific areas of the building. In the specific case of hotels, Jung offers each a custom-made solution in line with its possibilities and objectives. (Author)

  8. Overview of HVAC system simulation

    NARCIS (Netherlands)

    Trcka, M.; Hensen, J.L.M.

    2010-01-01

    The paper gives an overview of heating, ventilation and air-conditioning (HVAC) system modeling and simulation. The categorization of tools for HVAC system design and analysis with respect to which problems they are meant to deal with is introduced. Each categorization is explained and example tools

  9. Noise suppression in duct

    International Nuclear Information System (INIS)

    Ahmed, A.; Barfeh, M.A.G.

    2001-01-01

    In air-conditioning system the noise generated by supply fan is carried by conditioned air through the ductwork. The noise created in ductwork run may be transmission, regenerative and ductborne. Transmission noise is fan noise, regenerative noise is due to turbulence in flow and ductborne noise is the noise radiating from duct to surroundings. Some noise is attenuated in ducts also but if noise level is high then it needs to be attenuated. A simple mitre bend can attenuate-noise. This principle is extended to V and M-shape ducts with inside lining of fibreglass, which gave maximum attenuation of 77 dB and 62 dB respectively corresponding to 8 kHz frequency as compared to mitre, bend giving maximum 18 dB attenuation. Sound level meter measured sound levels with octave band filter and tests were conducted in anechoic room. A V-shape attenuator can be used at fan outlet and high frequency noise can be minimized greatly. (author)

  10. HVAC retrofit for healthy schools

    International Nuclear Information System (INIS)

    Thompson, R.C.; Fisher, G.; Brennan, T.; Turner, W.A.; McKnight, F.

    1991-01-01

    The Environmental Protection Agency has evaluated the impacts of HVAC systems and building dynamics on radon concentrations in 26 schools across the United States. Diagnostic data indicated that radon was not the only indoor air pollutant in these schools. As a result, an essential step in the School Evaluation Program is determination of the feasibility of using HVAC technology for radon remediation in addition to general indoor air improvement. In 1990, the EPA sponsored the HVAC retrofit of two schools in Maine. This paper presents the information gained by these case studies. First, the extensive pre-retrofit diagnostics and characterizations of the two schools are reviewed. Then follows a discussion of why and how the HVAC systems, including unit ventilators, central air-handling units, and heat recovery ventilation, were retrofitted. Finally, an appraisal of the post-retrofit radon and CO 2 levels is made, along with presentation of related data such as retrofit costs and energy and comfort impacts

  11. Higher Efficiency HVAC Motors

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, Charles Joseph [QM Power, Inc., Kansas City, MO (United States)

    2018-02-13

    The objective of this project was to design and build a cost competitive, more efficient heating, ventilation, and air conditioning (HVAC) motor than what is currently available on the market. Though different potential motor architectures among QMP’s primary technology platforms were investigated and evaluated, including through the building of numerous prototypes, the project ultimately focused on scaling up QM Power, Inc.’s (QMP) Q-Sync permanent magnet synchronous motors from available sub-fractional horsepower (HP) sizes for commercial refrigeration fan applications to larger fractional horsepower sizes appropriate for HVAC applications, and to add multi-speed functionality. The more specific goal became the research, design, development, and testing of a prototype 1/2 HP Q-Sync motor that has at least two operating speeds and 87% peak efficiency compared to incumbent electronically commutated motors (EC or ECM, also known as brushless direct current (DC) motors), the heretofore highest efficiency HVACR fan motor solution, at approximately 82% peak efficiency. The resulting motor prototype built achieved these goals, hitting 90% efficiency and .95 power factor at full load and speed, and 80% efficiency and .7 power factor at half speed. Q-Sync, developed in part through a DOE SBIR grant (Award # DE-SC0006311), is a novel, patented motor technology that improves on electronically commutated permanent magnet motors through an advanced electronic circuit technology. It allows a motor to “sync” with the alternating current (AC) power flow. It does so by eliminating the constant, wasteful power conversions from AC to DC and back to AC through the synthetic creation of a new AC wave on the primary circuit board (PCB) by a process called pulse width modulation (PWM; aka electronic commutation) that is incessantly required to sustain motor operation in an EC permanent magnet motor. The Q-Sync circuit improves the power factor of the motor by removing all

  12. Technical Assessment: WRAP 1 HVAC Passive Shutdown

    International Nuclear Information System (INIS)

    Ball, D.E.; Nash, C.R.; Stroup, J.L.

    1993-01-01

    As the result of careful interpretation of DOE Order 6430.lA and other DOE Orders, the HVAC system for WRAP 1 has been greatly simplified. The HVAC system is now designed to safely shut down to Passive State if power fails for any reason. The fans cease functioning, allowing the Zone 1 and Zone 2 HVAC Confinement Systems to breathe with respect to atmospheric pressure changes. Simplifying the HVAC system avoided overdesign. Construction costs were reduced by eliminating unnecessary equipment. This report summarizes work that was done to define the criteria, physical concepts, and operational experiences that lead to the passive shutdown design for WRAP 1 confinement HVAC systems

  13. Reciprocity principle in duct acoustics

    Science.gov (United States)

    Cho, Y.-C.

    1979-01-01

    Various reciprocity relations in duct acoustics have been derived on the basis of the spatial reciprocity principle implied in Green's functions for linear waves. The derivation includes the reciprocity relations between mode conversion coefficients for reflection and transmission in nonuniform ducts, and the relation between the radiation of a mode from an arbitrarily terminated duct and the absorption of an externally incident plane wave by the duct. Such relations are well defined as long as the systems remain linear, regardless of acoustic properties of duct nonuniformities which cause the mode conversions.

  14. Study on HVAC system in nuclear facility

    International Nuclear Information System (INIS)

    Baeg, S. Y.; Song, W. S.; Oh, Y. O.; Ju, Y. S.; Hong, K. P.

    2003-01-01

    Heating, Ventilation and Air Conditioning (HVAC) system in nuclear facility should be equipped and constructed more stable and allowable than that in common facility. The purpose of HVAC system is the maintenance of optimum working environment, the protection of worker against a contaminated air and the prevention of atmospheric contamination due to an outward ventilation, etc.. The basic scheme of a safety operation of nuclear facility is to prevent the atmospheric contamination even in low level. The adaptability of HVAC system which is in operation. In this study, the design requirements of HVAC system in nuclear facility and the HVAC systems in foreign countries are reviewed, and the results can be utilized in the design of HVAC system in nuclear facility

  15. An integrated control-oriented modelling for HVAC performance benchmarking

    NARCIS (Netherlands)

    Satyavada, Harish; Baldi, S.

    2016-01-01

    Energy efficiency in building heating, ventilating and air conditioning (HVAC) equipment requires the development of accurate models for testing HVAC control strategies and corresponding energy consumption. In order to make the HVAC control synthesis computationally affordable, such

  16. Breathing Easier: HVAC Specifications for Schools.

    Science.gov (United States)

    Trent, C. Curtis; Trent, Warren C.

    1996-01-01

    A major source of indoor air contamination in schools originates within the heating, ventilating, and air-conditioning systems (HVAC), with draw-through systems being the worst offenders. Lists provisions for designing an HVAC system and a set of criteria to adhere to when planning new construction or renovations. (nine references) (MLF)

  17. Workplace Trends In HVAC/R

    Science.gov (United States)

    Strang, Lynn; Todd, CeCe

    2013-01-01

    This article presents trends in the heating, ventilation, air conditioning and refrigeration (HVAC/R) industry, with an emphasis on the importance of technician training programs as exemplified at the East Valley Institute of Technology (EVIT) in Mesa, Arizona. The article states that HVAC workers are increasingly helping their consumers "go…

  18. Propagation of sound waves in ducts

    DEFF Research Database (Denmark)

    Jacobsen, Finn

    2000-01-01

    Plane wave propagation in ducts with rigid walls, radiation from ducts, classical four-pole theory for composite duct systems, and three-dimentional waves in wave guides of various cross-sectional shape are described.......Plane wave propagation in ducts with rigid walls, radiation from ducts, classical four-pole theory for composite duct systems, and three-dimentional waves in wave guides of various cross-sectional shape are described....

  19. HVAC-DYNAMIC; A training simulator for dynamic analysis of HVAC plants

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, M; Novakovic, V [SINTEF Division of Applied Thermodynamic, HVAC Group, Trondheim (Norway); Oegaard, O [SINTEF Division of Automatic Control, Trondheim (Norway); Brustad, G [Computer Aided Modelling, CAMO A/S, Trondheim (Norway)

    1989-01-01

    HVAC-DYNAMIC is a software tool for the dynamic simulation of Heating, Ventilation and Air Conditioning (HVAC) plants. The program is designed to be used by HVAC engineers during design or troubleshooting of plants and by plant operators in their training. The program is based on a set of the most-used HVAC plant configurations and requires only a minimum of knowledge in numeric methods and programming. A brief presentation of the program structure and examples showing some of the application of the program are given. 4 figs., 4 refs.

  20. HVAC-DYNAMIC: a training simulator for dynamic analysis of HVAC plants

    Directory of Open Access Journals (Sweden)

    Morten Heintz

    1989-07-01

    Full Text Available HVAC-DYNAMIC is a software tool for the dynamic simulation of Heating, Ventilation and Air Conditioning (HVAC plants. The program is designed to be used by HVAC engineers during design or troubleshooting of plants and by plant operators in their training. The program is based on a set of the most-used HVAC plant configurations and requires only a minimum of knowledge in numeric methods and programming. A brief presentation of the program structure and examples showing some of the application of the program are given.

  1. ENERGY STAR Certified Light Commercial HVAC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.1 ENERGY STAR Program Requirements for Light Commercial HVAC that are effective as of...

  2. HVAC design manual for hospitals and clinics

    National Research Council Canada - National Science Library

    2013-01-01

    "Provides in-depth design recommendations and proven, cost effective, and reliable solutions for health care HVAC design that provide low maintenance cost and high reliability based on best practices...

  3. Optimization of the structural design of HVAC ducts and their supports

    International Nuclear Information System (INIS)

    DeMatias, I.P.; Barrio, M.

    1987-01-01

    This paper describes the computerized process of qualification and design based on experience accumulated in structural designs of HVAC systems in nuclear power plants, using CAD/CAE systems. Such computerization has drastically reduced the number of manhours employed to generate the information necessary to issue duct and support fabrication drawings. During the analysis stage, the requirements for qualification of ducts and supports contained in CONAGT ANSI/ASME AG-1 have been considered. The data package applicable to the process consists of a set of computer programs which may be used independently or combined. A significant portion of such programs governs the graphic design. Moreover, analyses are performed on results of the different types of tests carried out to date, and on those necessary to determine the mechanisms of failures in ducts, and in order to be able to calibrate design criteria currently in use

  4. The map of energy flow in HVAC systems

    International Nuclear Information System (INIS)

    Perez-Lombard, Luis; Ortiz, Jose; Maestre, Ismael R.

    2011-01-01

    Highlights: → Discussion of the four stages in the 'HVAC systems energy chain'. → Examination of HVAC systems as energy conversion devices. → Analysis of HVAC Sankey diagrams. → Discussion of HVAC loads and HVAC energy losses. -- Abstract: Heating, ventilation and air conditioning (HVAC) systems are the most energy consuming building services representing approximately half of the final energy use in the building sector and between one tenth and one fifth of the energy consumption in developed countries. Despite their significant energy use, there is a lack of a consistent and homogeneous framework to efficiently guide research and energy policies, mainly due to the complexity and variety of HVAC systems but also to insufficient rigour in their energy analysis. This paper reviews energy related aspects of HVAC systems with the aim of establishing a common ground for the analysis of their energy efficiency. The paper focuses on the map of energy flow to deliver thermal comfort: the HVAC energy chain. Our approach deals first with thermal comfort as the final service delivered to building occupants. Secondly, conditioned spaces are examined as the systems where useful heat (or coolth) is degraded to provide comfort. This is followed by the analysis of HVAC systems as complex energy conversion devices where energy carriers are transformed into useful heat and coolth, and finally, the impact of HVAC energy consumption on energy resources is discussed.

  5. Residential and Light Commercial HVAC. Teacher Edition.

    Science.gov (United States)

    Stephenson, David; Fulkerson, Dan, Ed.

    This curriculum guide contains 18 units of instruction for a competency-based course in residential and light commercial heating, ventilating, and air conditioning (HVAC). Introductory materials include a competency profile and an instructional/task analysis that correlates job training with related information for this course. Each instructional…

  6. HVAC systems and nuclear plant safety. Final report, May 1992

    International Nuclear Information System (INIS)

    1992-05-01

    The primary objective of this study was to provide perspective on the overall risk impact of heating, ventilating, and air conditioning (HVAC) system problems. Industry experience with HVAC system problems is documented and analyzed. In addition, the results of 10 plant-specific probabilistic risk assessments (PRA) were reviewed to determine the contribution of HVAC systems to the risk of core damage. The PRAs included in this review cover a broad range of plant types and operating conditions. The review found that the impact of HVAC systems on risk is plant specific. These results exhibit a broad range of frequencies for HVAC contribution to risk, and the percentage of total core damage due to HVAC problems also had a wide variability. Plant-specific differences in design, environment, operation, and maintenance are the primary factors in determining the risk contribution of HVAC systems. (author)

  7. Introduction to Heating, Ventilation and Air Conditioning (HVAC). Introduction to Construction Series. Instructor Edition.

    Science.gov (United States)

    Associated General Contractors of America, Washington, DC.

    This module on introductory heating, ventilating, and air conditioning (HVAC) is one of a series of modules designed to teach basic skills necessary for entry-level employment in this field. The module contains four instructional units that cover the following topics: (1) HVAC materials; (2) HVAC tools; (3) HVAC layout; and (4) HVAC basic skills.…

  8. Control strategy optimization of HVAC plants

    Energy Technology Data Exchange (ETDEWEB)

    Facci, Andrea Luigi; Zanfardino, Antonella [Department of Engineering, University of Napoli “Parthenope” (Italy); Martini, Fabrizio [Green Energy Plus srl (Italy); Pirozzi, Salvatore [SIAT Installazioni spa (Italy); Ubertini, Stefano [School of Engineering (DEIM) University of Tuscia (Italy)

    2015-03-10

    In this paper we present a methodology to optimize the operating conditions of heating, ventilation and air conditioning (HVAC) plants to achieve a higher energy efficiency in use. Semi-empiric numerical models of the plant components are used to predict their performances as a function of their set-point and the environmental and occupied space conditions. The optimization is performed through a graph-based algorithm that finds the set-points of the system components that minimize energy consumption and/or energy costs, while matching the user energy demands. The resulting model can be used with systems of almost any complexity, featuring both HVAC components and energy systems, and is sufficiently fast to make it applicable to real-time setting.

  9. Control strategy optimization of HVAC plants

    International Nuclear Information System (INIS)

    Facci, Andrea Luigi; Zanfardino, Antonella; Martini, Fabrizio; Pirozzi, Salvatore; Ubertini, Stefano

    2015-01-01

    In this paper we present a methodology to optimize the operating conditions of heating, ventilation and air conditioning (HVAC) plants to achieve a higher energy efficiency in use. Semi-empiric numerical models of the plant components are used to predict their performances as a function of their set-point and the environmental and occupied space conditions. The optimization is performed through a graph-based algorithm that finds the set-points of the system components that minimize energy consumption and/or energy costs, while matching the user energy demands. The resulting model can be used with systems of almost any complexity, featuring both HVAC components and energy systems, and is sufficiently fast to make it applicable to real-time setting

  10. Cutting the cost of hospital HVAC.

    Science.gov (United States)

    Ruddell, Steve

    2011-09-01

    Steve Ruddell, head of global marketing, Motors & Generators, at ABB, emphasises the importance of a good motor management and maintenance policy in getting the best performance from, and reducing the energy consumption of, hospitals' HVAC systems, also explaining why investing in energy-efficient, low voltage drives, and high efficiency electric motors, to control such equipment, can pay major dividends for estates and facilities teams.

  11. System-Level Monitoring and Diagnosis of Building HVAC System

    OpenAIRE

    Wu, Siyu

    2013-01-01

    Heating, ventilation, and air conditioning (HVAC) is an indoor environmental technology that is extensively instrumented for large-scale buildings. Among all subsystems of buildings, the HVAC system dominates the energy consumption and accounts for 57% of the energy used in U.S. commercial and residential buildings. Unfortunately, the HVAC system may fail to meet the performance expectations due to various faults, including not only complete hardware failures, but also non-optimal operations....

  12. Modeling and Control of AHUs in Building HVAC Systems

    OpenAIRE

    Liang, Wei

    2014-01-01

    Heating, ventilation and air conditioning (HVAC) is a mechanical system that provides thermal comfort and accepted indoor air quality often instrumented for large-scale buildings. The HVAC system takes a dominant portion of overall building energy consumption and accounts for 50% of the energy used in the U.S. commercial and residential buildings in 2012. The performance and energy saving of building HVAC systems can be significantly improved by the implementation of better and smarter contro...

  13. Intelligent control of HVAC systems. Part I: Modeling and synthesis

    Directory of Open Access Journals (Sweden)

    Adrian TOADER

    2013-03-01

    Full Text Available This is the first part of a work on intelligent type control of Heating, Ventilating and Air-Conditioning (HVAC systems. The study is performed from the perspective of giving a unitary control method to ensure high energy efficiency and air quality improving. To illustrate the proposed HVAC control technique, in this first part it is considered as benchmark problem a single thermal space HVAC system. The construction of the mathematical model is performed only with a view to obtain a framework of HVAC intelligent control validation by numerical simulations. The latter will be reported in a second part of the study.

  14. Development of a computer design system for HVAC

    International Nuclear Information System (INIS)

    Miyazaki, Y.; Yotsuya, M.; Hasegawa, M.

    1993-01-01

    The development of a computer design system for HVAC (Heating, Ventilating and Air Conditioning) system is presented in this paper. It supports the air conditioning design for a nuclear power plant and a reprocessing plant. This system integrates various computer design systems which were developed separately for the various design phases of HVAC. the purposes include centralizing the HVAC data, optimizing design, and reducing the designing time. The centralized HVAC data are managed by a DBMS (Data Base Management System). The DBMS separates the computer design system into a calculation module and the data. The design system can thus be expanded easily in the future. 2 figs

  15. [Air quality control systems: heating, ventilating, and air conditioning (HVAC)].

    Science.gov (United States)

    Bellucci Sessa, R; Riccio, G

    2004-01-01

    After a brief illustration of the principal layout schemes of Heating, Ventilating, and Air Conditioning (HVAC), the first part of this paper summarizes the standards, both voluntary and compulsory, regulating HVAC facilities design and installation with regard to the question of Indoor Air Quality (IAQ). The paper then examines the problem of ventilation systems maintenance and the essential hygienistic requirements in whose absence HVAC facilities may become a risk factor for people working or living in the building. Lastly, the paper deals with HVAC design strategies and methods, which aim not only to satisfy comfort and air quality requirements, but also to ensure easy and effective maintenance procedures.

  16. The effect of cleanliness control during installation work on the amount of accumulated dust in ducts of new HVAC installations.

    Science.gov (United States)

    Holopainen, R; Tuomainen, M; Asikainen, V; Pasanen, P; Säteri, J; Seppänen, O

    2002-09-01

    The aim of this study was to evaluate the amount of dust in supply air ducts in recently installed ventilation systems. The samples for the determination of dust accumulation were collected from supply air ducts in 18 new buildings that have been constructed according to two different cleanliness control levels classified as category P1 (low oil residues and protected against contaminations) and category P2, as defined in the Classification of Indoor Climate, Construction and Building Materials. In the ducts installed according to the requirements of cleanliness category P1 the mean amount of accumulated dust was 0.9 g/m2 (0.4-2.9 g/m2), and in the ducts installed according to the cleanliness category P2 it was 2.3 g/m2 (1.2-4.9 g/m2). A significant difference was found in the mean amounts of dust between ducts of categories P1 and P2 (P < 0.008). The cleanliness control procedure in category P1 proved to be a useful and effective tool for preventing dust accumulation in new air ducts during the construction process. Additionally, the ducts without residual oil had lower amounts of accumulated dust indicating that the demand for oil free components in the cleanliness classification is reasonable.

  17. Maintenance of HVAC-systems and components: How to prevent pollution from HVAC-systems?

    NARCIS (Netherlands)

    Müller, B.; Björkroth, M.; Plitt, U.; Bluyssen, P.M.

    2000-01-01

    In the beginning of 1998 a three-year European project, AIRLESS, was started to develop strategies, principles and protocols to improve and control the performance of HVAC-systems and its components for incorporation in codes and guidelines. Twelve institutes, universities and companies, from seven

  18. Why, when and how do HVAC-systems pollute? Characterisation of HVAC-systems related pollution

    NARCIS (Netherlands)

    Bluyssen, P.M.; Björkroth, M.; Müller, B.; Oliveira Fernandes, E. de; Roulet, C.A.

    2000-01-01

    In the beginning of 1998 a three-year European project, AIRLESS, was started to develop strategies, principles and protocols to improve and control the performance of HVAC-systems and its components for incorporation in codes and guidelines. Twelve institutes, universities and companies from seven

  19. Integrated dynamic modelling and multivariable control of HVAC components

    NARCIS (Netherlands)

    Satyavada, H.; Babuska, R.; Baldi, S.; Stoustrup, Jakob; Rantzer, Anders; Jørgensen, John Bagterp

    2016-01-01

    The field of energy efficiency in buildings offers challenging opportunities from a control point of view. Heating, Ventilation and Air-Conditioning (HVAC) units in buildings must be accurately controlled so as to ensure the occupants' comfort and reduced energy consumption. While the existing HVAC

  20. Design Concepts for Optimum Energy Use in HVAC Systems.

    Science.gov (United States)

    Electric Energy Association, New York, NY.

    Much of the innovative work in the design and application of heating, ventilating, and air conditioning (HVAC) systems is concentrated on improving the cost effectiveness of such systems through optimizing energy use. One approach to the problem is to reduce a building's HVAC energy demands by designing it for lower heat gains and losses in the…

  1. RECOMMENDED HVAC STANDARD OF THE FLORIDA RADON RESEARCH PROGRAM

    Science.gov (United States)

    The report contains the recommended language for the heating, ventilation, and air conditioning (HVAC) section of the "Florida Code for Radon-resistant Construction and Mitigation." t deals with elements of construction that relate to the HVAC of houses. ts primary intent is to p...

  2. Applying power electronics to residential HVAC

    International Nuclear Information System (INIS)

    Sulfstede, L.

    1991-01-01

    This paper outlines several of the market and application issues bearing on the economics residential variable speed air conditioners and heat pumps. Technical details of capacity modulized systems have been avoided, along with design issues and tradeoffs involving power semiconductors, motor torque and speed control strategies- and silicon integration for these applications. The intention is to provoke new creative technical solutions but perhaps more importantly, to involve new marketing strategies that will develop the mature potential of air conditioning products containing power electronics to enable them to generate the tough HVAC market, competing successfully against conventional systems

  3. Towards Autonomous Control of HVAC Systems

    DEFF Research Database (Denmark)

    Brath, P.

    autonomous control. Together with better tuned controllers and more dedicated control it would be possible to decrease the energy consumption, save money and increase the indoor air climate. A flexible HVAC test system was designed and implemented. Standard components and sensors were used in the design...... temperature controller, based on airflow control, was designed. Feedback linearisation is used together with an auto-tuning procedure, based on relay feedback. Design of a new CO2 controller was made to achieve a demand controlled ventilation system, in order to save energy. Feedback linearisation was used...

  4. Best practices guide for residential HVAC Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.

    2003-08-11

    This best practices guide for residential HVAC system retrofits is aimed at contractors who want guidance on delivering energy efficient, cost effective and innovative products. It has been developed around the idea of having packages of changes to the building HVAC system and building envelope that are climate and house construction dependent. These packages include materials, procedures and equipment and are designed to remove some of the guesswork from a builder, contractor, installer or homeowner decisions about how best to carry out HVAC changes. The packages are not meant to be taken as rigid requirements--instead they are systems engineered guidelines that form the basis for energy efficient retrofits. Similar approaches have been taken previously for new construction to develop extremely energy efficient homes that are comfortable safe and durable, and often cost less than standard construction. This is best epitomized by the Building America program whose partners have built thousands of residences throughout the U.S. using these principles. The differences between retrofitting and new construction tend to limit the changes one can make to a building, so these packages rely on relatively simple and non-intrusive technologies and techniques. The retrofits also focus on changes to a building that will give many years of service to the occupants. Another key aspect of these best practices is that we need to know how a house is working so that we know what parts have the potential for improvement. To do this we have put together a set of diagnostic tools that combine physical measurements and checklists/questionnaires. The measured test results, observations and homeowner answers to questions are used to direct us towards the best retrofits applicable to each individual house. The retrofits will depend on the current condition of the building envelope and HVAC system, the local climate, the construction methods used for the house, and the presence of various

  5. Optimal Model-Based Control in HVAC Systems

    DEFF Research Database (Denmark)

    Komareji, Mohammad; Stoustrup, Jakob; Rasmussen, Henrik

    2008-01-01

    is developed. Then the optimal control structure is designed and implemented. The HVAC system is splitted into two subsystems. By selecting the right set-points and appropriate cost functions for each subsystem controller the optimal control strategy is respected to gaurantee the minimum thermal and electrical......This paper presents optimal model-based control of a heating, ventilating, and air-conditioning (HVAC) system. This HVAC system is made of two heat exchangers: an air-to-air heat exchanger (a rotary wheel heat recovery) and a water-to- air heat exchanger. First dynamic model of the HVAC system...... energy consumption. Finally, the controller is applied to control the mentioned HVAC system and the results show that the expected goals are fulfilled....

  6. Optimal Set-Point Synthesis in HVAC Systems

    DEFF Research Database (Denmark)

    Komareji, Mohammad; Stoustrup, Jakob; Rasmussen, Henrik

    2007-01-01

    This paper presents optimal set-point synthesis for a heating, ventilating, and air-conditioning (HVAC) system. This HVAC system is made of two heat exchangers: an air-to-air heat exchanger and a water-to-air heat exchanger. The objective function is composed of the electrical power for different...... components, encompassing fans, primary/secondary pump, tertiary pump, and air-to-air heat exchanger wheel; and a fraction of thermal power used by the HVAC system. The goals that have to be achieved by the HVAC system appear as constraints in the optimization problem. To solve the optimization problem......, a steady state model of the HVAC system is derived while different supplying hydronic circuits are studied for the water-to-air heat exchanger. Finally, the optimal set-points and the optimal supplying hydronic circuit are resulted....

  7. HVAC system optimisation-in-building section

    Energy Technology Data Exchange (ETDEWEB)

    Lu, L.; Cai, W.; Xie, L.; Li, S.; Soh, Y.C. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore (Singapore)

    2004-07-01

    This paper presents a practical method to optimise in-building section of centralised Heating, Ventilation and Air-Conditioning (HVAC) systems which consist of indoor air loops and chilled water loops. First, through component characteristic analysis, mathematical models associated with cooling loads and energy consumption for heat exchangers and energy consuming devices are established. By considering variation of cooling load of each end user, adaptive neuro-fuzzy inference system (ANFIS) is employed to model duct and pipe networks and obtain optimal differential pressure (DP) set points based on limited sensor information. A mix-integer nonlinear constraint optimization of system energy is formulated and solved by a modified genetic algorithm. The main feature of our paper is a systematic approach in optimizing the overall system energy consumption rather than that of individual component. A simulation study for a typical centralized HVAC system is provided to compare the proposed optimisation method with traditional ones. The results show that the proposed method indeed improves the system performance significantly. (author)

  8. HVAC system optimization - in-building section

    Energy Technology Data Exchange (ETDEWEB)

    Lu Lu; Wenjian Cai; Lihua Xie; Shujiang Li; Yeng Chai Soh [Nanyang Technological Univ., Singapore (Singapore). School of Electrical and Electronic Engineering

    2005-01-01

    This paper presents a practical method to optimize in-building section of centralized Heating, Ventilation and Air-conditioning (HVAC) systems which consist of indoor air loops and chilled water loops. First, through component characteristic analysis, mathematical models associated with cooling loads and energy consumption for heat exchangers and energy consuming devices are established. By considering variation of cooling load of each end user, adaptive neuro-fuzzy inference system (ANFIS) is employed to model duct and pipe networks and obtain optimal differential pressure (DP) set points based on limited sensor information. A mix-integer nonlinear constraint optimization of system energy is formulated and solved by a modified genetic algorithm. The main feature of our paper is a systematic approach in optimizing the overall system energy consumption rather than that of individual component. A simulation study for a typical centralized HVAC system is provided to compare the proposed optimization method with traditional ones. The results show that the proposed method indeed improves the system performance significantly. (author)

  9. Classroom HVAC: Improving ventilation and saving energy -- field study plan

    Energy Technology Data Exchange (ETDEWEB)

    Apte, Michael G.; Faulkner, David; Hodgson, Alfred T.; Sullivan, Douglas P.

    2004-10-14

    The primary goals of this research effort are to develop, evaluate, and demonstrate a very practical HVAC system for classrooms that consistently provides classrooms (CRs) with the quantity of ventilation in current minimum standards, while saving energy, and reducing HVAC-related noise levels. This research is motivated by the public benefits of energy efficiency, evidence that many CRs are under-ventilated, and public concerns about indoor environmental quality in CRs. This document provides a summary of the detailed plans developed for the field study that will take place in 2005 to evaluate the energy and IAQ performance of a new classroom HVAC technology. The field study will include measurements of HVAC energy use, ventilation rates, and IEQ conditions in 10 classrooms with the new HVAC technology and in six control classrooms with a standard HVAC system. Energy use and many IEQ parameters will be monitored continuously, while other IEQ measurements will be will be performed seasonally. Continuously monitored data will be remotely accessed via a LonWorks network. Instrument calibration plans that vary with the type of instrumentation used are established. Statistical tests will be employed to compare energy use and IEQ conditions with the new and standard HVAC systems. Strengths of this study plan include the collection of real time data for a full school year, the use of high quality instrumentation, the incorporation of many quality control measures, and the extensive collaborations with industry that limit costs to the sponsors.

  10. A review of different strategies for HVAC energy saving

    International Nuclear Information System (INIS)

    Vakiloroaya, Vahid; Samali, Bijan; Fakhar, Ahmad; Pishghadam, Kambiz

    2014-01-01

    Highlights: • Various strategies for HVAC energy saving are described and reviewed. • The influence of each strategy on the HVAC energy saving is investigated. • Combination of existing air conditioning technologies appears to be effective for the energy conservation and comfort. • A comparison study between these approaches is carried out. • Changing the HVAC configuration has the potential to increase or reduce energy savings, depending on several factors. - Abstract: Decreasing the energy consumption of heating, ventilation and air conditioning (HVAC) systems is becoming increasingly important due to rising cost of fossil fuels and environmental concerns. Therefore, finding novel ways to reduce energy consumption in buildings without compromising comfort and indoor air quality is an ongoing research challenge. One proven way of achieving energy efficiency in HVAC systems is to design systems that use novel configurations of existing system components. Each HVAC discipline has specific design requirements and each presents opportunities for energy savings. Energy efficient HVAC systems can be created by re-configuring traditional systems to make more strategic use of existing system parts. Recent research has demonstrated that a combination of existing air conditioning technologies can offer effective solutions for energy conservation and thermal comfort. This paper investigates and reviews the different technologies and approaches, and demonstrates their ability to improve the performance of HVAC systems in order to reduce energy consumption. For each strategy, a brief description is first presented and then by reviewing the previous studies, the influence of that method on the HVAC energy saving is investigated. Finally, a comparison study between these approaches is carried out

  11. SURFACE INDUSTRIAL HVAC SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    M.M. Ansari

    2005-04-05

    The purpose of this system description document (SDD) is to establish requirements that drive the design of the surface industrial heating, ventilation, and air-conditioning (HVAC) system and its bases to allow the design effort to proceed to license application. This SDD will be revised at strategic points as the design matures. This SDD identifies the requirements and describes the system design, as it currently exists, with emphasis on attributes of the design provided to meet the requirements. This SDD is an engineering tool for design control; accordingly, the primary audience and users are design engineers. This SDD is part of an iterative design process. It leads the design process with regard to the flowdown of upper tier requirements onto the system. Knowledge of these requirements is essential to performing the design process. The SDD follows the design with regard to the description of the system. The description that provided in this SDD reflects the current results of the design process.

  12. D-Zero HVAC Heat Pump Controls

    International Nuclear Information System (INIS)

    Markley, Dan

    2004-01-01

    This engineering note documents the integration of Dzero Heat Pump 1 through Heat Pump 15 into the cryo/gas process control system commonly referred to as the cryo control system. Heat pumps 1 through 15 control the ambient air temperature on the 3rd, 5th, and 6th floor office areas at Dzero. The entire Johnson HVAC control system was replaced with a Siemens control system in 1999 leaving behind the 15 heat pumps with stand-alone Johnson controllers. Now, these 15 heat pump Johnson controllers are being replaced with small stand alone Beckhoff BC9000 controllers. The Beckhoff BC9000 controllers are network able into the existing Intellution control system. The Beckhoff BC9000 controllers use the cryo private Ethernet network and an OPC driver to get data into the Intellution SCADA node databases. The BC9000 is also programmed over this same Ethernet network.

  13. Transactive Control of Commercial Building HVAC Systems

    Energy Technology Data Exchange (ETDEWEB)

    Corbin, Charles D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Makhmalbaf, Atefe [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Huang, Sen [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mendon, Vrushali V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhao, Mingjie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Somasundaram, Sriram [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liu, Guopeng [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ngo, Hung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Katipamula, Srinivas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-12-30

    This document details the development and testing of market-based transactive controls for building heating, ventilating and air conditioning (HVAC) systems. These controls are intended to serve the purposes of reducing electricity use through conservation, reducing peak building electric demand, and providing demand flexibility to assist with power system operations. This report is the summary of the first year of work conducted under Phase 1 of the Clean Energy and Transactive Campus Project. The methods and techniques described here were first investigated in simulation, and then subsequently deployed to a physical testbed on the Pacific Northwest National Laboratory (PNNL) campus for validation. In this report, we describe the models and control algorithms we have developed, testing of the control algorithms in simulation, and deployment to a physical testbed. Results from physical experiments support previous simulation findings, and provide insights for further improvement.

  14. Review of Residential Low-Load HVAC Systems

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Scott A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thornton, Brian A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Widder, Sarah H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-09-01

    In support of the U.S. Department of Energy’s (DOE’s) Building America Program, Pacific Northwest National Laboratory (PNNL) conducted an investigation to inventory commercially available HVAC technologies that are being installed in low-load homes. The first step in this investigation was to conduct a review of published literature to identify low-load HVAC technologies available in the United States and abroad, and document the findings of existing case studies that have evaluated the performance of the identified technologies. This report presents the findings of the literature review, identifies gaps in the literature or technical understanding that must be addressed before low-load HVAC technologies can be fully evaluated, and introduces PNNL’s planned research and analysis for this project to address identified gaps and potential future work on residential low-load HVAC systems.

  15. Strategy Guideline: Transitioning HVAC Companies to Whole House Performance Contractors

    Energy Technology Data Exchange (ETDEWEB)

    Burdick, A.

    2012-05-01

    This report describes the findings from research IBACOS conducted related to heating, ventilation, and air conditioning (HVAC) companies who have made the decision to transition to whole house performance contracting (WHPC).

  16. Strategy Guideline. Transitioning HVAC Companies to Whole House Performance Contractors

    Energy Technology Data Exchange (ETDEWEB)

    Burdick, Arlan [IBACOS, Inc., Pittsburgh, PA (United States)

    2012-05-01

    This report describes the findings from research IBACOS conducted related to heating, ventilation, and air conditioning (HVAC) companies who have made the decision to transition to whole house performance contracting (WHPC).

  17. The Design of HVAC System in the Conventional Facility of Proton Accelerator Research Center

    International Nuclear Information System (INIS)

    Jeon, G. P.; Kim, J. Y.; Choi, B. H.

    2007-01-01

    The HVAC systems for conventional facility of Proton Accelerator Research Center consist of 3 systems : accelerator building HVAC system, beam application building HVAC system and miscellaneous HVAC system. We designed accelerator building HVAC system and beam application research area HVAC system in the conventional facilities of Proton Accelerator research center. Accelerator building HVAC system is divided into accelerator tunnel area, klystron area, klystron gallery area, accelerator assembly area. Also, Beam application research area HVAC system is divided into those of beam experimental hall, accelerator control area, beam application research area and Ion beam application building. In this paper, We described system design requirements and explained system configuration for each systems. We presented operation scenario of HVAC system in the Conventional Facility of Proton Accelerator Research Center

  18. [Analysis and research on cleaning points of HVAC systems in public places].

    Science.gov (United States)

    Yang, Jiaolan; Han, Xu; Chen, Dongqing; Jin, Xin; Dai, Zizhu

    2010-03-01

    To analyze cleaning points of HVAC systems, and to provides scientific base for regulating the cleaning of HVAC systems. Based on the survey results on the cleaning situation of HVAC systems around China for the past three years, we analyzes the cleaning points of HVAC systems from various aspects, such as the major health risk factors of HVAC systems, the formulation strategy of the cleaning of HVAC systems, cleaning methods and acceptance points of the air ducts and the parts of HVAC systems, the onsite protection and individual protection, the waste treatment and the cleaning of the removed equipment, inspection of the cleaning results, video record, and the final acceptance of the cleaning. The analysis of the major health risk factors of HVAC systems and the formulation strategy of the cleaning of HVAC systems is given. The specific methods for cleaning the air ducts, machine units, air ports, coil pipes and the water cooling towers of HVAC systems, the acceptance points of HVAC systems and the requirements of the report on the final acceptance of the cleaning of HVAC systems are proposed. By the analysis of the points of the cleaning of HVAC systems and proposal of corresponding measures, this study provides the base for the scientific and regular launch of the cleaning of HVAC systems, a novel technology service, and lays a foundation for the revision of the existing cleaning regulations, which may generate technical and social benefits to some extent.

  19. VARIABLE SPEED INTEGRATED INTELLIGENT HVAC BLOWER

    Energy Technology Data Exchange (ETDEWEB)

    Shixiao Wang; Herman Wiegman; Wilson Wu; John Down; Luana Iorio; Asha Devarajan; Jing Wang; Ralph Carl; Charlie Stephens; Jeannine Jones; Paul Szczesny

    2001-11-14

    This comprehensive topical report discusses the key findings in the development of a intelligent integrated blower for HVAC applications. The benefits of rearward inclined blades over that of traditional forward inclined blades is well documented and a prototype blower design is presented. A comparison of the proposed blower to that of three typical units from the industry is presented. The design of the blower housing is also addressed and the impact of size limitations on static efficiency is discussed. Issues of air flow controllability in the rearward inclined blower is addressed and a solution to this problem is proposed. Several motor design options are discussed including inside-out radial flux designs and novel axial flux designs, all are focused on the various blower needs. The control of the motor-blower and airflow through the use of a high density inverter stage and modern digital signal processor is presented. The key technical challenges of the approach are discussed. The use of the motor as a sensor in the larger heating/ventilating system is also discussed. Diagnostic results for both the motor itself and the blower system are presented.

  20. Energization of Long HVAC Cables in Parallel - Analysis and Estimation Formulas

    DEFF Research Database (Denmark)

    Silva, Filipe Faria Da; Bak, Claus Leth

    2012-01-01

    The installation of long HVAC cables has recently become more common and it tends to increase during the next years. Consequently, the energization of long HVAC cables in parallel is also a more common condition. The energization of HVAC cables in parallel resembles the en-ergization of capacitor...... has several simplifications and does not always provide accurate results. This paper proposes a new formula that can be used for the estimation of these two quantities for two HVAC cables in parallel....

  1. Tracer gas dispersion in ducts-study of a new compact device using arrays of sonic micro jets

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.R. [Instituto Nacional de Engenharia e Tecnologia Industrial (INETI), Lisboa (Portugal); Afonso, C.F. [Faculdade de Engenharia, Universidade do Porto Departmento de Mecanica e Gestao Industrial, Porto (Portugal)

    2004-07-01

    One of the most feasible ways to measure duct airflows is by tracer gas techniques, especially for complex situations when the duct lengths are short as well as their access, which makes extremely difficult or impossible other methods to be implemented. One problem associated with the implementation of tracer gas technique when the ducts lengths are short is due to the impossibility of achieving complete mixing of the tracer with airflow and its sampling. In this work, the development of a new device for the injection of tracer gas in ducts is discussed as well as a new tracer-sampling device. The developed injection device has a compact tubular shape, with magnetic fixation to be easy to apply in duct walls. An array of sonic micro jets in counter current direction, with the possibility of angular movement according to its main axle ensures a complete mixing of the tracer in very short distances. The tracer-sampling device, with a very effective integration function, feeds the sampling system for analysis. Both devices were tested in a wind tunnel of approximately 21 m total length. The tests distances between injection and integration device considered were: X/Dh = 22; X/Dh = 4; X/Dh 2; and X/Dh = 1. For very short distances of X/Dh = 2 and X/Dh = 1, semi-empirical expressions were needed. A good reproducibility of airflow rate values was obtained. These preliminary tests showed that the practical implementation of tracer gas techniques in HVAC systems for measuring airflow rates with a very short mixing distance is possible with the devices developed. (author)

  2. HVAC retrofit evaluations: Persuading owners to do it right

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.G. [Linford (Robert G.), Oakland, CA (United States)

    1997-11-01

    HVAC system retrofit evaluations for commercial buildings are complex and, at best, imperfect. The number of variables even for a simple system is large. For a complex system, they can be nearly overwhelming. One of the most difficult questions owners of older buildings face is to decide when is it cost effective to replace or upgrade the HVAC system rather than to repair (or ignore) specific components. Similarly, two of the major questions a prospective buyer faces in evaluating a building during the due diligence process are: how well does the HVAC system work today, and how well will it work in the future and at what cost? These are addressed in this article.

  3. Heat recovery unit operation of HVAC system in IMEF

    International Nuclear Information System (INIS)

    Paek, S. R.; Oh, Y. W.; Song, E. S.; Park, D. K.; Joo, Y. S.; Hong, K. P.

    2003-01-01

    HVAC system including a supply and exhaust air system in IMEF(Irradiated Materials Examination Facility) is an essential facility for preventing a leakage of radioactive materials and for a preservation of a working environment. It costs a lot to operate the HVAC system in IMEF because our ventilation type is once-through system, and an air flow is maintained from low level contamination area to high level and maintained high turns of ventilation air under certain conditions. As HRU(Heat Recovery Unit) at HVAC system based on PIEF(Post Irradiation Examination Facility) operation experiences is designed and adopted, it prevents from a heating coil freezing destruction in winter and makes much energy saving etc.. Heat pipe type HRU is adopted in IMEF, and a construction and operation result of HRU is examined

  4. 77 FR 72763 - Energy Conservation Program: Certification of Commercial and Industrial HVAC, Refrigeration and...

    Science.gov (United States)

    2012-12-06

    ... Commercial and Industrial HVAC, Refrigeration and Water Heating Equipment AGENCY: Office of Energy Efficiency...; commercial heating, ventilating, air-conditioning (HVAC) equipment; and commercial water heating equipment... refrigeration equipment; commercial HVAC equipment; commercial WH equipment; and walk-in coolers and freezers...

  5. Introduction to Heating, Ventilation and Air Conditioning (HVAC). Instructor Edition. Introduction to Construction Series.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This instructor's guide contains the materials required to teach a competency-based introductory course in heating, ventilating, and air conditioning (HVAC) to students who have chosen to explore careers in construction. It contains three units: HVAC materials, HVAC tools, and applied skills. Each instructional unit includes some or all of the…

  6. 10 CFR 431.402 - Preemption of State regulations for commercial HVAC & WH products.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Preemption of State regulations for commercial HVAC & WH... regulations for commercial HVAC & WH products. Beginning on the effective date of such standard, an energy conservation standard set forth in this Part for a commercial HVAC & WH product supersedes any State or local...

  7. 77 FR 76825 - Energy Conservation Program: Certification of Commercial and Industrial HVAC, Refrigeration and...

    Science.gov (United States)

    2012-12-31

    ... Energy Conservation Program: Certification of Commercial and Industrial HVAC, Refrigeration and Water... provisions for commercial refrigeration equipment; commercial heating, ventilating, air-conditioning (HVAC...; commercial HVAC equipment; commercial WH equipment; and walk-in coolers and freezers (June 30 Final Rule). 76...

  8. Ultraviolet Extensions

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] Side-by-Side Comparison Click on image for larger view This ultraviolet image from NASA's Galaxy Evolution Explorer shows the Southern Pinwheel galaxy, also know as Messier 83 or M83. It is located 15 million light-years away in the southern constellation Hydra. Ultraviolet light traces young populations of stars; in this image, young stars can be seen way beyond the main spiral disk of M83 up to 140,000 light-years from its center. Could life exist around one of these far-flung stars? Scientists say it's unlikely because the outlying regions of a galaxy are lacking in the metals required for planets to form. The image was taken at scheduled intervals between March 15 and May 20, 2007. It is one of the longest-exposure, or deepest, images ever taken of a nearby galaxy in ultraviolet light. Near-ultraviolet light (or longer-wavelength ultraviolet light) is colored yellow, and far-ultraviolet light is blue. What Lies Beyond the Edge of a Galaxy The side-by-side comparison shows the Southern Pinwheel galaxy, or M83, as seen in ultraviolet light (right) and at both ultraviolet and radio wavelengths (left). While the radio data highlight the galaxy's long, octopus-like arms stretching far beyond its main spiral disk (red), the ultraviolet data reveal clusters of baby stars (blue) within the extended arms. The ultraviolet image was taken by NASA's Galaxy Evolution Explorer between March 15 and May 20, 2007, at scheduled intervals. Back in 2005, the telescope first photographed M83 over a shorter period of time. That picture was the first to reveal far-flung baby stars forming up to 63,000 light-years from the edge of the main spiral disk. This came as a surprise to astronomers because a galaxy's outer territory typically lacks high densities of star-forming materials. The newest picture of M83 from the Galaxy Evolution Explorer is shown at the right, and was taken over a longer period of time. In fact, it is one of the

  9. Plutonium Finishing Plant (PFP) HVAC System Component Index; FINAL

    International Nuclear Information System (INIS)

    DICK, J.D.

    1999-01-01

    This document identities the components, design media, procedures and defines the critical characteristics of Commercial Grade Items necessary to ensure the HVAC system provides these functions. This document lists safety class (SC) and safety significant (SS) components for the Heating Ventilation Air Conditioning (HVAC) and specifies the critical characteristics for Commercial Grade Items (CGI), as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to properly perform its safety function. There may be several manufacturers or models that meet the critical characteristics for any one item

  10. Ultraviolet sterilization

    International Nuclear Information System (INIS)

    Schenck, G.O.

    1987-01-01

    Artificial ultraviolet radiation sources can supply bactericidal energy in such a high dosage that in less than a second a higher degree of disinfection is accomplished than by sun irradiation in hours. Bacteria, viruses, phages, and organic micropollutants can be degraded by photochemical wet combustion down to and below detection limits of organic carbon. There are no known ultraviolet-resistant microorganisms. There are limitations to ultraviolet treatment which can often be overcome by adequate technical measures. Unlike other water purification processes, ultraviolet irradiation only exterminates living organisms. The radiation must be able to penetrate to the objects of the kill; in a dose large enough to kill, and long enough to kill and prevent new growth. Contrary to filters, ultraviolet flow-through reactors do not restrict free flow significantly. In contrast to distillation, ultraviolet irradiation imposes no phase changes to the water. Used as a sequence in ultrapure water systems, maintenance requirements are virtually nonexistent; because of the absence of dissolved and particulate matter in purified water, mechanical cleaning of the photoreactor chambers is not essential. The process is highly economical; energy consumption is low and supervision minimal. 103 refs., 45 figs., 15 tabs

  11. Low sound level source path contribution on a HVAC

    NARCIS (Netherlands)

    Bree, H.E. de; Basten, T.G.H.

    2008-01-01

    For compliance test purposes, the noise level of a HVAC is usually measured with a pressure microphone positioned at a certain distance. This measurement is normally performed in an anechoic room. However, this method doesn't provide the engineer any insight on what noise sources do contribute to

  12. D0 HVAC System Controls Evaluation of Upgrade Options

    International Nuclear Information System (INIS)

    Markley, D.; Simon, P.

    1998-01-01

    This engineering note documents three different options for upgrading the Dzero HVAC control system. All three options leave the current field hardware and field devices intact and upgrade the computer control hardware and software. Dzero will be heading into a physics run starting in 2000. This physics run could last several years. The Dzero HVAC system is an integral part of climate control and electronics cooling. The current HVAC control system is based upon a 1985 Johnson Controls System. In order to enter the next long-term physics run with a solid HVAC control system, the current control system needs to be upgraded. This proposal investigates three options: (1) Replacement to the next generation of Johnson Controls Hardware and Software with the Johnson Controls operator interface - FESS; (2) Replacement to the next generation of Johnson Controls Hardware and Software with the FIX32 Operator Interface - FESS/Dzero; and (3) Replacement with a commercially available Programmable Logic Controller (PLC) WITH THE FIX 32 Operator Interface - Dzero.

  13. Towards an integral approach of building and HVAC system

    NARCIS (Netherlands)

    Hensen, J.L.M.

    1993-01-01

    The dynamic thermal interaction between a building and the HVAC systems which service it is still difficult to predict. As this thermal interaction becomes more critical in practice, related knowledge and evaluation tools become increasingly important. It is argued why these need to be based on an

  14. Illinois Occupational Skill Standards: HVAC/R Technician Cluster.

    Science.gov (United States)

    Illinois Occupational Skill Standards and Credentialing Council, Carbondale.

    This document, which is intended to serve as a guide for work force preparation program providers, details the Illinois occupational skill standards for programs preparing students for employment in jobs in the heating, ventilation, air conditioning, and refrigeration (HVAC/R) industry. Agency partners involved in this project include: the…

  15. Maximize Benefits, Minimize Risk: Selecting the Right HVAC Firm.

    Science.gov (United States)

    Golden, James T.

    1993-01-01

    An informal survey of 20 major urban school districts found that 40% were currently operating in a "break down" maintenance mode. A majority, 57.9%, also indicated they saw considerable benefits in contracting for heating, ventilating, and air conditioning (HVAC) maintenance services with outside firms. Offers guidelines in selecting…

  16. Building Assessment Survey and Evaluation Study Summarized Data - HVAC Characteristics

    Science.gov (United States)

    In the Building Assessment Survey and Evaluation (BASE) Study Information on the characteristics of the heating, ventilation, and air conditioning (HVAC) system(s) in the entire BASE building including types of ventilation, equipment configurations, and operation and maintenance issues was acquired by examining the building plans, conducting a building walk-through, and speaking with the building owner, manager, and/or operator.

  17. INFLUENCE OF RESIDENTIAL HVAC DUTY CYCLE ON INDOOR AIR QUALITY

    Science.gov (United States)

    Measurements of duty cycle, the fraction of time the heating and cooling (HVAC) system was operating, were made in homes during the spring season of the RTP Particulate Matter Panel Study and the Tampa Asthmatic Children's Study. A temperature sensor/logger placed on an outlet...

  18. Reducing Building HVAC Costs with Site-Recovery Energy

    Science.gov (United States)

    Pargeter, Stephen J.

    2012-01-01

    Building owners are caught between two powerful forces--the need to lower energy costs and the need to meet or exceed outdoor air ventilation regulations for occupant health and comfort. Large amounts of energy are wasted each day from commercial, institutional, and government building sites as heating, ventilation, and air conditioning (HVAC)…

  19. Application of modeling and simulation to HVAC systems

    NARCIS (Netherlands)

    Hensen, J.L.M.

    1996-01-01

    This paper attempts to describe the advantages and disadvantages of different modelling approaches for design and performance evaluation of heating, ventilating, and air-conditioning (HVAC) systems for buildings. Merits and drawbacks of the various modelling methods are illustrated by case study

  20. Advanced HVAC modeling with FemLab/Simulink/MatLab

    NARCIS (Netherlands)

    Schijndel, van A.W.M.

    2003-01-01

    The combined MatLab toolboxes FemLab and Simulink are evaluated as solvers for HVAC problems based on partial differential equations (PDEs). The FemLab software is designed to simulate systems of coupled PDEs, 1-D, 2-D or 3-D, nonlinear and time dependent. In order to show how the program works, a

  1. HVAC system simulation: overview, issues and some solutions

    NARCIS (Netherlands)

    Trcka, M.; Hensen, J.L.M.

    2011-01-01

    Integrated performance simulation of buildings’ heating, ventilation and air-conditioning (HVAC) systems can help in reducing energy consumption and increasing occupant comfort. Recognizing this fact, in the last forty years many tools have been developed to help achieving this goal. In this paper

  2. HVAC System Replacements for the Spanish Nuclear Fleet

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, J.; Gensollen, T.; Pérez, C.

    2015-07-01

    The European Union and its Member States have established regulations to phase out ozone-depleting chlorofluorocarbons (CFCs). The chiller systems installed at the Spanish nuclear fleet contained zone depleting refrigerants (such as R-11, R-12, and R-22), which are being phased out of service. Due to the different material and thermodynamic properties of the replacement refrigerant (e.g. R-134A), a complete chiller system replacement is needed to comply with the EU regulations for CFCs. Delivering state of the art HVAC and Chiller systems that comply with the Nuclear Plant design basis, licensing basis, system and component specifications as well as European Union (EU) and Spanish codes and standards can be challenging for products purchased from US based manufacturers. Procurement specifications and Request for Quotes (RFQs) issued today for the procurement of original Plant components and systems will contain references to numerous codes and standards that were not in effect at the time the original components were specified and procured. The reference to EU and Spanish codes and standards that are unfamiliar to the HVAC suppliers can lead to uncertainty and concern related to specification compliance. The unnecessary burden of ambiguous codes and standards complicates the proposal process and introduces pricing uncertainty and contract risk. A review of the EU and Spanish national codes and standards that are often referenced in HVAC system related RFQs need to be performed to determine what codes and standards are applicable to HVAC systems designed, manufactured and tested in the US for export to Spain for installation in Spanish NPPs. Lessons learned and best practices should be applied to help both the Supplier (HVAC OEM) and the Purchaser Plant Operator) to optimize the procurement process and improve the quality of offerings to comply with applicable codes and standards. (Author)

  3. Particle loading rates for HVAC filters, heat exchangers, and ducts.

    Science.gov (United States)

    Waring, M S; Siegel, J A

    2008-06-01

    The rate at which airborne particulate matter deposits onto heating, ventilation, and air-conditioning (HVAC) components is important from both indoor air quality (IAQ) and energy perspectives. This modeling study predicts size-resolved particle mass loading rates for residential and commercial filters, heat exchangers (i.e. coils), and supply and return ducts. A parametric analysis evaluated the impact of different outdoor particle distributions, indoor emission sources, HVAC airflows, filtration efficiencies, coils, and duct system complexities. The median predicted residential and commercial loading rates were 2.97 and 130 g/m(2) month for the filter loading rates, 0.756 and 4.35 g/m(2) month for the coil loading rates, 0.0051 and 1.00 g/month for the supply duct loading rates, and 0.262 g/month for the commercial return duct loading rates. Loading rates are more dependent on outdoor particle distributions, indoor sources, HVAC operation strategy, and filtration than other considered parameters. The results presented herein, once validated, can be used to estimate filter changing and coil cleaning schedules, energy implications of filter and coil loading, and IAQ impacts associated with deposited particles. The results in this paper suggest important factors that lead to particle deposition on HVAC components in residential and commercial buildings. This knowledge informs the development and comparison of control strategies to limit particle deposition. The predicted mass loading rates allow for the assessment of pressure drop and indoor air quality consequences that result from particle mass loading onto HVAC system components.

  4. Validation of the criteria for initiating the cleaning of heating, ventilation, and air-conditioning (HVAC) ductwork under real conditions.

    Science.gov (United States)

    Lavoie, Jacques; Marchand, Geneviève; Cloutier, Yves; Lavoué, Jérôme

    2011-08-01

    Dust accumulation in the components of heating, ventilation, and air-conditioning (HVAC) systems is a potential source of contaminants. To date, very little information is available on recognized methods for assessing dust buildup in these systems. The few existing methods are either objective in nature, involving numerical values, or subjective in nature, based on experts' judgments. An earlier project aimed at assessing different methods of sampling dust in ducts was carried out in the laboratories of the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST). This laboratory study showed that all the sampling methods were practicable, provided that a specific surface-dust cleaning initiation criterion was used for each method. However, these conclusions were reached on the basis of ideal conditions in a laboratory using a reference dust. The objective of this present study was to validate these laboratory results in the field. To this end, the laboratory sampling templates were replicated in real ducts and the three sampling methods (the IRSST method, the method of the U.S. organization National Air Duct Cleaner Association [NADCA] and that of the French organization Association pour la Prévention et l'Étude de la Contamination [ASPEC]) were used simultaneously in a statistically representative number of systems. The air return and supply ducts were also compared. Cleaning initiation criteria under real conditions were found to be 6.0 mg/100 cm(2) using the IRSST method, 2.0 mg/100 cm(2) using the NADCA method, and 23 mg/100 cm(2) using the ASPEC method. In the laboratory study, the criteria using the same methods were 6.0 for the IRSST method, 2.0 for the NADCA method, and 3.0 for the ASPEC method. The laboratory criteria for the IRSST and NADCA methods were therefore validated in the field. The ASPEC criterion was the only one to change. The ASPEC method therefore allows for the most accurate evaluation of dust accumulation in HVAC

  5. Development of the Aging Management Program for HVAC Systems

    International Nuclear Information System (INIS)

    Cho, Hong Seok; Lee, Dong Min; Lee, Jang Wook; Cho, Ki Hyun; Cho, Sang Bum; Choi, Sang Hoon

    2008-01-01

    The HVAC(heating, ventilation and air conditioning) systems in nuclear power plants are consisted of fan, damper, duct, filter and cooling coil, which is equipped in the safety-related building such as main control room, auxiliary building and containment building. These systems are designed to maintain the required ambient air temperature in all plant areas for the comfort and safety of personnel and for environmental requirement of equipment and to ensure that the gaseous radioactivity emission to the environment is kept below permissible discharge limits. The purpose of this study is to establish the inspection plan to ensure that touch up parts of the duct are sound and to develop the aging management program for maintaining effectively HVAC systems

  6. Decentralized Optimization for a Novel Control Structure of HVAC System

    Directory of Open Access Journals (Sweden)

    Shiqiang Wang

    2016-01-01

    Full Text Available A decentralized control structure is introduced into the heating, ventilation, and air conditioning (HVAC system to solve the high maintenance and labor cost problem in actual engineering. Based on this new control system, a decentralized optimization method is presented for sensor fault repair and optimal group control of HVAC equipment. Convergence property of the novel method is theoretically analyzed considering both convex and nonconvex systems with constraints. In this decentralized control system, traditional device is fitted with a control chip such that it becomes a smart device. The smart device can communicate and operate collaboratively with the other devices to accomplish some designated tasks. The effectiveness of the presented method is verified by simulations and hardware tests.

  7. Design and Operation of 3-Pin FTL HVAC System

    International Nuclear Information System (INIS)

    Chi, D. Y.; Sim, B. S.; Park, S. K.; Park, K. N.; Lee, J. M.; Ahn, S. H.; Lee, C. Y.; Kim, Y. J.

    2005-01-01

    According to the increasing demand for irradiation tests to develop new fuels, the 3-Pin FTL(Fuel Test Loop for 3 pin test fuel) facility has now been under design to conduct in-core fuel performance tests at the operating conditions, which will be installed at HANARO. The HVAC system of the FTL will be dependent on that of the HANARO. The FTL has three equipments rooms, which are the room 1, room 2 and the control room. The high pressure and high temperature equipments will be installed in the room 1. The atmosphere of the room 1 shall be maintained under the designed condition. This paper describes the design of the FTL HVAC system in the room 1

  8. ANFIS -Based Navigation for HVAC Service Robot with Image Processing

    International Nuclear Information System (INIS)

    Salleh, Mohd Zoolfadli Md; Rashid, Nahrul Khair Alang Md; Mustafah, Yasir Mohd

    2013-01-01

    In this paper, we present an ongoing work on the autonomous navigation of a mobile service robot for Heat, Ventilation and Air Condition (HVAC) ducting. CCD camera mounted on the front-end of our robot is used to analyze the ducts openings (blob analysis) in order to differentiate them from other landmarks (blower fan, air outlets and etc). Distance between the robot and duct openings is measured using ultrasonic sensor. Controller chosen is ANFIS where its architecture accepts three inputs; recognition of duct openings, robot positions and distance while the outputs is maneuver direction (left or right).45 membership functions are created from which produces 46 training epochs. In order to demonstrate the functionality of the system, a working prototype is developed and tested inside HVAC ducting in ROBOCON Lab, IIUM

  9. An evaluation of damping ratios for HVAC duct systems using vibration test data

    International Nuclear Information System (INIS)

    Gunyasu, K.; Horimizu, Y.; Kawakami, A.; Iokibe, H.; Yamazaki, T.

    1988-01-01

    The function of Heating Ventilating Air Conditioning (HVAC) systems must be maintained including HVAC duct systems to keep the operation of safety-related equipment in nuclear power plants during earthquake excitations. Therefore, it is important to carry out seismic design for HVAC duct systems. In the previous aseismic design for HVAC duct systems, the 0.5% damping ratio has been used in Japan. In recent years, vibration tests, held on actual duct systems in nuclear power plants and mockup duct systems were performed in order to investigate damping ratios for HVAC duct systems. Based on the results, it was confirmed that the damping ratio for HVAC duct systems, evaluated from these tests, were much greater than the 0.5% damping ratio used in the previous aseismic design of Japan. The new damping ratio in aseismic design was proposed to be 2.5%. The present paper describes the results of the above mentioned investigation

  10. HVAC; Heating, Ventilation, Air Conditioning - Aerosol Duct Sealant

    Science.gov (United States)

    2016-09-01

    material was applied. Annual energy and cost savings were predicted based on a typical weather year for each site. The installation of the duct...Balance reports; Visible dust streaks on duct work, ceilings near supply diffusers, or electrical boxes; Comfort complaints Specific Leakage...energy consumption , depending on the HVAC system type and the location of the ducts that were sealed. The cost effectiveness of the technology is

  11. Integrated high efficiency blower apparatus for HVAC systems

    Science.gov (United States)

    Liu, Xiaoyue; Weigman, Herman; Wang, Shixiao

    2007-07-24

    An integrated centrifugal blower wheel for a heating, ventilation and air conditioning (HVAC) blower unit includes a first blade support, a second blade support, and a plurality of S-shaped blades disposed between the first and second blade supports, wherein each of the S-shaped blades has a trailing edge bent in a forward direction with respect to a defined direction of rotation of the wheel.

  12. HVAC fault tree analysis for WIPP integrated risk assessment

    International Nuclear Information System (INIS)

    Kirby, P.; Iacovino, J.

    1990-01-01

    In order to evaluate the public health risk from operation of the Waste Isolation Pilot Plant (WIPP) due to potential radioactive releases, a probabilistic risk assessment of waste handling operations was conducted. One major aspect of this risk assessment involved fault tree analysis of the plant heating, ventilation, and air conditioning (HVAC) systems, which comprise the final barrier between waste handling operations and the environment. 1 refs., 1 tab

  13. HVAC design guidelines for effective indoor air quality

    International Nuclear Information System (INIS)

    Bladykas, M.P.

    1993-01-01

    Building owners, designers and occupants need to consider all the design measures that contribute to high indoor air quality. Building occupants, furnishings, equipment, and ambient air pollution all contribute to surmounting indoor air quality concerns. However, these can be minimized by following HVAC design guidelines which promote high indoor air quality while maintaining reasonable energy-efficiency. The possible liabilities and loss of business productivity due to air quality problems are too great to ignore

  14. A comfort-based, energy-aware HVAC agent and its applications in the smart grid

    OpenAIRE

    Auffenberg, Frederik

    2017-01-01

    In this thesis, we introduce a novel heating, ventilation and air conditioning (HVAC) agent that maintains a comfortable thermal environmant for its users while minimising energy consumption of the HVAC system and incorporating demand side management (DSM) signals to shift HVAC loads towards achieving more desirable overall load profiles. To do so, the agent needs to be able to accurately predict user comfort, for example by using a thermal comfort model. Existing thermal comfort models are u...

  15. Effects of explosion-generated shock waves in ducts

    International Nuclear Information System (INIS)

    Busby, M.R.; Kahn, J.E.; Belk, J.P.

    1976-01-01

    An explosion in a space causes an increase in temperature and pressure. To quantify the challenge that will be presented to essential components in a ventilation system, it is necessary to analyze the dynamics of a shock wave generated by an explosion, with attention directed to the propagation of such a wave in a duct. Using the equations of unsteady flow and shock tube theory, a theoretical model has been formulated to provide flow properties behind moving shock waves that have interacted with various changes in duct geometry. Empirical equations have been derived to calculate air pressure, temperature, Mach number, and velocity in a duct following an explosion

  16. Solar ultraviolet hazards

    International Nuclear Information System (INIS)

    Azmah Ali

    1995-01-01

    The paper discussed the following subjects: the sources of ultraviolet radiation, solar ultraviolet radiation definition, effects of over exposure to solar ultraviolet radiation, exposure limits and radiation protection of this radiation

  17. Weather data around the world for design of field hospital HVAC

    NARCIS (Netherlands)

    Forejt, L.; Hensen, J.L.M.; Drkal, F.; Barankova, P.

    2006-01-01

    Field hospital (FH) is a military mobile complex to be deployed in almost any climate around the world. Heating, ventilation and air-conditioning (HVAC) system for the Czech Republic FH units is being redesigned. Computer simulation software will be used for the design of HVAC under variety of

  18. Considerations to Prevent Growth and Spread of Legionella in HVAC Systems.

    Science.gov (United States)

    Coleman, Jeff

    1998-01-01

    Discusses the threat posed by the Legionnaire's Disease bacterium and the germ's ability to thrive in heating, ventilating, and air conditioning (HVAC) systems, especially in standing water. Describes ways to minimize disease risk through HVAC system design (such as locating cooling towers away from air intakes) and ways to maintain a clean…

  19. HVAC SYSTEMS AS EMISSION SOURCES AFFECTING INDOOR AIR QUALITY: A CRITICAL REVIEW

    Science.gov (United States)

    The paper discusses results of an evaluation of literature on heating, ventilating, and air-conditioning (HVAC) systems as contaminant emission sources that affect indoor air quality (IAQ). The various literature sources and methods for characterizing HVAC emission sources are re...

  20. Integrovany pristup k reseni systemu vytapeni,vetrani a klimatizace v budovach (HVAC)

    NARCIS (Netherlands)

    Hensen, J.L.M.

    1994-01-01

    Towards an integral approach of building and HVAC system The dynamic thermal interacion between a building and the HVAC systems which service it, is still difficult to predict. As this thermal interacition becomes more critical in practice, related knowledge and evaluation tools become increasingly

  1. HVAC System Automatic Controls and Indoor Air Quality in Schools. Technical Bulletin.

    Science.gov (United States)

    Wheeler, Arthur E.

    Fans, motors, coils, and other control components enable a heating, ventilating, and air-conditioning (HVAC) system to function smoothly. An explanation of these control components and how they make school HVAC systems work is provided. Different systems may be compared by counting the number of controlled devices that are required. Control…

  2. HVAC SYSTEMS AS A TOOL IN CONTROLLING INDOOR AIR QUALITY: A LITERATURE REVIEW

    Science.gov (United States)

    The report gives results of a review of literature on the use of heating, ventilating, and air-conditioning (HVAC) systems to control indoor air quality (IAQ). Although significant progress has been made in reducing the energy consumption of HVAC systems, their effect on indoor a...

  3. HVAC SYSTEMS IN THE CURRENT STOCK OF US K-12 SCHOOLS

    Science.gov (United States)

    The report summarizes information on heating, ventilating, an air- conditioning (HVAC) systems commonly found in U. S. school buildings and the effect that operating these systems has on indoor radon levels. The report describes the ability of various HVAC systems to pressurize a...

  4. Critical control points for the management of microbial growth in HVAC systems

    NARCIS (Netherlands)

    Gommers, S; Franchimon, F.; Bronswijk, van J.E.M.H.; Strøm-Tejsen, P; Olesen, BW; Wargocki, P; Zukowska, D; Toftum, J

    2008-01-01

    Office buildings with HVAC systems consistently report Sick Building Symptoms that are derived from microbial growth. We used the HACCP methodology to find the main critical control points (CCPs) for microbial management of HVAC systems in temperate climates. Desk research revealed relative humidity

  5. Energy-Smart Choices for Schools. An HVAC Comparison Tool. [CD-ROM].

    Science.gov (United States)

    Geothermal Heat Pump Consortium, Inc., Washington, DC.

    A CD ROM program provides comparison construction cost capabilities for heating, ventilation, and air conditioning (HVAC) systems in educational facilities. The program combines multiple types of systems with square footage data on low and high construction cost and school size to automatically calculate HVAC comparative construction costs. (GR)

  6. Air Cleaning Devices for HVAC Supply Systems in Schools. Technical Bulletin.

    Science.gov (United States)

    Wheeler, Arthur E.

    Guidelines for maintaining indoor air quality in schools with HVAC air cleaning systems are provided in this document. Information is offered on the importance of air cleaning, sources of air contaminants and indoor pollutants, types of air cleaners and particulate filters used in central HVAC systems, vapor and gas removal, and performance…

  7. Filtration effectiveness of HVAC systems at near-roadway schools.

    Science.gov (United States)

    McCarthy, M C; Ludwig, J F; Brown, S G; Vaughn, D L; Roberts, P T

    2013-06-01

    Concern for the exposure of children attending schools located near busy roadways to toxic, traffic-related air pollutants has raised questions regarding the environmental benefits of advanced heating, ventilation, and air-conditioning (HVAC) filtration systems for near-road pollution. Levels of black carbon and gaseous pollutants were measured at three indoor classroom sites and at seven outdoor monitoring sites at Las Vegas schools. Initial HVAC filtration systems effected a 31-66% reduction in black carbon particle concentrations inside three schools compared with ambient air concentrations. After improved filtration systems were installed, black carbon particle concentrations were reduced by 74-97% inside three classrooms relative to ambient air concentrations. Average black carbon particle concentrations inside the schools with improved filtration systems were lower than typical ambient Las Vegas concentrations by 49-96%. Gaseous pollutants were higher indoors than outdoors. The higher indoor concentrations most likely originated at least partially from indoor sources, which were not targeted as part of this intervention. Recent literature has demonstrated adverse health effects in subjects exposed to ambient air near major roadways. Current smart growth planning and infill development often require that buildings such as schools are built near major roadways. Improving the filtration systems of a school's HVAC system was shown to decrease children's exposure to near-roadway diesel particulate matter. However, reducing exposure to the gas-phase air toxics, which primarily originated from indoor sources, may require multiple filter passes on recirculated air. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  8. HVAC systems in a field laboratory for indoor climate study

    DEFF Research Database (Denmark)

    Fang, Lei; Melikov, Arsen Krikor; Olesen, Bjarne W.

    2012-01-01

    This paper presents the design of a HVAC system for a field lab. The design integrated mixing ventilation, displacement ventilation, low impulse vertical ventilation, personalized ventilation, natural ventilation, hybrid ventilation, active chilled beams, radiant ceiling and floor, and heat...... with the controlled room temperature in the range from 10 to 35 °C and relative humidity in the range from 15 to 80 %. The field lab can be used to test the performance of each system included in the field lab as well as the combined performance of two or more systems....

  9. HVAC optimization as facility requirements change with corporate restructuring

    Energy Technology Data Exchange (ETDEWEB)

    Rodak, R.R.; Sankey, M.S.

    1997-06-01

    The hyper-competitive, dynamic 1990`s forced many corporations to {open_quotes}Right-Size,{close_quotes} relocating resources and equipment -- even consolidating. These changes led to utility reduction if HVAC optimization was thoroughly addressed, and energy conservation opportunities were identified and properly designed. This is true particularly when the facility`s heating and cooling systems are matched to correspond with the load changes attributed to the reduction of staff and computers. Computers have been downsized and processing power per unit of energy input increased, thus, the need for large mainframe computer centers, and their associated high intensity energy usage, have been decreased or eliminated. Cooling, therefore, also has been reduced.

  10. 78 FR 15653 - Notice of Intent To Form the Commercial HVAC, WH, and Refrigeration Certification Working Group...

    Science.gov (United States)

    2013-03-12

    ... DEPARTMENT OF ENERGY 10 CFR Part 429 Notice of Intent To Form the Commercial HVAC, WH, and... Requirements for Commercial HVAC, WH, and Refrigeration Equipment AGENCY: Office of Energy Efficiency and... commercial heating, ventilation, and air-conditioning (HVAC), water heating (WH), and refrigeration equipment...

  11. Modeling and Measurement Constraints in Fault Diagnostics for HVAC Systems

    Energy Technology Data Exchange (ETDEWEB)

    Najafi, Massieh; Auslander, David M.; Bartlett, Peter L.; Haves, Philip; Sohn, Michael D.

    2010-05-30

    Many studies have shown that energy savings of five to fifteen percent are achievable in commercial buildings by detecting and correcting building faults, and optimizing building control systems. However, in spite of good progress in developing tools for determining HVAC diagnostics, methods to detect faults in HVAC systems are still generally undeveloped. Most approaches use numerical filtering or parameter estimation methods to compare data from energy meters and building sensors to predictions from mathematical or statistical models. They are effective when models are relatively accurate and data contain few errors. In this paper, we address the case where models are imperfect and data are variable, uncertain, and can contain error. We apply a Bayesian updating approach that is systematic in managing and accounting for most forms of model and data errors. The proposed method uses both knowledge of first principle modeling and empirical results to analyze the system performance within the boundaries defined by practical constraints. We demonstrate the approach by detecting faults in commercial building air handling units. We find that the limitations that exist in air handling unit diagnostics due to practical constraints can generally be effectively addressed through the proposed approach.

  12. Intelligent control of HVAC systems. Part II: perceptron performance analysis

    Directory of Open Access Journals (Sweden)

    Ioan URSU

    2013-09-01

    Full Text Available This is the second part of a paper on intelligent type control of Heating, Ventilating, and Air-Conditioning (HVAC systems. The whole study proposes a unified approach in the design of intelligent control for such systems, to ensure high energy efficiency and air quality improving. In the first part of the study it is considered as benchmark system a single thermal space HVAC system, for which it is assigned a mathematical model of the controlled system and a mathematical model(algorithm of intelligent control synthesis. The conception of the intelligent control is of switching type, between a simple neural network, a perceptron, which aims to decrease (optimize a cost index,and a fuzzy logic component, having supervisory antisaturating role for neuro-control. Based on numerical simulations, this Part II focuses on the analysis of system operation in the presence only ofthe neural control component. Working of the entire neuro-fuzzy system will be reported in a third part of the study.

  13. Efficiency improvement of variable speed electrical drives for HVAC applications

    Energy Technology Data Exchange (ETDEWEB)

    Abrahamsen, F.; Blaabjerg, F.; Pedersen, J.K. [Aalborg Univ., Inst. of Energy Technology, Aalborg East (Denmark)

    2000-07-01

    A large part of the produced electrical energy is consumed by ventilators, pumps and compressors, the so-called HVAC applications. A lot of this energy can be saved by speed control, but even with the large saving obtained alone by introduction of variable speed, it is still essential to optimise the control of the variable speed drive and to optimise the electrical machine with respect to efficiency. Experiments are made with energy optimal induction motor control on a 2.2 kW variable speed pump system. It is demonstrated that 10% of the consumed energy can typically be saved by energy optimal motor control compared with constant V/Hz control. In a comparison of induction motors and permanent magnet synchronous motors for a variable speed pump application it is shown that for 2.2 kW motors an investment in high-efficiency or PM motors are typically paid back within 2.5 years and 7 years respectively. For a 90 kW PM motor the pay-back time would be 24 years. It is today not profitable to use PM motors for variable speed HVAC applications above 2 kW rated motor power. A further study is required to determine this limit in power rating more precisely. (orig.)

  14. Neural computing thermal comfort index for HVAC systems

    International Nuclear Information System (INIS)

    Atthajariyakul, S.; Leephakpreeda, T.

    2005-01-01

    The primary purpose of a heating, ventilating and air conditioning (HVAC) system within a building is to make occupants comfortable. Without real time determination of human thermal comfort, it is not feasible for the HVAC system to yield controlled conditions of the air for human comfort all the time. This paper presents a practical approach to determine human thermal comfort quantitatively via neural computing. The neural network model allows real time determination of the thermal comfort index, where it is not practical to compute the conventional predicted mean vote (PMV) index itself in real time. The feed forward neural network model is proposed as an explicit function of the relation of the PMV index to accessible variables, i.e. the air temperature, wet bulb temperature, globe temperature, air velocity, clothing insulation and human activity. An experiment in an air conditioned office room was done to demonstrate the effectiveness of the proposed methodology. The results show good agreement between the thermal comfort index calculated from the neural network model in real time and those calculated from the conventional PMV model

  15. Exergy optimization of cooling tower for HGSHP and HVAC applications

    International Nuclear Information System (INIS)

    Singh, Kuljeet; Das, Ranjan

    2017-01-01

    Highlights: • Development of new correlations for outlet parameters with all inlet parameters. • Simultaneous achievement of required heat load and minimum exergy destruction. • Multiple combinations of parameters found for same heat load at minimized exergy. • Study useful for optimum control of cooling tower under varying ambient conditions. • Generalized optimization study can be implemented for any mechanical cooling tower. - Abstract: In the present work, a constrained inverse optimization method for building cooling applications is proposed to control the mechanical draft wet cooling tower by minimizing the exergy destruction and satisfying an imposed heat load under varying environmental conditions. The optimization problem is formulated considering the cooling dominated heating, ventilation and air conditioning (HVAC) and hybrid ground source heat pump (HGSHP). As per the requirement, new second degree correlations for the tower outlet parameters (water temperature, air dry and wet-bulb temperatures) with five inlet parameters (dry-bulb temperature, relative humidity, water inlet temperature, water and air mass flow rates) are developed. The Box–Behnken design response surface method is implemented for developing the correlations. Subsequently, the constrained optimization problem is solved using augmented Lagrangian genetic algorithm. This work further developed optimum inlet parameters operating curves for the HGSHP and the HVAC systems under varying environmental conditions aimed at minimizing the exergy destruction along with the fulfillment of the required heat load.

  16. 'Consolidation' of HVAC and cooling systems at CERN

    CERN Document Server

    Inigo-Golfin, J; Pepinster, P; CERN. Geneva. TS Department

    2008-01-01

    A â€ワconsolidation” of installations after they have reached the end of their predetermined life-time is part of the life cycle of industrial installations, regardless how well maintained they are. The â€ワconsolidation” plan might cover the replacement of obsolete equipment, partial refurbishment, the work requested to comply with new standards and applicable rules (environmental aspects) until the complete replacement of the whole installation. This â€ワconsolidation” process is all the more critical since the installation dates of the existing cooling and HVAC equipment at CERN spans over a period of 50 years and â€ワconsolidation” in the past has been not been systematic, being most of the time associated with new projects. This paper describes the reasons behind the recent â€ワconsolidation” requests for cooling and HVAC equipment both for the accelerators backbone and in tertiary buildings. A criticality analysis is given, based on the criteria laid down in the p...

  17. System solution to improve energy efficiency of HVAC systems

    Science.gov (United States)

    Chretien, L.; Becerra, R.; Salts, N. P.; Groll, E. A.

    2017-08-01

    According to recent surveys, heating and air conditioning systems account for over 45% of the total energy usage in US households. Three main types of HVAC systems are available to homeowners: (1) fixed-speed systems, where the compressor cycles on and off to match the cooling load; (2) multi-speed (typically, two-speed) systems, where the compressor can operate at multiple cooling capacities, leading to reduced cycling; and (3) variable-speed systems, where the compressor speed is adjusted to match the cooling load of the household, thereby providing higher efficiency and comfort levels through better temperature and humidity control. While energy consumption could reduce significantly by adopting variable-speed compressor systems, the market penetration has been limited to less than 10% of the total HVAC units and a vast majority of systems installed in new construction remains single speed. A few reasons may explain this phenomenon such as the complexity of the electronic circuitry required to vary compressor speed as well as the associated system cost. This paper outlines a system solution to boost the Seasonal Energy Efficiency Rating (SEER) of a traditional single-speed unit through using a low power electronic converter that allows the compressor to operate at multiple low capacity settings and is disabled at high compressor speeds.

  18. Ultraviolet radiation

    International Nuclear Information System (INIS)

    Hawk, J.

    1986-01-01

    Ultraviolet radiation (UVR) from the sun or artificial sources is reflected or transmitted at the surface of the skin, about 5% of normally incident rays being directly reflected. The transmitted fraction is scattered, photochemically absorbed or dissipated as heat within the skin, or passes from it to contribute to the variable total amount of reflected and transmitted radiation. The UVR absorbers in skin are not definitely known, but DNA is a definite target and probably lipoprotein membranes, RNA, proteins, mucopolysaccharides, elastin and collagen. Photochemical or free radical damage to absorber or nearby organelles leads to pharmacological, ultrastructural, histological and clinical changes. Most frequent DNA damage is pyrimidine dimer formation, apparently inhibiting cell function and replication. This is largely enzymatically repaired in man in the dark by excision repair, post-replication repair and possible other enzymatic mechanisms, and at least in some organisms by light-induced photoreactivation repair. UVR exposure causes well recognized acute and chronic clinical syndromes in man. These are discussed in this paper

  19. Real-time supervision of building HVAC system performance

    Energy Technology Data Exchange (ETDEWEB)

    Djuric, Natasa

    2008-07-01

    This thesis presents techniques for improving building HVAC system performance in existing buildings generated using simulation-based tools and real data. Therefore, one of the aims has been to research the needs and possibilities to assess and improve building HVAC system performance. In addition, this thesis aims at an advanced utilization of building energy management system (BEMS) and the provision of useful information to building operators using simulation tools. Buildings are becoming more complex systems with many elements, while BEMS provide many data about the building systems. There are, however, many faults and issues in building performance, but there are legislative and cost-benefit forces induced by energy savings. Therefore, both BEMS and the computer-based tools have to be utilized more efficiently to improve building performance. The thesis consists of four main parts that can be read separately. The first part explains the term commissioning and the commissioning tool work principal based on literature reviews. The second part presents practical experiences and issues introduced through the work on this study. The third part deals with the computer-based tools application in design and operation. This part is divided into two chapters. The first deals with improvement in the design, and the second deals with the improvement in the control strategies. The last part of the thesis gives several rules for fault diagnosis developed using simulation tools. In addition, this part aims at the practical explanation of the faults in the building HVAC systems. The practical background for the thesis was obtained though two surveys. The first survey was carried out with the aim to find the commissioning targets in Norwegian building facilities. In that way, an overview of the most typical buildings, HVAC equipment, and their related problems was obtained. An on-site survey was carried out on an example building, which was beneficial for introducing the

  20. Design principles of a nuclear and industrial HVAC of IFMIF

    International Nuclear Information System (INIS)

    Pruneri, Giuseppe; Ibarra, A.; Heidinger, R.; Knaster, J.; Sugimoto, M.

    2016-01-01

    Highlights: • Parameter of Derivate air Contamination (DAC) allows to associate the type of air ventilation. • The construction and operation of IFMIF will be subjected to the regulations of the country in which it will be sited. • Structures, systems and components are assigned a particular safety important components (SIC, 1–2 and Non-SIC) clarification that is based on the consequences of their failure. • Reliability, Availability, Maintainability and Inspectability (RAMI) analysis has given a great contribution of the facility to optimize the configuration, particularly for the HVAC system. - Abstract: In 2013, the IFMIF, the International Fusion Material Irradiation Facility, presently in its Engineering Validation and Engineering Design Activities (EVEDA) phase, framed by the Broader Approach Agreement between Japan and EURATOM, accomplished in 2013 its mandate to provide the engineering design of the plant on schedule [1]. The IFMIF aims to qualify and characterize materials that are capable of withstanding the intense neutron flux originated in D-T reactions of future fusion reactors due to a neutron flux with a broad peak at 14 MeV, which is able to provide >20 dpa/fpy on small specimens in this EVEDA phase. The successful operation of such a challenging plant demands a careful assessment of the Conventional Facilities (CF), which have adequate redundancies to allow for the target plant availability [2]. The present paper addresses the design proposed in the IFMIF Intermediate Engineering Design Report regarding the CF, particularly the IFMIF's Nuclear and Industrial HVAC design. A preliminary feasibility study, including the initial configuration, calculations and reliability/availability analysis, were performed. The nuclear HVAC design was developed progressively; first, by establishing a conceptual design, starting from the system functional description, followed by the identification of the corresponding interfacing systems and their

  1. Modeling of HVAC operational faults in building performance simulation

    International Nuclear Information System (INIS)

    Zhang, Rongpeng; Hong, Tianzhen

    2017-01-01

    Highlights: •Discuss significance of capturing operational faults in existing buildings. •Develop a novel feature in EnergyPlus to model operational faults of HVAC systems. •Compare three approaches to faults modeling using EnergyPlus. •A case study demonstrates the use of the fault-modeling feature. •Future developments of new faults are discussed. -- Abstract: Operational faults are common in the heating, ventilating, and air conditioning (HVAC) systems of existing buildings, leading to a decrease in energy efficiency and occupant comfort. Various fault detection and diagnostic methods have been developed to identify and analyze HVAC operational faults at the component or subsystem level. However, current methods lack a holistic approach to predicting the overall impacts of faults at the building level—an approach that adequately addresses the coupling between various operational components, the synchronized effect between simultaneous faults, and the dynamic nature of fault severity. This study introduces the novel development of a fault-modeling feature in EnergyPlus which fills in the knowledge gap left by previous studies. This paper presents the design and implementation of the new feature in EnergyPlus and discusses in detail the fault-modeling challenges faced. The new fault-modeling feature enables EnergyPlus to quantify the impacts of faults on building energy use and occupant comfort, thus supporting the decision making of timely fault corrections. Including actual building operational faults in energy models also improves the accuracy of the baseline model, which is critical in the measurement and verification of retrofit or commissioning projects. As an example, EnergyPlus version 8.6 was used to investigate the impacts of a number of typical operational faults in an office building across several U.S. climate zones. The results demonstrate that the faults have significant impacts on building energy performance as well as on occupant

  2. Design principles of a nuclear and industrial HVAC of IFMIF

    Energy Technology Data Exchange (ETDEWEB)

    Pruneri, Giuseppe [IFMIF/EVEDA, Project Team, Rokkasho (Japan); Ibarra, A. [CIEMAT, Madrid (Spain); Heidinger, R. [F4E, Garching (Germany); Knaster, J. [IFMIF/EVEDA Project Team, Rokkasho (Japan); Sugimoto, M. [JAEA, Rokkasho (Japan)

    2016-02-15

    Highlights: • Parameter of Derivate air Contamination (DAC) allows to associate the type of air ventilation. • The construction and operation of IFMIF will be subjected to the regulations of the country in which it will be sited. • Structures, systems and components are assigned a particular safety important components (SIC, 1–2 and Non-SIC) clarification that is based on the consequences of their failure. • Reliability, Availability, Maintainability and Inspectability (RAMI) analysis has given a great contribution of the facility to optimize the configuration, particularly for the HVAC system. - Abstract: In 2013, the IFMIF, the International Fusion Material Irradiation Facility, presently in its Engineering Validation and Engineering Design Activities (EVEDA) phase, framed by the Broader Approach Agreement between Japan and EURATOM, accomplished in 2013 its mandate to provide the engineering design of the plant on schedule [1]. The IFMIF aims to qualify and characterize materials that are capable of withstanding the intense neutron flux originated in D-T reactions of future fusion reactors due to a neutron flux with a broad peak at 14 MeV, which is able to provide >20 dpa/fpy on small specimens in this EVEDA phase. The successful operation of such a challenging plant demands a careful assessment of the Conventional Facilities (CF), which have adequate redundancies to allow for the target plant availability [2]. The present paper addresses the design proposed in the IFMIF Intermediate Engineering Design Report regarding the CF, particularly the IFMIF's Nuclear and Industrial HVAC design. A preliminary feasibility study, including the initial configuration, calculations and reliability/availability analysis, were performed. The nuclear HVAC design was developed progressively; first, by establishing a conceptual design, starting from the system functional description, followed by the identification of the corresponding interfacing systems and their

  3. Energy Savings Potential and RD&D Opportunities for Commercial Building HVAC Systems

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting, Burlington, MA (United States); Shandross, Richard [Navigant Consulting, Burlington, MA (United States); Young, Jim [Navigant Consulting, Burlington, MA (United States); Petritchenko, Oxana [Navigant Consulting, Burlington, MA (United States); Ringo, Decker [Navigant Consulting, Burlington, MA (United States); McClive, Sam [Navigant Consulting, Burlington, MA (United States)

    2017-12-01

    The Building Technologies Office (BTO) commissioned this characterization and technology assessment of heating, ventilation, and air-conditioning (HVAC) systems for commercial buildings. The main objectives of this study: Identify a wide range of technology options in varying stages of development that could reduce commercial HVAC energy consumption; Characterize these technology options based on their technical energy-savings potential, development status, non-energy benefits, and other factors affecting end-user acceptance and the ability to compete with conventional HVAC technologies; Make specific recommendations to DOE and other stakeholders on potential research, development, and demonstration (RD&D) activities that would support further development of the most promising technology options.

  4. Recommended HVAC standard of the Florida Radon Research Program. Final report, Mar-Sep 90

    International Nuclear Information System (INIS)

    Cummings, J.B.

    1992-01-01

    The report contains the recommended language for the heating, ventilation, and air-conditioning (HVAC) section of the 'Florida Code for Radon-resistant Construction and Mitigation.' It deals with elements of construction that relate to the HVAC of houses. Its primary intent is to prevent pressure differentials in houses that can increase the transport of radon into houses. Three pathways of compliance are available to meet the requirements of the HVAC portion of the standards. The first is purely prescriptive. The second is a performance and prescriptive approach. The third is a marketplace approach

  5. Building America Expert Meeting Report: Transitioning Traditional HVAC Contractors to Whole House Performance Contractors

    Energy Technology Data Exchange (ETDEWEB)

    Burdick, A.

    2011-10-01

    This report outlines findings resulting from a U.S. Department of Energy Building America expert meeting to determine how HVAC companies can transition from a traditional contractor status to a service provider for whole house energy upgrade contracting. IBACOS has embarked upon a research effort under the Building America Program to understand business impacts and change management strategies for HVAC companies. HVAC companies can implement these strategies in order to quickly transition from a 'traditional' heating and cooling contractor to a service provider for whole house energy upgrade contracting. Due to HVAC service contracts, which allow repeat interaction with homeowners, HVAC companies are ideally positioned in the marketplace to resolve homeowner comfort issues through whole house energy upgrades. There are essentially two primary ways to define the routes of transition for an HVAC contractor taking on whole house performance contracting: (1) Sub-contracting out the shell repair/upgrade work; and (2) Integrating the shell repair/upgrade work into their existing business. IBACOS held an Expert Meeting on the topic of Transitioning Traditional HVAC Contractors to Whole House Performance Contractors on March 29, 2011 in San Francisco, CA. The major objectives of the meeting were to: Review and validate the general business models for traditional HVAC companies and whole house energy upgrade companies Review preliminary findings on the differences between the structure of traditional HVAC Companies and whole house energy upgrade companies Seek industry input on how to structure information so it is relevant and useful for traditional HVAC contractors who are transitioning to becoming whole house energy upgrade contractors Seven industry experts identified by IBACOS participated in the session along with one representative from the National Renewable Energy Laboratory (NREL). The objective of the meeting was to validate the general operational

  6. Co-simulation of innovative integrated HVAC systems in buildings

    Energy Technology Data Exchange (ETDEWEB)

    Trcka, Marija; Hensena, Jan L.M.; Wetter, Michael

    2010-06-21

    Integrated performance simulation of buildings HVAC systems can help in reducing energy consumption and increasing occupant comfort. However, no single building performance simulation (BPS) tool offers sufficient capabilities and flexibilities to analyze integrated building systems and to enable rapid prototyping of innovative building and system technologies. One way to alleviate this problem is to use co-simulation, as an integrated approach to simulation. This article elaborates on issues important for co-simulation realization and discusses multiple possibilities to justify the particular approach implemented in the here described co-simulation prototype. The prototype is validated with the results obtained from the traditional simulation approach. It is further used in a proof-of-concept case study to demonstrate the applicability of the method and to highlight its benefits. Stability and accuracy of different coupling strategies are analyzed to give a guideline for the required coupling time step.

  7. Magnetohydrodynamic flow in ducts with discontinuous electrical insulation

    International Nuclear Information System (INIS)

    Mistrangelo, C.; Bühler, L.

    2015-01-01

    Highlights: • Liquid metal MHD flows in ducts with flow channel inserts. • Study of the influence of local interruption of electrical insulation. • 3D numerical simulations. - Abstract: In liquid metal blankets the interaction of the moving breeder with the intense magnetic field that confines the fusion plasma results in significant modifications of the velocity distribution and increased pressure drop compared to hydrodynamic flows. Those changes are due to the occurrence of electromagnetic forces that slow down the core flow and which are balanced by large driving pressure heads. The resulting magnetohydrodynamic (MHD) pressure losses are proportional to the electric current density induced in the fluid and they can be reduced by electrically decoupling the wall from the liquid metal. For applications to dual coolant blankets it is foreseen to loosely insert electrically insulating liners into the ducts. In long channels the insulation could consist of a number of shorter inserts, which implies a possible local interruption of the insulation. Three dimensional numerical simulations have been performed to investigate MHD flows in electrically well-conducting channels with internal discontinuous insulating inserts. The local jump in the electric conductivity of the duct wall results in induced 3D electric currents and related electromagnetic forces yielding additional pressure losses and increased velocity in boundary layers parallel to the magnetic field.

  8. Filter forensics: microbiota recovery from residential HVAC filters.

    Science.gov (United States)

    Maestre, Juan P; Jennings, Wiley; Wylie, Dennis; Horner, Sharon D; Siegel, Jeffrey; Kinney, Kerry A

    2018-01-30

    Establishing reliable methods for assessing the microbiome within the built environment is critical for understanding the impact of biological exposures on human health. High-throughput DNA sequencing of dust samples provides valuable insights into the microbiome present in human-occupied spaces. However, the effect that different sampling methods have on the microbial community recovered from dust samples is not well understood across sample types. Heating, ventilation, and air conditioning (HVAC) filters hold promise as long-term, spatially integrated, high volume samplers to characterize the airborne microbiome in homes and other climate-controlled spaces. In this study, the effect that dust recovery method (i.e., cut and elution, swabbing, or vacuuming) has on the microbial community structure, membership, and repeatability inferred by Illumina sequencing was evaluated. The results indicate that vacuum samples captured higher quantities of total, bacterial, and fungal DNA than swab or cut samples. Repeated swab and vacuum samples collected from the same filter were less variable than cut samples with respect to both quantitative DNA recovery and bacterial community structure. Vacuum samples captured substantially greater bacterial diversity than the other methods, whereas fungal diversity was similar across all three methods. Vacuum and swab samples of HVAC filter dust were repeatable and generally superior to cut samples. Nevertheless, the contribution of environmental and human sources to the bacterial and fungal communities recovered via each sampling method was generally consistent across the methods investigated. Dust recovery methodologies have been shown to affect the recovery, repeatability, structure, and membership of microbial communities recovered from dust samples in the built environment. The results of this study are directly applicable to indoor microbiota studies utilizing the filter forensics approach. More broadly, this study provides a

  9. Evaluation of High-Performance Rooftop HVAC Unit Naval Air Station Key West, Florida

    Energy Technology Data Exchange (ETDEWEB)

    Howett, Daniel H. [ORNL; Desjarlais, Andre Omer [ORNL; Cox, Daryl [ORNL

    2018-01-01

    This report documents performance of a high performance rooftop HVAC unit (RTU) at Naval Air Station Key West, FL. This report was sponsored by the Federal Energy Management Program as part of the "High Performance RTU Campaign".

  10. Building Assessment Survey and Evaluation (BASE) Study: Summarized Data - Test Space HVAC Characteristics

    Science.gov (United States)

    Information on the characteristics of the heating, ventilation, and air conditioning (HVAC) system(s) in the entire BASE building including types of ventilation, equipment configurations, and operation and maintenance issues

  11. Review of Control Techniques for HVAC Systems—Nonlinearity Approaches Based on Fuzzy Cognitive Maps

    Directory of Open Access Journals (Sweden)

    Farinaz Behrooz

    2018-02-01

    Full Text Available Heating, Ventilating, and Air Conditioning (HVAC systems are the major energy-consuming devices in buildings. Nowadays, due to the high demand for HVAC system installation in buildings, designing an effective controller in order to decrease the energy consumption of the devices while meeting the thermal comfort demands in buildings are the most important goals of control designers. The purpose of this article is to investigate the different control methods for Heating, Ventilating, and Air Conditioning and Refrigeration (HVAC & R systems. The advantages and disadvantages of each control method are discussed and finally the Fuzzy Cognitive Map (FCM method is introduced as a new strategy for HVAC systems. The FCM method is an intelligent and advanced control technique to address the nonlinearity, Multiple-Input and Multiple-Output (MIMO, complexity and coupling effect features of the systems. The significance of this method and improvements by this method are compared with other methods.

  12. Building America Expert Meeting Report. Transitioning Traditional HVAC Contractors to Whole House Performance Contractors

    Energy Technology Data Exchange (ETDEWEB)

    Burdick, Arlan [IBACOS Inc., Pittsburgh, PA (United States)

    2011-10-01

    This expert meeting was hosted by the IBACOS Building America research team to determine how HVAC companies can transition from a traditional contractor status to a service provider for whole house energy upgrade contracting.

  13. Small Business Voucher CRADA Report: Natural Gas Powered HVAC System for Commercial and Residential Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Betts, Daniel [Be Power Tech, Deerfield Beach, FL (United States); Ally, Moonis Raza [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mudiraj, Shyam [Be Power Tech, Deerfield Beach, FL (United States); Tilghman, Matthew [Be Power Tech, Deerfield Beach, FL (United States); Graham, Matthew [Be Power Tech, Deerfield Beach, FL (United States)

    2017-04-30

    Be Power Tech is commercializing BeCool, the first integrated electricity-producing heating, ventilation, and air conditioning (HVAC) system using a non-vapor compression cycle (VCC), packaged rooftop HVAC unit that also produces base-load electricity, heating, ventilation, and air conditioning. BeCool is a distributed energy resource with energy storage that eliminates the tremendous peak electricity demand associated with commonly used electricity-powered vapor compression air conditioning systems.

  14. Expert Meeting Report: HVAC Fault Detection, DIagnosis, and Repair/Replacement

    Energy Technology Data Exchange (ETDEWEB)

    Springer, David [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2016-05-01

    The concept for the expert meeting described in this report was to bring together most of the stakeholders in the area of FDD, including academic researchers, manufacturers, educators, program managers and implementers, representatives of standards organizations, utilities, HVAC contractors, and home performance contractors to identify the major gaps and to develop ideas about what can be done to capitalize on the residential HVAC efficiency resource.

  15. Expert Meeting Report: HVAC Fault Detection, Diagnosis, and Repair/Replacement

    Energy Technology Data Exchange (ETDEWEB)

    Springer, David [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States). Davis Energy Group

    2016-05-01

    The concept for the expert meeting described in this report was to bring together most of the stakeholders in the area of FDD, including academic researchers, manufacturers, educators, program managers and implementers, representatives of standards organizations, utilities, HVAC contractors, and home performance contractors to identify the major gaps and to develop ideas about what can be done to capitalize on the residential HVAC efficiency resource.

  16. Microwave-Irradiation-Assisted HVAC Filtration for Inactivation of Viral Aerosols (Postprint)

    Science.gov (United States)

    2012-02-01

    Baggiani, A. and Senesi, S. (2004). Effect of Microwave Radiation on Bacillus subtilis Spores . J. Appl. Microbiol. 97: 1220–1227. Damit, B., Lee, C.N...AFRL-RX-TY-TP-2012-0020 MICROWAVE-IRRADIATION-ASSISTED HVAC FILTRATION FOR INACTIVATION OF VIRAL AEROSOLS POSTPRINT Myung-Heui Woo and...12-APR-2011 -- 11-DEC-2011 Microwave Irradiation-Assisted HVAC Filtration for Inactivation of Viral Aerosols (POSTPRINT) FA8650-06-C-5913 0602102F

  17. Evaluation of sampling methods for Bacillus spore-contaminated HVAC filters

    OpenAIRE

    Calfee, M. Worth; Rose, Laura J.; Tufts, Jenia; Morse, Stephen; Clayton, Matt; Touati, Abderrahmane; Griffin-Gatchalian, Nicole; Slone, Christina; McSweeney, Neal

    2013-01-01

    The objective of this study was to compare an extraction-based sampling method to two vacuum-based sampling methods (vacuum sock and 37 mm cassette filter) with regards to their ability to recover Bacillus atrophaeus spores (surrogate for Bacillus anthracis) from pleated heating, ventilation, and air conditioning (HVAC) filters that are typically found in commercial and residential buildings. Electrostatic and mechanical HVAC filters were tested, both without and after loading with dust to 50...

  18. HVAC Modeling for Cost of Ownership Assessment in Biotechnology & Drugs Manufacturing

    OpenAIRE

    Broomes, Peter; Dornfeld, David A

    2003-01-01

    Heating, ventilation, and air conditioning (HVAC) systems used in the clean room environment of biotechnology and drug development and manufacturing, are extremely energy and water intensive and represent a significant operating cost for these facilities [1]. HVAC systems are also the primary source of environmental emissions for the majority of companies operating within the biotechnology and drugs sector. While the processes used in drug manufacture have negligible environmental impact...

  19. Building occupancy diversity and HVAC (heating, ventilation, and air conditioning) system energy efficiency

    International Nuclear Information System (INIS)

    Yang, Zheng; Ghahramani, Ali; Becerik-Gerber, Burcin

    2016-01-01

    Approximately forty percent of total building energy consumption is attributed to HVAC (heating, ventilation, and air conditioning) systems that aim to maintain healthy and comfortable indoor environments. An HVAC system is a network with several subsystems, and there exist heat transfer and balance among the zones of a building, as well as heat gains and losses through a building's envelope. Diverse occupancy (diversity in terms of when and how occupants occupy a building) in spaces could result in increase of loads that are not actual demands for an HVAC system, leading into inefficiencies. This paper introduces a framework to quantitatively evaluate the energy implications of occupancy diversity at the building level, where building information modeling is integrated to provide building geometries, HVAC system layouts, and spatial information as inputs for computing potential energy implications if occupancy diversity were to be eliminated. An agglomerate hierarchical clustering-based iterative evaluation algorithm is designed for iteratively eliminating occupancy diversity. Whole building energy simulations for a real-world building, as well as virtual reference buildings demonstrate that the proposed framework could effectively quantify the HVAC system energy efficiency affected by occupancy diversity and the framework is generalizable to different building geometries, layouts, and occupancy diversities. - Highlights: • Analyze relationships between occupancy diversity and HVAC energy efficiency. • Integrate BIM for quantifying energy implications of occupancy diversity. • Demonstrate the effectiveness and generalizability of iterative evaluation algorithm. • Improve agglomerative hierarchical clustering process using heap data structure.

  20. Case study field evaluation of a systems approach to retrofitting a residential HVAC system

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; McWiliams, Jennifer A.; Konopacki, Steven J.

    2003-09-01

    This case study focusing on a residence in northern California was undertaken as a demonstration of the potential of a systems approach to HVAC retrofits. The systems approach means that other retrofits that can affect the HVAC system are also considered. For example, added building envelope insulation reduces building loads so that smaller capacity HVAC system can be used. Secondly, we wanted to examine the practical issues and interactions with contractors and code officials required to accomplish the systems approach because it represents a departure from current practice. We identified problems in the processes of communication and installation of the retrofit that led to compromises in the final energy efficiency of the HVAC system. These issues must be overcome in order for HVAC retrofits to deliver the increased performance that they promise. The experience gained in this case study was used to optimize best practices guidelines for contractors (Walker 2003) that include building diagnostics and checklists as tools to assist in ensuring the energy efficiency of ''house as a system'' HVAC retrofits. The best practices guidelines proved to be an excellent tool for evaluating the eight existing homes in this study, and we received positive feedback from many potential users who reviewed and used them. In addition, we were able to substantially improve the energy efficiency of the retrofitted case study house by adding envelope insulation, a more efficient furnace and air conditioner, an economizer and by reducing duct leakage.

  1. Non-Intrusive Load Monitoring of HVAC Components using Signal Unmixing

    Energy Technology Data Exchange (ETDEWEB)

    Rahimpour, Alireza [University of Tennessee, Knoxville (UTK); Qi, Hairong [ORNL; Fugate, David L [ORNL; Kuruganti, Teja [ORNL

    2015-01-01

    Heating, Ventilating and Air Conditioning units (HVAC) are a major electrical energy consumer in buildings. Monitoring of the operation and energy consumption of HVAC would increase the awareness of building owners and maintenance service providers of the condition and quality of performance of these units, enabling conditioned-based maintenance which would help achieving higher energy efficiency. In this paper, a novel non-intrusive load monitoring method based on group constrained non-negative matrix factorization is proposed for monitoring the different components of HVAC unit by only measuring the whole building aggregated power signal. At the first level of this hierarchical approach, power consumption of the building is decomposed to energy consumption of the HVAC unit and all the other electrical devices operating in the building such as lighting and plug loads. Then, the estimated power signal of the HVAC is used for estimating the power consumption profile of the HVAC major electrical loads such as compressors, condenser fans and indoor blower. Experiments conducted on real data collected from a building testbed maintained at the Oak Ridge National Laboratory (ORNL) demonstrate high accuracy on the disaggregation task.

  2. Airside HVAC BESTEST. Adaptation of ASHRAE RP 865 Airside HVAC Equipment Modeling Test Cases for ASHRAE Standard 140. Volume 1, Cases AE101-AE445

    Energy Technology Data Exchange (ETDEWEB)

    Neymark, J. [J. Neymark & Associates, Golden, CO (United States); Kennedy, M. [Mike D. Kennedy, Inc., Townsend, WA (United States); Judkoff, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gall, J. [AAON, Inc., Tulsa, OK (United States); Knebel, D. [AAON, Inc., Tulsa, OK (United States); Henninger, R. [GARD Analytics, Inc., Arlington Heights, IL (United States); Witte, M. [GARD Analytics, Inc., Arlington Heights, IL (United States); Hong, T. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); McDowell, T. [Thermal Energy System Specialists, Madison, WI (United States); Yan, D. [Tsinghua Univ., Beijing (China); Zhou, X. [Tsinghua Univ., Beijing (China)

    2016-03-01

    This report documents a set of diagnostic analytical verification cases for testing the ability of whole building simulation software to model the air distribution side of typical heating, ventilating and air conditioning (HVAC) equipment. These cases complement the unitary equipment cases included in American National Standards Institute (ANSI)/American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard 140, Standard Method of Test for the Evaluation of Building Energy Analysis Computer Programs, which test the ability to model the heat-transfer fluid side of HVAC equipment.

  3. Review of the Operability for the Components Under the Loss of the HVAC System of the Pump Room

    International Nuclear Information System (INIS)

    Hwang Mee Jeong; Yoon, Churl; Yang, Joon Eon; Park, Joo Hwan

    2005-01-01

    In this paper, we estimated the temperature of the pump rooms and reviewed the operability of the components under the loss of the HVAC (Heating, Ventilation, and Air Condition) system. The issues relevant to the HVAC system in the PSA (Probabilistic Safety Assessment) FT (Fault Tree) model are as follows: does the loss of the HVAC system bring about a function failure of other components?. Can the operator take action to reduce the temperature of the room in case of a HVAC function failure?. At present we do not know whether a component will lose its function or not under the loss of the HVAC. ASME Standard describes that a recovery action can be credited if the related recovery action is included in the procedure or there are similar recovery experiences in the plant. However, there is no description about the recovery action of the HVAC in the EOP (Emergency Operation Procedure) of the UCN3, 4 under the situation of a loss of the HVAC. Even though we consider this assumption positively, it would be limited to the rooms such as the Switchgear Room, Inverter Room, and Main Control Room etc. where a real recovery action can be performed easily. However, if we consider the HVAC failure in the PSA FT model according to the above background, the problem is that the unavailability induced from the loss of a HVAC is highly unrealistically. From a viewpoint of the PSA, it is not true that the related system always fails even though the HVAC system fails. Therefore, we reviewed the necessity of the HVAC model through the identification of the operable temperature of the components' within the pump room and the change of the temperature of the pump room under the situation of a loss of the HVAC system

  4. RADON MITIGATION IN SCHOOLS: HVAC SYTEMS IN SCHOOLS TEND TO HAVE A GREATER IMPACT ON RADON LEVELS THAN HVAC SYSTEMS IN HOMES

    Science.gov (United States)

    The first part of this two-part paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., heating, ventilation, and air conditioing -- HVAC-- system design and operationg) that influence radon entry and mitigation system ...

  5. RELIABILITY ANALYSIS OF THE ELECTRICAL POWER DISTRIBUTION SYSTEM TO SELECTED PORTIONS OF THE NUCLEAR HVAC SYSTEM

    International Nuclear Information System (INIS)

    Ramirez, N.

    2004-01-01

    A design requirement probability of 0.01 or less in a 4-hour period ensures that the nuclear heating, ventilation, and air-conditioning (HVAC) system in the primary confinement areas of the Dry Transfer Facilities (DTFs) and Fuel Handling Facility (FHF) is working during a Category 1 drop event involving commercial spent nuclear fuel (CSNF) assemblies (BSC 2004a , Section 5.1.1.48). This corresponds to an hourly HVAC failure rate of 2.5E-3 per hour or less, which is contributed to by two dominant causes: equipment failure and loss of electrical power. Meeting this minimum threshold ensures that a Category 1 initiating event followed by the failure of HVAC is a Category 2 event sequence. The two causes for the loss of electrical power include the loss of offsite power and the loss of onsite power distribution. Thus, in order to meet the threshold requirement aforementioned, the failure rate of mechanical equipment, loss of offsite power, and loss of onsite power distribution must be less than or equal to 2.5E-3 per hour for the nuclear HVAC system in the primary confinement areas of the DTFs and FHF. The loss of offsite power occurs at a frequency of 1.1E-5 per hour (BSC 2004a, Section 5.1.1.48). The purpose of this analysis is to determine the probability of occurrence of the unavailability of the nuclear HVAC system in the primary confinement areas of the DTFs and FHF due to loss of electrical power. In addition, this analysis provides insights on the contribution to the unavailability of the HVAC system due to equipment failure. The scope of this analysis is limited to finding the frequency of loss of electrical power to the nuclear HVAC system in the primary confinement areas of the DTFs and FHF

  6. ISH. HVAC engineering yearbook 1999; ISH. Jahrbuch fuer Gebaeudetechnik 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    The 1999 HVAC engineering yearbook contains contributions on energy conservation and optimization in the fields of ventilation and air conditioning: inter alia, solar cooling and air conditioning, optimum rating of ventilator units, and cooling ceilings with ventilation function. In the field of heating, the following topics are addressed, equally under the aspect of energy conservation: condensing boiler technology, hydraulic balancing of heating pipe systems and sequential boiler switching using fuzzy control. Further works deal with rational use of electricity in buildings, and building automation. 17 papers are individually listed in the Energy database. [Deutsch] Das Jahrbuch fuer Gebaeudetechnik 1999 enthaelt Beitraege zur Energieeinsparung und Optimierung auf den Gebieten Lueftung und Klimatisierung, u. a. solare Kuehlung und Klimatisierung, optimale Auslegung von Ventilator-Aggregaten und Kuehldecken mit Lueftungsfunktion. Auf dem Gebiet der Heizung werden ebenfalls unter dem Gesichtspunkt Energieeinsparung die Brennwerttechnologie, der hydraulische Abgleich von Heizungsrohrnetzen sowie Kesselfolgeschaltungen mit Fuzzy Control angesprochen. Weitere Arbeiten befassen sich mit der rationellen Elektrizitaetsverwendung in Geb auden sowie der Gebaeudeautomation. Fuer die Datenbank Energy wurden 17 Arbeiten separat aufgenommen.

  7. Monitoring-based HVAC commissioning of an existing office building for energy efficiency

    International Nuclear Information System (INIS)

    Wang, Liping; Greenberg, Steve; Fiegel, John; Rubalcava, Alma; Earni, Shankar; Pang, Xiufeng; Yin, Rongxin; Woodworth, Spencer; Hernandez-Maldonado, Jorge

    2013-01-01

    Highlights: ► Demonstrated monitoring-based HVAC commissioning using an existing office building. ► Diagnosed various types of faulty operation in the HVAC system by trend data analyses. ► Identified a list of energy saving measures for the HVAC system. ► Quantified energy saving potential for each commissioning measure using calibrated energy simulation model. ► Achieved an actual energy saving of 10% after the implementations of cost-effective measures. -- Abstract: The performance of Heating, Ventilation and Air Conditioning (HVAC) systems may fail to satisfy design expectations due to improper equipment installation, equipment degradation, sensor failures, or incorrect control sequences. Commissioning identifies and implements cost-effective operational and maintenance measures in buildings to bring them up to the design intent or optimum operation. An existing office building is used as a case study to demonstrate the process of commissioning. Building energy benchmarking tools are applied to evaluate the energy performance for screening opportunities at the whole building level. A large natural gas saving potential was indicated by the building benchmarking results. Faulty operations in the HVAC systems, such as improper operations of air-side economizers, simultaneous heating and cooling, and ineffective optimal start, were identified through trend data analyses and functional testing. The energy saving potential for each commissioning measure is quantified with a calibrated building simulation model. An actual energy saving of 10% was realized after the implementations of cost-effective measures.

  8. The effects of HVAC system design and operation on radon entry into school buildings

    International Nuclear Information System (INIS)

    Turner, W.A.; Leovic, K.W.; Craig, A.B.

    1990-01-01

    Heating, ventilating, and air conditioning (HVAC) systems in schools vary considerably and tend to have a greater impact on pressure differentials--and consequently radon levels--than do heating and air-conditioning systems in houses. If the HVAC system induces a negative pressure relative to the subslab area, radon can be pulled into the building. If the HVAC system pressurizes the building, it can prevent radon entry as long as the fan is running. However, school HVAC systems are normally set back or turned off on evenings and weekends and, even if the HVAC system pressurizes the school during operation, indoor radon levels may build up during setback periods. In this paper many of the historical methods utilized to deliver ventilation air (outdoor air) over the past 40 years are summarized. In addition, for each type of system presented, the possible impact the ventilation system might be expected to have (positive or negative) on the pressure of the building envelope (and subsequent radon levels in the building) is discussed

  9. Review on the HVAC System Modeling Types and the Shortcomings of Their Application

    Directory of Open Access Journals (Sweden)

    Raad Z. Homod

    2013-01-01

    Full Text Available The modeling of the heating, ventilation, and air conditioning (HVAC system is a prominent topic because of its relationship with energy savings and environmental, economical, and technological issues. The modeling of the HVAC system is concerned with the indoor thermal sensation, which is related to the modeling of building, air handling unit (AHU equipments, and indoor thermal processes. Until now, many HVAC system modeling approaches are made available, and the techniques have become quite mature. But there are some shortcomings in application and integration methods for the different types of the HVAC model. The application and integration processes will act to accumulate the defective characteristics for both AHU equipments and building models such as nonlinear, pure lag time, high thermal inertia, uncertain disturbance factors, large-scale systems, and constraints. This paper shows types of the HVAC model and the advantages and disadvantages for each application of them, and it finds out that the gray-box type is the best one to represent the indoor thermal comfort. But its application fails at the integration method where its response deviated to unreal behavior.

  10. Economic Optimal HVAC Design for Hybrid GEOTABS Buildings and CO2 Emissions Analysis

    Directory of Open Access Journals (Sweden)

    Damien Picard

    2018-02-01

    Full Text Available In the early design phase of a building, the task of the Heating, Ventilation and Air Conditioning (HVAC engineer is to propose an appropriate HVAC system for a given building. This system should provide thermal comfort to the building occupants at all time, meet the building owner’s specific requirements, and have minimal investment, running, maintenance and replacement costs (i.e., the total cost and energy use or environmental impact. Calculating these different aspects is highly time-consuming and the HVAC engineer will therefore only be able to compare a (very limited number of alternatives leading to suboptimal designs. This study presents therefore a Python tool that automates the generation of all possible scenarios for given thermal power profiles and energy load and a given database of HVAC components. The tool sizes each scenario properly, computes its present total cost (PC and the total CO 2 emissions associated with the building energy use. Finally, the different scenarios can be searched and classified to pick the most appropriate scenario. The tool uses static calculations based on standards, manufacturer data and basic assumptions similar to those made by engineers in the early design phase. The current version of the tool is further focused on hybrid GEOTABS building, which combines a GEOthermal heat pump with a Thermally Activated System (TABS. It should further be noted that the tool optimizes the HVAC system but not the building envelope, while, ideally, both should be simultaneously optimized.

  11. Minimization of energy consumption in HVAC systems with data-driven models and an interior-point method

    International Nuclear Information System (INIS)

    Kusiak, Andrew; Xu, Guanglin; Zhang, Zijun

    2014-01-01

    Highlights: • We study the energy saving of HVAC systems with a data-driven approach. • We conduct an in-depth analysis of the topology of developed Neural Network based HVAC model. • We apply interior-point method to solving a Neural Network based HVAC optimization model. • The uncertain building occupancy is incorporated in the minimization of HVAC energy consumption. • A significant potential of saving HVAC energy is discovered. - Abstract: In this paper, a data-driven approach is applied to minimize energy consumption of a heating, ventilating, and air conditioning (HVAC) system while maintaining the thermal comfort of a building with uncertain occupancy level. The uncertainty of arrival and departure rate of occupants is modeled by the Poisson and uniform distributions, respectively. The internal heating gain is calculated from the stochastic process of the building occupancy. Based on the observed and simulated data, a multilayer perceptron algorithm is employed to model and simulate the HVAC system. The data-driven models accurately predict future performance of the HVAC system based on the control settings and the observed historical information. An optimization model is formulated and solved with the interior-point method. The optimization results are compared with the results produced by the simulation models

  12. A complete geothermal energy cycle with heat pumps and hybrid HVAC systems for the city of Denizli, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Eltez, M. [Ege Univ., Izmir (Turkey). Mechanical Engineering Dept.; Kilkis, I.B. [Heatway Radiant Floors and Snowmelting, Springfield, MO (United States)]|[Middle East Technical Univ., Ankara (Turkey)

    1995-12-31

    This paper discusses general aspects of maximizing geofluid effectiveness by employing hybrid cycle plants coupled to district HVAC systems. Alternative and new techniques in space heating and cooling are also discussed. A case study is presented for the district HVAC system for the city of Denizli in Turkey. Results are compared with an open-cycle, open-loop system.

  13. Selecting HVAC Systems for Schools To Balance the Needs for Indoor Air Quality, Energy Conservation and Maintenance. Technical Bulletin.

    Science.gov (United States)

    Wheeler, Arthur E.; Kunz, Walter S., Jr.

    Although poor air quality in a school can have multiple causes, the heating, ventilating, and air-conditioning (HVAC) system plays a major role. Suggestions that architects, facilities managers, school board members, and administrators can use in selecting HVAC systems are discussed. Focus is on the performance criteria for classroom systems, and…

  14. Energy Renovations: Volume 14: HVAC - A Guide for Contractors to Share with Homeowners

    Energy Technology Data Exchange (ETDEWEB)

    Gilbride, Theresa L.; Baechler, Michael C.; Hefty, Marye G.; Hand, James R.; Love, Pat M.

    2011-08-29

    This report was prepared by PNNL for DOE's Building America program and is intended as a guide that energy performance contractors can share with homeowners to describe various energy-efficient options for heating, cooling, and ventilating existing homes. The report provides descriptions of many common and not-so-common HVAC systems, including their advantages and disadvantages, efficiency ranges and characteristics of high-performance models, typical costs, and climate considerations. The report also provides decision trees and tables of useful information for homeowners who are making decisions about adding, replacing, or upgrading existing HVAC equipment in their homes. Information regarding home energy performance assessments (audits) and combustion safety issues when replacing HVAC equipment are also provided.

  15. Application of optimization techniques on lumped HVAC models for energy conservation

    Energy Technology Data Exchange (ETDEWEB)

    Wemhoff, A.P. [Department of Mechanical Engineering, Villanova University, Villanova, PA 19085 (United States)

    2010-12-15

    Heating, ventilating, and air conditioning (HVAC) systems comprise nearly one third of annual household energy consumption in the United States. HVAC energy use can be reduced by applying controls. This study applies a novel control method on a system with arbitrary steady-state and transient load distributions. The new method uses multi-dimensional interpolation between optimized control configurations for various steady-state load distributions. Demonstration of the new method on a two-room HVAC system predicts power savings for an arbitrary steady load that is nearly equivalent to that using a Variable-Air-Volume (VAV) with chiller modulation. However, the new method provides better energy savings for arbitrary transient loads: 19% energy savings over an uncontrolled system compared to energy savings of 6% for a VAV with chiller modulation. The average transient temperature deviation from setpoint using the new method is slightly better than that using VAV with chiller modulation. (author)

  16. Energy Savings Potential and RD&D Opportunities for Non-Vapor-Compression HVAC Technologies

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-03-01

    While vapor-compression technologies have served heating, ventilation, and air-conditioning (HVAC) needs very effectively, and have been the dominant HVAC technology for close to 100 years, the conventional refrigerants used in vapor-compression equipment contribute to global climate change when released to the atmosphere. This Building Technologies Office report: --Identifies alternatives to vapor-compression technology in residential and commercial HVAC applications --Characterizes these technologies based on their technical energy savings potential, development status, non-energy benefits, and other factors affecting end-user acceptance and their ability to compete with conventional vapor-compression systems --Makes specific research, development, and deployment (RD&D) recommendations to support further development of these technologies, should DOE choose to support non-vapor-compression technology further.

  17. Applications of heat pipes for HVAC dehumidification at Walt Disney World

    International Nuclear Information System (INIS)

    Allen, P.J.; Dinh, K.

    1993-01-01

    This paper presents the theory and application of heat pipes for HVAC dehumidification purposes. In HVAC applications, a heat pipe is used as a heat exchanger that transfers heat from the return air directly to the supply air. The air is pre-cooled entering the cooling coil and reheated using the same heat removed from the return air. While consuming no energy, the heat pipe lets the evaporator coil operate at a lower temperature, increasing the moisture removal capabilities of the HVAC system by 50% to 100%. WALT DISNEY WORLD is currently testing several heat pipe applications ranging from 1 to 240 tons. The applications include (1) water attractions (2) museums/artifacts areas (3) resort guest rooms and (4) locker rooms. Actual energy usage and relative humidity reductions are shown to determine the effectiveness of the heat pipe as an energy efficient method of humidity control

  18. HVAC in sustainable office buildings a bridge between owners and engineers

    CERN Document Server

    Hovorka, Frank; Kurnitski, Jarek; Litiu, Andrei

    2012-01-01

    This guidebook aims to build a bridge between the real estate community and the engineering community. It explains the challenges of property valuation based on real data and how the sustainability and HVAC-technology can have an impact on value. It also gathers the latest HVAC- and other technologies used in sustainable buildings and gives some real case study examples. But maybe the most important part in terms of improved communication between the owners and engineers is the list of questions to be asked during the life time of a building. It is impossible to give all the right answers in this guidebook, but we will raise some pertinent questions. As climates and cultures are different, as well as existing building types and energy production, the same solutions do not solve problems universally. This guidebook is aimed for the owners and architects as well as engineers. It doesn’t require deep technical knowhow of HVAC-systems or real estate valuation.

  19. Transient pattern analysis for fault detection and diagnosis of HVAC systems

    International Nuclear Information System (INIS)

    Cho, Sung-Hwan; Yang, Hoon-Cheol; Zaheer-uddin, M.; Ahn, Byung-Cheon

    2005-01-01

    Modern building HVAC systems are complex and consist of a large number of interconnected sub-systems and components. In the event of a fault, it becomes very difficult for the operator to locate and isolate the faulty component in such large systems using conventional fault detection methods. In this study, transient pattern analysis is explored as a tool for fault detection and diagnosis of an HVAC system. Several tests involving different fault replications were conducted in an environmental chamber test facility. The results show that the evolution of fault residuals forms clear and distinct patterns that can be used to isolate faults. It was found that the time needed to reach steady state for a typical building HVAC system is at least 50-60 min. This means incorrect diagnosis of faults can happen during online monitoring if the transient pattern responses are not considered in the fault detection and diagnosis analysis

  20. Assessment of auditory impression of the coolness and warmness of automotive HVAC noise.

    Science.gov (United States)

    Nakagawa, Seiji; Hotehama, Takuya; Kamiya, Masaru

    2017-07-01

    Noise induced by a heating, ventilation and air conditioning (HVAC) system in a vehicle is an important factor that affects the comfort of the interior of a car cabin. Much effort has been devoted to reduce noise levels, however, there is a need for a new sound design that addresses the noise problem from a different point of view. In this study, focusing on the auditory impression of automotive HVAC noise concerning coolness and warmness, psychoacoustical listening tests were performed using a paired comparison technique under various conditions of room temperature. Five stimuli were synthesized by stretching the spectral envelopes of recorded automotive HVAC noise to assess the effect of the spectral centroid, and were presented to normal-hearing subjects. Results show that the spectral centroid significantly affects the auditory impression concerning coolness and warmness; a higher spectral centroid induces a cooler auditory impression regardless of the room temperature.

  1. In-the-loop simulation of electronic automatic temperature control systems: HVAC modeling

    Energy Technology Data Exchange (ETDEWEB)

    Domschke, R.; Matthes, M. [Visteon Deutschland GmbH, Kerpen (Germany)

    2006-07-01

    The Electronic Automatic Temperature Control (EATC) ensures the occupant comfort and provides safety features like rapid defrost and demist protection. Doing this, the EATC controller provides a direct interface to the end consumer and has a considerable impact on customer satisfaction. The In-the-loop (IL) simulation process is an integral part of Visteons model-based development process. It helps to design and calibrate the EATC controller. It consists of several IL simulation techniques like Model-in-the-loop (MIL), Software-in-the-loop (SIL) and Hardware-in-the-loop (HIL). In this article, we will focus on MIL/SIL Simulations. MIL/SIL allows simulation of the EATC controller in a virtual vehicle environment from the early states of and throughout the development process. This ensures a rapid, high quality and robust development process. The MIL/SIL model contains a thermal vehicle model, a heating, ventilation and air conditioning (HVAC) unit model and a model of the EATC controller itself. The thermal vehicle model simulates transient temperature and humidity conditions in the passenger compartment of a vehicle, settings from the controller, heat fluxes through the vehicle shell and windows, solar load and several further boundary conditions. Whereas the thermal vehicle model of a specific vehicle can be adapted from a default data base, one has to pay special attention to the HVAC unit model. Visteon has developed a special, physically based HVAC unit model to be adapted and implemented into the MIL/SIL simulation. This HVAC model enables a straightforward implementation of different HVAC architectures into the MIL/SIL simulation. Moreover, changes in the HVAC settings (i.e. different blower/scroll assemblies) can be assessed and the influence on passenger comfort can be quantified. Examples of the MIL/SIL simulation demonstrate the benefits of this approach. Results are discussed and a further outlook provided. (orig.)

  2. Novel activity classification and occupancy estimation methods for intelligent HVAC (heating, ventilation and air conditioning) systems

    International Nuclear Information System (INIS)

    Rana, Rajib; Kusy, Brano; Wall, Josh; Hu, Wen

    2015-01-01

    Reductions in HVAC (heating, ventilation and air conditioning) energy consumption can be achieved by limiting heating in the winter or cooling in the summer. However, the resulting low thermal comfort of building occupants may lead to an override of the HVAC control, which revokes its original purpose. This has led to an increased interest in modeling and real-time tracking of location, activity, and thermal comfort of building occupants for HVAC energy management. While thermal comfort is well understood, it is difficult to measure in real-time environments where user context changes dynamically. Encouragingly, plethora of sensors available on smartphone unleashes the opportunity to measure user contexts in real-time. An important contextual information for measuring thermal comfort is Metabolism rate, which changes based on current physical activities. To measure physical activity, we develop an activity classifier, which achieves 10% higher accuracy compared to Support Vector Machine and k-Nearest Neighbor. Office occupancy is another contextual information for energy-efficient HVAC control. Most of the phone based occupancy estimation techniques will fail to determine occupancy when phones are left at desk while sitting or attending meetings. We propose a novel sensor fusion method to detect if a user is near the phone, which achieves more than 90% accuracy. Determining activity and occupancy our proposed algorithms can help maintaining thermal comfort while reducing HVAC energy consumptions. - Highlights: • We propose activity and occupancy detection for efficient HVAC control. • Activity classifier achieves 10% higher accuracy than SVM and kNN. • For occupancy detection we propose a novel sensor fusion method. • Using Weighted Majority Voting we fuse microphone and accelerometer data on phone. • We achieve more than 90% accuracy in detecting occupancy.

  3. Selecting HVAC Systems to Achieve Comfortable and Cost-effective Residential Net-Zero Energy Buildings.

    Science.gov (United States)

    Wu, Wei; Skye, Harrison M; Domanski, Piotr A

    2018-02-15

    HVAC is responsible for the largest share of energy use in residential buildings and plays an important role in broader implementation of net-zero energy building (NZEB). This study investigated the energy, comfort and economic performance of commercially-available HVAC technologies for a residential NZEB. An experimentally-validated model was used to evaluate ventilation, dehumidification, and heat pump options for the NZEB in the mixed-humid climate zone. Ventilation options were compared to mechanical ventilation without recovery; a heat recovery ventilator (HRV) and energy recovery ventilator (ERV) respectively reduced the HVAC energy by 13.5 % and 17.4 % and reduced the building energy by 7.5 % and 9.7 %. There was no significant difference in thermal comfort between the ventilation options. Dehumidification options were compared to an air-source heat pump (ASHP) with a separate dehumidifier; the ASHP with dedicated dehumidification reduced the HVAC energy by 7.3 % and the building energy by 3.9 %. The ASHP-only option (without dedicated dehumidification) reduced the initial investment but provided the worst comfort due to high humidity levels. Finally, ground-source heat pump (GSHP) alternatives were compared to the ASHP; the GSHP with two and three boreholes reduced the HVAC energy by 26.0 % and 29.2 % and the building energy by 13.1 % and 14.7 %. The economics of each HVAC configuration was analyzed using installation cost data and two electricity price structures. The GSHPs with the ERV and dedicated dehumidification provided the highest energy savings and good comfort, but were the most expensive. The ASHP with dedicated dehumidification and the ERV (or HRV) provided reasonable payback periods.

  4. HVAC--the importance of clean intake section and dry air filter in cold climate.

    Science.gov (United States)

    Hanssen, S O

    2004-01-01

    HVAC systems, if properly designed, installed, operated and maintained, will improve thermal conditions and air quality indoors. However, the success strongly depends on the design of the system and the quality of the components we use in our HVAC installations. Regrettably, several investigations have revealed that many HVAC installations have a lot of operational and maintenance problems, especially related to moisture, rain and snow entrainment. In short, it seems that too little attention is placed on the design of the intake section, despite the fact that there exists a large number of national and international guidelines and recommendations. This is a serious problem because the air intake is the initial component of the ventilation plant and as such the first line of defense against debris and other outdoor air pollutants. Unfortunately, the design is often an argued compromise between the architect, the civil engineer and the HVAC engineer. In the future, the technical, hygienic and microbiological feature of air intakes must be better ensured in order to avoid the air intake becoming a risk component as regards contamination and indoor air quality. Further, it seems that the magnitude of the problem is not well known, or recognized, by the building designers, engineers and professionals involved in the construction and operation of buildings. This fact needs to be addressed more seriously, because obviously there is a big difference between the idealistic architectonic design, engineering intentions and the real life situation. Several practical recommendations for design and operation of HVAC systems are presented. Following the recommendations will result in less pollution from the HVAC-system and increased indoor environmental quality.

  5. Effect of enhanced ultraviolet germicidal irradiation in the heating ventilation and air conditioning system on ventilator-associated pneumonia in a neonatal intensive care unit.

    Science.gov (United States)

    Ryan, R M; Wilding, G E; Wynn, R J; Welliver, R C; Holm, B A; Leach, C L

    2011-09-01

    The objective of this study was to test the hypothesis that enhanced ultraviolet germicidal irradiation (eUVGI) installed in our neonatal intensive care unit (NICU) heating ventilation and air conditioning system (HVAC) would decrease HVAC and NICU environment microbes, tracheal colonization and ventilator-associated pneumonia (VAP). The study was designed as a prospective interventional pre- and post-single-center study. University-affiliated Regional Perinatal Center NICU. Intubated patients in the NICU were evaluated for colonization, and a high-risk sub-population of infants <30 weeks gestation ventilated for ≥ 14 days was studied for VAP. eUVGI was installed in the NICU's remote HVACs. The HVACs, NICU environment and intubated patients' tracheas were cultured pre- and post-eUVGI for 12 months. The high-risk patients were studied for VAP (positive bacterial tracheal culture, increased ventilator support, worsening chest radiograph and ≥ 7 days of antibiotics). Pseudomonas, Klebsiella, Serratia, Acinetobacter, Staphylococcus aureus and Coagulase-negative Staphylococcus species were cultured from all sites. eUVGI significantly decreased HVAC organisms (baseline 500,000 CFU cm(-2); P=0.015) and NICU environmental microbes (P<0.0001). Tracheal microbial loads decreased 45% (P=0.004), and fewer patients became colonized. VAP in the high-risk cohort fell from 74% (n=31) to 39% (n=18), P=0.04. VAP episodes per patient decreased (Control: 1.2 to eUVGI: 0.4; P=0.004), and antibiotic usage was 62% less (P=0.013). eUVGI decreased HVAC microbial colonization and was associated with reduced NICU environment and tracheal microbial colonization. Significant reductions in VAP and antibiotic use were also associated with eUVGI in this single-center study. Large randomized multicenter trials are needed.

  6. Harmonic modelling, propagation and mitigation for large wind power plants connected via long HVAC cables

    DEFF Research Database (Denmark)

    Dowlatabadi, Mohammadkazem Bakhshizadeh; Hjerrild, Jesper; Kocewiak, Łukasz

    2016-01-01

    This paper presents a state-of-the-art review on grid connection of large offshore wind power plants (OWPPs) using extra-long high voltage AC (HVAC) cables. The paper describes research by DONG Energy Wind Power in close collaboration with Aalborg University addressing related challenges through...... an industrial PhD project. The overall goal is to gain a better understanding of extra-long HVAC cable connected OWPPs, in order to ensure reliability and availability of OWPPs. This will reduce the cost of energy, as the risk of costly delays and modifications after the project has been commissioned can...

  7. Global optimization for overall HVAC systems - Part I problem formulation and analysis

    International Nuclear Information System (INIS)

    Lu Lu; Cai Wenjian; Chai, Y.S.; Xie Lihua

    2005-01-01

    This paper presents the global optimization technologies for overall heating, ventilating and air conditioning (HVAC) systems. The objective function of global optimization and constraints are formulated based on mathematical models of the major components. All these models are associated with power consumption components and heat exchangers for transferring cooling load. The characteristics of all the major components are briefly introduced by models, and the interactions between them are analyzed and discussed to show the complications of the problem. According to the characteristics of the operating components, the complicated original optimization problem for overall HVAC systems is transformed and simplified into a compact form ready for optimization

  8. Research and Development Opportunities for Joining Technologies in HVAC&R

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting, Burlington, MA (United States); Guernsey, Matt [Navigant Consulting, Burlington, MA (United States); Young, Jim [Navigant Consulting, Burlington, MA (United States)

    2015-10-01

    The Building Technologies Office (BTO) works with researchers and industry partners to develop and deploy technologies that can substantially reduce energy consumption and greenhouse gas (GHG) emissions in residential and commercial buildings. This opportunity assessment aims to advance BTO’s energy savings, GHG reduction, and other program goals by identifying research and development (R&D) initiatives for joining technologies in heating, ventilation, air-conditioning, and refrigeration (HVAC&R) systems. Improving joining technologies for HVAC&R equipment has the potential to increase lifetime equipment operating efficiency, decrease equipment and project cost, and most importantly reduce hydroflourocarbon (HFC) refrigerant leakage to support HFC phasedown and GHG reduction goals.

  9. Fungal colonization of air filters for use in heating, ventilating, and air conditioning (HVAC) systems.

    Science.gov (United States)

    Simmons, R B; Crow, S A

    1995-01-01

    New and used cellulosic air filters for HVAC systems including those treated with antimicrobials were suspended in vessels with a range of relative humidities (55-99%) and containing non-sterile potting soil which stimulates fungal growth. Most filters yielded fungi prior to suspension in the chambers but only two of 14 nontreated filters demonstrated fungal colonization following use in HVAC systems. Filters treated with antimicrobials, particularly a phosphated amine complex, demonstrated markedly less fungal colonization than nontreated filters. In comparison with nontreated cellulosic filters, fungal colonization of antimicrobial-treated cellulosic filters was selective and delayed.

  10. Simplified frequency-dependent formulae for series-impedance matrices of single-core HVAC cables

    DEFF Research Database (Denmark)

    Silva, Filipe Miguel Faria da

    2015-01-01

    The installation of HVAC underground cables became more common in recent years, a trend expected to continue in the future. Underground cables are more complex than overhead lines and the calculation of their resistance and reactance can be challenging and time consuming for frequencies that are ......The installation of HVAC underground cables became more common in recent years, a trend expected to continue in the future. Underground cables are more complex than overhead lines and the calculation of their resistance and reactance can be challenging and time consuming for frequencies...

  11. Power Flow Analysis of HVAC and HVDC Transmission Systems for Offshore WindParks

    DEFF Research Database (Denmark)

    da Silva, Filipe Miguel Faria; Castro, Rui

    2009-01-01

    As the onshore wind resource is running shorter, wind power promoters are paying attention to the offshore resources. As in most cases there is no load offshore, wind power must be transmitted to the main land. To do so, two options are available: HVAC and HVDC transmission systems. In this paper...... that HVAC solution is limited by the distance to shore and by the wind transmitted power. HVDC options do not show these limitations, but are more expensive and more delicate to deal with, because there is a lack of operational experience, so far....

  12. High accuracy acoustic relative humidity measurement in duct flow with air

    NARCIS (Netherlands)

    Schaik, van W.; Grooten, M.H.M.; Wernaart, T.; Geld, van der C.W.M.

    2010-01-01

    An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and

  13. Building America Best Practices Series Volume 14 - HVAC. A Guide for Contractors to Share with Homeowners

    Energy Technology Data Exchange (ETDEWEB)

    Baechler, Michael C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gilbride, Theresa L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hefty, Marye G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hand, James R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Love, Pat M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2011-08-01

    This guide, which is part of a series of Best Practices guides produced by DOE’s Building America program, describes ways homeowners can reduce their energy costs and improve the comfort, health, and safety of their homes by upgrading their heating, ventilation, and air conditioning (HVAC) equipment.

  14. Study on the Operating Strategy of HVAC Systems for Nuclear Decommissioning Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung-hwan; Han, Sung-heum; Lee, Jae-gon [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    According as Kori nuclear power plant unit 1 was determined to be defueled in 2017, various studies on nuclear plant decommissioning have been performed. In nuclear decommissioning plant, HVAC systems with large fan and electric coil have to be operated for long periods of time to support various types of work from defueled phase to final dismantling phase. So, in view of safety and utility costs, their overall operating strategy need to be established prior to defueled phase. This study presents HVAC system operating strategy at each decommissioning phase, that is, defueled plant operating phase, SSCs(systems, structures, components) decontamination and dismantling phases. In defueled plant operating phase, all fuel assemblies in reactor vessel are transferred to spent fuel pool(SFP) permanently. In defueled plant operation phase, reduction of the operating system trains is more practicable than the introduction of new HVAC components with reduced capacity. And, based on the result of the accident analyses for this phase, HVAC design bases such as MCR habitability requirement can be mitigated. According to these results, associated SSCs also can be downgraded. In similar approach, at each phase of plant decommissioning, proper inside design conditions and operating strategies should be re-established.

  15. Energy Performance and CO2 Emissions of HVAC Systems in Commercial Buildings

    Directory of Open Access Journals (Sweden)

    Rafat Al-Waked

    2017-10-01

    Full Text Available Energy performance of buildings has attracted much attention among building physicists and engineers worldwide. The effects of building heating; ventilation; and air conditioning (HVAC systems’ design upgrade on the building energy performance are the focus of the current study. The adopted HVAC system consisted of chilled ceiling and chilled beam systems served by a centrifugal water chiller. An energy simulation study was undertaken in accordance with the national Australian built environment rating system-rules for collecting and using data. A three-dimensional simulation study was carried out utilizing the virtual environment-integrated environmental solutions software. Results from the current study have shown the importance of utilizing energy-efficient HVAC systems and HVAC strategies for achieving a high building energy star rating. Recommended strategies in order to achieve the nominated star rating; as predicted by the simulation analysis; were presented. Moreover; the effects of solar radiation inside the building atrium were significant; which cannot be overcome by simply installing a low shading coefficient glazing type at the atrium skylight. In addition to providing chilled ceiling technology; a high efficiency chiller and low energy lighting; it is recommended that the building be well tuned during the commissioning period. The current approach could be extended to accommodate higher energy ratings of commercial buildings at different locations worldwide.

  16. Integrated Simulation for HVAC Performance Prediction: State-of-the-Art Illustration

    NARCIS (Netherlands)

    Hensen, J.L.M.; Clarke, J.A.

    2000-01-01

    This paper aims to outline the current state-of-the-art in integrated building simulation for performance prediction of heating, ventilating and air-conditioning (HVAC) systems. The ESP-r system is used as an example where integrated simulation is a core philosophy behind the development. The

  17. RELATIONSHIP BETWEEN HVAC SYSTEM OPERATION, AIR EXCHANGE RATE, AND INDOOR-OUTDOOR PARTICULATE MATTER RATIOS

    Science.gov (United States)

    Measurements of duty cycle , the fraction of time the heating and cooling (HVAC) system was operating, were made in each participant's home during the spring season of the RTP Particulate Matter Panel Study. A miniature temperature sensor/data logger combination placed on the ...

  18. Multi-objective optimization of HVAC system with an evolutionary computation algorithm

    International Nuclear Information System (INIS)

    Kusiak, Andrew; Tang, Fan; Xu, Guanglin

    2011-01-01

    A data-mining approach for the optimization of a HVAC (heating, ventilation, and air conditioning) system is presented. A predictive model of the HVAC system is derived by data-mining algorithms, using a dataset collected from an experiment conducted at a research facility. To minimize the energy while maintaining the corresponding IAQ (indoor air quality) within a user-defined range, a multi-objective optimization model is developed. The solutions of this model are set points of the control system derived with an evolutionary computation algorithm. The controllable input variables - supply air temperature and supply air duct static pressure set points - are generated to reduce the energy use. The results produced by the evolutionary computation algorithm show that the control strategy saves energy by optimizing operations of an HVAC system. -- Highlights: → A data-mining approach for the optimization of a heating, ventilation, and air conditioning (HVAC) system is presented. → The data used in the project has been collected from an experiment conducted at an energy research facility. → The approach presented in the paper leads to accomplishing significant energy savings without compromising the indoor air quality. → The energy savings are accomplished by computing set points for the supply air temperature and the supply air duct static pressure.

  19. Residential and Light Commercial HVAC. Teacher Edition and Student Edition. Second Edition.

    Science.gov (United States)

    Stephenson, David

    This package contains teacher and student editions of a residential and light commercial heating, ventilation, and air conditioning (HVAC) course of study. The teacher edition contains information on the following: using the publication; national competencies; competency profile; related academic and workplace skills list; tools, equipment, and…

  20. Evaluation of the ultimate pressure capacity of rectangular HVAC ducts for nuclear pwoer plants

    International Nuclear Information System (INIS)

    Wedellsborg, B.W.

    1984-01-01

    Typical Category I HVAC ducts in a nuclear plant must be designed for loads and load combinations including positive and negative pressure loads which are generated due to the normal operation and postulated accident conditions. These pressure loads most often govern the design of the HVAC ducts. Structural design criteria are presently based on the AISI Code which limits the duct panel width-to-thickness ratio to a maximum of 500 and the maximum height-to-thickness ratio to 200, unless it can be shown by structural tests that larger ratios can be used. Test Programs performed on rectangular HVAC ducts subjected to vacumm loads have substantiated the use of ducts having panel width to thickness ratios of up to 1600. The results of the test programs were subsequently incorporated into the design through a more rational analytical design method which was developed from and correlates well with the test results. The purpose of this paper is to present the analytical design method and its correlation with the test results. Simple formulae for the design of rectangular HVAC ducts are presented. Lower bound values of duct sheet, and stiffener ultimate loads are derived, and correlated with recent test results. Analytically predicted ultimate pressures are also compared with other available duct test data

  1. Assessment of microbiological indoor air quality in an Italian office building equipped with an HVAC system.

    Science.gov (United States)

    Bonetta, Sa; Bonetta, Si; Mosso, S; Sampò, S; Carraro, E

    2010-02-01

    The purpose of this study was to evaluate the level and composition of bacteria and fungi in the indoor air of an Italian office building equipped with a heating, ventilation and air conditioning (HVAC) system. Airborne bacteria and fungi were collected in three open-space offices during different seasons. The microbial levels in the outdoor air, supply air diffusers, fan coil air flow and air treatment unit humidification water tank were used to evaluate the influence of the HVAC system on indoor air quality (IAQ). A medium-low level of bacterial contamination (50-500 CFU/m(3)) was found in indoor air. Staphylococcus and Micrococcus were the most commonly found genera, probably due to human presence. A high fungal concentration was measured due to a flood that occurred during the winter. The indoor seasonal distribution of fungal genera was related to the fungal outdoor distribution. Significant seasonal and daily variation in airborne microorganisms was found, underlining a relationship with the frequency of HVAC system switching on/off. The results of this monitoring highlight the role of the HVAC system on IAQ and could be useful to better characterise bacterial and fungal population in the indoor air of office buildings.

  2. Energy efficient HVAC control in historical buildings : a case study for the Amsterdam Museum

    NARCIS (Netherlands)

    Kompatscher, K.; Seuren, S.; Kramer, R.P.; Van Schijndel, J.A.W.M.; Schellen, H.L.

    2017-01-01

    Museums are often located in historical buildings. To provide suitable housing in a historical building for a museum, these buildings are usually adapted to suit the need for object preservation through HVAC control. Maintaining a strict indoor climate and limiting short fluctuations in indoor

  3. Comparison of co-simulation approaches for building and HVAC/R system simulation

    NARCIS (Netherlands)

    Trcka, M.; Wetter, M.; Hensen, J.L.M.; Jiang, Yi

    2007-01-01

    Appraisal of modern performance-based energy codes, as well as heating, ventilation, airconditioning and refrigeration (HVAC/R) system design require use of an integrated building and system performance simulation program. However, the required scope of the modeling library of such integrated tools

  4. Thermal analysis of an HVAC system with TRV controlled hydronic radiator

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh; Stoustrup, Jakob; Rasmussen, Henrik

    2010-01-01

    A model for an HVAC system is derived in this paper. The HVAC system consists of a room and a hydronic radiator with temperature regulating valve (TRV) which has a step motor to adjust the valve opening. The heating system and the room are simulated as a unit entity for thermal analysis and contr......A model for an HVAC system is derived in this paper. The HVAC system consists of a room and a hydronic radiator with temperature regulating valve (TRV) which has a step motor to adjust the valve opening. The heating system and the room are simulated as a unit entity for thermal analysis...... and controller design. A discrete-element model with interconnected small scaled elements is proposed for the radiator. This models the radiator more precisely than that of a lumped model in terms of transfer delay and radiator gain. This precise modeling gives us an intuition into a regular unwanted phenomenon...... which occurs in low demand situations. When flow is very low in radiator and the supply water temperature and the pressure drop across the valve is constant, oscillation in room temperature occurs. One reason could be the large gain of radiator in low demand conditions compared to the high demand...

  5. Photodetector of ultraviolet radiation

    International Nuclear Information System (INIS)

    Dorogan, V.; Branzari, V.; Vieru, T.; Manole, M.; Canter, V.

    2000-01-01

    The invention relates to photodetectors on base of semiconductors of ultraviolet radiation and may be used in optoelectronic system for determining the intensity and the dose of ultraviolet radiation emitted by the Sun or other sources. Summary of the invention consists in the fact that in the photodetector of ultraviolet radiation the superficial potential barrier is divided into two identical elements, electrically isolated each of the other, one of them being covered with a layer of transparent material for visible and infrared radiation and absorption the ultra violet radiation. The technical result consists in mutual compensation of visible and infrared components of the radiation spectrum

  6. Warming impact on energy use of HVAC system in buildings of different thermal qualities and in different climates

    International Nuclear Information System (INIS)

    Kharseh, Mohamad; Altorkmany, Lobna; Al-Khawaj, Mohammed; Hassani, Ferri

    2014-01-01

    Highlights: • Improving TQBE reduces heating load, while it might increase cooling load. • Warming impact on energy use of HVAC varies from one climate to another. • Warming impact on energy use of HVAC depends on building’s thermal quality. • In mild climate, warming does not have a significant impact on energy use of HVAC. - Abstract: In order to combat climate change, energy use in the building must be further reduced. Heating ventilation and air conditioning (HVAC) systems in residential buildings account for considerable fraction of global energy consumption. The potential contribution the domestic sector can make in reducing energy consumption is recognized worldwide. The driving energy of HVACs depends on the thermal quality of the building envelope (TQBE) and outside temperature. Definitely, building regulations are changing with the time toward reduce the thermal loads of buildings. However, most of the existing residential buildings were built to lower TQBE. For instant, 72% of residential dwellings in the 15-EU were built before 1972. To investigate the impact of warming on driving energy of HVACs of a residential building a computer model was developed. Three climate categories/cities were considered, i.e. Stockholm (cold), Istanbul (mild), and Doha (hot). In each city, two buildings were modeled: one was assumed to be built according to the current local buildings regulations (standard TQBE), while the anther was built to lower TQBE. The simulations were run for present and future (in 2050) outdoor designing conditions. The calculations show that the impact of the warming on annual driving energy of HVACs (reduction or increase) depends very much on the climate category and on the TQBE. Based on the climate and TQBE, the change in annual HVACs energy varies from −7.4% (in cold climate) to 12.7% (in hot climate). In mild climate, it was shown that the warming does not have significant impact on annual HVACs energy. Improving the TQBE can

  7. A Study on the Determination of Power Supply Class for HVAC System in KJRR

    International Nuclear Information System (INIS)

    Kim, Hagtae; Kim, Minjin; Suh, Yong-Suk; Kim, Jun-Yeon; Chae, Hee-Taek

    2016-01-01

    The purpose of this paper is to propose an appropriate electrical class, power supply class, and operation logic for the major equipment of the HVAC system such as a Confinement Isolation Damper (CID), Fission Molybdenum Isolation Damper (FID), Air Handling Unit (AHU), Air Cleaning Unit (ACU), and Contaminated Air Purification System (CAPS) in light of their functional requirements and importance. The classification for the overall HVAC system of the KJRR is a safety class NNS, Non-Seismic category, quality class S, and electrical class Non-1E. Exceptionally, the CID and FID are safety class 3, seismic category I, and quality class Q. The electrical class for the major equipment of the HVAC system should be determined considering the operation concept during Loss of Normal Electric Power (LOEP) regardless of the safety class. In this paper, the electrical and power supply class is determined and the operation logic is proposed for the major equipment of the HVAC system for the KJRR such as the CID, FID, CAPS, ACU, and AHU. The electrical class Non-1E is determined to implement a fail closed for the enhancement of safety. The power supply class is based on the functional requirements of each equipment. The CID, FID, CAPS, and ACU are Class III, but the AHU is Class IV by reflecting the importance and electrical load. After the recovery of the power supply, there is a difference in the operation concept for the HVAC system between the reactor building and fission molybdenum production building depending on the operator's residence time. The CID and CAPS are operated manually through procedures for checking the accident status, and the FID and ACU are operated automatically without special procedures

  8. Performance evaluation of control room HVAC and air cleaning systems under accident conditions

    International Nuclear Information System (INIS)

    Almerico, F.; Machiels, A.J.; Ornberg, S.C.; Lahti, G.P.

    1985-01-01

    In light water reactors, control rooms and technical support centers must be designed to provide habitable environments in accordance with the requirements specified in General Design Criterion 19 of Appendix A, 10 CFR Part 50. Therefore, the effectiveness of HVAC and air cleaning system designs with respect to plant operator protection has to be evaluated by the system designer. Guidance for performing the analysis has been previously given in ANSI/ASME N509-1980 as well as in presentations at past Air Cleaning Conferences. The previous work is extended and the methodology used in a generic, interactive computer program that performs Main Control Room and Technical Support Center (TSC) habitability analyses for LWR nuclear power plants is presented. For given accident concentrations of radionuclides or hazardous gases in the outdoor air intakes and plant spaces surrounding the Main Control Room (or TSC), the program models the performance of the HVAC and air cleaning system designs, and determines control room (or TSC) contaminant concentrations and plant operator protection factors. Calculated or actual duct leakage, air cleaning efficiency, and airborne contamination are taken into account. Flexibility of the model allows for the representation of most control rooms (or TSC) and associated HVAC and air cleaning system conceptual designs that have been used by the US architect/engineers. The program replaced tedious calculations to determine the effects of HVAC ductwork and equipment leakage and permits (1) parametric analyses of various HVAC system design options early in the conceptual phase of a project, and (2) analysis of the effects of leakage test results on contaminant room concentrations, and therefore operator doses

  9. A Study on the Determination of Power Supply Class for HVAC System in KJRR

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hagtae; Kim, Minjin; Suh, Yong-Suk; Kim, Jun-Yeon; Chae, Hee-Taek [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The purpose of this paper is to propose an appropriate electrical class, power supply class, and operation logic for the major equipment of the HVAC system such as a Confinement Isolation Damper (CID), Fission Molybdenum Isolation Damper (FID), Air Handling Unit (AHU), Air Cleaning Unit (ACU), and Contaminated Air Purification System (CAPS) in light of their functional requirements and importance. The classification for the overall HVAC system of the KJRR is a safety class NNS, Non-Seismic category, quality class S, and electrical class Non-1E. Exceptionally, the CID and FID are safety class 3, seismic category I, and quality class Q. The electrical class for the major equipment of the HVAC system should be determined considering the operation concept during Loss of Normal Electric Power (LOEP) regardless of the safety class. In this paper, the electrical and power supply class is determined and the operation logic is proposed for the major equipment of the HVAC system for the KJRR such as the CID, FID, CAPS, ACU, and AHU. The electrical class Non-1E is determined to implement a fail closed for the enhancement of safety. The power supply class is based on the functional requirements of each equipment. The CID, FID, CAPS, and ACU are Class III, but the AHU is Class IV by reflecting the importance and electrical load. After the recovery of the power supply, there is a difference in the operation concept for the HVAC system between the reactor building and fission molybdenum production building depending on the operator's residence time. The CID and CAPS are operated manually through procedures for checking the accident status, and the FID and ACU are operated automatically without special procedures.

  10. HVAC-DYNAMICS - a tool for quality assurance in relation to delivery of air-conditioning systems. [Heating, ventilating and air conditioning]. HVAC-DYNAMICS - et redskap for kvalitetsikring av sluttleveransen i klima-anlegg

    Energy Technology Data Exchange (ETDEWEB)

    Novakovic, V [SINTEF Varmeteknikk, Seksjon VVS (NO)

    1990-07-01

    HVAC-DYNAMICS is a computerized tool for quality assurance of the functioning of an air-conditioning system at the time of delivery. The system's efficiency in the case of fluctuating and critical operation is evaluated. The HVAC-DYNAMICS gives an optimal choice for air-conditioning systems regarding indoor climate, efficiency demands and energy consumption. The program can also be use for calibration of regulators, fault-finding, and training purposes. (CLS).

  11. Draft PRN 2006-A: Use of Antimicrobial Pesticide Products in Heating, Ventilation, Air Conditioning and Refrigeration Systems (HVAC&R)

    Science.gov (United States)

    This draft notice provides guidance to registrants of EPA-registered antimicrobial products whose labels bear general directions related to hard, non-porous or porous surfaces, but which are not but which are not specifically registered for HVAC uses.

  12. Heating, Ventilation, Air Conditioning, and Refrigeration (HVAC/R), AFSC 3E1X1. OSSN 2368

    National Research Council Canada - National Science Library

    1999-01-01

    Survey Coverage: The Heating, Ventilation, Air Conditioning, and Refrigeration (HVAC/R) career ladder, AFSC 3E1X1, was surveyed to gather data needed to guide the development and evaluation of training...

  13. Wavelet based artificial neural network applied for energy efficiency enhancement of decoupled HVAC system

    International Nuclear Information System (INIS)

    Jahedi, G.; Ardehali, M.M.

    2012-01-01

    Highlights: ► In HVAC systems, temperature and relative humidity are coupled and dynamic mathematical models are non-linear. ► A wavelet-based ANN is used in series with an infinite impulse response filter for self tuning of PD controller. ► Energy consumption is evaluated for a decoupled bi-linear HVAC system with variable air volume and variable water flow. ► Substantial enhancement in energy efficiency is realized, when the gain coefficients of PD controllers are tuned adaptively. - Abstract: Control methodologies could lower energy demand and consumption of heating, ventilating and air conditioning (HVAC) systems and, simultaneously, achieve better comfort conditions. However, the application of classical controllers is unsatisfactory as HVAC systems are non-linear and the control variables such as temperature and relative humidity (RH) inside the thermal zone are coupled. The objective of this study is to develop and simulate a wavelet-based artificial neural network (WNN) for self tuning of a proportional-derivative (PD) controller for a decoupled bi-linear HVAC system with variable air volume and variable water flow responsible for controlling temperature and RH of a thermal zone, where thermal comfort and energy consumption of the system are evaluated. To achieve the objective, a WNN is used in series with an infinite impulse response (IIR) filter for faster and more accurate identification of system dynamics, as needed for on-line use and off-line batch mode training. The WNN-IIR algorithm is used for self-tuning of two PD controllers for temperature and RH. The simulation results show that the WNN-IIR controller performance is superior, as compared with classical PD controller. The enhancement in efficiency of the HVAC system is accomplished due to substantially lower consumption of energy during the transient operation, when the gain coefficients of PD controllers are tuned in an adaptive manner, as the steady state setpoints for temperature and

  14. Locating and Quantifying Broadband Fan Sources Using In-Duct Microphones

    Science.gov (United States)

    Dougherty, Robert P.; Walker, Bruce E.; Sutliff, Daniel L.

    2010-01-01

    In-duct beamforming techniques have been developed for locating broadband noise sources on a low-speed fan and quantifying the acoustic power in the inlet and aft fan ducts. The NASA Glenn Research Center's Advanced Noise Control Fan was used as a test bed. Several of the blades were modified to provide a broadband source to evaluate the efficacy of the in-duct beamforming technique. Phased arrays consisting of rings and line arrays of microphones were employed. For the imaging, the data were mathematically resampled in the frame of reference of the rotating fan. For both the imaging and power measurement steps, array steering vectors were computed using annular duct modal expansions, selected subsets of the cross spectral matrix elements were used, and the DAMAS and CLEAN-SC deconvolution algorithms were applied.

  15. Archtechtual Envilomental and Eequipment Laboratory Issues on HVAC System in a Commercial Kitchen(Educational Practice through Research)

    OpenAIRE

    吉野, 一; Hajime, Yoshino

    2017-01-01

    Generally, large amount of heat, oil fume including chemical substances and exhaust gases were generated during cooking in commercial kitchens. Therefore, it is important to keep highly safe and good hygienic condition by HVAC System. In this paper, health effect of oil fume and fire spread were surveyed based on investigation of previous studies. Lastly, current issues and future prospects of commercial kitchens HVAC system in Japan were described.

  16. State of the Art of HVAC Technology in Europe and America

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.; Kazanci, Ongun Berk

    2015-01-01

    of energy sources and energy generators are very much similar. This paper will present state-of the art-off energy efficient systems that will provide a good indoor environmental quality at a decreased energy use. Low Temperature Heating and High Temperature Cooling systems are an important requirement...... mechanisms and media to emit and remove heat or moisture from indoor spaces (e.g. hydronic radiant heating and cooling systems, fan-coil units, and active beams). The main differences between HVAC systems in Europe, North America and other parts of the world are often the indoor terminal units. Type...... for increasing the energy efficiency of HVAC (heating, ventilation and air-conditioning) systems and for increasing the amount of renewable energy used. Especially these types of systems are getting increasing attention in Europe and North-America. In the present study, operation characteristics, possibilities...

  17. Designing the controllability of a HVAC-plant by dynamic simulation

    Energy Technology Data Exchange (ETDEWEB)

    Novakovic, V; Grindal, A

    1994-05-01

    This paper was presented at CLIMA 2000 - The international conference on energy and environmental matters in built environment, London, 1.-3. November 1993. Nowadays, HVAC engineers can use dynamic simulation programs in their everyday work. Such tools provide the ability to analyze different system configurations and to check the obtained states even before the building and plant are constructed. To encourage its wider use, the authors present in this paper the experiences obtained with the simulation program HVAC-DYNAMICS. The program was used to simulate the retrofitting of a heat recovery wheel to a conventional ventilation plant with a hot water heating coil. The effects of different design parameters on the controllability of the plant were investigated. Interestingly, some commonly recommended ``clever`` configurations can lead to unexpected control scenarios. 4 refs., 3 figs., 2 tabs.

  18. Smart HVAC Control in IoT: Energy Consumption Minimization with User Comfort Constraints

    Directory of Open Access Journals (Sweden)

    Jordi Serra

    2014-01-01

    of heating, ventilation, and air conditioning (HVAC systems in smart grids with variable energy price. To that end, first, we propose an energy scheduling method that minimizes the energy consumption cost for a particular time interval, taking into account the energy price and a set of comfort constraints, that is, a range of temperatures according to user’s preferences for a given room. Then, we propose an energy scheduler where the user may select to relax the temperature constraints to save more energy. Moreover, thanks to the IoT paradigm, the user may interact remotely with the HVAC control system. In particular, the user may decide remotely the temperature of comfort, while the temperature and energy consumption information is sent through Internet and displayed at the end user’s device. The proposed algorithms have been implemented in a real testbed, highlighting the potential gains that can be achieved in terms of both energy and cost.

  19. Preventive maintenance basis: Volume 19 -- HVAC -- chillers and compressors. Final report

    International Nuclear Information System (INIS)

    Worledge, D.; Hinchcliffe, G.

    1997-12-01

    US nuclear power plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This document provides a program of preventive maintenance tasks suitable for application to HVAC -- Chillers and Compressors. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used in conjunction with material from other sources, to develop a complete PM program or to improve an existing program

  20. A Statistical Approach for Selecting Buildings for Experimental Measurement of HVAC Needs

    Directory of Open Access Journals (Sweden)

    Malinowski Paweł

    2017-03-01

    Full Text Available This article presents a statistical methodology for selecting representative buildings for experimentally evaluating the performance of HVAC systems, especially in terms of energy consumption. The proposed approach is based on the k-means method. The algorithm for this method is conceptually simple, allowing it to be easily implemented. The method can be applied to large quantities of data with unknown distributions. The method was tested using numerical experiments to determine the hourly, daily, and yearly heat values and the domestic hot water demands of residential buildings in Poland. Due to its simplicity, the proposed approach is very promising for use in engineering applications and is applicable to testing the performance of many HVAC systems.

  1. Efficient HVAC. New products; Climatización eficiente. Nuevos productos

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-07-01

    Jung is responding to the challenge of energy efficiency, ease of operation and economic profitability in all of its solutions for the tertiary sector, whether for newly constructed buildings or refurbishments, for full management of the electrical system or the partial control of lighting, HVAC, mood settings, access control, etc., for the bedrooms or specific areas of the building. In the specific case of hotels, Jung offers each a custom-made solution in line with its possibilities and objectives. (Author)

  2. System optimization for HVAC energy management using the robust evolutionary algorithm

    International Nuclear Information System (INIS)

    Fong, K.F.; Hanby, V.I.; Chow, T.T.

    2009-01-01

    For an installed centralized heating, ventilating and air conditioning (HVAC) system, appropriate energy management measures would achieve energy conservation targets through the optimal control and operation. The performance optimization of conventional HVAC systems may be handled by operation experience, but it may not cover different optimization scenarios and parameters in response to a variety of load and weather conditions. In this regard, it is common to apply the suitable simulation-optimization technique to model the system then determine the required operation parameters. The particular plant simulation models can be built up by either using the available simulation programs or a system of mathematical expressions. To handle the simulation models, iterations would be involved in the numerical solution methods. Since the gradient information is not easily available due to the complex nature of equations, the traditional gradient-based optimization methods are not applicable for this kind of system models. For the heuristic optimization methods, the continual search is commonly necessary, and the system function call is required for each search. The frequency of simulation function calls would then be a time-determining step, and an efficient optimization method is crucial, in order to find the solution through a number of function calls in a reasonable computational period. In this paper, the robust evolutionary algorithm (REA) is presented to tackle this nature of the HVAC simulation models. REA is based on one of the paradigms of evolutionary algorithm, evolution strategy, which is a stochastic population-based searching technique emphasized on mutation. The REA, which incorporates the Cauchy deterministic mutation, tournament selection and arithmetic recombination, would provide a synergetic effect for optimal search. The REA is effective to cope with the complex simulation models, as well as those represented by explicit mathematical expressions of

  3. Portable refrigerant charge meter and method for determining the actual refrigerant charge in HVAC systems

    Science.gov (United States)

    Gao, Zhiming; Abdelaziz, Omar; LaClair, Tim L.

    2017-08-08

    A refrigerant charge meter and a method for determining the actual refrigerant charge in HVAC systems are described. The meter includes means for determining an optimum refrigerant charge from system subcooling and system component parameters. The meter also includes means for determining the ratio of the actual refrigerant charge to the optimum refrigerant charge. Finally, the meter includes means for determining the actual refrigerant charge from the optimum refrigerant charge and the ratio of the actual refrigerant charge to the optimum refrigerant charge.

  4. Comparative guide to emerging diagnostic tools for large commercial HVAC systems

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, Hannah; Piette, Mary Ann

    2001-05-01

    This guide compares emerging diagnostic software tools that aid detection and diagnosis of operational problems for large HVAC systems. We have evaluated six tools for use with energy management control system (EMCS) or other monitoring data. The diagnostic tools summarize relevant performance metrics, display plots for manual analysis, and perform automated diagnostic procedures. Our comparative analysis presents nine summary tables with supporting explanatory text and includes sample diagnostic screens for each tool.

  5. Comparative guide to emerging diagnostic tools for large commercial HVAC systems; TOPICAL

    International Nuclear Information System (INIS)

    Friedman, Hannah; Piette, Mary Ann

    2001-01-01

    This guide compares emerging diagnostic software tools that aid detection and diagnosis of operational problems for large HVAC systems. We have evaluated six tools for use with energy management control system (EMCS) or other monitoring data. The diagnostic tools summarize relevant performance metrics, display plots for manual analysis, and perform automated diagnostic procedures. Our comparative analysis presents nine summary tables with supporting explanatory text and includes sample diagnostic screens for each tool

  6. Potential of HVAC and solar technologies for hospital retrofit to reduce heating energy consumption

    Science.gov (United States)

    Pop, Octavian G.; Abrudan, Ancuta C.; Adace, Dan S.; Pocola, Adrian G.; Balan, Mugur C.

    2018-02-01

    The study presents a combination of several energy efficient technologies together with their potential to reduce the energy consumption and to increase the comfort through the retrofit of a hospital building. The existing situation is characterized by an old and inefficient heating system, by the complete missing of any ventilation and by no cooling. The retrofit proposal includes thermal insulation and a distributed HVAC system consisting of several units that includes air to air heat exchangers and air to air heat pumps. A condensing boiler was also considered for heating. A solar thermal system for preparing domestic hot water and a solar photovoltaic system to assist the HVAC units are also proposed. Heat transfer principles are used for modelling the thermal response of the building to the environmental parameters and thermodynamic principles are used for modelling the behaviour of HVAC, solar thermal system and photovoltaic system. All the components of the heating loads were determined for one year period. The study reveals the capacity of the proposed systems to provide ventilation and thermal comfort with a global reduction of energy consumption of 71.6 %.

  7. Analysis on energy saving potential of integrated supermarket HVAC and refrigeration systems using multiple subcoolers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liang [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); China R and D Center, Carrier Corporation, No. 3239 Shen Jiang Road, Shanghai 201206 (China); Zhang, Chun-Lu [China R and D Center, Carrier Corporation, No. 3239 Shen Jiang Road, Shanghai 201206 (China)

    2010-02-15

    The paper presents a model-based analysis on the energy saving potential of supermarket HVAC (heating, ventilating, and air-conditioning) and refrigeration systems using multiple subcoolers among the high-temperature HVAC system, the medium-temperature refrigeration system, and the low-temperature refrigeration system. The principle of energy reduction is to have the higher COP (coefficient of performance) system generate more cooling capacity to increase the cooling capacity or reduce the power consumption of the lower COP system. The subcooler could be placed between the medium-temperature and low-temperature systems, between the high-temperature and medium-temperature systems, and between the high-temperature and low-temperature systems. All integration scenarios of adding one, two and three subcoolers have been investigated. The energy saving potential varies with the load ratio between high-, medium- and low-temperature systems, COP of three systems, and the ''on-off'' duty time of HVAC system. The optimal sequence of adding subcoolers is also proposed. (author)

  8. Evaluation of sampling methods for Bacillus spore-contaminated HVAC filters.

    Science.gov (United States)

    Calfee, M Worth; Rose, Laura J; Tufts, Jenia; Morse, Stephen; Clayton, Matt; Touati, Abderrahmane; Griffin-Gatchalian, Nicole; Slone, Christina; McSweeney, Neal

    2014-01-01

    The objective of this study was to compare an extraction-based sampling method to two vacuum-based sampling methods (vacuum sock and 37mm cassette filter) with regards to their ability to recover Bacillus atrophaeus spores (surrogate for Bacillus anthracis) from pleated heating, ventilation, and air conditioning (HVAC) filters that are typically found in commercial and residential buildings. Electrostatic and mechanical HVAC filters were tested, both without and after loading with dust to 50% of their total holding capacity. The results were analyzed by one-way ANOVA across material types, presence or absence of dust, and sampling device. The extraction method gave higher relative recoveries than the two vacuum methods evaluated (p≤0.001). On average, recoveries obtained by the vacuum methods were about 30% of those achieved by the extraction method. Relative recoveries between the two vacuum methods were not significantly different (p>0.05). Although extraction methods yielded higher recoveries than vacuum methods, either HVAC filter sampling approach may provide a rapid and inexpensive mechanism for understanding the extent of contamination following a wide-area biological release incident. Published by Elsevier B.V.

  9. Determining Off-Cycle Fuel Economy Benefits of 2-Layer HVAC Technology

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Eric W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Moniot, Matthew [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jehlik, Forrest [Argonne National Laboratory; Chevers, Netsanet [Toyota Motor North America R& D; Hirabayshi, Hidekazu [Toyota Motor North America R& D; Song, Yuanpei [DENSO International America Inc.

    2018-04-03

    This work presents a methodology to determine the off-cycle fuel economy benefit of a 2-Layer HVAC system which reduces ventilation and heat rejection losses of the heater core versus a vehicle using a standard system. Experimental dynamometer tests using EPA drive cycles over a broad range of ambient temperatures were conducted on a highly instrumented 2016 Lexus RX350 (3.5L, 8 speed automatic). These tests were conducted to measure differences in engine efficiency caused by changes in engine warmup due to the 2-Layer HVAC technology in use versus the technology being disabled (disabled equals fresh air-considered as the standard technology baseline). These experimental datasets were used to develop simplified response surface and lumped capacitance vehicle thermal models predictive of vehicle efficiency as a function of thermal state. These vehicle models were integrated into a database of measured on road testing and coupled with U.S. typical meteorological data to simulate vehicle efficiency across seasonal thermal and operational conditions for hundreds of thousands of drive cycles. Fuel economy benefits utilizing the 2-Layer HVAC technology are presented in addition to goodness of fit statistics of the modeling approach relative to the experimental test data.

  10. Chapter 19: HVAC Controls (DDC/EMS/BAS) Evaluation Protocol. The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

    Energy Technology Data Exchange (ETDEWEB)

    Kurnik, Charles W. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Romberger, Jeff [SBW Consulting, Inc., Bellevue, WA (United States)

    2017-10-09

    The HVAC Controls Evaluation Protocol is designed to address evaluation issues for direct digital controls/energy management systems/building automation systems (DDC/EMS/BAS) that are installed to control heating, ventilation, and air-conditioning (HVAC) equipment in commercial and institutional buildings. (This chapter refers to the DDC/EMS/BAS measure as HVAC controls.) This protocol may also be applicable to industrial facilities such as clean rooms and labs, which have either significant HVAC equipment or spaces requiring special environmental conditions.

  11. Ultraviolet radiation and immunosuppression.

    LENUS (Irish Health Repository)

    Murphy, G M

    2009-11-01

    Ultraviolet (UV) radiation is a complete carcinogen. The effects of UV radiation are mediated via direct damage to cellular DNA in the skin and suppression of image surveillance mechanisms. In the context of organ transplantation, addiction of drugs which suppress the immune system add greatly to the carcinogenicity of UV radiation. This review considers the mechanisms of such effects.

  12. Stellar extreme ultraviolet astronomy

    International Nuclear Information System (INIS)

    Cash, W.C. Jr.

    1978-01-01

    The design, calibration, and launch of a rocket-borne imaging telescope for extreme ultraviolet astronomy are described. The telescope, which employed diamond-turned grazing incidence optics and a ranicon detector, was launched November 19, 1976, from the White Sands Missile Range. The telescope performed well and returned data on several potential stellar sources of extreme ultraviolet radiation. Upper limits ten to twenty times more sensitive than previously available were obtained for the extreme ultraviolet flux from the white dwarf Sirius B. These limits fall a factor of seven below the flux predicted for the star and demonstrate that the temperature of Sirius B is not 32,000 K as previously measured, but is below 30,000 K. The new upper limits also rule out the photosphere of the white dwarf as the source of the recently reported soft x-rays from Sirius. Two other white dwarf stars, Feige 24 and G191-B2B, were observed. Upper limits on the flux at 300 A were interpreted as lower limits on the interstellar hydrogen column densities to these stars. The lower limits indicate interstellar hydrogen densitites of greater than .02 cm -3 . Four nearby stars (Sirius, Procyon, Capella, and Mirzam) were observed in a search for intense low temperature coronae or extended chromospheres. No extreme ultraviolet radiation from these stars was detected, and upper limits to their coronal emisson measures are derived

  13. Ultraviolet fire detector

    Science.gov (United States)

    Turnage, J. E.; Linford, R. M. F.; Cornish, S. D.

    1976-01-01

    System is capable of detecting ultraviolet light emitted by match size flame at distance of 10 ft. System is not affected by high energy or particulate radiation and is therefore particularly suited for applications around nuclear plants and X-ray equipment.

  14. Psoriasis and ultraviolet radiation

    International Nuclear Information System (INIS)

    Farber, E.M.; Nall, L.

    1993-01-01

    Prevention and detection screening programs as a public health service in curtailing the ever-increasing incidence of all forms of skin cancer are reviewed. The effect of solar and artificial ultraviolet radiation on the general population and persons with psoriasis is examined. 54 refs

  15. Numerical investigation of fully-developed magneto-hydro-dynamic flows in ducts

    International Nuclear Information System (INIS)

    Dajeh, D. A.

    1996-01-01

    In this paper a numerical study is presented for fuly developed magnetic-hydrodynamic flows in ducts under a uniform transverse implied magnetic field. Afinite different scheme comprising of modified ADI 'Alternating Direction Implicit' method and a SOUR 'Sucessive-Over and under relaxation' method are used to solve the set of governing equations. Computations are carried out for a different shape of ducts over a wide range of Hartman number, up to five thousands, which is an important parameter in the nuclear fusion reactor design. (author).16 refs., 7 figs., 3 tabs

  16. 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.

  17. Design and Implementation of Energy Efficiency in HVAC Systems Based on Robust PID Control for Industrial Applications

    Directory of Open Access Journals (Sweden)

    Muharrem Imal

    2015-01-01

    Full Text Available Energy efficiency in heating, ventilating, and air-conditioning (HVAC systems is a primary concern in process projects, since the energy consumption has the highest percentage in HVAC for all processes. Without sacrifice of thermal comfort, to reset the suitable operating parameters, such as the humidity and air temperature, would have energy saving with immediate effect. In this paper, the simulation-optimization approach described the effective energy efficiency for HVAC systems which are used in industrial process. Due to the complex relationship of the HVAC system parameters, it is necessary to suggest optimum settings for different operations in response to the dynamic cooling loads and changing weather conditions during a year. Proportional-integral-derivative (PID programming was developed which can effectively handle the discrete, nonlinear and highly constrained optimization problems. Energy efficiency process has been made by controlling of alternative current (AC drivers for ventilation and exhaust fans, according to supplied air flow capacity and differential air pressure between supplied and exhaust air. Supervisory controller software was developed by using programmable controllers and human machine interface (HMI units. The new designed HVAC control system would have a saving potential of about 40% as compared to the existing operational settings, without any extra cost.

  18. Commissioning of building HVAC systems for improvement of energy performance; Commissioning of building HVAC systems for improvement of energy performance. Teilnahme IEA-ECBCS Annex 40 (Betreiberkompetenz)

    Energy Technology Data Exchange (ETDEWEB)

    Chuard, J.-M.

    2005-06-15

    This paper takes a look at the tasks performed in Task 40 of the 'Energy Conservation in Buildings and Community Systems ECBCS' programme of the International Energy Agency IEA that is taking a look at the commissioning of building HVAC systems with the aim of improving the energy performance of such systems. Emphasis is put on the Swiss contribution to the task. This well-illustrated paper presents information on the structure of the task, time-lines and a diagram for its implementation structures. Also, the countries participating in Task 40 and their representatives are listed, and various work already published by the annex is noted. The paper places a focus on operator competence and lists points to be taken into account when carrying out work on optimising energy consumption. The various processes involved are noted and discussed. Management guidelines are presented and economical and market aspects are discussed. Finally, projects that will continue the work are noted.

  19. Commissioning of building HVAC systems for improvement of energy performance; Commissioning of building HVAC systems for improvement of energy performance. Teilnahme IEA-ECBCS Annex 40 (Betreiberkompetenz)

    Energy Technology Data Exchange (ETDEWEB)

    Chuard, J -M

    2005-06-15

    This paper takes a look at the tasks performed in Task 40 of the 'Energy Conservation in Buildings and Community Systems ECBCS' programme of the International Energy Agency IEA that is taking a look at the commissioning of building HVAC systems with the aim of improving the energy performance of such systems. Emphasis is put on the Swiss contribution to the task. This well-illustrated paper presents information on the structure of the task, time-lines and a diagram for its implementation structures. Also, the countries participating in Task 40 and their representatives are listed, and various work already published by the annex is noted. The paper places a focus on operator competence and lists points to be taken into account when carrying out work on optimising energy consumption. The various processes involved are noted and discussed. Management guidelines are presented and economical and market aspects are discussed. Finally, projects that will continue the work are noted.

  20. Whole house particle removal and clean air delivery rates for in-duct and portable ventilation systems.

    Science.gov (United States)

    Macintosh, David L; Myatt, Theodore A; Ludwig, Jerry F; Baker, Brian J; Suh, Helen H; Spengler, John D

    2008-11-01

    A novel method for determining whole house particle removal and clean air delivery rates attributable to central and portable ventilation/air cleaning systems is described. The method is used to characterize total and air-cleaner-specific particle removal rates during operation of four in-duct air cleaners and two portable air-cleaning devices in a fully instrumented test home. Operation of in-duct and portable air cleaners typically increased particle removal rates over the baseline rates determined in the absence of operating a central fan or an indoor air cleaner. Removal rates of 0.3- to 0.5-microm particles ranged from 1.5 hr(-1) during operation of an in-duct, 5-in. pleated media filter to 7.2 hr(-1) for an in-duct electrostatic air cleaner in comparison to a baseline rate of 0 hr(-1) when the air handler was operating without a filter. Removal rates for total particulate matter less than 2.5 microm in aerodynamic diameter (PM2.5) mass concentrations were 0.5 hr(-1) under baseline conditions, 0.5 hr(-1) during operation of three portable ionic air cleaners, 1 hr(-1) for an in-duct 1-in. media filter, 2.4 hr(-1) for a single high-efficiency particle arrestance (HEPA) portable air cleaner, 4.6 hr(-1) for an in-duct 5-in. media filter, 4.7 hr(-1) during operation of five portable HEPA filters, 6.1 hr(-1) for a conventional in-duct electronic air cleaner, and 7.5 hr(-1) for a high efficiency in-duct electrostatic air cleaner. Corresponding whole house clean air delivery rates for PM2.5 attributable to the air cleaner independent of losses within the central ventilation system ranged from 2 m3/min for the conventional media filter to 32 m3/min for the high efficiency in-duct electrostatic device. Except for the portable ionic air cleaner, the devices considered here increased particle removal indoors over baseline deposition rates.

  1. Using variable speed drives technology to reap rewards of efficient HVAC design

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    Electric motors are continuously running at full speed with vanes and throttles used to modulate the output, in most HVAC applications. This results in an excessive wastage of electrical energy, and the solution is the variable speed drive, which can save vast amounts of energy in fans, pumps and compressors across the HVAC system. Users of traditional control methods will not benefit from the energy savings that are possible through variable speed drives because the motor speed remains the same, with the result that some, and in some cases most, of the energy drawn will be wasted. Variable speed drives are more efficient because they control output by regulating the motor speed, rather than run the motor at full speed and use restrictions to reduce the flow. Recently, small so-called micro-drives have been launched, cutting the cost for most variable speed operation. Variable speed motors can also introduce new features to the HVAC system. An example of how drives can save money and improve the indoor climate is cited for Heathrow airport. There, the gateroom was earlier controlled by modulating valves in both heater and cooler coils, with two fans that operated continuously at rated speed. This system was very inefficient because the occupancy of the gateroom varied between zero and maximum several times daily. A new system was installed using two AC drives, in which one drive controls the supply air fan and the other the return air fan. The energy savings amounted to 89% during two tests and 77% in a third. A pump installation in the district heating system of Strasbourg, Germany, showed the savings that are possible in pump applications

  2. Energy consumption reduction in existing HVAC-R systems via a power law controlling kit

    International Nuclear Information System (INIS)

    Pinnola, C.F.; Vargas, J.V.C.; Buiar, C.L.; Ordonez, J.C.

    2015-01-01

    This paper presents an alternative solution for reducing energy consumption in heating, ventilation, air conditioning and refrigeration (HVAC-R) systems. For that, an existing typical commercial refrigeration system was equipped with a novel control system based on a power law, using a frequency inverter and a programmable logic controller (PLC). Hence, it was possible to compare the operation and energy consumption of the system with the power law control and with the on-off system, quantifying the obtained gains. The experimental unit consisted of a cooling chamber, an enclosing chamber (antechamber), and a vapor compression refrigeration system, i.e., an example of a practical commercial cooling system. A set of graphs shows the experimental measurements performed with the two systems. In this way, the measured temperatures in some selected points of the two systems, as well as the consumption in kWh for a period of 6 h and 10 min were compared in the tests. The main conclusions of this work are: i) The system operating with the power law control with respect to the conventional on-off control, showed energy consumption savings of up to 31% in a test period of 6 h and 10 min, and ii) The system compressor cycling frequency in the system operating with the power law control is smaller than with the traditional on-off system. Therefore, the study shows that the developed power law control kit has potential to be installed in any existing system with immediate significant energy savings with no need for HVAC-R hardware changes. - Highlights: • An energy consumption reduction strategy for HVAC-R systems is presented. • Power law and on-off control actions are experimentally compared. • Energy savings of 31% were obtained with power law control. • Compressor cycling frequency is smaller with power law control. • Power law control kit has potential to be installed in any existing system

  3. Airflow Measurement of the Car HVAC Unit Using Hot-wire Anemometry

    Directory of Open Access Journals (Sweden)

    Fojtlín Miloš

    2016-01-01

    Full Text Available Thermal environment in a vehicular cabin significantly influence drivers’ fatigue and passengers’ thermal comfort. This environment is traditionally managed by HVAC cabin system that distributes air and modifies its properties. In order to simulate cabin thermal behaviour, amount of the air led through car vents must be determined. The aim of this study was to develop methodology to measure airflow from the vents, and consequently calculate corresponding air distribution coefficients. Three climatic cases were selected to match European winter, summer, and spring / fall conditions. Experiments were conducted on a test vehicle in a climatic chamber. The car HVAC system was set to automatic control mode, and the measurements were executed after the system stabilisation—each case was independently measured three times. To be able to evaluate precision of the method, the airflow was determined at the system inlet (HVAC suction and outlet (each vent, and the total airflow values were compared. The airflow was calculated by determining a mean value of the air velocity multiplied by an area of inlet / outlet cross-section. Hot-wire anemometry was involved to measure the air velocity. Regarding the summer case, total airflow entering the cabin was around 57 l s-1 with 60 % of the air entering the cabin through dashboard vents; no air was supplied to the feet compartment. The remaining cases had the same total airflow of around 42 l s-1, and the air distribution was focused mainly on feet and windows. The inlet and outlet airflow values show a good match with a maximum mass differential of 8.3 %.

  4. Ventilation, temperature, and HVAC characteristics in small and medium commercial buildings in California.

    Science.gov (United States)

    Bennett, D H; Fisk, W; Apte, M G; Wu, X; Trout, A; Faulkner, D; Sullivan, D

    2012-08-01

    This field study of 37 small and medium commercial buildings throughout California obtained information on ventilation rate, temperature, and heating, ventilating, and air-conditioning (HVAC) system characteristics. The study included seven retail establishments; five restaurants; eight offices; two each of gas stations, hair salons, healthcare facilities, grocery stores, dental offices, and fitness centers; and five other buildings. Fourteen (38%) of the buildings either could not or did not provide outdoor air through the HVAC system. The air exchange rate averaged 1.6 (s.d. = 1.7) exchanges per hour and was similar between buildings with and without outdoor air supplied through the HVAC system, indicating that some buildings have significant leakage or ventilation through open windows and doors. Not all buildings had sufficient air exchange to meet ASHRAE 62.1 Standards, including buildings used for fitness centers, hair salons, offices, and retail establishments. The majority of the time, buildings were within the ASHRAE temperature comfort range. Offices were frequently overcooled in the summer. All of the buildings had filters, but over half the buildings had a filter with a minimum efficiency reporting value rating of 4 or lower, which are not very effective for removing fine particles. Most U.S. commercial buildings (96%) are small- to medium-sized, using nearly 18% of the country's energy, and sheltering a large population daily. Little is known about the ventilation systems in these buildings. This study found a wide variety of ventilation conditions, with many buildings failing to meet relevant ventilation standards. Regulators may want to consider implementing more complete building inspections at commissioning and point of sale. © 2012 John Wiley & Sons A/S.

  5. Effectiveness of HVAC duct cleaning procedures in improving indoor air quality.

    Science.gov (United States)

    Ahmad, I; Tansel, B; Mitrani, J D

    2001-12-01

    Indoor air quality has become one of the most serious environmental concerns as an average person spends about 22 hr indoors on a daily basis. The study reported in this article, was conducted to determine the effectiveness of three commercial HVAC (Heating Ventilation Air Conditioning) duct cleaning processes in reducing the level of airborne particulate matter and viable bioaerosols. The three HVAC sanitation processes were: (1) Contact method (use of conventional vacuum cleaning of interior duct surfaces); (2) Air sweep method (use of compressed air to dislodging dirt and debris); (3) Rotary brush method (insertion of a rotary brush into the ductwork to agitate and dislodge the debris). Effectiveness of these sanitation processes was evaluated in terms of airborne particulate and viable bioaerosol concentrations in residential homes. Eight identical homes were selected in the same neighborhood. Two homes were cleaned using each procedure and two were used as controls. It was found that both particle count readings and bioaerosol concentrations were higher when cleaning was being performed than before or after cleaning, which suggests that dirt, debris and other pollutants may become airborne as a result of disturbances caused by the cleaning processes. Particle count readings at 0.3 micron size were found to have increased due to cigarette smoking. Particle counts at 1.0 micron size were reduced due to HVAC duct cleaning. Post-level bioaerosol concentrations, taken two days after cleaning, were found to be lower than the pre-level concentrations suggesting that the cleaning procedures were effective to some extent. Homes cleaned with the Air Sweep procedure showed the highest degree of reduction in bioaerosol concentration among the three procedures investigated.

  6. Predicting the Room Air Temperature of the Containment Spray Pump Room for the Loss of HVAC Accidents

    International Nuclear Information System (INIS)

    Yoon, Churl; Park, Jin Hee; Lim, Ho Gon; Han, Sang Hoon

    2007-01-01

    In PSA Models, the HVAC system is essential for the various vital mitigation safety systems operating during a mission time. So far, the unavailability of the safety system when the HVAC system is unavailable, has been applied conservatively or optimistically based on operating experience and expert judgment, so the total core damage frequency could be unrealistic. In this paper, we performed a heat up calculation for the Containment Spray Pump Room at Kori 3 and 4 Units using a CFD code to estimate the operability of the CS pump and its support systems in the pump room under the situation of a loss of the HVAC. The result of this calculation could be applied the PSA Model for Risk Informed Regulation for Kori Units 3 and 4

  7. Non-linear HVAC computations using least square support vector machines

    International Nuclear Information System (INIS)

    Kumar, Mahendra; Kar, I.N.

    2009-01-01

    This paper aims to demonstrate application of least square support vector machines (LS-SVM) to model two complex heating, ventilating and air-conditioning (HVAC) relationships. The two applications considered are the estimation of the predicted mean vote (PMV) for thermal comfort and the generation of psychrometric chart. LS-SVM has the potential for quick, exact representations and also possesses a structure that facilitates hardware implementation. The results show very good agreement between function values computed from conventional model and LS-SVM model in real time. The robustness of LS-SVM models against input noises has also been analyzed.

  8. Control of space HVAC systems. Proceedings. Regelung von raumlufttechnischen Anlagen. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This GMA report presents automation concepts for the control of space HVAC systems using new support methods and means like computer technology and digital simulation methods while considering control problems associated with the application of such methods and means. Both technical and economic aspects are discussed. New findings also concern the structurization and design of control systems, modelling of component and system behaviour for scale-up and simulation of plants. Each of the 10 papers was abstracted for entry into the data base. (HW).

  9. A Comfort-Aware Energy Efficient HVAC System Based on the Subspace Identification Method

    Directory of Open Access Journals (Sweden)

    O. Tsakiridis

    2016-01-01

    Full Text Available A proactive heating method is presented aiming at reducing the energy consumption in a HVAC system while maintaining the thermal comfort of the occupants. The proposed technique fuses time predictions for the zones’ temperatures, based on a deterministic subspace identification method, and zones’ occupancy predictions, based on a mobility model, in a decision scheme that is capable of regulating the balance between the total energy consumed and the total discomfort cost. Simulation results for various occupation-mobility models demonstrate the efficiency of the proposed technique.

  10. Control of Variable-Speed Pressurization Fan for an Offshore HVAC System

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Pedersen, Simon; Løhndorf, Petar Durdevic

    2014-01-01

    all the way above the ambient pressure according to safety regulations. Meanwhile, the indoor air needs to be regularly changed in order to guarantee the indoor air quality. Both requirements could be possibly achieved by automatically manipulating either the throttle valve located at the terminal....... This paper proposes a set of control solutions to regulate the variablespeed pressurization fan system such that the energy efficiency of the considered HVAC system can be explicitly considered. A combined feed-forward with a PI-based feedback control solution, and a MPC solution are proposed based...

  11. DISAIN SISTEM KENDALI MESIN AIR LEAK TEST MENGGUNAKAN SISTEM KENDALI PLC OMRON CJ2M DI HVAC (HEATING, VENTILATING, AND AIR CONDITIONING LINE 6

    Directory of Open Access Journals (Sweden)

    Syahril Ardi

    2015-03-01

    Full Text Available Pada proses produksi pembuatan komponen HVAC (Heating, Ventilating, and Air Conditioning dari perusahaan manufaktur di Indonesia, memerlukan proses pengecekan kebocoran pada bagian HVAC. Proses pengecekan ini dilakukan untuk memastikan tidak ada komponen HVAC yang bocor sebelum dikirim ke pihak pelanggan. Penelitian ini dilakukan untuk membuat system dan alat air leak test. Mesin air leak test ini menggunakan prinsip kerja differential pressure air leak test, yaitu metode yang membandingkan antara tekanan udara yang diberikan ke produk dan master produk. Pada penelitian ini, kami membuat disain mesin air leak test menggunakan sistem kendali berupa air leak tester, PLC, dan HMI. Berdasarkan kondisi dengan kapasitas produksi yang meningkat karena bertambahnya permintaan dari customer, dapat ditanggulangi dengan adanya share loading produksi dari HVAC line 4 ke line baru, yaitu HVAC line 6. Hasil yang didapat dari pengujian deteksi kebocoran produk,didapat nilai parameter kebocoran produk sebesar 2.23 ml/min.

  12. Occupational applications of ultraviolet radiation

    International Nuclear Information System (INIS)

    Eriksen, P.

    1987-01-01

    A large population of workers are exposed to ultraviolet radiation in various occupational environments which often necessitates protection. Since ultraviolet radiation may create other environmental problems an occupational hazard- and protection evaluation can be complicated. Threshold Limit Values adopted by the American Conference of Governmental Industrial Hygienists (ACGIH) on ultraviolet radiation are used in most countries as guidelines for risk assessment and control measures. This review addresses the levels of ultraviolet radiation met in occupational environments, its measurement and evaluation, and discusses different protection methods. Ultraviolet lasers are beginning to find their way into industrial processes but are still limited in number and they will not be covered here. Emphasis is on broad band incoherent radiation in high risk environments such as welding, and on the evaluation of protective eyewear, see-through curtains and plastics. Other occupational risks associated with the emission of ultraviolet radiation are discussed

  13. Modernisation of space HVAC systems with high energy consumption; Sanierung von RLT-Anlagen mit hohen Energieverbraeuchen

    Energy Technology Data Exchange (ETDEWEB)

    Willan, U. [ROM (Rud. Otto Meyer) - Technik fuer Mensch und Umwelt, Hamburg (Germany). Zentralbereich Ingenieurtechnik

    1997-12-31

    For office buildings and similarly used buildings, concepts are developed for the modernization of space hvac systems. The state of work in the following sectors is discussed: optimum comparison processes for space HVAC systems, measurements to assess the performance of alternative dehumidification and cooling systems, heat-physiological space model. (MSK) [Deutsch] Fuer Buerobauten und Gebaeude aehnlicher Nutzung werden Sanierungskonzepte fuer RLT-Anlagen erarbeitet. Im Folgenden wird der Stand der Arbeiten in den Bereichen: optimale Vergleichsprozesse fuer RLT-Anlagen, messtechnische Beurteilung alternativer Entfeuchtungs- und Kuehlsysteme sowie ein waermetechnisches Raummodell erlaeutert.

  14. HVAC system operational strategies for reduced energy consumption in buildings with intermittent occupancy: The case of mosques

    International Nuclear Information System (INIS)

    Budaiwi, I.; Abdou, A.

    2013-01-01

    Highlights: • Proper operational zoning in the early design phase of mosques can lead to up to 30% reduction in the annual cooling energy. • Energy performance index of 71.0 kW h/m 2 yr for an insulated mosque can be realized with A/C proper intermitted operation. • 23% energy saving can be achieved when a properly oversized A/C is operated intermittently for 1 h during each prayer. • 13% reduction in cooling energy use can be achieved when A/C operation precedes worshippers’ occupancy in mosques. • Envelope insulation and A/C intermittent operation with proper operational zoning leads to more than 46% savings in energy. - Abstract: Mosques are places of worship for Muslims with unique functional requirements and operational characteristics. They are partially or fully occupied for about an hour for five intermittent periods during the day. In hot climates, maintaining indoor thermal comfort requires a considerable amount of energy that can be reduced by proper operational zoning and effective HVAC operation strategies. The objective of this paper is to investigate the impact of operational zoning and HVAC system intermittent operation strategies on the energy performance of mosques while thermal comfort is maintained. Energy simulation modeling is used for evaluating alternative zoning and HVAC operation strategies. Results indicate that up to 23% reduction in annual cooling energy is achieved by employing suitable HVAC operation strategy and system over-sizing, and 30% reduction is achieved by appropriate operational zoning. Comparing the cooling energy consumption of HVAC summer continuous operation of an un-insulated mosque with the consumption of the insulated mosque with properly oversized HVAC system operated for 1 h during each prayer, indicated that as much as 46% of cooling energy reduction can be achieved. Furthermore, utilizing proper operational zoning and HVAC operation strategies is expected to bring about an additional significant energy

  15. Transparent ultraviolet photovoltaic cells.

    Science.gov (United States)

    Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

    2016-02-15

    Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future.

  16. New-construction techniques and HVAC overpressurization for radon reduction in schools

    International Nuclear Information System (INIS)

    Saum, D.; Witter, K.A.; Craig, A.B.

    1988-01-01

    Construction of a school in Fairfax County, Virginia, is being carefully monitored since elevated indoor radon levels have been identified in many existing houses near the site. Soil gas radon concentrations measured prior to pouring of the slabs were also indicative of a potential radon problem should the soil gas enter the school; however, subslab radon measurements collected thus far are lower than anticipated. Radon-resistant features have been incorporated into construction of the school and include the placing of at least 100 mm of clean coarse aggregate under the slab and a plastic film barrier between the aggregate and the slab, the sealing of all expansion joints, the sealing or plugging of all utility penetrations where possible, and the painting of interior block walls. In addition, the school's heating, ventilating, and air-conditioning (HVAC) system has been designed to operate continuously in overpressurization to help reduce pressure-driven entry of radon-containing soil gas into the building. Following completion, indoor radon levels in the school will be monitored to determine the effectiveness of these radon-resistant new-construction techniques and HVAC overpressurization in limiting radon entry into the school

  17. Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes - Business Case Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Van D [ORNL

    2007-05-01

    The long range strategic goal of the Department of Energy's Building Technologies (DOE/BT) Program is to create, by 2020, technologies and design approaches that enable the construction of net-zero energy homes at low incremental cost (DOE/BT 2005). A net zero energy home (NZEH) is a residential building with greatly reduced needs for energy through efficiency gains, with the balance of energy needs supplied by renewable technologies. While initially focused on new construction, these technologies and design approaches are intended to have application to buildings constructed before 2020 as well resulting in substantial reduction in energy use for all building types and ages. DOE/BT's Emerging Technologies (ET) team is working to support this strategic goal by identifying and developing advanced heating, ventilating, air-conditioning, and water heating (HVAC/WH) technology options applicable to NZEHs. Although the energy efficiency of heating, ventilating, and air-conditioning (HVAC) equipment has increased substantially in recent years, new approaches are needed to continue this trend. Dramatic efficiency improvements are necessary to enable progress toward the NZEH goals, and will require a radical rethinking of opportunities to improve system performance. The large reductions in HVAC energy consumption necessary to support the NZEH goals require a systems-oriented analysis approach that characterizes each element of energy consumption, identifies alternatives, and determines the most cost-effective combination of options. In particular, HVAC equipment must be developed that addresses the range of special needs of NZEH applications in the areas of reduced HVAC and water heating energy use, humidity control, ventilation, uniform comfort, and ease of zoning. In FY05 ORNL conducted an initial Stage 1 (Applied Research) scoping assessment of HVAC/WH systems options for future NZEHs to help DOE/BT identify and prioritize alternative approaches for further

  18. Development and analysis of sustainable energy systems for building HVAC applications

    International Nuclear Information System (INIS)

    Khalid, F.; Dincer, I.; Rosen, M.A.

    2015-01-01

    The main HVAC applications considered in this paper are heating and cooling. Three newly developed systems for heating and cooling applications in buildings are proposed and assessed. Energy and exergy analyses are performed to assess the performance of heating, cooling and overall systems for each case, and the effects of various parameters on the energy and exergy efficiencies are examined. Also, the effect of changing the energy input for each system is also found in terms of overall efficiency. The overall system energy efficiency is found to be highest for the natural gas operated system with a vapour absorption chiller (system 1) at 27.5% and lowest for the photovoltaic (PV) and solar thermal operated system with vapour compression chiller (system 3) at 19.9%. The overall system exergy efficiency is found to be highest for the PV and solar thermal operated system with vapour compression chiller (system 3) at 3.9% and lowest for the PV and solar thermal operated system with heat pump (system 2) at 1.2%, respectively. - Highlights: • Three HVAC systems for buildings using renewable energy sources are proposed and assessed. • A performance improvement study is undertaken. • Parametric studies are carried out to determine the effects of various parameters on energy and exergy efficiencies

  19. D0 HVAC System Heat Pump Controller Programming, Networking, and Operating Information

    International Nuclear Information System (INIS)

    Anderson, B.

    1999-01-01

    The purpose of this engineering note is to provide the necessary information to setup, program, and network the Electronic Systems USA Heat Pump Controller with the LON network card and Intellution Fix32 to operate properly within the HVAC system at D-Zero. The heat pump controllers are used for local temperature control of the office environments on the fifth and six floors of D-Zero. Heat pump units 1-6 are located in the ceiling of the sixth floor. Heat pump units 7-12 are found in the fifth floor ceiling. Heat pump unit 13 is in the Southeast corner of the fifth floor. Prior to installation the heat pump controller must be properly prepared to operate correctly in the HVAC system. Each heat pump unit must contain firmware (software) version 1.31 to operate properly on the network. Controllers with version 1.30 will not be able to communicate over the LON network. The manufacturer can only update the firmware version. Before installation a series of heat pump setpoints must be manually set using the Intelligent Stat. Connect the Intelligent Stat via the serial cable or wired connection.

  20. Membrane heat exchanger in HVAC energy recovery systems, systems energy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nasif, M. [School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia); Opus International Consultants (New Zealand); AL-Waked, R. [Mechanical Engineering Department, Prince Mohammad Bin Fahd University (PMU), P.O. Box 1614, AlKhobar 31952 (Saudi Arabia); Morrison, G. [School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia); Behnia, M. [School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, NSW 2006 (Australia)

    2010-10-15

    The thermal performance of an enthalpy/membrane heat exchanger is experimentally investigated. The heat exchanger utilizes a 60gsm Kraft paper as the heat and moisture transfer surface for HVAC energy recovery. The heat exchanger sensible, latent and total effectiveness have been determined through temperature and moisture content measurements. The annual energy consumption of an air conditioner coupled with an enthalpy/membrane heat exchanger is also studied and compared with a conventional air conditioning cycle using in-house modified HPRate software. The heat exchanger effectiveness are used as thermal performance indicators and incorporated in the modified software. Energy analysis showed that an air conditioning system coupled with a membrane heat exchanger consumes less energy than a conventional air conditioning system in hot and humid climates where the latent load is high. It has been shown that in humid climate a saving of up to 8% in annual energy consumption can be achieved when membrane heat exchanger is used instead of a conventional HVAC system. (author)

  1. The necessity of HVAC system for the registered architectural cultural heritage building

    Science.gov (United States)

    Popovici, Cătălin George; Hudişteanu, Sebastian Valeriu; Cherecheş, Nelu-Cristian

    2018-02-01

    This study is intended to highlight the role of the ventilation and air conditioning system for a theatre. It was chosen as a case study the "Vasile Alecsandri" National Theatre of Jassy. The paper also sought to make a comparison in three distinct scenarios for HVAC Main Hall system - ventilation and air conditioning system of the Main Hall doesn't work; only the ventilation system of the Main Hall works and ventilation and air conditioning system of the Main Hall works. For analysing the comfort parameters, the ANSYS-Fluent software was used to build a 2D model of the building and simulation of HVAC system functionality during winter season, in all three scenarios. For the studied scenarios, the external conditions of Jassy and the indoor conditions of the theatre, when the entire spectacle hall is occupied were considered. The main aspects evaluated for each case were the air temperature, air velocity and relative humidity. The results are presented comparatively as plots and spectra of the interest parameters.

  2. Smart HVAC control in IoT: energy consumption minimization with user comfort constraints.

    Science.gov (United States)

    Serra, Jordi; Pubill, David; Antonopoulos, Angelos; Verikoukis, Christos

    2014-01-01

    Smart grid is one of the main applications of the Internet of Things (IoT) paradigm. Within this context, this paper addresses the efficient energy consumption management of heating, ventilation, and air conditioning (HVAC) systems in smart grids with variable energy price. To that end, first, we propose an energy scheduling method that minimizes the energy consumption cost for a particular time interval, taking into account the energy price and a set of comfort constraints, that is, a range of temperatures according to user's preferences for a given room. Then, we propose an energy scheduler where the user may select to relax the temperature constraints to save more energy. Moreover, thanks to the IoT paradigm, the user may interact remotely with the HVAC control system. In particular, the user may decide remotely the temperature of comfort, while the temperature and energy consumption information is sent through Internet and displayed at the end user's device. The proposed algorithms have been implemented in a real testbed, highlighting the potential gains that can be achieved in terms of both energy and cost.

  3. Preliminary CFD Analysis for HVAC System Design of a Containment Building

    Energy Technology Data Exchange (ETDEWEB)

    Son, Sung Man; Choi, Choengryul [ELSOLTEC, Yongin (Korea, Republic of); Choo, Jae Ho; Hong, Moonpyo; Kim, Hyungseok [KEPCO Engineering and Construction, Gimcheon (Korea, Republic of)

    2016-10-15

    HVAC (Heating, Ventilation, Air Conditioning) system has been mainly designed based on overall heat balance and averaging concepts, which is simple and useful for designing overall system. However, such a method has the disadvantage that cannot predict the local flow and temperature distributions in a containment building. In this study, a CFD (Computational Fluid Dynamics) preliminary analysis is carried out to obtain detailed flow and temperature distributions in a containment building and to ensure that such information can be obtained via CFD analysis. This approach can be useful for hydrogen analysis in an accident related to hydrogen released into a containment building. In this study, CFD preliminary analysis has been performed to obtain the detailed information of the reactor containment building by using the CFD analysis techniques and to ensure that such information can be obtained via CFD analysis. We confirmed that CFD analysis can offer enough detailed information about flow patterns and temperature field and that CFD technique is a useful tool for HVAC design of nuclear power plants.

  4. Preventive maintenance basis: Volume 21 -- HVAC, air handling equipment. Final report

    International Nuclear Information System (INIS)

    Worledge, D.; Hinchcliffe, G.

    1997-12-01

    US nuclear plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This report provides an overview of the PM Basis project and describes use of the PM Basis database. Volume 21 of the report provides a program of PM tasks suitable for application to HVAC-Air Handling Equipment. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs

  5. An innovative HVAC control system: Implementation and testing in a vehicular cabin.

    Science.gov (United States)

    Fojtlín, Miloš; Fišer, Jan; Pokorný, Jan; Povalač, Aleš; Urbanec, Tomáš; Jícha, Miroslav

    2017-12-01

    Personal vehicles undergo rapid development in every imaginable way. However, a concept of managing a cabin thermal environment remains unchanged for decades. The only major improvement has been an automatic HVAC controller with one user's input - temperature. In this case, the temperature is often deceiving because of thermally asymmetric and dynamic nature of the cabins. As a result, the effects of convection and radiation on passengers are not captured in detail what also reduces the potential to meet thermal comfort expectations. Advanced methodologies are available to assess the cabin environment in a fine resolution (e.g. ISO 14505:2006), but these are used mostly in laboratory conditions. The novel idea of this work is to integrate equivalent temperature sensors into a vehicular cabin in proximity of an occupant. Spatial distribution of the sensors is expected to provide detailed information about the local environment that can be used for personalised, comfort driven HVAC control. The focus of the work is to compare results given by the implemented system and a Newton type thermal manikin. Three different ambient settings were examined in a climate chamber. Finally, the results were compared and a good match of equivalent temperatures was found. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Performance Monitoring of Chilled-Water Distribution Systems Using HVAC-Cx.

    Science.gov (United States)

    Ferretti, Natascha Milesi; Galler, Michael A; Bushby, Steven T

    2017-01-01

    In this research we develop, test, and demonstrate the newest extension of the software HVAC-Cx (NIST and CSTB 2014), an automated commissioning tool for detecting common mechanical faults and control errors in chilled-water distribution systems (loops). The commissioning process can improve occupant comfort, ensure the persistence of correct system operation, and reduce energy consumption. Automated tools support the process by decreasing the time and the skill level required to carry out necessary quality assurance measures, and as a result they enable more thorough testing of building heating, ventilating, and air-conditioning (HVAC) systems. This paper describes the algorithm, developed by National Institute of Standards and Technology (NIST), to analyze chilled-water loops and presents the results of a passive monitoring investigation using field data obtained from BACnet ® (ASHRAE 2016) controllers and presents field validation of the findings. The tool was successful in detecting faults in system operation in its first field implementation supporting the investigation phase through performance monitoring. Its findings led to a full energy retrocommissioning of the field site.

  7. COMPREHENSIVE DIAGNOSTIC AND IMPROVEMENT TOOLS FOR HVAC-SYSTEM INSTALLATIONS IN LIGHT COMMERCIAL BUILDINGS

    Energy Technology Data Exchange (ETDEWEB)

    Abram Conant; Mark Modera; Joe Pira; John Proctor; Mike Gebbie

    2004-10-31

    Proctor Engineering Group, Ltd. (PEG) and Carrier-Aeroseal LLP performed an investigation of opportunities for improving air conditioning and heating system performance in existing light commercial buildings. Comprehensive diagnostic and improvement tools were created to address equipment performance parameters (including airflow, refrigerant charge, and economizer operation), duct-system performance (including duct leakage, zonal flows and thermal-energy delivery), and combustion appliance safety within these buildings. This investigation, sponsored by the National Energy Technology Laboratory, a division of the U.S. Department of Energy, involved collaboration between PEG and Aeroseal in order to refine three technologies previously developed for the residential market: (1) an aerosol-based duct sealing technology that allows the ducts to be sealed remotely (i.e., without removing the ceiling tiles), (2) a computer-driven diagnostic and improvement-tracking tool for residential duct installations, and (3) an integrated diagnosis verification and customer satisfaction system utilizing a combined computer/human expert system for HVAC performance. Prior to this work the aerosol-sealing technology was virtually untested in the light commercial sector--mostly because the savings potential and practicality of this or any other type of duct sealing had not been documented. Based upon the field experiences of PEG and Aeroseal, the overall product was tailored to suit the skill sets of typical HVAC-contractor personnel.

  8. Energy efficient model based algorithm for control of building HVAC systems.

    Science.gov (United States)

    Kirubakaran, V; Sahu, Chinmay; Radhakrishnan, T K; Sivakumaran, N

    2015-11-01

    Energy efficient designs are receiving increasing attention in various fields of engineering. Heating ventilation and air conditioning (HVAC) control system designs involve improved energy usage with an acceptable relaxation in thermal comfort. In this paper, real time data from a building HVAC system provided by BuildingLAB is considered. A resistor-capacitor (RC) framework for representing thermal dynamics of the building is estimated using particle swarm optimization (PSO) algorithm. With objective costs as thermal comfort (deviation of room temperature from required temperature) and energy measure (Ecm) explicit MPC design for this building model is executed based on its state space representation of the supply water temperature (input)/room temperature (output) dynamics. The controllers are subjected to servo tracking and external disturbance (ambient temperature) is provided from the real time data during closed loop control. The control strategies are ported on a PIC32mx series microcontroller platform. The building model is implemented in MATLAB and hardware in loop (HIL) testing of the strategies is executed over a USB port. Results indicate that compared to traditional proportional integral (PI) controllers, the explicit MPC's improve both energy efficiency and thermal comfort significantly. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Neuro-optimal operation of a variable air volume HVAC and R system

    International Nuclear Information System (INIS)

    Ning Min; Zaheeruddin, M.

    2010-01-01

    Low operational efficiency especially under partial load conditions and poor control are some reasons for high energy consumption of heating, ventilation, air conditioning and refrigeration (HVAC and R) systems. To improve energy efficiency, HVAC and R systems should be efficiently operated to maintain a desired indoor environment under dynamic ambient and indoor conditions. This study proposes a neural network based optimal supervisory operation strategy to find the optimal set points for chilled water supply temperature, discharge air temperature and VAV system fan static pressure such that the indoor environment is maintained with the least chiller and fan energy consumption. To achieve this objective, a dynamic system model is developed first to simulate the system behavior under different control schemes and operating conditions. A multi-layer feed forward neural network is constructed and trained in unsupervised mode to minimize the cost function which is comprised of overall energy cost and penalty cost when one or more constraints are violated. After training, the network is implemented as a supervisory controller to compute the optimal settings for the system. Simulation results show that compared to the conventional night reset operation scheme, the optimal operation scheme saves around 10% energy under full load condition and 19% energy under partial load conditions.

  10. High Accuracy Acoustic Relative Humidity Measurement inDuct Flow with Air

    Directory of Open Access Journals (Sweden)

    Cees van der Geld

    2010-08-01

    Full Text Available An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0–12 m/s with an error of ±0.13 m/s, temperature 0–100 °C with an error of ±0.07 °C and relative humidity 0–100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

  11. High accuracy acoustic relative humidity measurement in duct flow with air.

    Science.gov (United States)

    van Schaik, Wilhelm; Grooten, Mart; Wernaart, Twan; van der Geld, Cees

    2010-01-01

    An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0-12 m/s with an error of ± 0.13 m/s, temperature 0-100 °C with an error of ± 0.07 °C and relative humidity 0-100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

  12. A novel optimization algorithm based on epsilon constraint-RBF neural network for tuning PID controller in decoupled HVAC system

    International Nuclear Information System (INIS)

    Attaran, Seyed Mohammad; Yusof, Rubiyah; Selamat, Hazlina

    2016-01-01

    Highlights: • Decoupling of a heating, ventilation, and air conditioning system is presented. • RBF models were identified by Epsilon constraint method for temperature and humidity. • Control settings derived from optimization of the decoupled model. • Epsilon constraint-RBF based on PID controller was implemented to keep thermal comfort and minimize energy. • Enhancements of controller parameters of the HVAC system are desired. - Abstract: The energy efficiency of a heating, ventilating and air conditioning (HVAC) system optimized using a radial basis function neural network (RBFNN) combined with the epsilon constraint (EC) method is reported. The new method adopts the advanced algorithm of RBFNN for the HVAC system to estimate the residual errors, increase the control signal and reduce the error results. The objective of this study is to develop and simulate the EC-RBFNN for a self tuning PID controller for a decoupled bilinear HVAC system to control the temperature and relative humidity (RH) produced by the system. A case study indicates that the EC-RBFNN algorithm has a much better accuracy than optimization PID itself and PID-RBFNN, respectively.

  13. Legionellosis prevention in building water and HVAC systems a practical guide for design, operation and maintenance to minimize the risk

    CERN Document Server

    Joppolo, Cesare Maria; Pitera, Luca Alberto; Angermann, Jean Pierre; Izard, Mark

    2013-01-01

    This Guidebook is a practical guide for design, operation and maintenance to minimize the risk of legionellosis in building water and HVAC systmes. It is devided into several themes such as: Air conditioning of the air (by water – humidification), Production of hot water for washing (fundamentally but not only hot water for washing) and Evaporative cooling tower.

  14. Experimental investigation of cooling performance of a novel HVAC system combining natural ventilation with diffuse ceiling inlet and TABS

    DEFF Research Database (Denmark)

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

    2015-01-01

    Highlights •An experimental investigation of cooling performance of a combined HVAC system is carried out. •Cooling performance of TABS with and without the influence of diffuse ceiling is analyzed. •Radiant and convective heat transfer coefficients of TABS cooling are studied. •Cooling components...

  15. Comparison of Energy Performance of Different HVAC Systems for a Typical Office Room and a Typical Classroom

    DEFF Research Database (Denmark)

    Yu, Tao; Heiselberg, Per; Pomianowski, Michal Zbigniew

    the energy consumption for buildings with cooling demand in cold seasons. In this way, the building system can operate at a very low energy use all the year round. The main purpose of this task is to investigate the energy performance of different HVAC systems used in the office room and the classroom...

  16. Comparison of methods to evaluate the fungal biomass in heating, ventilation, and air-conditioning (HVAC) dust.

    Science.gov (United States)

    Biyeyeme Bi Mve, Marie-Jeanne; Cloutier, Yves; Lacombe, Nancy; Lavoie, Jacques; Debia, Maximilien; Marchand, Geneviève

    2016-12-01

    Heating, ventilation, and air-conditioning (HVAC) systems contain dust that can be contaminated with fungal spores (molds), which may have harmful effects on the respiratory health of the occupants of a building. HVAC cleaning is often based on visual inspection of the quantity of dust, without taking the mold content into account. The purpose of this study is to propose a method to estimate fungal contamination of dust in HVAC systems. Comparisons of different analytical methods were carried out on dust deposited in a controlled-atmosphere exposure chamber. Sixty samples were analyzed using four methods: culture, direct microscopic spore count (DMSC), β-N-acetylhexosaminidase (NAHA) dosing and qPCR. For each method, the limit of detection, replicability, and repeatability were assessed. The Pearson correlation coefficients between the methods were also evaluated. Depending on the analytical method, mean spore concentrations per 100 cm 2 of dust ranged from 10,000 to 682,000. Limits of detection varied from 120 to 217,000 spores/100 cm 2 . Replicability and repeatability were between 1 and 15%. Pearson correlation coefficients varied from -0.217 to 0.83. The 18S qPCR showed the best sensitivity and precision, as well as the best correlation with the culture method. PCR targets only molds, and a total count of fungal DNA is obtained. Among the methods, mold DNA amplification by qPCR is the method suggested for estimating the fungal content found in dust of HVAC systems.

  17. Value impact analysis of Generic Issue 143, Availability of Heating, Ventilation, Air Conditioning (HVAC) and Chilled Water Systems

    Energy Technology Data Exchange (ETDEWEB)

    Daling, P.M.; Marler, J.E.; Vo, T.V.; Phan, H.; Friley, J.R. [Pacific Northwest Lab., Richland, WA (United States)

    1993-11-01

    This study evaluates the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143, ``Availability of HVAC and Chilled Water Systems.`` The study identifies vulnerabilities related to failures of HVAC, chilled water, and room cooling systems; develops estimates of room heatup rates and safety-related equipment vulnerabilities following losses of HVAC/room cooler systems; develops estimates of the core damage frequencies and public risks associated with failures of these systems; develops three proposed resolution strategies to this generic issue; and performs a value/impact analysis of the proposed resolutions. Existing probabilistic risk assessments for four representative plants, including one plant from each vendor, form the basis for the core damage frequency and public risk calculations. Both internal and external events were considered. It was concluded that all three proposed resolution strategies exceed the $1,000/person-rem cost-effectiveness ratio. Additional evaluations were performed to develop ``generic`` insights on potential design-related and configuration-related vulnerabilities and potential high-frequency ({approximately}1E-04/RY) accident sequences that involve failures of HVAC/room cooling functions. It was concluded that, although high-frequency accident sequences may exist at some plants, these high-frequency sequences are plant-specific in nature or have been resolved through hardware and/or operational changes. The plant-specific Individual Plant Examinations are an effective vehicle for identification and resolution of these plant-specific anomalies and hardware configurations.

  18. Modular VSC converter based HVDC power transmission from offshore wind power plant: Compared to the conventional HVAC system

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Rasmussen, Tonny Wederberg; Jensen, Kim Høj

    2010-01-01

    power transmission options with HVDC systems are under consideration. In this paper, a comparison between a conventional HVAC transmission system and a HVDC system equipped with modular voltage source converters is provided. The comparison is based on the total energy transmission capability...

  19. Value impact analysis of Generic Issue 143, Availability of Heating, Ventilation, Air Conditioning (HVAC) and Chilled Water Systems

    International Nuclear Information System (INIS)

    Daling, P.M.; Marler, J.E.; Vo, T.V.; Phan, H.; Friley, J.R.

    1993-11-01

    This study evaluates the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143, ''Availability of HVAC and Chilled Water Systems.'' The study identifies vulnerabilities related to failures of HVAC, chilled water, and room cooling systems; develops estimates of room heatup rates and safety-related equipment vulnerabilities following losses of HVAC/room cooler systems; develops estimates of the core damage frequencies and public risks associated with failures of these systems; develops three proposed resolution strategies to this generic issue; and performs a value/impact analysis of the proposed resolutions. Existing probabilistic risk assessments for four representative plants, including one plant from each vendor, form the basis for the core damage frequency and public risk calculations. Both internal and external events were considered. It was concluded that all three proposed resolution strategies exceed the $1,000/person-rem cost-effectiveness ratio. Additional evaluations were performed to develop ''generic'' insights on potential design-related and configuration-related vulnerabilities and potential high-frequency (∼1E-04/RY) accident sequences that involve failures of HVAC/room cooling functions. It was concluded that, although high-frequency accident sequences may exist at some plants, these high-frequency sequences are plant-specific in nature or have been resolved through hardware and/or operational changes. The plant-specific Individual Plant Examinations are an effective vehicle for identification and resolution of these plant-specific anomalies and hardware configurations

  20. HVAC Trials.

    Science.gov (United States)

    Greim, Clifton W.; D'Angelo, David

    1999-01-01

    Explains how commissioning can help to ensure that all components in a new heating, ventilation, and air conditioning system will work together as designed. Bowdoin College's experience with commissioning is highlighted. (GR)

  1. Hybrid model predictive control of a residential HVAC system with on-site thermal energy generation and storage

    International Nuclear Information System (INIS)

    Fiorentini, Massimo; Wall, Josh; Ma, Zhenjun; Braslavsky, Julio H.; Cooper, Paul

    2017-01-01

    Highlights: • A comprehensive approach to managing thermal energy in residential buildings. • Solar-assisted HVAC system with on-site energy generation and storage. • Mixed logic-dynamical building model identified using experimental data. • Design and implementation of a logic-dynamical model predictive control strategy. • MPC applied to the Net-Zero Energy house winner of the Solar Decathlon China 2013. - Abstract: This paper describes the development, implementation and experimental investigation of a Hybrid Model Predictive Control (HMPC) strategy to control solar-assisted heating, ventilation and air-conditioning (HVAC) systems with on-site thermal energy generation and storage. A comprehensive approach to the thermal energy management of a residential building is presented to optimise the scheduling of the available thermal energy resources to meet a comfort objective. The system has a hybrid nature with both continuous variables and discrete, logic-driven operating modes. The proposed control strategy is organized in two hierarchical levels. At the high-level, an HMPC controller with a 24-h prediction horizon and a 1-h control step is used to select the operating mode of the HVAC system. At the low-level, each operating mode is optimised using a 1-h rolling prediction horizon with a 5-min control step. The proposed control strategy has been practically implemented on the Building Management and Control System (BMCS) of a Net Zero-Energy Solar Decathlon house. This house features a sophisticated HVAC system comprising of an air-based photovoltaic thermal (PVT) collector and a phase change material (PCM) thermal storage integrated with the air-handling unit (AHU) of a ducted reverse-cycle heat pump system. The simulation and experimental results demonstrated the high performance achievable using an HMPC approach to optimising complex multimode HVAC systems in residential buildings, illustrating efficient selection of the appropriate operating modes

  2. Energy Savings Potential of Flexible and Adaptive HVAC Distribution Systems for Office Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Loftness, Vivian; Brahme, Rohini; Mondazzi, Michelle; Vineyard, Edward; MacDonald, Michael

    2002-06-01

    It has been understood by architects and engineers that office buildings with easily re-configurable space and flexible mechanical and electrical systems are able to provide comfort that increases worker productivity while using less energy. Raised floors are an example of how fresh air, thermal conditioning, lighting needs, and network access can be delivered in a flexible manner that is not ''embedded'' within the structure. What are not yet documented is how well these systems perform and how much energy they can save. This area is being investigated in phased projects of the 21st Century Research Program of the Air-conditioning and Refrigeration Technology Institute. For the initial project, research teams at the Center for Building Performance and Diagnostics, Pittsburgh, Pennsylvania, and Oak Ridge National Laboratory, Oak Ridge, Tennessee, documented the diversity, performance, and incidence of flexible and adaptive HVAC systems. Information was gathered worldwide from journal and conference articles, case studies, manufactured products and assemblies, and interviews with design professionals. Their report thoroughly describes the variety of system types along with the various design alternatives observed for plenums, diffusers, individual control, and system integration. Many of the systems are illustrated in the report and the authors provide quantitative and qualitative comparisons. Among conclusions regarding key design issues, and barriers to widespread adoption, the authors state that flexible and adaptive HVAC systems, such as underfloor air, perform as well if not better than ceiling-based systems. Leading engineers have become active proponents after their first experience, which is resulting in these flexible and adaptive HVAC systems approaching 10 percent of the new construction market. To encourage adoption of this technology that improves thermal comfort and indoor air quality, follow-on work is required to further document

  3. A Study on the Application of UV Sterilization Method in HVAC System

    International Nuclear Information System (INIS)

    Cho, S. W.; Park, J. S.; Seo, I. W.; Lim, K. R.; An, W. S.; Oh, S. H.; Lee, K. W.; Kim, J. G.; Kwon, S. J.

    2005-04-01

    The objective of this report is to study on the application of UV sterilization method on HVAC system in building. One type of commercial UV lamp was utilized during this research. It was 1,050 mm length, 24.5 mm diameter, 65 w lamp output, single ended lamp intended for insertion into al frame from inside. Twenty six lamps were mounted and operated in cross flow. They were allowed to operate for at least 30 minutes prior to beginning each test. The test rig was operated at 2.5 m/s and 20 .deg. C, and the relatively humidity 21.6 %RH. The effect of UV sterilization are investigated that as the general virus about 94 %, the mold microbe about 64 % and the bacillus about 86 %, respectively. Following this report will be used important data for the design and manufacture of the UV

  4. The integrated engineering system for the HVAC branch. Annex; Das integrierte Ingenieursystem fuer die Haustechnikbranche; Anhang

    Energy Technology Data Exchange (ETDEWEB)

    Allenspach, J.; Duppenthaler, A.; Helbling, R.; Kohler, T.; Mantel, R.; Meineke, E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1994-01-01

    In 1987, the intention of the former Swiss Federal Institute for Reactor Research was to initiate a transfer of know-how into practice by launching this project. The increasing need for software engineering tools by heating, ventilation and air conditioning (HVAC) companies demanded a new tool; to realise it, a joint venture project with private industry should concentrate the individual capabilities of each partner toward this goal. The present report describes the concept of the integrated engineering system, its user interface, the models, graphics, tools, multiuser operation and the system boundary. Results of field tests are presented together with information of the availability of the system. The annex contains the agreement for the usage of the public-domain-version of the system, experience reports of pilot clients and the end user`s and developer`s documentation. (author) figs., tabs., refs.

  5. The Energy Implications of Air-Side Fouling in Constant Air Volume HVAC Systems

    Science.gov (United States)

    Wilson, Eric J. H.

    2011-12-01

    This thesis examines the effect of air-side fouling on the energy consumption of constant air volume (CAV) heating, ventilating, and air conditioning (HVAC) systems in residential and small commercial buildings. There is a particular focus on evaluating the potential energy savings that may result from the remediation of such fouling from coils, filters, and other air system components. A computer model was constructed to simulate the behavior of a building and its duct system under various levels of fouling. The model was verified through laboratory and field testing and then used to run parametric simulations to examine the range of energy impacts for various climates and duct system characteristics. A sensitivity analysis was conducted to determine the impact of parameters like duct insulation, duct leakage, duct location, and duct design on savings potential. Duct system pressures, temperatures, and energy consumption for two houses were monitored for one month. The houses' duct systems, which were both in conditioned space, were given a full cleaning, and were then monitored for another month. The flow rates at the houses improved by 10% and 6%. The improvements were primarily due to installing a new filter, as both houses had only light coil fouling. The results indicate that there was negligible change in heating energy efficiency due to the system cleaning. The parametric simulation results are in agreement with the field experiment: for systems in all eight climates, with flowrates degraded by 20% or less, if ducts are located within the thermal zone, HVAC source energy savings from cleaning are negligible or even slightly negative. However, if ducts are outside the thermal zone, savings are in the 1 to 5% range. For systems with flowrates degraded by 40%, if ducts are within the thermal zone, savings from cleaning occurs only for air conditioning energy, up to 8% in climates like Miami, FL. If ducts are outside the thermal zone, savings occurs with both

  6. Building HVAC control knowledge data schema – Towards a unified representation of control system knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yan; Treado, Stephen J.; Messner, John I.

    2016-12-01

    Building control systems for Heating, Ventilation, and Air Conditioning (HVAC) play a key role in realizing the functionality and operation of building systems and components. Building Control Knowledge (BCK) is the logic and algorithms embedded throughout building control system. There are different methods to represent the BCK. These methods differ in the selection of BCK representing elements and the format of those elements. There is a lack of standard data schema, for storing, retrieving, and reusing structured BCK. In this study, a modular data schema is created for BCK representation. The data schema contains eleven representing elements, i.e., control module name, operation mode, system schematic, control flow diagram, data point, alarm, parameter, control sequence, function, and programming code. Each element is defined with specific attributes. This data schema is evaluated through a case study demonstration. The demonstration shows a new way to represent the BCK with standard formats.

  7. A Study on the Application of UV Sterilization Method in HVAC System

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S. W.; Park, J. S.; Seo, I. W.; Lim, K. R.; An, W. S.; Oh, S. H.; Lee, K. W.; Kim, J. G.; Kwon, S. J

    2005-04-15

    The objective of this report is to study on the application of UV sterilization method on HVAC system in building. One type of commercial UV lamp was utilized during this research. It was 1,050 mm length, 24.5 mm diameter, 65 w lamp output, single ended lamp intended for insertion into al frame from inside. Twenty six lamps were mounted and operated in cross flow. They were allowed to operate for at least 30 minutes prior to beginning each test. The test rig was operated at 2.5 m/s and 20 .deg. C, and the relatively humidity 21.6 %RH. The effect of UV sterilization are investigated that as the general virus about 94 %, the mold microbe about 64 % and the bacillus about 86 %, respectively. Following this report will be used important data for the design and manufacture of the UV.

  8. Laboratory measurement of secondary pollutant yields from ozone reaction with HVAC filters

    International Nuclear Information System (INIS)

    Destaillats, Hugo; Chen, Wenhao; Apte, Michael; Li, Nuan; Spears, Michael; Almosni, Jeremie; Zhang, Jianshun Jensen; Fisk, William J.

    2009-01-01

    We used Proton Transfer Reaction - Mass Spectrometry (PTR-MS) and conventional sampling methods to monitor and identify trace level organic pollutants formed in heterogeneous reactions between ozone and HVAC filters in real time. Experiments were carried out using a bench-scale flow tube reactor operating with dry air and humidified air (50% RH), at realistically high ozone concentrations (150 ppbv). We explored different filter media (i.e., fiberglass and cotton/polyester blends) and different particle loadings (i.e., clean filter and filters loaded with particles for 3 months at the Lawrence Berkeley National Laboratory and the Port of Oakland, CA). Detailed emission dynamics of very low levels of certain organic pollutants from filter media upon ozone exposure in the presence of moisture have been obtained and analyzed.

  9. Impact of HVAC filter on indoor air quality in terms of ozone removal and carbonyls generation

    Science.gov (United States)

    Lin, Chi-Chi; Chen, Hsuan-Yu

    2014-06-01

    This study aims at detecting ozone removal rates and corresponding carbonyls generated by ozone reaction with HVAC filters from various building, i.e., shopping mall, school, and office building. Studies were conducted in a small-scale environmental chamber. By examining dust properties including organic carbon proportion and specific surface area of dusts adsorbed on filters along with ozone removal rates and carbonyls generation rate, the relationship among dust properties, ozone removal rates, and carbonyls generation was identified. The results indicate a well-defined positive correlation between ozone removal efficiency and carbonyls generation on filters, as well as a positive correlation among the mass of organic carbon on filters, ozone removal efficiency and carbonyls generations.

  10. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    Science.gov (United States)

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration.

  11. Ultraviolet photovoltaics: Share the spectrum

    Science.gov (United States)

    Milliron, Delia J.

    2017-08-01

    Electrically controlled windows require power to switch between transparent and tinted states. Now, an ultraviolet light-harvesting solar cell can power smart windows without compromising their control over heat and light.

  12. Solar ultraviolet radiation cataract.

    Science.gov (United States)

    Löfgren, Stefan

    2017-03-01

    Despite being a treatable disease, cataract is still the leading cause for blindness in the world. Solar ultraviolet radiation is epidemiologically linked to cataract development, while animal and in vitro studies prove a causal relationship. However, the pathogenetic pathways for the disease are not fully understood and there is still no perfect model for human age related cataract. This non-comprehensive overview focus on recent developments regarding effects of solar UV radiation wavebands on the lens. A smaller number of fundamental papers are also included to provide a backdrop for the overview. Future studies are expected to further clarify the cellular and subcellular mechanisms for UV radiation-induced cataract and especially the isolated or combined temporal and spatial effects of UVA and UVB in the pathogenesis of human cataract. Regardless of the cause for cataract, there is a need for advances in pharmaceutical or other treatment modalities that do not require surgical replacement of the lens. Copyright © 2016. Published by Elsevier Ltd.

  13. Ultraviolet radiation and cyanobacteria.

    Science.gov (United States)

    Rastogi, Rajesh Prasad; Sinha, Rajeshwar P; Moh, Sang Hyun; Lee, Taek Kyun; Kottuparambil, Sreejith; Kim, Youn-Jung; Rhee, Jae-Sung; Choi, Eun-Mi; Brown, Murray T; Häder, Donat-Peter; Han, Taejun

    2014-12-01

    Cyanobacteria are the dominant photosynthetic prokaryotes from an ecological, economical, or evolutionary perspective, and depend on solar energy to conduct their normal life processes. However, the marked increase in solar ultraviolet radiation (UVR) caused by the continuous depletion of the stratospheric ozone shield has fueled serious concerns about the ecological consequences for all living organisms, including cyanobacteria. UV-B radiation can damage cellular DNA and several physiological and biochemical processes in cyanobacterial cells, either directly, through its interaction with certain biomolecules that absorb in the UV range, or indirectly, with the oxidative stress exerted by reactive oxygen species. However, cyanobacteria have a long history of survival on Earth, and they predate the existence of the present ozone shield. To withstand the detrimental effects of solar UVR, these prokaryotes have evolved several lines of defense and various tolerance mechanisms, including avoidance, antioxidant production, DNA repair, protein resynthesis, programmed cell death, and the synthesis of UV-absorbing/screening compounds, such as mycosporine-like amino acids (MAAs) and scytonemin. This study critically reviews the current information on the effects of UVR on several physiological and biochemical processes of cyanobacteria and the various tolerance mechanisms they have developed. Genomic insights into the biosynthesis of MAAs and scytonemin and recent advances in our understanding of the roles of exopolysaccharides and heat shock proteins in photoprotection are also discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Ultraviolet radiation in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Taalas, P.; Koskela, T.; Damski, J.; Supperi, A. [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E. [Finnish Meteorological Inst., Sodankylae (Finland). Sodankylae Observatory

    1996-12-31

    Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s research projects. The main national level effort has been the Finnish Academy`s climatic change programme, SILMU 1990-95. This presentation summarises the scientific results reached during the SILMU project

  15. Ultraviolet radiation: the eye

    International Nuclear Information System (INIS)

    Cesarini, J.P.; Sliney, D.H.

    1996-01-01

    Under most conditions, the eye is well adapted to protect itself against ultraviolet radiation encountered in the outdoor environment as a result of the exposure geometry of the sun. Only when snow is on the ground does one experience acute effects of UV sunlight exposure (i.e. snow blindness, or photokeratitis). With regard to artificial sources, there are many occasions where one views bright light sources such as tungsten-halogen lamps, arc lamps and welding arcs. Such viewing is normally only momentary because of the aversion response to bright light and due to discomfort glare. However, such an aversion does not take place for germicidal lamps and other UV lamps which do not contain a strong visible component in their spectrum. The adverse effects from viewing such sources has been studied for decades and during the last two decades guidelines for limiting exposure to protect the eye have been developed. The guidelines were fostered to a large extent by the growing use of lasers and the quickly recognized hazard posed by viewing laser sources. (author)

  16. Ultraviolet radiation in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Taalas, P; Koskela, T; Damski, J; Supperi, A [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E [Finnish Meteorological Inst., Sodankylae (Finland). Sodankylae Observatory

    1997-12-31

    Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s research projects. The main national level effort has been the Finnish Academy`s climatic change programme, SILMU 1990-95. This presentation summarises the scientific results reached during the SILMU project

  17. Ultraviolet Communication for Medical Applications

    Science.gov (United States)

    2015-06-01

    DEI procured several UVC phosphors and tested them with vacuum UV (VUV) excitation. Available emission peaks include: 226 nm, 230 nm, 234 nm, 242...SUPPLEMENTARY NOTES Report contains color. 14. ABSTRACT Under this Phase II SBIR effort, Directed Energy Inc.’s (DEI) proprietary ultraviolet ( UV ...15. SUBJECT TERMS Non-line-of-sight (NLOS), networking, optical communication, plasma-shells, short range, ultraviolet ( UV ) light 16. SECURITY

  18. ULTRAVIOLET TECHNOLOGY FOR FOOD PRESERVATION

    OpenAIRE

    Guedes, AMM; Novello, D; Mendes, GMD; Cristianini, M

    2009-01-01

    ULTRAVIOLET TECHNOLOGY FOR FOOD PRESERVATION This literature review article had as objective to gather information about ultraviolet (UV) technology utilization on the food industry, its effects and potential application. Aspects as the origin, concept and applications of the technology on the equipment industry and running mechanisms were approached. The application of UV radiation on food decontamination is still little used due its low penetration, but it is known that it can be easily app...

  19. Determination of the radioactive material and plutonium holdup in ducts and piping in the 325 Building

    International Nuclear Information System (INIS)

    Haggard, D.L.; Tanner, J.E.; Tomeraasen, P.L.

    1996-08-01

    This report describes the measurements performed to determine the radionuclide content and mass of Pu in exposed ducts, filters, and piping in the 325 Building at the Hanford Site. This information is needed to characterize facility radiation levels, to verify compliance with criticality safety specifications, and to allow more accurate nuclear material control using nondestructive assay. Gamma assay was used to determine the gamma-emitting isotopes in ducts, filters, and piping. Passive neutron counting was used to estimate the Pu content. A high-purity Ge detector and a neutron slab detector containing 5 3 He proportional counters were used. Almost all the gamma activity is from 137 Cs and 60 Co. Estimated Pu mass gram equivalents in the basement ductwork and filters are 31 g; the radioactive liquid waste system (RLWS) line has 12 g; the laboratory vacuum system has 2 g equiv. Pu; the retention process sewer has 3 g. Total Pu mass holdup for basement areas range from 48 to 27 g. Estimated Pu mass gram equivalents for all laboratories range from 385 to 581 g. Individual laboratory estimates are tabulated. Total estimated Pu gram equivalent holdup and material in process for the facility is 410 g. In summary, results indicate that no significant Pu levels, from a criticality safety perspective, reside in the ductwork, laboratory vacuum system lines, RLWS pipes, or any one laboratory in the 325 Building

  20. Squaring the Circle: Geometric Skewness and Symmetry Breaking for Passive Scalar Transport in Ducts and Pipes.

    Science.gov (United States)

    Aminian, Manuchehr; Bernardi, Francesca; Camassa, Roberto; McLaughlin, Richard M

    2015-10-09

    We study the role geometry plays in the emergence of asymmetries in diffusing passive scalars advected by pressure-driven flows in ducts and pipes of different aspect ratios. We uncover nonintuitive, multi-time-scale behavior gauged by a new statistic, which we term "geometric skewness" S^{G}, which measures instantaneously forming asymmetries at short times due to flow geometry. This signature distinguishes elliptical pipes of any aspect ratio, for which S^{G}=0, from rectangular ducts whose S^{G} is generically nonzero, and, interestingly, shows that a special duct of aspect ratio ≈0.53335 behaves like a circular pipe as its geometric skewness vanishes. Using a combination of exact solutions, novel short-time asymptotics, and Monte Carlo simulations, we establish the relevant time scales for plateaus and extrema in the evolution of the skewness and kurtosis for our class of geometries. For ducts limiting to channel geometries, we present new exact, single-series formulas for the first four moments on slices used to benchmark Monte Carlo simulations.

  1. Numerical eduction of active multi-port data for in-duct obstructions

    Science.gov (United States)

    Sack, Stefan; Shur, Michael; Åbom, Mats; Strelets, Michael; Travin, Andrey

    2017-12-01

    A numerical method for aeroacoustic source characterization of in-duct components at frequencies beyond the cut-on frequencies of several acoustic modes is presented. Assuming linearity and time invariance, any ducted component can be fully characterized using a network (multi-port) model including source strength and scattering. A two-step multi-source approach is applied to numerical data in order to educe the multi-port characteristics. First, a scale resolving compressible flow simulation, here the Improved Delayed Detached Eddy Simulation (IDDES), is run to compute the channel flow that also contains the acoustic sources. Second, a linear acoustic computation, here the Linearized Navier Stokes Equations (LNSE), around a mean flow is solved for different acoustic loads to determine the component's scattering. The work uncovers the high potential of two-step numerical multi-port eduction methods. Particularly, it is shown that the acoustic source power spectra can be accurately extracted from IDDES data and the total acoustic power prediction is very good. Furthermore, a good result in the scattering data obtained from a second computationally inexpensive LNSE computation is achieved. The approach is interesting when describing mid-size duct systems, for example ventilation systems in aircraft and buildings, with a moderate number of higher order modes propagating in the considered frequency range. Therefore, the increasing availability of compressible flow data opens a wide field of applications.

  2. Market assessment for active solar heating and cooling products. Category B: a survey of decision-makers in the HVAC marketplace. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    A comprehensive evaluation of the market for solar heating and cooling products for new and retrofit markets is reported. The emphasis is on the analysis of solar knowledge among HVAC decision makers and a comprehensive evaluation of their solar attitudes and behavior. The data from each of the following sectors are described and analyzed: residential consumers, organizational and manufacturing buildings, HVAC engineers and architects, builders/developers, and commercial/institutional segments. (MHR)

  3. An analytical discrete-ordinates solution for an improved one-dimensional model of three-dimensional transport in ducts

    International Nuclear Information System (INIS)

    Garcia, R.D.M.

    2015-01-01

    Highlights: • An improved 1-D model of 3-D particle transport in ducts is studied. • The cases of isotropic and directional incidence are treated with the ADO method. • Accurate numerical results are reported for ducts of circular cross section. • A comparison with results of other authors is included. • The ADO method is found to be very efficient. - Abstract: An analytical discrete-ordinates solution is developed for the problem of particle transport in ducts, as described by a one-dimensional model constructed with two basis functions. Two types of particle incidence are considered: isotropic incidence and incidence described by the Dirac delta distribution. Accurate numerical results are tabulated for the reflection probabilities of semi-infinite ducts and the reflection and transmission probabilities of finite ducts. It is concluded that the developed solution is more efficient than commonly used numerical implementations of the discrete-ordinates method.

  4. Occupancy pattern in office buildings : consequences for HVAC system design and operation

    Energy Technology Data Exchange (ETDEWEB)

    Halvarsson, Johan

    2011-07-01

    The main objectives with the work presented in this thesis have been: (a) to contribute to an increased understanding of the consequences that the occupancy pattern can have on the indoor climate and for Heating, Ventilation and Air Conditioning (HVAC) system design and operation; and (b) to investigate how typical occupancy patterns can look like in office buildings. The occupancy pattern in an office is a function of the floor layout of the building, and the user organisation(s) occupying it and their way of working. The combination of these two, will decide how the users occupy the building, which in turn is an important design prerequisite/constraint for the HVAC system design process. There are many assessments related to indoor climate and HVAC that involve considerations of the occupancy pattern, reaching from estimates of internal heat and pollution loads to deciding on an appropriate control strategy of HVAC systems, or estimating the energy saving potential with demand controlled ventilation. A few numerical measures have been used to describe different aspects of the occupancy pattern. The zone based occupancy factor (OFz) expresses the ratio between the number of occupied sub-zones/rooms in a zone and the total number of sub-zones/rooms in the zone. OFz does not take the number of people into account, only whether a sub-zone/room is occupied or unoccupied. OFz can be used both to express instantaneous occupancy levels and averages over time. Superscript is used to specify the time, or time period, that the measure refers to. For instance, 06 18,wd OFz means the average OFz between 6 a.m. and 6 p.m. on working days, while the 95th percentile of OFz6{sub 1}8,wd , means the 95th percentile of all instantaneous values (one or five minute averages in the case studies) of OFz that have occurred during the same time period. The utilisation rate (UR) expresses the fraction of time that a room is occupied, within a specific time period. It is important to

  5. Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Van D [ORNL

    2006-11-01

    The long range strategic goal of the Department of Energy's Building Technologies (DOE/BT) Program is to create, by 2020, technologies and design approaches that enable the construction of net-zero energy homes at low incremental cost (DOE/BT 2005). A net zero energy home (NZEH) is a residential building with greatly reduced needs for energy through efficiency gains, with the balance of energy needs supplied by renewable technologies. While initially focused on new construction, these technologies and design approaches are intended to have application to buildings constructed before 2020 as well resulting in substantial reduction in energy use for all building types and ages. DOE/BT's Emerging Technologies (ET) team is working to support this strategic goal by identifying and developing advanced heating, ventilating, air-conditioning, and water heating (HVAC/WH) technology options applicable to NZEHs. Although the energy efficiency of heating, ventilating, and air-conditioning (HVAC) equipment has increased substantially in recent years, new approaches are needed to continue this trend. Dramatic efficiency improvements are necessary to enable progress toward the NZEH goals, and will require a radical rethinking of opportunities to improve system performance. The large reductions in HVAC energy consumption necessary to support the NZEH goals require a systems-oriented analysis approach that characterizes each element of energy consumption, identifies alternatives, and determines the most cost-effective combination of options. In particular, HVAC equipment must be developed that addresses the range of special needs of NZEH applications in the areas of reduced HVAC and water heating energy use, humidity control, ventilation, uniform comfort, and ease of zoning. In FY05 ORNL conducted an initial Stage 1 (Applied Research) scoping assessment of HVAC/WH systems options for future NZEHs to help DOE/BT identify and prioritize alternative approaches for further

  6. A realistic approach to modeling an in-duct desulfurization process based on an experimental pilot plant study

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, F.J.G.; Ollero, P. [University of Seville, Seville (Spain)

    2008-07-15

    This paper has been written to provide a realistic approach to modeling an in-duct desulfurization process and because of the disagreement between the results predicted by published kinetic models of the reaction between hydrated lime and SO{sub 2} at low temperature and the experimental results obtained in pilot plants where this process takes place. Results were obtained from an experimental program carried out in a 3-MWe pilot plant. Additionally, five kinetic models, from the literature, of the reaction of sulfation of Ca(OH){sub 2} at low temperatures were assessed by simulation and indicate that the desulfurization efficiencies predicted by them are clearly lower than those experimentally obtained in our own pilot plant as well as others. Next, a general model was fitted by minimizing the difference between the calculated and the experimental results from the pilot plant, using Matlab{sup TM}. The parameters were reduced as much as possible, to only two. Finally, after implementing this model in a simulation tool of the in-duct sorbent injection process, it was validated and it was shown to yield a realistic approach useful for both analyzing results and aiding in the design of an in-duct desulfurization process.

  7. Real-time performance assessment and adaptive control for a water chiller unit in an HVAC system

    Science.gov (United States)

    Bai, Jianbo; Li, Yang; Chen, Jianhao

    2018-02-01

    The paper proposes an adaptive control method for a water chiller unit in a HVAC system. Based on the minimum variance evaluation, the adaptive control method was used to realize better control of the water chiller unit. To verify the performance of the adaptive control method, the proposed method was compared with an a conventional PID controller, the simulation results showed that adaptive control method had superior control performance to that of the conventional PID controller.

  8. Coupling fast fluid dynamics and multizone airflow models in Modelica Buildings library to simulate the dynamics of HVAC systems

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Wei [Univ. of Miami, FL (United States). Dept. of Civil, Architectural and Environmental Engineering; Sevilla, Thomas Alonso [Univ. of Miami, FL (United States). Dept. of Civil, Architectural and Environmental Engineering; Zuo, Wangda [Univ. of Miami, FL (United States). Dept. of Civil, Architectural and Environmental Engineering; Sohn, Michael D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Div.

    2017-06-08

    Historically, multizone models are widely used in building airflow and energy performance simulations due to their fast computing speed. However, multizone models assume that the air in a room is well mixed, consequently limiting their application. In specific rooms where this assumption fails, the use of computational fluid dynamics (CFD) models may be an alternative option. Previous research has mainly focused on coupling CFD models and multizone models to study airflow in large spaces. While significant, most of these analyses did not consider the coupled simulation of the building airflow with the building's Heating, Ventilation, and Air-Conditioning (HVAC) systems. This paper tries to fill the gap by integrating the models for HVAC systems with coupled multizone and CFD simulations for airflows, using the Modelica simul ation platform. To improve the computational efficiency, we incorporated a simplified CFD model named fast fluid dynamics (FFD). We first introduce the data synchronization strategy and implementation in Modelica. Then, we verify the implementation using two case studies involving an isothermal and a non-isothermal flow by comparing model simulations to experiment data. Afterward, we study another three cases that are deemed more realistic. This is done by attaching a variable air volume (VAV) terminal box and a VAV system to previous flows to assess the capability of the models in studying the dynamic control of HVAC systems. Finally, we discuss further research needs on the coupled simulation using the models.

  9. Value-impact assessment for resolution of generic safety issue 143 - availability of HVAC and chilled water systems

    Energy Technology Data Exchange (ETDEWEB)

    Daling, P.M.; Marler, J.E.; Vo, T.V. [Pacific Northwest Laboratory, Richland, WA (United States)] [and others

    1995-02-01

    The Pacific Northwest Laboratory (PNL), under contract to the U.S. Nuclear Regulatory Commission (NRC), has conducted an assessment of the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143, {open_quotes}Availability of Heating, Ventilation, and Air Conditioning (HVAC) and Chilled Water Systems.{close_quotes} This assessment was conducted to identify vulnerabilities related to failure of HVAC, chilled water and room cooling systems and develop estimates of the core damage frequencies and public risks associated with failures of these systems. This information was used to develop proposed resolution strategies to this generic issue and perform a value/impact assessment to determine their cost-effectiveness. Probabilistic risk assessments (PRAs) for four representative plants from the basis for the core damage frequency and public risk calculations. Internally-initiated core damage sequences as well as external events were considered. Three proposed resolution strategies were developed for this safety issue and it was determined that all three were not cost-effective. Additional evaluations were performed to develop {open_quotes}generic{close_quotes} insights on potential design-related vulnerabilities and potential high-frequency accident sequences that involve failures of HVAC/room cooling functions.

  10. Value-impact assessment for resolution of generic safety issue 143 - availability of HVAC and chilled water systems

    International Nuclear Information System (INIS)

    Daling, P.M.; Marler, J.E.; Vo, T.V.

    1995-01-01

    The Pacific Northwest Laboratory (PNL), under contract to the U.S. Nuclear Regulatory Commission (NRC), has conducted an assessment of the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143, open-quotes Availability of Heating, Ventilation, and Air Conditioning (HVAC) and Chilled Water Systems.close quotes This assessment was conducted to identify vulnerabilities related to failure of HVAC, chilled water and room cooling systems and develop estimates of the core damage frequencies and public risks associated with failures of these systems. This information was used to develop proposed resolution strategies to this generic issue and perform a value/impact assessment to determine their cost-effectiveness. Probabilistic risk assessments (PRAs) for four representative plants from the basis for the core damage frequency and public risk calculations. Internally-initiated core damage sequences as well as external events were considered. Three proposed resolution strategies were developed for this safety issue and it was determined that all three were not cost-effective. Additional evaluations were performed to develop open-quotes genericclose quotes insights on potential design-related vulnerabilities and potential high-frequency accident sequences that involve failures of HVAC/room cooling functions

  11. Capability of air filters to retain airborne bacteria and molds in heating, ventilating and air-conditioning (HVAC) systems.

    Science.gov (United States)

    Möritz, M; Peters, H; Nipko, B; Rüden, H

    2001-07-01

    The capability of air filters (filterclass: F6, F7) to retain airborne outdoor microorganisms was examined in field experiments in two heating, ventilating and air conditioning (HVAC) systems. At the beginning of the 15-month investigation period, the first filter stages of both HVAC systems were equipped with new unused air filters. The number of airborne bacteria and molds before and behind the filters were determined simultaneously in 14 days-intervals using 6-stage Andersen cascade impactors. Under relatively dry ( 12 degrees C) outdoor air conditions air filters led to a marked reduction of airborne microorganism concentrations (bacteria by approximately 70% and molds by > 80%). However, during long periods of high relative humidity (> 80% R. H.) a proliferation of bacteria on air filters with subsequent release into the filtered air occurred. These microorganisms were mainly smaller than 1.1 microns therefore being part of the respirable fraction. The results showed furthermore that one possibility to avoid microbial proliferation is to limit the relative humidity in the area of the air filters to 80% R. H. (mean of 3 days), e.g. by using preheaters in front of air filters in HVAC-systems.

  12. Simulative Study into the Development of a Hybrid HVDC System Through a Comparative Research with HVAC: a Futuristic Approach

    Directory of Open Access Journals (Sweden)

    R. S. Narayan

    2017-06-01

    Full Text Available High Voltage Direct Current Transmission (HVDC is considered a better solution for bulk long distance transmissions. The increased use of HVDC is a result of its advantages over the HVAC systems and especially of its fault stability nature. A better solution is proposed by using a Voltage Source Controlled–HVDC as one of the infeed for the Multi-Infeed HVDC (MIDC or MI-HVDC systems. The main advantage with the VSC converter is its flexible power control which enhances the stability of the MIDC systems. In this paper, the behavior of an HVDC system is compared with that of an HVAC during faults. A Hybrid HVDC system that includes a LCC as a rectifier unit and a VSC converter as the inverter is being proposed. It is considered suitable for MIDC systems and particularly for supplying a weak AC system. The performance of the system during steady state and transient conditions for all the proposed topologies including HVDC, HVAC and Hybrid HVDC are studied in MATLAB/SIMULINK. All of the proposed control strategies are evaluated via a series of simulation case studies.

  13. Harmful effects of ultraviolet radiation

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Tanning for cosmetic purposes by sunbathing or by using artificial tanning devices is widespread. The hazards associated with exposure to ultraviolet radiation are of concern to the medical profession. Depending on the amount and form of the radiation, as well as on the skin type of the individual exposed, ultraviolet radiation causes erythema, sunburn, photodamage (photoaging), photocarcinogenesis, damage to the eyes, alteration of the immune system of the skin, and chemical hypersensitivity. Skin cancers most commonly produced by ultraviolet radiation are basal and squamous cell carcinomas. There also is much circumstantial evidence that the increase in the incidence of cutaneous malignant melanoma during the past half century is related to increased sun exposure, but this has not been proved. Effective and cosmetically acceptable sunscreen preparations have been developed that can do much to prevent or reduce most harmful effects to ultraviolet radiation if they are applied properly and consistently. Other safety measures include (1) minimizing exposure to ultraviolet radiation, (2) being aware of reflective surfaces while in the sun, (3) wearing protective clothing, (4) avoiding use of artificial tanning devices, and (5) protecting infants and children

  14. Future Directions in Ultraviolet Spectroscopy

    Science.gov (United States)

    Sonneborn, George (Editor); Moos, Warren; VanSteenberg, Michael

    2009-01-01

    The 'Future Directions in Ultraviolet Spectroscopy' conference was inspired by the accomplishments of the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission. The FUSE mission was launched in June 1999 and spent over eight years exploring the far-ultraviolet universe, gathering over 64 million seconds of high-resolution spectral data on nearly 3000 astronomical targets. The goal of this conference was not only to celebrate the accomplishments of FUSE, but to look toward the future and understand the major scientific drivers for the ultraviolet capabilities of the next generation fo space observatories. Invited speakers presented discussions based on measurements made by FUSE and other ultraviolet instruments, assessed their connection with measurements made with other techniques and, where appropriate, discussed the implications of low-z measurements for high-z phenomena. In addition to the oral presentations, many participants presented poster papers. The breadth of these presentation made it clear that much good science is still in progress with FUSE data and that these result will continue to have relevance in many scientific areas.

  15. Estimating occupant satisfaction of HVAC system noise using quality assessment index

    Directory of Open Access Journals (Sweden)

    Farhad Forouharmajd

    2012-01-01

    Full Text Available Noise may be defined as any unwanted sound. Sound becomes noise when it is too loud, unexpected, uncontrolled, happens at the wrong time, contains unwanted pure tones or unpleasant. In addition to being annoying, loud noise can cause hearing loss, and, depending on other factors, can affect stress level, sleep patterns and heart rate. The primary object for determining subjective estimations of loudness is to present sounds to a sample of listeners under controlled conditions. In heating, ventilation and air conditioning (HVAC systems only the ventilation fan industry (e.g., bathroom exhaust and sidewall propeller fans uses loudness ratings. In order to find satisfaction, percent of exposure to noise is the valuable issue for the personnel who are working in these areas. The room criterion (RC method has been defined by ANSI standard S12.2, which is based on measured levels of in HVAC systems noise in spaces and is used primarily as a diagnostic tool. The RC method consists of a family of criteria curves and a rating procedure. RC measures background noise in the building over the frequency range of 16-4000 Hz. This rating system requires determination of the mid-frequency average level and determining the perceived balance between high-frequency (HF sound and low-frequency (LF sound. The arithmetic average of the sound levels in the 500, 1000 and 2000 Hz octave bands is 44.6 dB; therefore, the RC 45 curve is selected as the reference for spectrum quality evaluation. The spectral deviation factors in the LF, medium-frequency sound and HF regions are 2.9, 7.5 and -2.3, respectively, giving a Quality Assessment Index (QAI of 9.8. This concludes the QAI is useful in estimating an occupant′s probable reaction when the system design does not produce optimum sound quality. Thus, a QAI between 5 and 10 dB represents a marginal situation in which acceptance by an occupant is questionable. However, when sound pressure levels in the 16 or 31.5 Hz octave

  16. Estimating occupant satisfaction of HVAC system noise using quality assessment index.

    Science.gov (United States)

    Forouharmajd, Farhad; Nassiri, Parvin; Monazzam, Mohammad R; Yazdchi, Mohammadreza

    2012-01-01

    Noise may be defined as any unwanted sound. Sound becomes noise when it is too loud, unexpected, uncontrolled, happens at the wrong time, contains unwanted pure tones or unpleasant. In addition to being annoying, loud noise can cause hearing loss, and, depending on other factors, can affect stress level, sleep patterns and heart rate. The primary object for determining subjective estimations of loudness is to present sounds to a sample of listeners under controlled conditions. In heating, ventilation and air conditioning (HVAC) systems only the ventilation fan industry (e.g., bathroom exhaust and sidewall propeller fans) uses loudness ratings. In order to find satisfaction, percent of exposure to noise is the valuable issue for the personnel who are working in these areas. The room criterion (RC) method has been defined by ANSI standard S12.2, which is based on measured levels of in HVAC systems noise in spaces and is used primarily as a diagnostic tool. The RC method consists of a family of criteria curves and a rating procedure. RC measures background noise in the building over the frequency range of 16-4000 Hz. This rating system requires determination of the mid-frequency average level and determining the perceived balance between high-frequency (HF) sound and low-frequency (LF) sound. The arithmetic average of the sound levels in the 500, 1000 and 2000 Hz octave bands is 44.6 dB; therefore, the RC 45 curve is selected as the reference for spectrum quality evaluation. The spectral deviation factors in the LF, medium-frequency sound and HF regions are 2.9, 7.5 and -2.3, respectively, giving a Quality Assessment Index (QAI) of 9.8. This concludes the QAI is useful in estimating an occupant's probable reaction when the system design does not produce optimum sound quality. Thus, a QAI between 5 and 10 dB represents a marginal situation in which acceptance by an occupant is questionable. However, when sound pressure levels in the 16 or 31.5 Hz octave bands exceed 65

  17. Ultraviolet-radiation-curable paints

    Energy Technology Data Exchange (ETDEWEB)

    Grosset, A M; Su, W F.A.; Vanderglas, E

    1981-09-30

    In product finishing lines, ultraviolet radiation curing of paints on prefabricated structures could be more energy efficient than curing by natural gas fired ovens, and could eliminate solvent emission. Diffuse ultraviolet light can cure paints on three dimensional metal parts. In the uv curing process, the spectral output of radiation sources must complement the absorption spectra of pigments and photoactive agents. Photosensitive compounds, such as thioxanthones, can photoinitiate unsaturated resins, such as acrylated polyurethanes, by a free radical mechanism. Newly developed cationic photoinitiators, such as sulfonium or iodonium salts (the so-called onium salts) of complex metal halide anions, can be used in polymerization of epoxy paints by ultraviolet light radiation. One-coat enamels, topcoats, and primers have been developed which can be photoinitiated to produce hard, adherent films. This process has been tested in a laboratory scale unit by spray coating these materials on three-dimensional objects and passing them through a tunnel containing uv lamps.

  18. Ultraviolet spectrophotometry of three LINERs

    Science.gov (United States)

    Goodrich, R. W.; Keel, W. C.

    1986-01-01

    Three galaxies known to be LINERs were observed spectroscopically in the ultraviolet in an attempt to detect the presumed nonthermal continuum source thought to be the source of photoionization in the nuclei. NGC 4501 was found to be too faint for study with the IUE spectrographs, while NGC 5005 had an extended ultraviolet light profile. Comparison with the optical light profile of NGC 5005 indicates that the ultraviolet source is distributed spatially in the same manner as the optical starlight, probably indicating that the ultraviolet excess is due to a component of hot stars in the nucleus. These stars contribute detectable absorption features longward of 2500 A; together with optical data, the IUE spectra suggest a burst of star formation about 1 billion yr ago, with a lower rate continuing to produce a few OB stars. In NGC 4579, a point source contributing most of the ultraviolet excess is found that is much different than the optical light distribution. Furthermore, the ultraviolet to X-ray spectral index in NGC 4579 is 1.4, compatible with the UV to X-ray indices found for samples of Seyfert galaxies. This provides compelling evidence for the detection of the photoionizing continuum in NGC 4579 and draws the research fields of normal galaxies and active galactic nuclei closer together. The emission-line spectrum of NGC 4579 is compared with calculations from a photoionization code, CLOUDY, and several shock models. The photoionization code is found to give superior results, adding to the increasing weight of evidence that the LINER phenomenon is essentially a scaled-down version of the Seyfert phenomenon.

  19. Analysis of the HVAC system's sound quality using the design of experiments

    International Nuclear Information System (INIS)

    Park, Sang Gil; Sim, Hyun Jin; Yoon, Ji Hyun; Jeong, Jae Eun; Choi, Byoung Jae; Oh, Jae Eung

    2009-01-01

    Human hearing is very sensitive to sound, so a subjective index of sound quality is required. Each situation of sound evaluation is composed of Sound Quality (SQ) metrics. When substituting the level of one frequency band, we could not see the tendency of substitution at the whole frequency band during SQ evaluation. In this study, the Design of Experiments (DOE) is used to analyze noise from an automotive Heating, Ventilating, and Air Conditioning (HVAC) system. The frequency domain is divided into 12 equal parts, and each level of the domain is given an increase or decrease due to the change in frequency band based on the 'loud' and 'sharp' sound of the SQ analyzed. By using DOE, the number of tests is effectively reduced by the number of experiments, and the main result is a solution at each band. SQ in terms of the 'loud' and 'sharp' sound at each band, the change in band (increase or decrease in sound pressure) or no change in band will have the most effect on the identifiable characteristics of SQ. This will enable us to select the objective frequency band. Through the results obtained, the physical level changes in arbitrary frequency domain sensitivity can be determined

  20. Energy Savings From System Efficiency Improvements in Iowa's HVAC SAVE Program

    Energy Technology Data Exchange (ETDEWEB)

    Yee, S. [Partnership for Advanced Residential Retrofit, Chicago, IL (United States); Baker, J. [Partnership for Advanced Residential Retrofit, Chicago, IL (United States); Brand, L. [Partnership for Advanced Residential Retrofit, Chicago, IL (United States); Wells, J. [Partnership for Advanced Residential Retrofit, Chicago, IL (United States)

    2013-08-01

    The objective of this project is to explore the energy savings potential of maximizing furnace and distribution system performance by adjusting operating, installation, and distribution conditions. The goal of the Iowa HVAC System Adjusted and Verified Efficiency (SAVE) program is to train contractors to measure installed system efficiency as a diagnostic tool to ensure that the homeowner achieves the energy reduction target for the home rather than simply performing a tune-up on the furnace or having a replacement furnace added to a leaky system. The PARR research team first examined baseline energy usage from a sample of 48 existing homes, before any repairs or adjustments were made, to calculate an average energy savings potential and to determine which system deficiencies were prevalent. The results of the baseline study of these homes found that, on average, about 10% of the space heating energy available from the furnace was not reaching the conditioned space. In the second part of the project, the team examined a sample of 10 homes that had completed the initial evaluation for more in-depth study. For these homes, the diagnostic data shows that it is possible to deliver up to 23% more energy from the furnace to the conditioned space by doing system tune ups with or without upgrading the furnace. Replacing the furnace provides additional energy reduction. The results support the author's belief that residential heating and cooling equipment should be tested and improved as a system rather than a collection of individual components.

  1. Power system technical performance issues related to the application of long HVAC cables

    DEFF Research Database (Denmark)

    Wiechowski, on behalf of Cigre WG C4.502, W.; Sluis, L. V. der; Ohno, Teruo

    2011-01-01

    This paper reports the progress of work of Cigre Working Group C4.502 “Power system technical performance issues related to the application of long HVAC cables”. The primary goal of the WG C4.502 is to write a technical brochure that will serve as practical guide for performing studies necessary...... for assessing the technical performance of HV/EHV systems with large share of AC cable lines. This paper besides providing a background for formulation of WG C4.502 and its overall aim, describes the tasks that were accomplished before the interim report was submitted to Study Committee C4 System Technical...... Performance in August 2010. The work in the WG is ongoing and final report will be ready according to the time schedule in 2012. The focus of this paper is in particular to show all issues related to system technical performance with assigned weights in terms of their importance and/or uniqueness for cable...

  2. Switched Control Strategies of Aggregated Commercial HVAC Systems for Demand Response in Smart Grids

    Directory of Open Access Journals (Sweden)

    Kai Ma

    2017-07-01

    Full Text Available This work proposes three switched control strategies for aggregated heating, ventilation, and air conditioning (HVAC systems in commercial buildings to track the automatic generation control (AGC signal in smart grid. The existing control strategies include the direct load control strategy and the setpoint regulation strategy. The direct load control strategy cannot track the AGC signal when the state of charge (SOC of the aggregated thermostatically controlled loads (TCLs exceeds their regulation capacity, while the setpoint regulation strategy provides flexible regulation capacity, but causes larger tracking errors. To improve the tracking performance, we took the advantages of the two control modes and developed three switched control strategies. The control strategies switch between the direct load control mode and the setpoint regulation mode according to different switching indices. Specifically, we design a discrete-time controller and optimize the controller parameter for the setpoint regulation strategy using the Fibonacci optimization algorithm, enabling us to propose two switched control strategies across multiple time steps. Furthermore, we extend the switched control strategies by introducing a two-stage regulation in a single time step. Simulation results demonstrate that the proposed switched control strategies can reduce the tracking errors for frequency regulation.

  3. A simplified modeling of mechanical cooling tower for control and optimization of HVAC systems

    International Nuclear Information System (INIS)

    Jin, Guang-Yu; Cai, Wen-Jian; Lu Lu; Lee, Eng Lock; Chiang, Andrew

    2007-01-01

    This paper proposes a new, simple, yet accurate mechanical cooling tower model for the purpose of energy conservation and management. On the basis of Merkel's theory and effectiveness-NTU method, the model is developed by energy balance and heat, mass transfer analysis. Commissioning information is then used to identified, only three model parameters by Levenberg-Marquardt method. Compared with the existing models, the proposed model has simple characteristic parameters to be determined and without requiring iterative computation when the operating point changes. The model is validated by real operating data from the cooling towers of a heating, ventilating and air conditioning (HVAC) system of a commercial hotel. The testing results show that the performance of the cooling tower varies from time to time due to different operating conditions and the proposed model is able to reflect these changes by tuning its parameters. With this feature, the proposed model can be simply used and accurately predict the performance of the real-time operating cooling tower

  4. Task parameters affecting ergonomic demands and productivity of HVAC duct installation.

    Science.gov (United States)

    Mitropoulos, Panagiotis; Hussain, Sanaa; Guarascio-Howard, Linda; Memarian, Babak

    2014-01-01

    Mechanical installation workers experience work-related musculoskeletal disorders (WMSDs) at high rates. (1) Quantify the ergonomic demands during HVAC installation, (2) identify the tasks and task parameters that generated extreme ergonomic demands, and (3) propose improvements to reduce the WMSDs among mechanical workers. The study focused on installation of rectangular ductwork components using ladders, and analyzed five operations by two mechanical contractors. Using continuous time observational assessment, the videotaped operations were analyzed along two dimensions: (1) the production tasks and durations, and (2) the ergonomic demands for four body regions (neck, arms/shoulders, back, and knees). The analysis identified tasks with low portion of productive time and high portion of extreme postures, and task parameters that generated extreme postures. Duct alignment was the task with the highest portion of extreme postures. The position of the ladder (angle and distance from the duct) was a task parameter that strongly influenced the extreme postures for back, neck and shoulders. Other contributing factors included the difficulty to reach the hand tools when working on the ladder, the congestion of components in the ceiling, and the space between the duct and the ceiling. The identified tasks and factors provide directions for improvement.

  5. Promoting high efficiency residential HVAC equipment: Lessons learned from leading utility programs

    Energy Technology Data Exchange (ETDEWEB)

    Neme, C.; Peters, J.; Rouleau, D.

    1998-07-01

    The Consortium for Energy Efficiency recently sponsored a study of leading electric utility efforts to promote high efficiency residential HVAC equipment. Given growing concerns from some utilities about the level of expenditures associated with rebate programs, special emphasis was placed on assessing the success of financing and other non-rebate options for promoting efficiency. Emphasis was also placed on review of efforts--rebate or otherwise--to push the market to very high levels of efficiency (i.e., SEER 13). This paper presents the results of the study. It includes discussion of key lessons from the utility programs analyzed. It also examines program participation rates and other potential indicators of market impacts. One notable conclusion is that several utility programs have pushed market shares for SEER 12 equipment to about 50% (the national average is less than 20%). At least one utility program has achieved a 50% market share for SEER 13 equipment (the national average is less than 3%). In general, financing does not appear to have as broad an appeal as consumer rebates. However, one unique utility program which combines the other of customer financing with modest incentives to contractors--in the form of frequent seller points that can be redeemed for advertising, technician training, travel and other merchandise--offers some promise that high participation rates can be achieved without customer rebates.

  6. Ultraviolet observations of AM Herculis

    International Nuclear Information System (INIS)

    Tanzi, E.G.; Treves, A.; Milan Univ.; Sandford, M.C.W.; Willis, A.J.; Wilson, R.

    1980-01-01

    Seven ultraviolet spectra (1100-3200 Angstroem) of AM Her were obtained with the low resolution spectrometer of the IUE satellite. Strong emission features appear superimposed on a well defined continuum which is well fitted by a Fsub(lambda) D lambda -2 law. The observations are compared with the expectations from models of the source. (orig.) 891 WL/orig. 892 HIS

  7. Ultraviolet light and cutaneous lupus

    NARCIS (Netherlands)

    Bijl, Marc; Kallenberg, Cees G. M.

    2006-01-01

    Exposure to ultraviolet (UV) light is one of the major factors known to trigger cutaneous disease activity in (systemic) lupus erythematosus patients. UV light, UVB in particular, is a potent inducer of apoptosis. Currently, disturbed clearance of apoptotic cells is one of the concepts explaining

  8. Screening analysis for EPACT-covered commercial HVAC and water-heating equipment

    Energy Technology Data Exchange (ETDEWEB)

    S Somasundaram; PR Armstrong; DB Belzer; SC Gaines; DL Hadley; S Katipumula; DL Smith; DW Winiarski

    2000-05-25

    EPCA requirements state that if the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) amends efficiency levels prescribed in Standard 90.1-1989, then DOE must establish an amended uniform national manufacturing standard at the minimum level specified in amended Standard 90.1. However, DOE can establish higher efficiency levels if it can show through clear and convincing evidence that a higher efficiency level, that is technologically feasible and economically justified, would produce significant additional energy savings. On October 29, 1999, ASHRAE approved the amended Standard 90.1, which increases the minimum efficiency levels for some of the commercial heating, cooling, and water-heating equipment covered by EPCA 92. DOE asked Pacific Northwest National Laboratory (PNNL) to conduct a screening analysis to determine the energy-savings potential of the efficiency levels listed in Standard 90.1-1999. The analysis estimates the annual national energy consumption and the potential for energy savings that would result if the EPACT-covered products were required to meet these efficiency levels. The analysis also estimates additional energy-savings potential for the EPACT-covered products if they were to exceed the efficiency levels prescribed in Standard 90-1-1999. In addition, a simple life-cycle cost (LCC) analysis was performed for some alternative efficiency levels. This paper will describe the methodology, data assumptions, and results of the analysis. The magnitude of HVAC and SWH loads imposed on equipment depends on the building's physical and operational characteristics and prevailing climatic conditions. To address this variation in energy use, coil loads for 7 representative building types at 11 climate locations were estimated based on a whole-building simulation.

  9. Performance analysis of supply and return fans for HVAC systems under different operating strategies of economizer dampers

    Energy Technology Data Exchange (ETDEWEB)

    Nassif, Nabil [Florida Solar Energy Center, A Research Institute of the University of Center Florida, 1679 Clearlake Road, Cocoa, FL 32922 (United States)

    2010-07-15

    HVAC systems and associated equipment consume a relatively large fraction of total building energy consumption, a significant portion of which is attributed to fan operation. The operation of economizer dampers when installed can cause high energy consumption in fans if they are not functioning in proper and optimal manner. This will mainly be due to the potential high pressure drops through those dampers and associated high total pressures that should be developed by supply and/or return fans. It is then necessary to ensure that a proper strategy to operate optimally the economizer dampers is implemented with minimum fan energy use. The paper examines several operation strategies of the economizer dampers and investigates their effects on the performance of both the supply and return fans in HVAC system. It also discusses a new operating strategy for economizer dampers that can lead to lower fan energy use. The strategies are evaluated by simulations for a typically existing HVAC system. Several factors such as the building locations, system characteristics, resistance in the duct where the dampers are installed, supply air temperature and economizer control, and minimum ventilation requirements are also considered during the evaluations. The results show that the way of the economizer dampers been controlled has a significant effect on fan performance and its energy use. The proposed strategy if properly implemented can provide fan energy saving in the range of 5-30%, depending mainly on the number of hours when the system operates in the free cooling mode, damper characteristics, and minimum outdoor air. (author)

  10. Development of a method for bacteria and virus recovery from heating, ventilation, and air conditioning (HVAC) filters.

    Science.gov (United States)

    Farnsworth, James E; Goyal, Sagar M; Kim, Seung Won; Kuehn, Thomas H; Raynor, Peter C; Ramakrishnan, M A; Anantharaman, Senthilvelan; Tang, Weihua

    2006-10-01

    The aim of the work presented here is to study the effectiveness of building air handling units (AHUs) in serving as high volume sampling devices for airborne bacteria and viruses. An HVAC test facility constructed according to ASHRAE Standard 52.2-1999 was used for the controlled loading of HVAC filter media with aerosolized bacteria and virus. Nonpathogenic Bacillus subtilis var. niger was chosen as a surrogate for Bacillus anthracis. Three animal viruses; transmissible gastroenteritis virus (TGEV), avian pneumovirus (APV), and fowlpox virus were chosen as surrogates for three human viruses; SARS coronavirus, respiratory syncytial virus, and smallpox virus; respectively. These bacteria and viruses were nebulized in separate tests and injected into the test duct of the test facility upstream of a MERV 14 filter. SKC Biosamplers upstream and downstream of the test filter served as reference samplers. The collection efficiency of the filter media was calculated to be 96.5 +/- 1.5% for B. subtilis, however no collection efficiency was measured for the viruses as no live virus was ever recovered from the downstream samplers. Filter samples were cut from the test filter and eluted by hand-shaking. An extraction efficiency of 105 +/- 19% was calculated for B. subtilis. The viruses were extracted at much lower efficiencies (0.7-20%). Our results indicate that the airborne concentration of spore-forming bacteria in building AHUs may be determined by analyzing the material collected on HVAC filter media, however culture-based analytical techniques are impractical for virus recovery. Molecular-based identification techniques such as PCR could be used.

  11. A Study on Heat-up Phenomena of the RHR Pump Room in KORI Unit 2 for the Loss of HVAC Accidents

    International Nuclear Information System (INIS)

    Yoon, Churl; Park, Jin Hee; Lim, Ho Gon; Han, Sang Hoon

    2009-01-01

    In PSA(Probabilistic Safety Analysis) Models, the HVAC(Heating, Ventilation, and Air Condition) system is essential for the various vital mitigation safety systems operating during a mission time. So far, the unavailability of a safety system when the HVAC system fails has been applied conservatively or optimistically based on operating experience and expert judgment, so the total core damage frequency could be unrealistic. When the HVAC system of a nuclear power plant fails, it is one of the main issues in a PSA FT (Fault Tree) model to estimate the transient temperature variations of some component rooms. The purpose of this study is to establish a heat-up prediction model by using direct measuring and CFD(Computational Fluid Dynamics) analyses

  12. HVAC modifications and computerized energy analysis for the Operations Support Building at the Mars Deep Space Station at Goldstone

    Science.gov (United States)

    Halperin, A.; Stelzmuller, P.

    1986-01-01

    The key heating, ventilation, and air-conditioning (HVAC) modifications implemented at the Mars Deep Space Station's Operation Support Building at Jet Propulsion Laboratories (JPL) in order to reduce energy consumption and decrease operating costs are described. An energy analysis comparison between the computer simulated model for the building and the actual meter data was presented. The measurement performance data showed that the cumulative energy savings was about 21% for the period 1979 to 1981. The deviation from simulated data to measurement performance data was only about 3%.

  13. Thermal room modelling adapted to the test of HVAC control systems; Modele de zone adapte aux essais de regulateurs de systemes de chauffage et de climatisation

    Energy Technology Data Exchange (ETDEWEB)

    Riederer, P.

    2002-01-15

    Room models, currently used for controller tests, assume the room air to be perfectly mixed. A new room model is developed, assuming non-homogeneous room conditions and distinguishing between different sensor positions. From measurement in real test rooms and detailed CFD simulations, a list of convective phenomena is obtained that has to be considered in the development of a model for a room equipped with different HVAC systems. The zonal modelling approach that divides the room air into several sub-volumes is chosen, since it is able to represent the important convective phenomena imposed on the HVAC system. The convective room model is divided into two parts: a zonal model, representing the air at the occupant zone and a second model, providing the conditions at typical sensor positions. Using this approach, the comfort conditions at the occupant zone can be evaluated as well as the impact of different sensor positions. The model is validated for a test room equipped with different HVAC systems. Sensitivity analysis is carried out on the main parameters of the model. Performance assessment and energy consumption are then compared for different sensor positions in a room equipped with different HVAC systems. The results are also compared with those obtained when a well-mixed model is used. A main conclusion of these tests is, that the differences obtained, when changing the position of the controller's sensor, is a function of the HVAC system and controller type. The differences are generally small in terms of thermal comfort but significant in terms of overall energy consumption. For different HVAC systems the cases are listed, in which the use of a simplified model is not recommended. (author)

  14. Ultraviolet extensions of particle physics

    DEFF Research Database (Denmark)

    Berthier, Laure Gaëlle

    The discovery of the Higgs boson in 2012 at the Large Hadron Collider completed the Standard Model field content. Many questions though remain unanswered by the Standard Model triggering a search for new physics. New physics could manifest itself at the Large Hadron Collider by the discovery of new...... particles. However, the lack of new resonances might suggest that these new particles are still out of reach which leaves us with few options. Two possibilities are explored in this thesis. The first is to study precision measurements which might indicate new physics as small deviations from the Standard...... are expressed as power series with missing higher order terms. We also show how to connect ultraviolet models of new physics to the Standard Model effective field theory and calculate bounds on them using the Standard Model effective field theory fit results. Finally, we study a nonrelativistic ultraviolet...

  15. Fault ride-through and grid support of permanent magnet synchronous generator-based wind farms with HVAC and VSC-HVDC transmission systems

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe

    2012-01-01

    This paper describes fault ride-through and grid support of offshore wind farms based on permanent magnet synchronous generator (PMSG) wind turbines connected to the onshore AC network through two alternative transmission systems: high voltage AC (HVAC) or high voltage DC (HVDC) based on voltage...... source converters (VSC). The proposed configurations of the PMSG-based offshore wind farm and VSC-based HVDC are given as well as their control strategies under both steady state and fault state. The PMSG-based offshore wind farm is integrated into a test power transmission system via either HVAC or VSC...

  16. Effects of Recent Climate Change on Hourly Weather Data for HVAC Design: A Case Study of Osaka

    Directory of Open Access Journals (Sweden)

    Jihui Yuan

    2018-03-01

    Full Text Available The current design weather data used for heating, ventilation, and air conditioning (HVAC design in Japan was created using an old data period. New design weather data should be created to reflect recent local climate change. Based on our previous proposal of creating design weather data with two weather indices (dry-bulb temperature and enthalpy for HVAC design, design weather data for Osaka was created using more recently-measured weather data (period: 2001~2015 from the Japan Meteorological Agency (JMA in this study. The effect of recent climate change on the design weather data created with eight proposed methods was found. It showed the change in weather elements for cooling design clearly trends to warmer and drier weather, with more solar radiation and lower enthalpy, while the trends in heating design are less clear, mainly showing higher enthalpy. Furthermore, the difference in the peak load for the heating and cooling designs using the new and old design weather data was compared. The comparison showed that the minimum difference in peak load for the heating design was found using the mean daily dry-bulb temperature as the first and second indices; for the cooling design, the minimum difference in peak load was found using mean daily enthalpy as both the first and second indices.

  17. Report on HVAC option selections for a relocatable classroom energy and indoor environmental quality field study; TOPICAL

    International Nuclear Information System (INIS)

    Apte, Michael G.; Delp, Woody W.; Diamond, Richard C.; Hodgson, Alfred T.; Kumar, Satish; Rainer, Leo I.; Shendell, Derek G.; Sullivan, Doug P.; Fisk, William J.

    2001-01-01

    It is commonly assumed that efforts to simultaneously develop energy efficient building technologies and to improve indoor environmental quality (IEQ) are unfeasible. The primary reason for this is that IEQ improvements often require additional ventilation that is costly from an energy standpoint. It is currently thought that health and productivity in work and learning environments requires adequate, if not superior, IEQ. Despite common assumptions, opportunities do exist to design building systems that provide improvements in both energy efficiency and IEQ. This report outlines the selection of a heating, ventilation, and air conditioning (HVAC) system to be used in demonstrating such an opportunity in a field study using relocatable school classrooms. Standard classrooms use a common wall mounted heat pump HVAC system. After reviewing alternative systems, a wall-mounting indirect/direct evaporative cooling system with an integral hydronic gas heating is selected. The anticipated advantages of this system include continuous ventilation of 100 percent outside air at or above minimum standards, projected cooling energy reductions of about 70 percent, inexpensive gas heating, improved airborne particle filtration, and reduced peak load electricity use. Potential disadvantages include restricted climate regions and possible increases in indoor relative humidity levels under some conditions

  18. Fumigation of a laboratory-scale HVAC system with hydrogen peroxide for decontamination following a biological contamination incident.

    Science.gov (United States)

    Meyer, K M; Calfee, M W; Wood, J P; Mickelsen, L; Attwood, B; Clayton, M; Touati, A; Delafield, R

    2014-03-01

    To evaluate hydrogen peroxide vapour (H2 O2 ) for its ability to inactivate Bacillus spores within a laboratory-scale heating, ventilation and air-conditioning (HVAC) duct system. Experiments were conducted in a closed-loop duct system, constructed of either internally lined or unlined galvanized metal. Bacterial spores were aerosol-deposited onto 18-mm-diameter test material coupons and strategically placed at several locations within the duct environment. Various concentrations of H2 O2 and exposure times were evaluated to determine the sporicidal efficacy and minimum exposure needed for decontamination. For the unlined duct, high variability was observed in the recovery of spores between sample locations, likely due to complex, unpredictable flow patterns within the ducts. In comparison, the lined duct exhibited a significant desorption of the H2 O2 following the fumigant dwell period and thus resulted in complete decontamination at all sampling locations. These findings suggest that decontamination of Bacillus spore-contaminated unlined HVAC ducts by hydrogen peroxide fumigation may require more stringent conditions (higher concentrations, longer dwell duration) than internally insulated ductwork. These data may help emergency responders when developing remediation plans during building decontamination. © 2013 The Society for Applied Microbiology This article has been contributed to by US Government employees and their work is in the public domain in the USA.

  19. Design architecture for multi-zone HVAC control systems from existing single-zone systems using wireless sensor networks

    Science.gov (United States)

    Redfern, Andrew; Koplow, Michael; Wright, Paul

    2007-01-01

    Most residential heating, ventilating, and air-conditioning (HVAC) systems utilize a single zone for conditioning air throughout the entire house. While inexpensive, these systems lead to wide temperature distributions and inefficient cooling due to the difference in thermal loads in different rooms. The end result is additional cost to the end user because the house is over conditioned. To reduce the total amount of energy used in a home and to increase occupant comfort there is a need for a better control system using multiple temperature zones. Typical multi-zone systems are costly and require extensive infrastructure to function. Recent advances in wireless sensor networks (WSNs) have enabled a low cost drop-in wireless vent register control system. The register control system is controlled by a master controller unit, which collects sensor data from a distributed wireless sensor network. Each sensor node samples local settings (occupancy, light, humidity and temperature) and reports the data back to the master control unit. The master control unit compiles the incoming data and then actuates the vent resisters to control the airflow throughout the house. The control system also utilizes a smart thermostat with a movable set point to enable the user to define their given comfort levels. The new system can reduce the run time of the HVAC system and thus decreasing the amount of energy used and increasing the comfort of the home occupations.

  20. Ultraviolet divergences and supersymmetric theories

    International Nuclear Information System (INIS)

    Sagnotti, A.

    1984-09-01

    This article is closely related to the one by Ferrara in these same Proceedings. It deals with what is perhaps the most fascinating property of supersymmetric theories, their improved ultraviolet behavior. My aim here is to present a survey of the state of the art as of August, 1984, and a somewhat more detailed discussion of the breakdown of the superspace power-counting beyond N = 2 superfields. A method is also described for simplifying divergence calculations that uses the locality of subtracted Feynman integrals. 74 references

  1. Ultraviolet disinfection of potable water

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, R. L. [Metropolitan Water District of Southern California, Los Angeles, CA (United States)

    1990-06-15

    Because of upcoming surface and groundwater regulations regarding the control of microbiological and chemical contaminants, there is a need to evaluate the feasibility and effectiveness of ultraviolet (UV) radiation for primary disinfection of potable water supplies. Data is presented on microbicidal wavelengths of UV and distribution of energy output for low and medium-pressure arc lamps. Both systems were found to perform equally well for inactivating microorganisms, but each had distinct advantages in different applications. Approximate dosages for 90% inactivation of selected microorganisms by UV is presented in a table. Cost analysis for disinfection is presented in two tables as well as the advantages and disadvantages of UV disinfection.

  2. Ultraviolet disinfection of potable water

    International Nuclear Information System (INIS)

    Wolfe, R.L.

    1990-01-01

    Because of upcoming surface and groundwater regulations regarding the control of microbiological and chemical contaminants, there is a need to evaluate the feasibility and effectiveness of ultraviolet (UV) radiation for primary disinfection of potable water supplies. Data is presented on microbicidal wavelengths of UV and distribution of energy output for low and medium-pressure arc lamps. Both systems were found to perform equally well for inactivating microorganisms, but each had distinct advantages in different applications. Approximate dosages for 90% inactivation of selected microorganisms by UV is presented in a table. Cost analysis for disinfection is presented in two tables as well as the advantages and disadvantages of UV disinfection

  3. Ultraviolet divergences of Einstein gravity

    International Nuclear Information System (INIS)

    Goroff, M.H.

    1986-01-01

    The author discuss a two-loop calculation showing that the S matrix of Einstein's theory of gravity contains nonrenormalizable ultraviolet divergences in four dimension. The author discusses the calculation in both background field and normal field theory. The author describes a new method for dealing with ghost fields in gauge theories by combining them with suitable extensions of the gauge fields in higher dimensions. The author shows how using subtracted integrals in the calculation of higher loop graphs simplifies the calculation in the background field method by eliminating the need for mixed counterterms. Finally, the author makes some remarks about the implications of the result for supergravity theories

  4. Ultraviolet laser technology and applications

    CERN Document Server

    Elliott, David L

    1995-01-01

    Ultraviolet Laser Technology and Applications is a hands-on reference text that identifies the main areas of UV laser technology; describes how each is applied; offers clearly illustrated examples of UV opticalsystems applications; and includes technical data on optics, lasers, materials, and systems. This book is unique for its comprehensive, in-depth coverage. Each chapter deals with a different aspect of the subject, beginning with UV light itself; moving through the optics, sources, and systems; and concluding with detailed descriptions of applications in various fields.The text enables pr

  5. Proceedings of the 7th cogeneration and independent power congress, natural gas purchasing '92, HVAC controls and energy conservation '92, 1992 indoor air quality congress

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This book is covered under the following topics: Cogeneration and IPP Market Developments; Natural Gas Marketing and Deliverability Strategies; Identifying the Sources of IAQ Problems; User-Owner Cogeneration Systems; Strategies for International Power Development; Strategic Fuel Purchasing; Cogeneration and utility Power Plant Compliance Issues; New HVAC Design Trends; IAQ Practical solutions: Case Studies

  6. Dose modeling in ultraviolet phototherapy

    International Nuclear Information System (INIS)

    Grimes, David Robert; Robbins, Chris; O'Hare, Neil John

    2010-01-01

    Purpose: Ultraviolet phototherapy is widely used in the treatment of numerous skin conditions. This treatment is well established and largely beneficial to patients on both physical and psychological levels; however, overexposure to ultraviolet radiation (UVR) can have detrimental effects, such as erythemal responses and ocular damage in addition to the potentially carcinogenic nature of UVR. For these reasons, it is essential to control and quantify the radiation dose incident upon the patient to ensure that it is both biologically effective and has the minimal possible impact on the surrounding unaffected tissue. Methods: To date, there has been little work on dose modeling, and the output of artificial UVR sources is an area where research has been recommended. This work characterizes these sources by formalizing an approach from first principles and experimentally examining this model. Results: An implementation of a line source model is found to give impressive accuracy and quantifies the output radiation well. Conclusions: This method could potentially serve as a basis for a full computational dose model for quantifying patient dose.

  7. Evolution of solar ultraviolet luminosity

    International Nuclear Information System (INIS)

    Zahnle, K.J.; Walker, J.C.G.

    1982-01-01

    In view of the major role of the sun in defining the properties of planetary atmospheres, their evolution cannot be fully understood outside the context of an evolving sun. The ultraviolet radiation is especially interesting because of its strong interaction with planetary atmospheres. We use astronomical observation of stars that are analogous to the sun in order to reconstruct a tentative account of the evolution of solar UV luminosity. A wealth of evidence indicates that the young sun was a much more powerful source of energetic particles and radiation than it is today. While on the main sequence, solar activity has declined as an inverse power law of age (between t -5 and t/sup -1.2/) as a consequence of angular momentum loss to the solar wind. Recent IUE satellite observations of premain sequence stars suggest that before the sun reached the main sequence (at an age of about 50 m.y.), it may have emitted as much as 10 4 times as much ultraviolet radiation (γ<2000 A) than it does today. These results could impact our understanding of the photochemistry and escape of constituents of primordial planetary atmospheres

  8. Solar ultraviolet radiation effects on biological systems

    International Nuclear Information System (INIS)

    Diffey, B.L.

    1991-01-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK)

  9. Solar ultraviolet radiation effects on biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Diffey, B.L. (Dryburn Hospital, Durham (UK). Regional Medical Physics Dept.)

    1991-03-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK).

  10. Ultraviolet safety assessments of insect light traps.

    Science.gov (United States)

    Sliney, David H; Gilbert, David W; Lyon, Terry

    2016-01-01

    Near-ultraviolet (UV-A: 315-400 nm), "black-light," electric lamps were invented in 1935 and ultraviolet insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous ultraviolet emissions. A variety of UV "Black-light" ILTs were measured at a range of distances to assess potential exposures. Realistic time-weighted human exposures are shown to be well below current guidelines for human exposure to ultraviolet radiation. These UV-A exposures would be far less than the typical UV-A exposure in the outdoor environment. Proposals are made for realistic ultraviolet safety standards for ILT products.

  11. Energy demand and thermal comfort of HVAC systems with thermally activated building systems as a function of user profile

    Science.gov (United States)

    Pałaszyńska, Katarzyna; Bandurski, Karol; Porowski, Mieczysław

    2017-11-01

    Thermally Activated Building Systems (TABS) are a way to use building structure as a thermal energy storage. As a result, renewable energy sources may be used more efficiently. The paper presents numerical analysis of a HVAC system with TABS energy demand and indoor thermal comfort of a representative room in a non-residential building (governmental, commercial, educational). The purpose of analysis is to investigate the influence of a user profile on system performance. The time span of the analysis is one year - a typical meteorological year. The model was prepared using a generally accepted simulation tool - TRNSYS 17. The results help to better understand the interaction of a user profile with TABS. Therefore they are important for the development of optimal control algorithms for energy efficient buildings equipped with such systems.

  12. Energy demand and thermal comfort of HVAC systems with thermally activated building systems as a function of user profile

    Directory of Open Access Journals (Sweden)

    Pałaszyńska Katarzyna

    2017-01-01

    Full Text Available Thermally Activated Building Systems (TABS are a way to use building structure as a thermal energy storage. As a result, renewable energy sources may be used more efficiently. The paper presents numerical analysis of a HVAC system with TABS energy demand and indoor thermal comfort of a representative room in a non-residential building (governmental, commercial, educational. The purpose of analysis is to investigate the influence of a user profile on system performance. The time span of the analysis is one year – a typical meteorological year. The model was prepared using a generally accepted simulation tool – TRNSYS 17. The results help to better understand the interaction of a user profile with TABS. Therefore they are important for the development of optimal control algorithms for energy efficient buildings equipped with such systems.

  13. The Ultraviolet Albedo of Ganymede

    Science.gov (United States)

    McGrath, Melissa; Hendrix, A.

    2013-10-01

    A large set of ultraviolet images of Ganymede have been acquired with the Hubble Space Telescope over the last 15 years. These images have been used almost exclusively to study Ganymede’s stunning auroral emissions (Feldman et al. 2000; Eviatar et al. 2001; McGrath et al. 2004; Saur et al. 2011; McGrath et al. 2013), and even the most basic information about Ganymede’s UV albedo has yet to be gleaned from these data. We will present a first-cut analysis of both disk-averaged and spatially-resolved UV albedos of Ganymede, with focus on the spatially-resolved Lyman-alpha albedo, which has never been considered previously for this satellite. Ganymede's visibly bright regions are known to be rich in water ice, while the visibly dark regions seem to be more carbonaceous (Carlson et al., 1996). At Lyman-alpha, these two species should also have very different albedo values. References Carlson, R. and 39 co-authors, Near-infrared spectroscopy and spectral mapping of Jupiter and the Galilean satellites: Results from Galileo’s initial orbit, Science, 274, 385-388, 1996. Eviatar, A., D. F. Strobel, B. C. Wolven, P. D. Feldman, M. A. McGrath, and D. J. Williams, Excitation of the Ganymede ultraviolet aurora, Astrophys. J, 555, 1013-1019, 2001. Feldman, P. D., M. A. McGrath, D. F. Strobel, H. W. Moos, K. D. Retherford, and B. C. Wolven, HST/STIS imaging of ultraviolet aurora on Ganymede, Astrophys. J, 535, 1085-1090, 2000. McGrath M. A., Lellouch E., Strobel D. F., Feldman P. D., Johnson R. E., Satellite Atmospheres, Chapter 19 in Jupiter: The Planet, Satellites and Magnetosphere, ed. F. Bagenal, T. Dowling, W. McKinnon, Cambridge University Press, 2004. McGrath M. A., Jia, Xianzhe; Retherford, Kurt; Feldman, Paul D.; Strobel, Darrell F.; Saur, Joachim, Aurora on Ganymede, J. Geophys. Res., doi: 10.1002/jgra.50122, 2013. Saur, J., S. Duling, S., L. Roth, P. D. Feldman, D. F. Strobel, K. D. Retherford, M. A. McGrath, A. Wennmacher, American Geophysical Union, Fall Meeting

  14. Hand protection from ultraviolet exposure

    International Nuclear Information System (INIS)

    Khazova, M.; O'Hagan, J.B.

    2006-01-01

    Full text of publication follows: A number of industrial applications and public services involve exposure to ultraviolet radiation (U.V.R.) from a variety of lamps and lasers, for example, in forensic examination, biological trans-illuminators, dentistry, laser material processing, microelectronics, etc. The proposed European Union Directive on Optical Radiation would place specific requirements on employers to provide adequate safety measures to reduce exposure to U.V.R., including gloves for hand protection. The selection of gloves should be based on a risk assessment and on the performance characteristics of the gloves for the task. However, current International and national standards do not describe evaluation procedures of disposable gloves for hand protection against non-ionising radiation. A methodology for assessment of the UV protection level for disposable gloves and a simple measurement protocol are proposed, based on a common approach with UV protection by clothing and sunscreens. Glove Ultraviolet Protection Factor is defined as a time-scale increase in exposure permitted for the hand protected by a glove with respect to an unprotected hand. However, the wide variety of U.V.R. sources and the real-life conditions of glove use (stretching and wetting the surface by liquids) bring substantial challenges to the assessment method. Our study of ∼ 50 samples of widely used disposable gloves made of different materials (nitrile, vinyl, latex and chloroprene) showed that for all tested gloves a change in U.V.R. attenuation with stretching is characteristic for the type of glove material and can be included as a scaling factor in the definition of U.V.R. protection. Glove material has a bigger effect on U.V.R. protection level than variations in the glove thickness or its colour. The following approaches are suggested to overcome the problem of variable U.V.R. sources: - Worst case scenario minimal protection level, most restrictive case - Application

  15. Hand protection from ultraviolet exposure

    Energy Technology Data Exchange (ETDEWEB)

    Khazova, M.; O' Hagan, J.B. [Health Protection Agency, Radiation Protection Division, Chilton, Did cot (United Kingdom)

    2006-07-01

    Full text of publication follows: A number of industrial applications and public services involve exposure to ultraviolet radiation (U.V.R.) from a variety of lamps and lasers, for example, in forensic examination, biological trans-illuminators, dentistry, laser material processing, microelectronics, etc. The proposed European Union Directive on Optical Radiation would place specific requirements on employers to provide adequate safety measures to reduce exposure to U.V.R., including gloves for hand protection. The selection of gloves should be based on a risk assessment and on the performance characteristics of the gloves for the task. However, current International and national standards do not describe evaluation procedures of disposable gloves for hand protection against non-ionising radiation. A methodology for assessment of the UV protection level for disposable gloves and a simple measurement protocol are proposed, based on a common approach with UV protection by clothing and sunscreens. Glove Ultraviolet Protection Factor is defined as a time-scale increase in exposure permitted for the hand protected by a glove with respect to an unprotected hand. However, the wide variety of U.V.R. sources and the real-life conditions of glove use (stretching and wetting the surface by liquids) bring substantial challenges to the assessment method. Our study of {approx} 50 samples of widely used disposable gloves made of different materials (nitrile, vinyl, latex and chloroprene) showed that for all tested gloves a change in U.V.R. attenuation with stretching is characteristic for the type of glove material and can be included as a scaling factor in the definition of U.V.R. protection. Glove material has a bigger effect on U.V.R. protection level than variations in the glove thickness or its colour. The following approaches are suggested to overcome the problem of variable U.V.R. sources: - Worst case scenario minimal protection level, most restrictive case - Application

  16. Characterization and control of the microbial community affiliated with copper or aluminum heat exchangers of HVAC systems.

    Science.gov (United States)

    Schmidt, Michael G; Attaway, Hubert H; Terzieva, Silva; Marshall, Anna; Steed, Lisa L; Salzberg, Deborah; Hamoodi, Hameed A; Khan, Jamil A; Feigley, Charles E; Michels, Harold T

    2012-08-01

    Microbial growth in heating ventilation and air-conditioning (HVAC) systems with the subsequent contamination of indoor air is of increasing concern. Microbes and the subsequent biofilms grow easily within heat exchangers. A comparative study where heat exchangers fabricated from antimicrobial copper were evaluated for their ability to limit microbial growth was conducted using a full-scale HVAC system under conditions of normal flow rates using single-pass outside air. Resident bacterial and fungal populations were quantitatively assessed by removing triplicate sets of coupons from each exchanger commencing the fourth week after their installation for the next 30 weeks. The intrinsic biofilm associated with each coupon was extracted and characterized using selective and differential media. The predominant organisms isolated from aluminum exchangers were species of Methylobacterium of which at least three colony morphologies and 11 distinct PFGE patterns we found; of the few bacteria isolated from the copper exchangers, the majority were species of Bacillus. The concentrations and type of bacteria recovered from the control, aluminum, exchangers were found to be dependent on the type of plating media used and were 11,411-47,257 CFU cm(-2) per coupon surface. The concentration of fungi was found to average 378 CFU cm(-2). Significantly lower concentrations of bacteria, 3 CFU cm(-2), and fungi, 1 CFU cm(-2), were recovered from copper exchangers regardless of the plating media used. Commonly used aluminum heat exchangers developed stable, mixed, bacterial/fungal biofilms in excess of 47,000 organisms per cm(2) within 4 weeks of operation, whereas the antimicrobial properties of metallic copper were able to limit the microbial load affiliated with the copper heat exchangers to levels 99.97 % lower during the same time period.

  17. Energy Management in Small Commercial Buildings: A Look at How HVAC Contractors Can Deliver Energy Efficiency to this Segment

    Energy Technology Data Exchange (ETDEWEB)

    Hult, Erin; Granderson, Jessica; Mathew, Paul

    2014-07-01

    While buildings smaller than 50,000 sq ft account for nearly half of the energy used in US commercial buildings, energy efficiency programs to-date have primarily focused on larger buildings. Interviews with stakeholders and a review of the literature indicate interest in energy efficiency from the small commercial building sector, provided solutions are simple and low-cost. An approach to deliver energy management to small commercial buildings via HVAC contractors and preliminary demonstration findings are presented. The energy management package (EMP) developed includes five technical elements: benchmarking and analysis of monthly energy use; analysis of interval electricity data (if available), a one-hour onsite walkthrough, communication with the building owner, and checking of results. This data-driven approach tracks performance and identifies low-cost opportunities, using guidelines and worksheets for each element to streamline the delivery process and minimize the formal training required. This energy management approach is unique from, but often complementary to conventional quality maintenance or retrofit-focused programs targeting the small commercial segment. Because HVAC contractors already serve these clients, the transaction cost to market and deliver energy management services can be reduced to the order of hundreds of dollars per year. This business model, outlined briefly in this report, enables the offering to benefit the contractor and client even at the modest expected energy savings in small buildings. Results from a small-scale pilot of this approach validated that the EMP could be delivered by contractors in 4-8 hours per building per year, and that energy savings of 3-5percent are feasible through this approach.

  18. Galactic Astronomy in the Ultraviolet

    Science.gov (United States)

    Rastorguev, A. S.; Sachkov, M. E.; Zabolotskikh, M. V.

    2017-12-01

    We propose a number of prospective observational programs for the ultraviolet space observatory WSO-UV, which seem to be of great importance to modern galactic astronomy. The programs include the search for binary Cepheids; the search and detailed photometric study and the analysis of radial distribution of UV-bright stars in globular clusters ("blue stragglers", blue horizontal-branch stars, RR Lyrae variables, white dwarfs, and stars with UV excesses); the investigation of stellar content and kinematics of young open clusters and associations; the study of spectral energy distribution in hot stars, including calculation of the extinction curves in the UV, optical and NIR; and accurate definition of the relations between the UV-colors and effective temperature. The high angular resolution of the observatory allows accurate astrometric measurements of stellar proper motions and their kinematic analysis.

  19. Additive effects of ultraviolet radiation

    International Nuclear Information System (INIS)

    Cullen, A.P.

    1980-01-01

    A xenon-mercury high pressure lamp and a double monochromator were used to produce ultraviolet (uv) radiation at 295 nm. Pigmented rabbit eyes were irradiated and evaluated by slitlamp biomicroscopy. Corneal threshold (Hc) was 0.05 J.cm-2 and lens threshold (hL) was 0.75 J.cm-2. Other eyes were irradiated with 2 Hc and evaluated from 4 to 24 h at 4 h intervals. Corneal damage was only greater than that expected from a single Hc exposure if the separation between the two Hc exposures did not exceed 8 h. The most repeatable and reliable corneal response to these levels of uv was the development of corneal epithelial granules

  20. Ultraviolet Spectrophotometry of VV Cephei

    Directory of Open Access Journals (Sweden)

    Young Woon Kang

    1992-06-01

    Full Text Available The IUE archival spectra of VV Cephei were collected to investigate the eclipse nature in the ultraviolet. The temperature of the B star has been determined, as approximately 30000K, based on the flux distributions during egress. Light curves of VV Cephei were reduced from the spectrophotometry of the IUE archival spectra. Three light curves at the center wavelengths of 3250 Å, 2550 Å and 2850 Å have been analyzed by the modified Wilson and Devinney light curve program. The radii of the B star and M star were deduced to 0.05 and 0.22 of unit separation, respectively. The UV light curves show an evidence that the light was attenuated by the highly opaque atomsphere of the M star.

  1. Ultraviolet, Visible, and Fluorescence Spectroscopy

    Science.gov (United States)

    Penner, Michael H.

    Spectroscopy in the ultraviolet-visible (UV-Vis) range is one of the most commonly encountered laboratory techniques in food analysis. Diverse examples, such as the quantification of macrocomponents (total carbohydrate by the phenol-sulfuric acid method), quantification of microcomponents, (thiamin by the thiochrome fluorometric procedure), estimates of rancidity (lipid oxidation status by the thiobarbituric acid test), and surveillance testing (enzyme-linked immunoassays), are presented in this text. In each of these cases, the analytical signal for which the assay is based is either the emission or absorption of radiation in the UV-Vis range. This signal may be inherent in the analyte, such as the absorbance of radiation in the visible range by pigments, or a result of a chemical reaction involving the analyte, such as the colorimetric copper-based Lowry method for the analysis of soluble protein.

  2. Inspection and maintenance of HVAC systems : what you need to know; L'inspection et l'entretien des systemes de CVCA : ce qu'il faut savoir

    Energy Technology Data Exchange (ETDEWEB)

    Tapp, D. [Groupe Gesfor Poirier, Pinchin Inc., Montreal, PQ (Canada)

    2010-01-01

    This article described an inspection and maintenance program (IMP) that ensures the cleanliness of building's heating, ventilating and air conditioning (HVAC) system. Air quality can be compromised over time as dust accumulates in filters and on internal surfaces of an HVAC. Since mould spores and bacteria are significant components of dust, an excessive accumulation of dust in an HVAC system can lead to microbiological growth issues, particularly in humid conditions. Damaged dampers, missing screens and clogged or inefficient drains can generate indoor air quality issues. As such, preventive inspection of ventilation systems can identify deficiencies as well as future problems. This article also highlighted the integrated services provided by the Gesfor Poirier, Pinchin Group regarding industrial hygiene, health and safety inspection and remediation of HVAC systems and management of asbestos and other hazardous materials in buildings. 4 figs.

  3. Proposal for the award of a contract for the design, supply, installation and commissioning of a Heating, Ventilation and Air-Conditioning (HVAC) system for the computer room of the CERN Control Centre

    CERN Document Server

    2012-01-01

    Proposal for the award of a contract for the design, supply, installation and commissioning of a Heating, Ventilation and Air-Conditioning (HVAC) system for the computer room of the CERN Control Centre

  4. Assessment of organic compound exposures, thermal comfort parameters, and HVAC system-driven air exchange rates in public school portable classrooms in California

    Energy Technology Data Exchange (ETDEWEB)

    Shendell, Derek Garth [Univ. of California, Los Angeles, CA (United States)

    2003-01-01

    The prevalence of prefabricated, portable classrooms (portables, relocatables, RCs) has increased due to class size reduction initiatives and limited resources. Classroom mechanical wall-mount heating, ventilation, and air conditioning (HVAC) systems may function improperly or not be maintained; lower ventilation rates may impact indoor air and environmental quality (IEQ). Materials in portables may off-gas volatile organic compounds (VOCs), including formaldehyde, as a function of age, temperature, and humidity. For a pilot study, public K-12 schools located in or serving target areas within five Los Angeles County communities were identified. In two communities where school districts (SD) consented, 1-3 randomly selected portables, one newer and one older, and one main building control classroom from each participating school were included. Sampling was conducted over a five-day school week in the cooling and heating seasons, or repeated twice in the cooling season. Measurements included passive samplers for VOCs, formaldehyde and acetaldehyde, and air exchange rate (AER) calculation; indoor air temperature and humidity; technician walk-through surveys; an interview questionnaire above HVAC system operation and maintenance (O and M). For an intervention study evaluating advanced HVAC technologies in comparison to the common conventional technology, and materials for source reduction of VOCs, four RC were manufactured and located in pairs at two schools in two recruited Northern California SD in different climate zones. RCs were built with the two HVAC systems, cabinetry and conduit for monitoring equipment, and standard or advanced interior finish materials. Each RC was its own control in a case-crossover design--HVAC systems alternately operated for 1-2 week intervals in the 2001-02 school year, with IEQ monitoring including aldehyde and indoor air temperature and humidity data. Measured classroom AER were low, formaldehyde concentrations were below the state

  5. Stratospheric ozone, ultraviolet radiation and climate change

    International Nuclear Information System (INIS)

    Boucher, O.

    2008-01-01

    It is well known that an overexposure to ultraviolet radiation is associated with a number of health risks such as an increased risk of cataracts and skin cancers. At a time when climate change is often blamed for all our environmental problems, what is the latest news about the stratospheric ozone layer and other factors controlling ultraviolet radiation at the surface of the Earth? Will the expected changes in the chemical composition of the atmosphere and changes in our climate increase or decrease the risk for skin cancer? This article investigates the role of the various factors influencing ultraviolet radiation and presents the latest knowledge on the subject. (author)

  6. Ultraviolet safety assessments of insect light traps

    OpenAIRE

    Sliney, David H.; Gilbert, David W.; Lyon, Terry

    2016-01-01

    ABSTRACT Near-ultraviolet (UV-A: 315?400?nm), ?black-light,? electric lamps were invented in 1935 and ultraviolet insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous ultraviolet emissions. A variety of UV ?Black-light? ILTs were measured at...

  7. Some aspects of vacuum ultraviolet radiation physics

    CERN Document Server

    Damany, Nicole; Vodar, Boris

    2013-01-01

    Some Aspects of Vacuum Ultraviolet Radiation Physics presents some data on the state of research in vacuum ultraviolet radiation in association with areas of physics. Organized into four parts, this book begins by elucidating the optical properties of solids in the vacuum ultraviolet region (v.u.v.), particularly the specific methods of determination of optical constants in v.u.v., the properties of metals, and those of ionic insulators. Part II deals with molecular spectroscopy, with emphasis on the spectra of diatomic and simple polyatomic molecules, paraffins, and condensed phases. Part III

  8. Stimulation of hair cells with ultraviolet light

    Science.gov (United States)

    Azimzadeh, Julien B.; Fabella, Brian A.; Hudspeth, A. J.

    2018-05-01

    Hair bundles are specialized organelles that transduce mechanical inputs into electrical outputs. To activate hair cells, physiologists have resorted to mechanical methods of hair-bundle stimulation. Here we describe a new method of hair-bundle stimulation, irradiation with ultraviolet light. A hair bundle illuminated by ultraviolet light rapidly moves towards its tall edge, a motion typically associated with excitatory stimulation. The motion disappears upon tip-link rupture and is associated with the opening of mechanotransduction channels. Hair bundles can be induced to move sinusoidally with oscillatory modulation of the stimulation power. We discuss the implications of ultraviolet stimulation as a novel hair-bundle stimulus.

  9. Experimental study and modelling of the well-mixing length. Application to the representativeness of sampling points in duct

    International Nuclear Information System (INIS)

    Alengry, Jonathan

    2014-01-01

    Monitoring of gaseous releases from nuclear installations in the environment and air cleaning efficiency measurement are based on regular measurements of concentrations of contaminants in outlet chimneys and ventilation systems. The concentration distribution may be heterogeneous at the measuring point if the distance setting of the mixing is not sufficient. The question is about the set up of the measuring point in duct and the error compared to the homogeneous concentration in case of non-compliance with this distance. This study defines the so-called 'well mixing length' from laboratory experiments. The bench designed for these tests allowed to reproduce flows in long circular and rectangular ducts, each including a bend. An optical measurement technique has been developed, calibrated and used to measure the concentration distribution of a tracer injected in the flow. The experimental results in cylindrical duct have validated an analytical model based on the convection-diffusion equation of a tracer, and allowed to propose models of good mixing length and representativeness of sampling points. In rectangular duct, the acquired measures constitute a first database on the evolution of the homogenization of a tracer, in the perspective of numerical simulations exploring more realistic conditions for measurements in situ. (author) [fr

  10. Free cooling potential of a PCM-based heat exchanger coupled with a novel HVAC system for simultaneous heating and cooling of buildings

    DEFF Research Database (Denmark)

    Maccarini, Alessandro; Hultmark, Göran; Bergsøe, Niels Christian

    2018-01-01

    . In particular, a model of a PCM-based heat exchanger was developed in this work by using the programming language Modelica. This device was designed to store cold energy during night-time and release it during daytime through the water circuit. Results for a typical office building model showed...... that the integration of free cooling devices can significantly reduce the primary energy use of the novel HVAC system. In particular, the thermal plant configuration including the PCM-based heat exchanger made it possible to almost completely avoid the use of mechanical cooling, leading to annual primary energy......This article presents a simulation-based study that estimates the primary energy use of a novel HVAC system for different configurations of a thermal plant. The main characteristic of the system is its ability to provide simultaneous heating and cooling to buildings by using a single hydronic...

  11. Photodetector of ultra-violet radiation

    International Nuclear Information System (INIS)

    Dorogan, V.; Vieru, T.; Coseac, V.; Chirita, F.

    1999-01-01

    The invention relates to photodetectors on the semiconductors base, in particular, to photodetectors of ultra-violet radiation and can be used in the optoelectronics systems for determining the intensity and dose of ultraviolet radiation emitted by the Sun and other sources. In the structure of the photodetector of ultraviolet radiation with a superficial potential barrier formed of semiconductors A 3 B 5 with the prohibited power width Eg 1 , solid solutions thereof with the prohibited power width Eg 2 and SnO 2 or ITO, in the semiconductors A 3 B 5 at a surface distance less than the absorption length of the visible radiation it is formed an isotype heterojunction between the semiconductors A 3 B 5 and solid solutions thereof with the prohibited power width Eg 2 > Eg 1 . The technical result consists in manufacturing of a photodetector sensitive solely to the ultraviolet radiation

  12. Outdoor ultraviolet exposure of children and adolescents

    International Nuclear Information System (INIS)

    Diffey, B.L.; Gibson, C.J.

    1996-01-01

    The weekday and weekend outdoor ultraviolet exposure of young people from primary and secondary schools in three geographically distinct regions of England was determined over a 3-month period in summer. Ultraviolet exposure was measured using personal film badges worn by each young person and time spent outdoors, in hourly intervals, assessed using exposure records. In each area a class of 9-10 year-old children from a primary school and a class of 14-15-year-old adolescents from a secondary school took part, giving a total of 180 subjects. We found that primary school children received higher outdoor ultraviolet exposure than young people in secondary schools, and geographical differences in exposure could not be accounted for solely by differences in ambient ultraviolet. There was little difference between the exposure of males and females. Children and adolescents did not behave as homogeneous groups with regard to exposure. (Author)

  13. Ultraviolet light - nature's own disinfection process

    Energy Technology Data Exchange (ETDEWEB)

    Munkeberg, T [Thorolf Gregersen a/s, Oslo (Norway)

    1978-05-18

    Ultraviolet radiation from the sun is the means by which natural pollution products, as well as much of the smaller amount of pollution products produced by man, are converted and returned to the cycle of nature. Artificial ultraviolet radiation offers an optimum method for the disinfection of drinking water and can be used in the long term without undesireable effects on man or the enviromment. There is no evidence that ultraviolet irradiation leads to radiation resistant mutations of bacteria. The geometrical arrangement of ultraviolet disinfection units is described and the capacities of typical units is mentioned as being 600-800 m/sup 3/ /hr, though there is no reason why this should not be increased.

  14. Ultraviolet light - nature's own disinfection process

    International Nuclear Information System (INIS)

    Munkeberg, T.

    1978-01-01

    Ultraviolet radiation from the sun is the means by which natural pollution products, as well as much of the smaller amount of pollution products produced by man, are converted and returned to the cycle of nature. Artificial ultraviolet radiation offers an optimum method for the disinfection of drinking water and can be used in the long term without undesireable effects on man or the enviromment. There is no evidence that ultraviolet irradiation leads to radiation resistant mutations of bacteria. The geometrical arrangement of ultraviolet disinfection units is described and the capacities of typical units is mentioned as being 600-800 m 3 /hr, though there is no reason why this should not be increased. (JIW)

  15. Inactivation of mitochondrial ATPase by ultraviolet light

    International Nuclear Information System (INIS)

    Chavez, E.; Cuellar, A.

    1984-01-01

    The present work describes experiments that show that far-ultraviolet irradiation induce the inhibition of ATPase activity in both membrane-bound and soluble F1. It was also found that ultraviolet light promotes the release of tightly bound adenine nucleotides from F1-ATPase. Experiments carried out with submitochondrial particles indicate that succinate partially protects against these effects of ultraviolet light. Titration of sulfhydryl groups in both irradiated submitochondrial particles and soluble F1-ATPase indicates that a conformational change induced by photochemical modifications of amino acid residues appears involved in the inactivation of the enzyme. Finally, experiments are described which show that the tyrosine residue located in the active site of F1-ATPase is modified by ultraviolet irradiation

  16. Stability and Transient Effects in Ultraviolet Filaments

    National Research Council Canada - National Science Library

    Niday, Thomas

    2004-01-01

    .... Much of the work in this field has been done with infrared pulses; however, it has been proposed that ultraviolet pulses have the advantage that longer pulse lengths can be used, thereby delivering more energy...

  17. PMMA Wettability Caused by Ultraviolet Radiation

    OpenAIRE

    Dehtjars, J; Lancere, L; Poļaka, N; Soudnikovich, A; Tjuļkins, F; Valters, V

    2010-01-01

    The article is targeted to explore ultraviolet radiation (UV) influence on PMMAf or eye prostheses. UV beingt he Sun lightc omponenta nd could effect PMMA surface that in turn contributesi nteractionw ith tear. PMMA wettabilityw as poweredb y UV.

  18. Ultraviolet treatment on high performance filaments

    International Nuclear Information System (INIS)

    Gu Huang

    2005-01-01

    Quartz, Kevlar, carbon, and glass filaments were irradiated by ultraviolet ray with various periods. Tensile strength of the treated fibres was tested and analyzed, and the outward appearance of the treated filaments was shown

  19. Vacuum-Ultraviolet Photovoltaic Detector.

    Science.gov (United States)

    Zheng, Wei; Lin, Richeng; Ran, Junxue; Zhang, Zhaojun; Ji, Xu; Huang, Feng

    2018-01-23

    Over the past two decades, solar- and astrophysicists and material scientists have been researching and developing new-generation semiconductor-based vacuum ultraviolet (VUV) detectors with low power consumption and small size for replacing traditional heavy and high-energy-consuming microchannel-detection systems, to study the formation and evolution of stars. However, the most desirable semiconductor-based VUV photovoltaic detector capable of achieving zero power consumption has not yet been achieved. With high-crystallinity multistep epitaxial grown AlN as a VUV-absorbing layer for photogenerated carriers and p-type graphene (with unexpected VUV transmittance >96%) as a transparent electrode to collect excited holes, we constructed a heterojunction device with photovoltaic detection for VUV light. The device exhibits an encouraging VUV photoresponse, high external quantum efficiency (EQE) and extremely fast tempera response (80 ns, 10 4 -10 6 times faster than that of the currently reported VUV photoconductive devices). This work has provided an idea for developing zero power consumption and integrated VUV photovoltaic detectors with ultrafast and high-sensitivity VUV detection capability, which not only allows future spacecraft to operate with longer service time and lower launching cost but also ensures an ultrafast evolution of interstellar objects.

  20. Human exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Bernhardt, J.H.; Matthes, R.

    1987-01-01

    Ultraviolet radiation is that part of the electromagnetic spectrum located between the softest ionizing radiation and visible radiation. The lower limit of 100 nm is equivalent to photon energies of 12.4 eV, which corresponds approximately to the limit for the production of ionization in biologically important materials. A historical subdividing of the UV-region takes some of the biological effects into account. In this arrangement the range 400-315 nm, the so-called black light region, is called UV-A. In this wavelength region, fluorescence can be induced in many substances. UV-B covers the range 315-280 nm (the skin erythemal region). Most of the biologically active and potentially harmful UV from the sun reaching the surface of the earth is part of this spectral region. UV-C includes the radiation of wavelengths less than 280 nm (the germicidal region). It should be noted that this classification is somewhat arbitrary, and today it is more usual to evaluate the biological effectiveness of the whole UV-range from 200 to 400 nm

  1. Unintentional exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Sliney, D.H.

    1987-01-01

    To evaluate the risks from unintentional exposure to ultraviolet radiation (UVR), and to consider hazard control regulation, one must face first the problem of their state of scientific knowledge and the public's perception of UVR. Few people in the general public would question the health benefits of sunlight. Many flock to the beaches each summer to develop a healthy tan. Since the 1920's scientists have recognized that most of the benefits--and risks--of sunlight exposure result from the UVR present in sunlight. Dermatologists warn sunbathers to avoid exposure or protect themselves against the intense midday UVR or risk skin cancer. A growing number of scientists warn of hazards to the eye if UVR--perhaps even shorter visible wavelengths--are not filtered by lenses. In addition to any intentional exposure for health or cosmetic purposes, many people are also exposed to UVR without being aware of it or without their intent to be exposed. Outdoor workers are exposed to sunlight, many industrial workers (e.g., welders) are exposed to UVR from arc sources, some UVR penetrates clothing, and people indoors are exposed to UVR from artificial lighting

  2. Dermal damage from ultraviolet radiation

    International Nuclear Information System (INIS)

    Kligman, L.H.

    1988-01-01

    Ultraviolet (UV) radiation is increasingly recognized as the cause of a vast number of changes in the skin of humans and animals. These include alterations at the molecular, cellular, tissue and systematic levels. In the recent past, much has been learned about the immediate effects in skin of acute UV exposure (i.e. sunburn) with its epidermal cell death, inflammation and vasolidation. With chronic exposure, many of the clinical and histologic effects can be seen only after decades. Visually, these are hyper- and hypopigmented macules, dry scaly, wrinkled skin with a variety of benign, pre-malignant and malignant neoplasms. All epidermal in origin, they lead, inexorably in humans, to the appearance the authors described as photo-aged. Underlying many of these visible manifestations are drastic changes in the dermis. These relate chiefly to destruction of mature collagen, with a compensatory overproduction of reticulin fibers, hyperplasia of elastic fibers eventuating in elastosis, increased levels of the glycosaminoglycans (GAGs) comprising the ground substance and changes in the microvasculature. First described in actinically damaged humans, systematic investigation required an animal model

  3. Masks for extreme ultraviolet lithography

    International Nuclear Information System (INIS)

    Cardinale, G; Goldsmith, J; Kearney, P A; Larson, C; Moore, C E; Prisbrey, S; Tong, W; Vernon, S P; Weber, F; Yan, P-Y.

    1998-01-01

    In extreme ultraviolet lithography (EUVL), the technology specific requirements on the mask are a direct consequence of the utilization of radiation in the spectral region between 10 and 15 nm. At these wavelengths, all condensed materials are highly absorbing and efficient radiation transport mandates the use of all-reflective optical systems. Reflectivity is achieved with resonant, wavelength-matched multilayer (ML) coatings on all of the optical surfaces - including the mask. The EUV mask has a unique architecture - it consists of a substrate with a highly reflective ML coating (the mask blank) that is subsequently over-coated with a patterned absorber layer (the mask). Particulate contamination on the EUVL mask surface, errors in absorber definition and defects in the ML coating all have the potential to print in the lithographic process. While highly developed technologies exist for repair of the absorber layer, no viable strategy for the repair of ML coating defects has been identified. In this paper the state-of-the-art in ML deposition technology, optical inspection of EUVL mask blank defects and candidate absorber patterning approaches are reviewed

  4. Ultraviolet complete dark energy model

    Science.gov (United States)

    Narain, Gaurav; Li, Tianjun

    2018-04-01

    We consider a local phenomenological model to explain a nonlocal gravity scenario which has been proposed to address dark energy issues. This nonlocal gravity action has been seen to fit the data as well as Λ -CDM and therefore demands a more fundamental local treatment. The induced gravity model coupled with higher-derivative gravity is exploited for this proposal, as this perturbatively renormalizable model has a well-defined ultraviolet (UV) description where ghosts are evaded. We consider a generalized version of this model where we consider two coupled scalar fields and their nonminimal coupling with gravity. In this simple model, one of the scalar field acquires a vacuum expectation value (VEV), thereby inducing a mass for one of the scalar fields and generating Newton's constant. The induced mass however is seen to be always above the running energy scale thereby leading to its decoupling. The residual theory after decoupling becomes a platform for driving the accelerated expansion under certain conditions. Integrating out the residual scalar generates a nonlocal gravity action. The leading term of which is the nonlocal gravity action used to fit the data of dark energy.

  5. Influence of near ultraviolet light on microorganisms

    International Nuclear Information System (INIS)

    Fraikin, G.Y.A.; Rubin, L.B.

    1980-01-01

    Our results and the recent literature data on the biological action of near ultraviolet light (300-380 nm) are examined in the review. Factual material is presented on the principles governing the manifestation of the following effects of near ultraviolet light in microorganisms: inactivation, delayed growth, photoreactivation, photoprotection, photoinduced sporulation (in fungi), and carotene synthesis. The mature and possible mechanisms of the effects examined are discussed

  6. Ultraviolet colors of subdwarf O stars

    International Nuclear Information System (INIS)

    Wesselius, P.R.

    1978-01-01

    The group of subdwarf O stars consisting of field stars and some central stars of old planetary nebulae does occupy an interesting place in the HR diagram. Greenstein and Sargent (1974) have tried to establish this place, and conclude that especially the hottest ones need ultraviolet data to improve the values of effective temperature and absolute luminosity. The author therefore observed some twenty sdO stars in the far ultraviolet using the spectrophotometer in the Netherlands' satellite ANS. (Auth.)

  7. Extreme Ultraviolet Explorer Bright Source List

    Science.gov (United States)

    Malina, Roger F.; Marshall, Herman L.; Antia, Behram; Christian, Carol A.; Dobson, Carl A.; Finley, David S.; Fruscione, Antonella; Girouard, Forrest R.; Hawkins, Isabel; Jelinsky, Patrick

    1994-01-01

    Initial results from the analysis of the Extreme Ultraviolet Explorer (EUVE) all-sky survey (58-740 A) and deep survey (67-364 A) are presented through the EUVE Bright Source List (BSL). The BSL contains 356 confirmed extreme ultraviolet (EUV) point sources with supporting information, including positions, observed EUV count rates, and the identification of possible optical counterparts. One-hundred twenty-six sources have been detected longward of 200 A.

  8. Ultraviolet photoelectron spectroscopy of transient species

    International Nuclear Information System (INIS)

    Leeuw, D.M. de.

    1979-01-01

    Transient species are studied in the isolation of the gas phase using ultraviolet photoelectron spectroscopy (PES). A description of the equipment used and a discussion of some theoretical topics, which play a role in the interpretation of PE spectra, are given. Koopmans' theorem, Hartree-Fock-Slater (HFS) calculations and the sum rule are discussed. A versatile ultraviolet PE spectrometer, designed specifically for this purpose, has been built and the construction and performance of this instrument are described. (Auth.)

  9. Ultraviolet Behavior of N = 8 Supergravity

    International Nuclear Information System (INIS)

    Dixon, Lance J.

    2010-01-01

    In these lectures the author describes the remarkable ultraviolet behavior of N = 8 supergravity, which through four loops is no worse than that of N = 4 super-Yang-Mills theory (a finite theory). I also explain the computational tools that allow multi-loop amplitudes to be evaluated in this theory - the KLT relations and the unitarity method - and sketch how ultraviolet divergences are extracted from the amplitudes.

  10. Rapid Deployment of Optimal Control for Building HVAC Systems Using Innovative Software Tools and a Hybrid Heuristic/Model Based Control Approach

    Science.gov (United States)

    2017-03-21

    Tutorial. European Journal Of Control. Vol 13/2-3, pp 242–260. Parrish, K., J. Granderson, A. Mercado, P. Mathew. 2013. Improving Energy Efficiency...successfully, the project as a whole was not able to successfully demonstrate the technology. Anecdotal evidence, academic studies, and system simulations...Oceanography Center HVAC heating, ventilating, and air-conditioning NPS Naval Postgraduate School NRL U.S. Naval Research Laboratory NSAM Naval

  11. An HVAC [heating, ventilation, and air-conditioning] fault-tree analysis for WIPP [Waste Isolation Pilot Plant] integrated risk assessment

    International Nuclear Information System (INIS)

    Kirby, P.N.; Iacovino, J.M.

    1990-01-01

    In order to evaluate the public health risk of potential radioactive releases from operation of the Waste Isolation Pilot Plant (WIPP), a probabilistic risk assessment of waste-handling operations was conducted. One major aspect of this risk assessment involved fault-tree analysis of the plant heating, ventilation, and air-conditioning (HVAC) systems, which constitute the final barrier between waste-handling operations and the environment. The WIPP site is designed to receive and store two types of waste: contact-handled transuranic (CH TRU) wastes to be shipped in 208-ell drums and remote-handled (RH) TRU wastes to be shipped in shielded casks. The identification of accident sequences for CH waste operations revealed no identified accidents that could release significant radioactive particulates to the environment without a failure in the HVAC systems. When the HVAC fault-tree results were combined with other critical system fault trees and the analysis of waste-handling accident sequences, the approximation of the overall WIPP plant risk due to airborne releases was determined to be 2.6 x 10 -7 fatalities per year for the population within a 50-mile radius of the WIPP site. This risk was demonstrated to be well below the risk of fatality from other voluntary and involuntary activities for the population within the vicinity of the WIPP

  12. PROJETO DE UM CONTROLADOR PROPORCIONAL-INTEGRAL PARA O SISTEMA DE CONTROLE DE QUALIDADE DO AR E DE UM NOVO SISTEMA DE CONTROLE HVAC

    Directory of Open Access Journals (Sweden)

    Millene Caroline Albino de Oliveira

    2015-09-01

    Full Text Available Uma sala do Perlstein Hall, da Illinois Institute of Techonology, (Chicago, IL, USA possui um sistema de aquecimento, ventilação e ar condicionado (em inglês – HVAC equipado com um sensor de gás carbônico, cujo intuito é regular diretamente a qualidade do ar e assegurar que a sala esteja em condições aceitáveis. Este procedimento, porém, pode colocar uma carga extra no sistema HVAC e aumentar o consumo de energia. Desta forma, o objetivo principal do trabalho foi o desenvolvimento e a aplicação de uma estratégia de controle de temperatura e concentração de CO2 para o sistema em questão, utilizando um controlador Proporcional-Integral (PI. Dados coletados em testes realizados na sala foram utilizados para a estimação dos parâmetros das funções de transferência e dos controladores. Inicialmente, os controladores foram testados separadamente e, em seguida, em conjunto. Pode-se observar que o controlador PI obteve bons resultados, apesar do overshoot e oscilações do sistema já observados pela literatura, conseguindo atingir o set point desejado de temperatura de 70°F e de concentração de CO2 de 150 ppm. Palavras-chave: HVAC, Controle, controlador PI.

  13. Stage 1 performance qualification of heat-ventilation air-conditioning (HVAC) system for the manufacturing of Tc-99m Generator at Nuclear Malaysia

    International Nuclear Information System (INIS)

    Yen Ng; Noriah Jamal; Rehir Dahalan; Wan Anuar Wan Awang; Noraisyah Yusof; Shaharum Ramli; Jusnan Hashim; Ariff Hamzah; Wan Firdaus Wan Ishak; Yahaya Talib; Othman Mahmud; Asmah Mohibat; Shafii Khamis; Zulkifli Mohamed Hashim; Zakaria Ibrahim; Shaaban Kasim

    2007-01-01

    Manufacturing of Tc-99m generator is carried out in clean room Block 21 of Malaysian Nuclear Agency, which need to comply current Good Manufacturing Practice requirement. High-ventilation air conditioning (HVAC) is a new renovated system. It is a critical system for maintaining suitable temperature, relative humidity and pressure differential in the clean room. The objective of this paper is to present results on Stage 1 Performance Qualification (PQ) for HVAC. This PQ stage 1 was done from 7 February 2007 till 16 March 2007. Temperature, Relative Humidity and Pressure Differential for each compartment in the clean room was monitored twice daily. The Measurement of air-born particle count was done weekly. Settle plate for microbial test was also done weekly. The results were then analyzed and compared with the pre-determined specification. We found that temperature was within the specs, namely 24 +20 degree C. Relative humidity was less than 65%. Pressure differential shows variation, some compartments are below the specs namely 1-3 mm H 2 O. Air-born particle and microbial test also meet the requirement. The results show that all parameters meeting the specs excepts for the pressure differential for certain compartments are a bit low, but is sufficient to create proper air flow and not cause any risk of cross contamination. The existing HVAC system in the clean room is in compliance to the pre-determined specification. However, further improvement can be made by increasing the pressure differential between compartments. (Author)

  14. Ultraviolet resources over Northern Eurasia.

    Science.gov (United States)

    Chubarova, Natalia; Zhdanova, Yekaterina

    2013-10-05

    We propose a new climatology of UV resources over Northern Eurasia, which includes the assessments of both detrimental (erythema) and positive (vitamin D synthesis) effects of ultraviolet radiation on human health. The UV resources are defined by using several classes and subclasses - UV deficiency, UV optimum, and UV excess - for 6 different skin types. To better quantifying the vitamin D irradiance threshold we accounted for an open body fraction S as a function of effective air temperature. The spatial and temporal distribution of UV resources was estimated by radiative transfer (RT) modeling (8 stream DISORT RT code) with 1×1° grid and monthly resolution. For this purpose special datasets of main input geophysical parameters (total ozone content, aerosol characteristics, surface UV albedo, UV cloud modification factor) have been created over the territory of Northern Eurasia. The new approaches were used to retrieve aerosol parameters and cloud modification factor in the UV spectral region. As a result, the UV resources were obtained for clear-sky and mean cloudy conditions for different skin types. We show that the distribution of UV deficiency, UV optimum and UV excess is regulated by various geophysical parameters (mainly, total ozone, cloudiness and open body fraction) and can significantly deviate from latitudinal dependence. We also show that the UV optimum conditions can be simultaneously observed for people with different skin types (for example, for 4-5 skin types at the same time in spring over Western Europe). These UV optimum conditions for different skin types occupy a much larger territory over Europe than that over Asia. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Ultraviolet Spectroscopy of Asteroid(4) Vesta

    Science.gov (United States)

    Li, Jian-Yang; Bodewits, Dennis; Feaga, Lori M.; Landsman, Wayne; A'Hearn, Michael F.; Mutchler, Max J.; Russell, Christopher T.; McFadden, Lucy A.; Raymond, Carol A.

    2011-01-01

    We report a comprehensive review of the UV-visible spectrum and rotational lightcurve of Vesta combining new observations by Hubble Space Telescope and Swift with archival International Ultraviolet Explorer observations. The geometric albedos of Vesta from 220 nm to 953 nm arc derived by carefully comparing these observations from various instruments at different times and observing geometries. Vesta has a rotationally averaged geometric albedo of 0.09 at 250 nm, 0.14 at 300 nm, 0.26 at 373 nm, 0.38 at 673 nm, and 0.30 at 950 nm. The linear spectral slope in the ultraviolet displays a sharp minimum ncar sub-Earth longitude of 20deg, and maximum in the eastern hemisphere. This is completely consistent with the distribution of the spectral slope in the visible wavelength. The uncertainty of the measurement in the ultraviolet is approx.20%, and in the visible wavelengths better than 10%. The amplitude of Vesta's rotational lightcurves is approx.10% throughout the range of wavelengths we observed, but is smaller at 950 nm (approx.6%) ncar the 1-micron mafic band center. Contrary to earlier reports, we found no evidence for any difference between the phasing of the ultraviolet and visible/ncar-infrared lightcurves with respect to sub-Earth longitude. Vesta's average spectrum between 220 and 950 nm can well be described by measured reflectance spectra of fine particle howardite-like materials of basaltic achondrite meteorites. Combining this with the in-phase behavior of the ultraviolet, visible. and ncar-infrared lightcurves, and the spectral slopes with respect to the rotational phase, we conclude that there is no global ultraviolet/visible reversal on Vesta. Consequently, this implies lack of global space weathering on Vesta. Keyword,: Asteroid Vesta; Spectrophotometry; Spectroscopy; Ultraviolet observations; Hubble Space Telescope observations

  16. Calificación del sistema de HVAC en una planta de producción de IFA

    Directory of Open Access Journals (Sweden)

    Otto Reyes

    2006-12-01

    Full Text Available La calificación de áreas asépticas constituye uno de los requerimientos esenciales en el cumplimiento de regulaciones nacionales para la fabricación de productos estériles. Se realizó la calificación inicial (as built de una Planta de Ingrediente Farmacéutico Activo (IFA para la fabricación de vacunas contra tétanos, fiebre tifoidea y tos ferina. Las comprobaciones estuvieron basadas en normas internacionales y para ello se empleó un equipamiento que cumple con los requerimientos para la industria farmacéutica. Pudo comprobarse que el sistema de clima es capaz de garantizar los parámetros críticos de operación de las áreas limpias, aunque algunos criterios de pruebas opcionales no fueron cumplidos.Los resultados obtenidos sirven como referencia para el control de los parámetros del sistema de HVAC y para la toma de acciones correctivas.

  17. Analysis of an HVAC system for the molten cuprous chloride pouring operation in an industrial hydrogen production facility

    Energy Technology Data Exchange (ETDEWEB)

    Ghandehariun, S.; Talimi, M.; Rosen, M.A.; Naterer, G.F. [University of Ontario Inst. of Technology, Oshawa, ON (Canada). Faculty of Engineering and Applied Science

    2010-07-01

    Hydrogen can be produced by thermochemical water decomposition from various heat sources. The copper-chlorine (Cu-Cl) cycle is a potential future cycle that could be linked with nuclear reactors to thermally decompose water into oxygen and hydrogen, through intermediate copper and chlorine compounds. Heat is transferred between various processes. Effective heat recovery from the molten CuCl within the cycle is important for achieving high efficiency. This paper described the fundamentals of a preliminary HVAC system design for the molten CuCl pouring operation in an industrial facility, and the use of air cleaning devices to remove contaminants before discharge to the outdoor air. Heat recovery from molten CuCl involves calculating duct diameters to provide the desired duct air velocity through the system. The fan size is determined by evaluating the static pressure. An adequate supply of make-up air must be provided to replace the air exhausted through the ventilation system. This paper described the economics of the ventilation system as well as ways to protect employee health and minimize the costs associated with exhaust ventilation. 20 refs., 1 tab., 5 figs.

  18. Integrated analysis of CFD data with K-means clustering algorithm and extreme learning machine for localized HVAC control

    International Nuclear Information System (INIS)

    Zhou, Hongming; Soh, Yeng Chai; Wu, Xiaoying

    2015-01-01

    Maintaining a desired comfort level while minimizing the total energy consumed is an interesting optimization problem in Heating, ventilating and air conditioning (HVAC) system control. This paper proposes a localized control strategy that uses Computational Fluid Dynamics (CFD) simulation results and K-means clustering algorithm to optimally partition an air-conditioned room into different zones. The temperature and air velocity results from CFD simulation are combined in two ways: 1) based on the relationship indicated in predicted mean vote (PMV) formula; 2) based on the relationship extracted from ASHRAE RP-884 database using extreme learning machine (ELM). Localized control can then be effected in which each of the zones can be treated individually and an optimal control strategy can be developed based on the partitioning result. - Highlights: • The paper provides a visual guideline for thermal comfort analysis. • CFD, K-means, PMV and ELM are used to analyze thermal conditions within a room. • Localized control strategy could be developed based on our clustering results

  19. Ultraviolet radiation therapy and UVR dose models

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, David Robert, E-mail: davidrobert.grimes@oncology.ox.ac.uk [School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland and Cancer Research UK/MRC Oxford Institute for Radiation Oncology, Gray Laboratory, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ (United Kingdom)

    2015-01-15

    Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed.

  20. Ultraviolet radiation therapy and UVR dose models

    International Nuclear Information System (INIS)

    Grimes, David Robert

    2015-01-01

    Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed

  1. Solar ultraviolet irradiance variations: a review

    International Nuclear Information System (INIS)

    Lean, J.

    1987-01-01

    Despite the geophysical importance of solar ultraviolet radiation, specific aspects of its temporal variations have not yet been adequately determined experimentally, nor are the mechanisms for the variability completely understood. Satellite observations have verified the reality of solar ultraviolet irradiance variations over time scales of days and months, and model calculations have confirmed the association of these short-term variations with the evolution and rotation of regions of enhanced magnetic activity on the solar disc. However, neither rocket nor satellite measurements have yet been made with sufficient accuracy and regularity to establish unequivocally the nature of the variability over the longer time of the 11-year solar cycle. The comparative importance for the long-term variations of local regions of enhanced magnetic activity and global scale activity perturbations is still being investigated. Solar ultraviolet irradiance variations over both short and long time scales are reviewed, with emphasis on their connection to solar magnetic activity. Correlations with ground-based measures of solar variability are examined because of the importance of the ground-based observations as historical proxies of ultraviolet irradiance variations. Current problems in understanding solar ultraviolet irradiance variations are discussed, and the measurements planned for solar cycle 22, which may resolve these problems, are briefly described. copyright American Geophysical Union 1987

  2. Mutations induced by ultraviolet light

    International Nuclear Information System (INIS)

    Pfeifer, Gerd P.; You, Young-Hyun; Besaratinia, Ahmad

    2005-01-01

    The different ultraviolet (UV) wavelength components, UVA (320-400 nm), UVB (280-320 nm), and UVC (200-280 nm), have distinct mutagenic properties. A hallmark of UVC and UVB mutagenesis is the high frequency of transition mutations at dipyrimidine sequences containing cytosine. In human skin cancers, about 35% of all mutations in the p53 gene are transitions at dipyrimidines within the sequence 5'-TCG and 5'-CCG, and these are localized at several mutational hotspots. Since 5'-CG sequences are methylated along the p53 coding sequence in human cells, these mutations may be derived from sunlight-induced pyrimidine dimers forming at sequences that contain 5-methylcytosine. Cyclobutane pyrimidine dimers (CPDs) form preferentially at dipyrimidines containing 5-methylcytosine when cells are irradiated with UVB or sunlight. In order to define the contribution of 5-methylcytosine to sunlight-induced mutations, the lacI and cII transgenes in mouse fibroblasts were used as mutational targets. After 254 nm UVC irradiation, only 6-9% of the base substitutions were at dipyrimidines containing 5-methylcytosine. However, 24-32% of the solar light-induced mutations were at dipyrimidines that contain 5-methylcytosine and most of these mutations were transitions. Thus, CPDs forming preferentially at dipyrimidines with 5-methylcytosine are responsible for a considerable fraction of the mutations induced by sunlight in mammalian cells. Using mouse cell lines harboring photoproduct-specific photolyases and mutational reporter genes, we showed that CPDs (rather than 6-4 photoproducts or other lesions) are responsible for the great majority of UVB-induced mutations. An important component of UVB mutagenesis is the deamination of cytosine and 5-methylcytosine within CPDs. The mutational specificity of long-wave UVA (340-400 nm) is distinct from that of the shorter wavelength UV and is characterized mainly by G to T transversions presumably arising through mechanisms involving oxidized DNA

  3. Mutagenesis of Trichoderma Viride by Ultraviolet and Plasma

    International Nuclear Information System (INIS)

    Yao Risheng; Li Manman; Deng Shengsong; Hu Huajia; Wang Huai; Li Fenghe

    2012-01-01

    Considering the importance of a microbial strain capable of increased cellulase production, a mutant strain UP4 of Trichoderma viride was developed by ultraviolet (UV) and plasma mutation. The mutant produced a 21.0 IU/mL FPase which was 98.1% higher than that of the parent strain Trichoderma viride ZY-1. In addition, the effect of ultraviolet and plasma mutagenesis was not merely simple superimposition of single ultraviolet mutation and single plasma mutation. Meanwhile, there appeared a capsule around some of the spores after the ultraviolet and plasma treatment, namely, the spore surface of the strain became fuzzy after ultraviolet or ultraviolet and plasma mutagenesis.

  4. Mutagenesis of Trichoderma Viride by Ultraviolet and Plasma

    Science.gov (United States)

    Yao, Risheng; Li, Manman; Deng, Shengsong; Hu, Huajia; Wang, Huai; Li, Fenghe

    2012-04-01

    Considering the importance of a microbial strain capable of increased cellulase production, a mutant strain UP4 of Trichoderma viride was developed by ultraviolet (UV) and plasma mutation. The mutant produced a 21.0 IU/mL FPase which was 98.1% higher than that of the parent strain Trichoderma viride ZY-1. In addition, the effect of ultraviolet and plasma mutagenesis was not merely simple superimposition of single ultraviolet mutation and single plasma mutation. Meanwhile, there appeared a capsule around some of the spores after the ultraviolet and plasma treatment, namely, the spore surface of the strain became fuzzy after ultraviolet or ultraviolet and plasma mutagenesis.

  5. The ultraviolet variations of iota Cas

    Science.gov (United States)

    Molnar, M. R.; Mallama, A. D.; Soskey, D. G.; Holm, A. V.

    1976-01-01

    The Ap variable star iota Cas was observed with the photometers on OAO-2 covering the spectral range 1430-4250 A. The ultraviolet light curves show a double wave with primary minimum and maximum at phase ? 0.00 and 0.35, respectively. Secondary minimum light is at phase ? 0.65 with secondary maximum at phase ? 0.85. The light curves longward of 3150 A vary in opposition to those shortward of this 'null region'. Ground-based coude spectra show that the Fe II and Cr II line strengths have a double-wave variation such that maximum strength occurs at minimum ultraviolet light. We suggest that the strong ultraviolet opacities due to photoionization and line blanketing by these metals may cause the observed photometric variations. We have also constructed an oblique-rotator model which shows iron and chromium lying in a great circle band rather than in circular spots.

  6. JUDE: An Ultraviolet Imaging Telescope pipeline

    Science.gov (United States)

    Murthy, J.; Rahna, P. T.; Sutaria, F.; Safonova, M.; Gudennavar, S. B.; Bubbly, S. G.

    2017-07-01

    The Ultraviolet Imaging Telescope (UVIT) was launched as part of the multi-wavelength Indian AstroSat mission on 28 September, 2015 into a low Earth orbit. A 6-month performance verification (PV) phase ended in March 2016, and the instrument is now in the general observing phase. UVIT operates in three channels: visible, near-ultraviolet (NUV) and far-ultraviolet (FUV), each with a choice of broad and narrow band filters, and has NUV and FUV gratings for low-resolution spectroscopy. We have written a software package (JUDE) to convert the Level 1 data from UVIT into scientifically useful photon lists and images. The routines are written in the GNU Data Language (GDL) and are compatible with the IDL software package. We use these programs in our own scientific work, and will continue to update the programs as we gain better understanding of the UVIT instrument and its performance. We have released JUDE under an Apache License.

  7. The ultraviolet telescope on the Astron satellite

    International Nuclear Information System (INIS)

    Boyarchuk, A.A.

    1987-01-01

    On 23 March 1983 in the USSR, the Astron astrophysical satellite, with the largest ultraviolet telescope (the UVT) in the world (main mirror diameter 80 cm) and a set of X-ray instruments on board was placed in a high-apogee orbit. The design of the ultraviolet telescope and the results of some of the observations carried out with it are described here. The X-ray instruments are discussed in a separate article. The ultraviolet telescope on the Astron astrophysical satellite is a result of the joint efforts of scientists and engineers at the Crimean Astrophysical Observatory (Academy of Sciences of the USSR), the Byurakan Astrophysical Observatory (Academy of Sciences of the Armenian USSR), and several industrial enterprises in our country. The Laboratoire d'Astronomie Spatiale (CNRS, Marseille, France) played a large role in building the spectrometer for the UVT

  8. Modelling and Display of the Ultraviolet Sky

    Science.gov (United States)

    Daniels, J.; Henry, R.; Murthy, J.; Allen, M.; McGlynn, T. A.; Scollick, K.

    1994-12-01

    A computer program is currently under development to model in 3D - one dimension of which is wavelength - all the known and major speculated sources of ultraviolet (900 A - 3100 A ) radiation over the celestial sphere. The software is being written in Fortran 77 and IDL and currently operates under IRIX (the operating system of the Silicon Graphics Iris Machine); all output models are in FITS format. Models along with display software will become available to the astronomical community. The Ultraviolet Sky Model currently includes the Zodiacal Light, Point Sources of Emission, and the Diffuse Galactic Light. The Ultraviolet Sky Model is currently displayed using SkyView: a package under development at NASA/ GSFC, which allows users to retrieve and display publically available all-sky astronomical survey data (covering many wavebands) over the Internet. We present a demonstration of the SkyView display of the Ultraviolet Model. The modelling is a five year development project: the work illustrated here represents product output at the end of year one. Future work includes enhancements to the current models and incorporation of the following models: Galactic Molecular Hydrogen Fluorescence; Galactic Highly Ionized Atomic Line Emission; Integrated Extragalactic Light; and speculated sources in the intergalactic medium such as Ionized Plasma and radiation from Non-Baryonic Particle Decay. We also present a poster which summarizes the components of the Ultraviolet Sky Model and outlines a further package that will be used to display the Ultraviolet Model. This work is supported by United States Air Force Contract F19628-93-K-0004. Dr J. Daniels is supported with a post-doctoral Fellowship from the Leverhulme Foundation, London, United Kingdom. We are also grateful for the encouragement of Dr Stephen Price (Phillips Laboratory, Hanscomb Air Force Base, MA)

  9. Molecular geometry in the ultraviolet absorption spectra

    International Nuclear Information System (INIS)

    Albuquerque, S.F. de; Monteiro, L.S.; Adamis, L.M.B.; Baltar, M.C.P.; Silva, R.M. da

    1977-01-01

    The ultraviolet absorption spectra may be sensibly affected by steric effects. These effects can cause a lot of difficulties and unexpected changes in spectrum. The most general source of such difficulties is steric inhibition of resonance. In addition to this, ultraviolet epectra may be markedly changed by steric factors which change the positions of dipoles in the molecule with respect to each other and by the interaction of nonconjugated chromophores suitably located in space. We have studied in detail each of these effects presenting a lot of usual and importants examples in Organic Chemistry. Others relevants subjects were not considerated in this present work [pt

  10. Disinfection of drinking water by ultraviolet light

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    It is no longer mandatory that a given residue of chlorine is present in drinking water and this has led to interest in the use of ultraviolet radiation for disinfection of water in large public waterworks. After a brief discussion of the effect of ultraviolet radiation related to wavelength, the most usual type of irradiation equipment is briefly described. Practioal considerations regarding the installation, such as attenuation of the radiation due to water quality and deposits are presented. The requirements as to dose and residence time are also discussed and finally it is pointed out that hydraulic imperfections can reduce the effectiveness drastically. (JIW)Ψ

  11. Nanoscale freestanding gratings for ultraviolet blocking filters

    Energy Technology Data Exchange (ETDEWEB)

    van Beek, J.T.; Fleming, R.C.; Hindle, P.S.; Prentiss, J.D.; Schattenburg, M.L. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Ritzau, S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1998-11-01

    Ultraviolet (UV) blocking filters are needed for atomic flux imaging in environments where high levels of ultraviolet radiation are present. Freestanding gratings are a promising candidate for UV filtering. They have a high aspect ratio ({approximately}13), narrow ({approximately}40 nm) slots, and effectively block UV radiation. The grating fabrication process makes use of several etching, electroplating, and lithographic steps and includes an optional step to plug pinholes induced by particles during processing. Gratings were successfully manufactured and tested. Measured UV transmissions of {approximately}10{sup {minus}5} and particle transmissions of {approximately}10{percent} are in agreement with theoretical predictions. {copyright} {ital 1998 American Vacuum Society.}

  12. Quartz glass behavior at ultraviolet spectrum region

    International Nuclear Information System (INIS)

    Braga, A.F.B.; Barbosa, L.C.; Evora, C.A.P.D.

    1990-01-01

    Melted quartz ingots were produced from raw materials of different sources. Behavior studies of these three different quartz glass were made at the eletromagnetic spectrum ultraviolet region. The atomic absorption spectroscopy was used as an analysis technique of the alkaline, transition and aluminum metal traces. It was found that the alkaline, transition and aluminum metals impurities present a great influence on the melted quartz spectral behavior at the ultraviolet region. It was stated that measurments at this spectrum region constitute an important characterization technique to natural quartz as well as melted quartz. (author) [pt

  13. Plasmonic enhancement of ultraviolet fluorescence

    Science.gov (United States)

    Jiao, Xiaojin

    Plasmonics relates to the interaction between electromagnetic radiation and conduction electrons at metallic interfaces or in metallic nanostructures. Surface plasmons are collective electron oscillations at a metal surface, which can be manipulated by shape, texture and material composition. Plasmonic applications cover a broad spectrum from visible to near infrared, including biosensing, nanolithography, spectroscopy, optoelectronics, photovoltaics and so on. However, there remains a gap in this activity in the ultraviolet (UV, research. Motivating factors in the study of UV Plasmonics are the direct access to biomolecular resonances and native fluorescence, resonant Raman scattering interactions, and the potential for exerting control over photochemical reactions. This dissertation aims to fill in the gap of Plasmonics in the UV with efforts of design, fabrication and characterization of aluminium (Al) and magnesium (Mg) nanostructures for the application of label-free bimolecular detection via native UV fluorescence. The first contribution of this dissertation addresses the design of Al nanostructures in the context of UV fluorescence enhancement. A design method that combines analytical analysis with numerical simulation has been developed. Performance of three canonical plasmonic structures---the dipole antenna, bullseye nanoaperture and nanoaperture array---has been compared. The optimal geometrical parameters have been determined. A novel design of a compound bullseye structure has been proposed and numerically analyzed for the purpose of compensating for the large Stokes shift typical of UV fluorescence. Second, UV lifetime modification of diffusing molecules by Al nanoapertures has been experimentally demonstrated for the first time. Lifetime reductions of ~3.5x have been observed for the high quantum yield (QY) laser dye p-terphenyl in a 60 nm diameter aperture with 50 nm undercut. Furthermore, quantum-yield-dependence of lifetime reduction has been

  14. ESA innovation rescues Ultraviolet Observatory

    Science.gov (United States)

    1995-10-01

    Astrophysicist Freeman J. Dyson from the Institute for Advanced Studies in Princeton characterizes IUE as "A little half-meter mirror sitting in the sky, unnoticed by the public, pouring out results". By use of the IUE satellite, astronomers obtain access to the ultraviolet radiation of celestial bodies in unique ways not available by any other means, neither from the ground nor by any other spacecraft currently in orbit. IUE serves a wide community of astronomers all over Europe, the United States and many other parts of the world. It allows the acquisition of critical data for fundamental studies of comets and their evaporation when they approach the Sun, of the mechanisms driving the stellar winds which make many stars lose a significant fraction of their mass (before they die slowly as White Dwarfs or in sudden Supernova explosions), as well as in the search to understand the ways in which black holes possibly power the violent nuclei of Active galaxies. One year ago the project was threatened with termination and serious concern was expressed by astronomers about the potential loss of IUE's capabilities, as a result of NASA not continuing to operate the spacecraft. Under the leadership of ESA, the three Agencies involved in the operations of IUE (ESA, NASA and the United Kingdom's Particle Physics and Astronomy Research Council, PPARC), reviewed the operations agreements of the Project. A minor investment allowing the implementation of modern management and engineering techniques as well as a complete revision of the communication infrastructure of the project and continuous improvements in efficiency in the ESA management, also taking advantage of today's technologies, both in computing and communications, have made it possible to continue IUE operations within the financial means available, with ESA taking up most of NASA's share in the operations. According to Dr. Willem Wamsteker, ESA's Dutch IUE Project Scientist, "it was a extremely interesting

  15. Far-ultraviolet spectral changes of titanium dioxide with gold nanoparticles by ultraviolet and visible light

    Science.gov (United States)

    Tanabe, Ichiro; Kurawaki, Yuji

    2018-05-01

    Attenuated total reflectance spectra including the far-ultraviolet (FUV, ≤ 200 nm) region of titanium dioxide (TiO2) with and without gold (Au) nanoparticles were measured. A newly developed external light-irradiation system enabled to observe spectral changes of TiO2 with Au nanoparticles upon light irradiations. Absorption in the FUV region decreased and increased by the irradiation with ultraviolet and visible light, respectively. These spectral changes may reflect photo-induced electron transfer from TiO2 to Au nanoparticles under ultraviolet light and from Au nanoparticles to TiO2 under visible light, respectively.

  16. Solar ultraviolet radiation in a changing climate

    Science.gov (United States)

    The projected large increases in damaging ultraviolet radiation as a result of global emissions of ozone-depleting substances have been forestalled by the success of the Montreal Protocol. New challenges are now arising in relation to climate change. We highlight the complex inte...

  17. Habitat impact on ultraviolet reflectance in moths

    Czech Academy of Sciences Publication Activity Database

    Zapletalová, Lenka; Zapletal, Michal; Konvička, Martin

    2016-01-01

    Roč. 45, č. 5 (2016), s. 1300-1305 ISSN 0046-225X R&D Projects: GA ČR(CZ) GA14-33733S Institutional support: RVO:60077344 Keywords : Lepidoptera * ultraviolet reflectance * mimicry Subject RIV: EH - Ecology, Behaviour Impact factor: 1.601, year: 2016

  18. Characterization of ethanol concentrations at ultraviolet wavelength ...

    African Journals Online (AJOL)

    This paper presents the measurement of optical absorption spectrum for different concentrations of ethanol at ultraviolet wavelength. Ethanol absorption spectrum was measured using portable spectroscopy setup from Avantes. It consists of Balanced Deuterium Halogen light source and spectrometer. The light source can ...

  19. Ultraviolet spectra of Mg in liquid helium

    International Nuclear Information System (INIS)

    Moriwaki, Y.; Morita, N.

    1999-01-01

    Emission and absorption spectra of Mg atoms implanted in liquid helium have been observed in the ultraviolet region. We have presented a model of exciplex formation of Mg-He 10 and found that this model is more suitable for understanding the dynamics in the 3s3p 1 P→3s 21 S transition than the bubble model. (orig.)

  20. Combined ultraviolet studies of astronomical sources

    Science.gov (United States)

    Baliunas, S. L.; Dupree, A. K.; Elvis, M.; Huchra, J. P.; Kenyon, S.; Raymond, J. C.

    1986-01-01

    Topics addressed include: Cygnus Loop; P Cygni profiles in dwarf novae; YY Gem; nova shells; HZ Herculis; activity cycles in cluster giants; Alpha Ori; metal deficient giant stars; ultraviolet spectra of symbiotic stars detected by the Very Large Array; time variability in symbiotic stars; blue galaxies; and quasistellar objects with X-ray spectra.

  1. The impact of ultraviolet radiation on timber

    International Nuclear Information System (INIS)

    Dawson, B.

    1993-01-01

    Photochemical degradation of timber, the outcome of exposure of timber to ultraviolet radiation, is a light induced chemical and physical decay. Timber is a collection of dead wood cells. Impacts of radiation on the growing tree are therefore outside the scope of this paper, which is primarily concerned with timber as a material. (author). 5 refs. 2 figs

  2. 21 CFR 878.4635 - Ultraviolet lamp for tanning.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultraviolet lamp for tanning. 878.4635 Section 878... tanning. (a) Identification. An ultraviolet lamp for tanning is a device that is a lamp (including a fixture) intended to provide ultraviolet radiation to tan the skin. See § 1040.20 of this chapter. (b...

  3. 21 CFR 880.6710 - Medical ultraviolet water purifier.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical ultraviolet water purifier. 880.6710... Miscellaneous Devices § 880.6710 Medical ultraviolet water purifier. (a) Identification. A medical ultraviolet water purifier is a device intended for medical purposes that is used to destroy bacteria in water by...

  4. International Energy Agency Building Energy Simulation Test and Diagnostic Method for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST); Volume 1: Cases E100-E200

    Energy Technology Data Exchange (ETDEWEB)

    Neymark, J.; Judkoff, R.

    2002-01-01

    This report describes the Building Energy Simulation Test for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST) project conducted by the Tool Evaluation and Improvement International Energy Agency (IEA) Experts Group. The group was composed of experts from the Solar Heating and Cooling (SHC) Programme, Task 22, Subtask A. The current test cases, E100-E200, represent the beginning of work on mechanical equipment test cases; additional cases that would expand the current test suite have been proposed for future development.

  5. Classical ultraviolet photoelectron spectroscopy of polymers

    International Nuclear Information System (INIS)

    Salaneck, W.R.

    2009-01-01

    Although X-ray photoelectron spectroscopy of polymers was well established by Clark and coworkers in the 1970s, ultraviolet photoelectron spectroscopy of polymer films, was developed later. Previous to the 1970s, the first attempts to use ultraviolet light on polymer films took the form of appearance potential (valence band edge) measurements. Only some years later could the full valence band region of thin polymer films, including insulating polymers, semiconducting polymers and electrically conducting polymers. The development of what might be termed 'classical ultraviolet photoelectron spectroscopy' of polymer films may be loosely based upon a variety of issues, including adapting thin polymer film technology to ultra high vacuum studies, the widespread use of helium resonance lamps for studies of solid surfaces, the combined advent of practical and sufficient theoretical-computational methods. The advent of, and the use of, easily available synchrotron radiation for multi-photon spectroscopies, nominally in the area of the near UV, is not included in the term 'classical'. At the same time, electrically conducting polymers were discovered, leading to applications of the corresponding semiconducting polymers, which added technologically driven emphasis to this development of ultraviolet photoelectron spectroscopy for polymer materials. This paper traces a limited number of highlights in the evolution of ultraviolet photoelectron spectroscopy of polymers, from the 1970s through to 2008. Also, since this issue is dedicated to Prof. Kazuhiko Seki, who has been a friend and competitor for over two decades, the author relies on some of Prof. Seki's earlier research, unpublished, on who-did-what-first. Prof. Seki's own contributions to the field, however, are discussed in other articles in this issue.

  6. Effect of ultraviolet exposure on mitochondrial respiratory system

    Energy Technology Data Exchange (ETDEWEB)

    Noda, K [Kurume Univ., Fukuoka (Japan). School of Medicine

    1975-09-01

    To find the photodynamic effect of ultraviolet light on the mitochondrial respiratory chain, mitochondria were obtained from rat livers, and the suspension was exposed to an extensive ultraviolet light. The oxygen consumption was measured polarographically with a Clark oxygen electrode. The effect of ultraviolet exposure on the five states of respiratory control (Chance and Williams), the P/O ratio, and the respiratory control index in mitochondria was discussed. The ultraviolet light with a dose of 9.6 x 10/sup 6/ erg/cm/sup 2/ caused the oxidative phosphorylation in mitochondria to uncouple. The 2nd phosphorylation site of the respiratory chain was susceptible to ultraviolet exposure. The stimulation of latent ATPase activity in mitochondria following exposure was observed by increasing exposure of ultraviolet light. However, DNP-stimulated ATPase was found to be stable in activity. The uncoupling of the respiratory chain by ultraviolet exposure was not detected if the mitochondrial suspension was preincubated with bovine serum albumin before exposure. The changes in light absorption of the mitochondrial suspension were followed at 520 nm after exposure. A close correlation was found between the ultraviolet exposure and swelling in mitochondria. But, the reversing contraction was observed by adding ATP to the swelled mitochondria. The peroxide compound was formed in mitochondria irradiated with ultraviolet light. The amount of compounds formed was dependent on the radiant energy of ultraviolet light. The possible mechanisms involved in the photodynamic effect of ultraviolet light to the mitochondrial respiration system were discussed.

  7. Evaluating the Sensitivity of the Mass-Based Particle Removal Calculations for HVAC Filters in ISO 16890 to Assumptions for Aerosol Distributions

    Directory of Open Access Journals (Sweden)

    Brent Stephens

    2018-02-01

    Full Text Available High efficiency particle air filters are increasingly being recommended for use in heating, ventilating, and air-conditioning (HVAC systems to improve indoor air quality (IAQ. ISO Standard 16890-2016 provides a methodology for approximating mass-based particle removal efficiencies for PM1, PM2.5, and PM10 using size-resolved removal efficiency measurements for 0.3 µm to 10 µm particles. Two historical volume distribution functions for ambient aerosol distributions are assumed to represent ambient air in urban and rural areas globally. The goals of this work are to: (i review the ambient aerosol distributions used in ISO 16890, (ii evaluate the sensitivity of the mass-based removal efficiency calculation procedures described in ISO 16890 to various assumptions that are related to indoor and outdoor aerosol distributions, and (iii recommend several modifications to the standard that can yield more realistic estimates of mass-based removal efficiencies for HVAC filters, and thus provide a more realistic representation of a greater number of building scenarios. The results demonstrate that knowing the PM mass removal efficiency estimated using ISO 16890 is not sufficient to predict the PM mass removal efficiency in all of the environments in which the filter might be used. The main reason for this insufficiency is that the assumptions for aerosol number and volume distributions can substantially impact the results, albeit with some exceptions.

  8. Thermal issues associated with the HVAC and lighting systems influences on the performance of the national ignition facility beam transport tubes

    International Nuclear Information System (INIS)

    Bernardin, J.D.; Parietti, L.; Martin, R.A.

    1998-01-01

    This report summarizes an investigation of the thermal issues related to the National Ignition Facility. In particular, the influences of the HVAC system and lighting fixtures on the operational performance of the laser guide beam tubes are reviewed and discussed. An analytical model of the oscillating HVAC air temperatures in the NIF switchyard and target bay will cause significant amounts of beam distortion. However, these negative effects can be drastically reduced by adding thermal insulation to the outside of the beam tubes. A computational fluid dynamics model and an analytical investigation found that the light-fixture to beam-tube separation distance must be on the order of 5.7 m (18.7 ft) to maintain acceptable beam operating performance in the current NIF design. By reducing the fluorescent light fixture power by 33% this separation distance can be reduced to 3.5 m (11.5 ft). If in addition, thermal insulation with a reflective aluminum foil covering is added to the outside of the beam tubes, the separation distance can be reduced further to 1.6m (5.2 ft). A 1.27 cm (0.5 in.) rigid foam insulation sheet with aluminum foil covering will provide adequate insulation for the beam tubes in the NIF switchyards and target bay. The material cost for this amount of insulation would be roughly $30,000

  9. ULTRAVIOLET HALOS AROUND SPIRAL GALAXIES. I. MORPHOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Hodges-Kluck, Edmund; Cafmeyer, Julian; Bregman, Joel N., E-mail: hodgeskl@umich.edu [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States)

    2016-12-10

    We examine ultraviolet halos around a sample of highly inclined galaxies within 25 Mpc to measure their morphology and luminosity. Despite contamination from galactic light scattered into the wings of the point-spread function, we find that ultraviolet (UV) halos occur around each galaxy in our sample. Around most galaxies the halos form a thick, diffuse disk-like structure, but starburst galaxies with galactic superwinds have qualitatively different halos that are more extensive and have filamentary structure. The spatial coincidence of the UV halos above star-forming regions, the lack of consistent association with outflows or extraplanar ionized gas, and the strong correlation between the halo and galaxy UV luminosity suggest that the UV light is an extragalactic reflection nebula. UV halos may thus represent 10{sup 6}–10{sup 7} M {sub ⊙} of dust within 2–10 kpc of the disk, whose properties may change with height in starburst galaxies.

  10. Contact lens disinfection by ultraviolet light

    International Nuclear Information System (INIS)

    Dolman, P.J.; Dobrogowski, M.J.

    1989-01-01

    A 253.7-nm ultraviolet light with an intensity of 1,100 microW/cm2 was tested for its germicidal activity against contact lenses and storage solutions contaminated with various corneal pathogens. The exposure time necessary to reduce a concentration of organisms from 10(6)/ml to less than 10/ml was 30 seconds for Staphylococcus aureus, 60 seconds for Pseudomonas aeruginosa, and 84 seconds for Candida albicans. The time necessary to sterilize a suspension of 10(4)/ml Acanthamoeba polyphaga was less than three minutes with this technique. Four brands of soft contact lenses were exposed to ultraviolet light for over eight hours without changing their appearance, comfort, or refraction

  11. Effective polycrystalline sensor of ultraviolet radiation

    Directory of Open Access Journals (Sweden)

    S.Yu. Pavelets

    2017-10-01

    Full Text Available Deposition of special thin layers with high and low resistance in space charge region of surface barrier photoconverters based on the p-Cu1.8S/n-CdS structure leads to a sufficient increase in photosensitivity and decrease in dark tunneling-recombination current. Highly efficient and stable polycrystalline photoconverters of ultraviolet radiation based on polycrystalline CdS have been obtained. Electrical and photoelectric properties have been investigated, and the main operational parameters of ultraviolet sensors have been adduced. The reasons for high stability of the parameters inherent to the p-Cu1.8S/n-CdS sensors are as follows: the absence of impurity components additionally doped to the barrier structure and stability of the photocurrent photoemission component.

  12. Subdwarf ultraviolet excesses and metal abundances

    International Nuclear Information System (INIS)

    Carney, B.W.

    1979-01-01

    The relation between stellar ultraviolet excesses and abundances is reexamined with the aid of new data, and an investigation is made of the accuracy of previous abundance analyses. A high-resolution echellogram of the subdwarf HD 201891 is analyzed to illustrate some of the problems. Generally, the earliest and latest analytical techniques yield consistent results for dwarfs. New UBV data yield normalized ultraviolet excesses, delta (U-B)/sub 0.6/, which are compared to abundances to produce a graphical relation that may be used to estimate [Fe/H] to +- 0.2 dex, given UBV colors accurate to +- 0.01 mag. The relation suggests a possible discontinuity between the halo and old-disk stars

  13. Cosmetic and medical applications of ultraviolet radiation

    International Nuclear Information System (INIS)

    Diffey, B.L.

    1987-01-01

    The social desirability of a tanned skin is apparent and many people associate a bronzed body with good health and a sense of well-being. In Northern Europe and America the lack of long periods of sunshine has led to the establishment of the suntanning industry where artificial sources of ultraviolet radiation emitting almost entirely in the UV-A region supplement sunlight exposure

  14. Ultraviolet stability in euclidean scalar field theories

    Energy Technology Data Exchange (ETDEWEB)

    Benfatto, G; Cassandro, M; Gallavotti, G; Nicolo, F; Olivieri, E; Presutti, E; Scacciatelli, E [Rome Univ. (Italy). Istituto di Matematica; Rome Univ. (Italy). Istituto di Fisica)

    1980-01-01

    We develop a technique for reducing the problem of the ultraviolet divergences and their removal to a free field problem. This work is an example of a problem to which a rather general method can be applied. It can be thought as an attempt towards a rigorous version (in 2 or 3 space-time dimensions) of the analysis of the structure of the functional integrals, the underlying mechanism being essentially the same as in Glimms approach.

  15. Ultraviolet signals in birds are special.

    OpenAIRE

    Hausmann, Franziska; Arnold, Kathryn E; Marshall, N Justin; Owens, Ian P F

    2003-01-01

    Recent behavioural experiments have shown that birds use ultraviolet (UV)-reflective and fluorescent plumage as cues in mate choice. It remains controversial, however, whether such UV signals play a special role in sexual communication, or whether they are part of general plumage coloration. We use a comparative approach to test for a general association between sexual signalling and either UV-reflective or fluorescent plumage. Among the species surveyed, 72% have UV colours and there is a si...

  16. Impurity study of TMX using ultraviolet spectroscopy

    International Nuclear Information System (INIS)

    Allen, S.L.; Strand, O.T.; Moos, H.W.; Fortner, R.J.; Nash, T.J.; Dietrich, D.D.

    1981-01-01

    An extreme ultraviolet (EUV) study of the emissions from intrinsic and injected impurities in TMX is presented. Two survey spectrographs were used to determine that the major impurities present were oxygen, nitrogen, carbon, and titanium. Three absolutely-calibrated monochromators were used to measure the time histories and radial profiles of these impurity emissions in the central cell and each plug. Two of these instruments were capable of obtaining radial profiles as a function of time in a single shot

  17. Minimal length uncertainty relation and ultraviolet regularization

    Science.gov (United States)

    Kempf, Achim; Mangano, Gianpiero

    1997-06-01

    Studies in string theory and quantum gravity suggest the existence of a finite lower limit Δx0 to the possible resolution of distances, at the latest on the scale of the Planck length of 10-35 m. Within the framework of the Euclidean path integral we explicitly show ultraviolet regularization in field theory through this short distance structure. Both rotation and translation invariance can be preserved. An example is studied in detail.

  18. The Ultraviolet Index: a useful tool.

    Science.gov (United States)

    Kinney, J P; Long, C S

    2000-09-01

    The Ultraviolet Index was developed in the United States in 1994 following successful use of ultraviolet (UV) alerts in other countries. This daily National Weather Service prediction is a calculation which integrates five data elements to yield the amount of UV radiation impacting the surface (1m2) at solar noon in 58 of the largest US population centers. This simple numeric prediction is then categorized by the Environmental Protection Agency into five "exposure levels" with protective actions recommended for each level. This information is disseminated through the media. Daily reminders seem to affect awareness and behavior in Canada, but US surveys indicate the need for better understanding through educational graphics. Comparing the UV Index to a precipitation prediction has merit in that it links a familiar daily prediction with implied appropriate protective measures. Graphics link the ideas that "when it rains it pours and when it shines it radiates." Beginning in schools, camps, and dermatology meetings, using the rain/shine analogy, a wider exposure to the Ultraviolet Index is proposed.

  19. Wireless Infrastructure for Performing Monitoring, Diagnostics, and Control HVAC and Other Energy-Using Systems in Small Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Patrick O' Neill

    2009-06-30

    This project focused on developing a low-cost wireless infrastructure for monitoring, diagnosing, and controlling building systems and equipment. End users receive information via the Internet and need only a web browser and Internet connection. The system used wireless communications for: (1) collecting data centrally on site from many wireless sensors installed on building equipment, (2) transmitting control signals to actuators and (3) transmitting data to an offsite network operations center where it is processed and made available to clients on the Web (see Figure 1). Although this wireless infrastructure can be applied to any building system, it was tested on two representative applications: (1) monitoring and diagnostics for packaged rooftop HVAC units used widely on small commercial buildings and (2) continuous diagnosis and control of scheduling errors such as lights and equipment left on during unoccupied hours. This project developed a generic infrastructure for performance monitoring, diagnostics, and control, applicable to a broad range of building systems and equipment, but targeted specifically to small to medium commercial buildings (an underserved market segment). The proposed solution is based on two wireless technologies. The first, wireless telemetry, is used for cell phones and paging and is reliable and widely available. This risk proved to be easily managed during the project. The second technology is on-site wireless communication for acquiring data from sensors and transmitting control signals. The technology must enable communication with many nodes, overcome physical obstructions, operate in environments with other electrical equipment, support operation with on-board power (instead of line power) for some applications, operate at low transmission power in license-free radio bands, and be low cost. We proposed wireless mesh networking to meet these needs. This technology is relatively new and has been applied only in research and tests

  20. Inhibition of seagrass photosynthesis by ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Trocine, R.P.; Rice, J.D.; Wells, G.N.

    1981-01-01

    Effects of ultraviolet-B radiation on the photosynthesis of seagrasses (Halophila engelmanni Aschers, Halodule wrightii Aschers, and Syringodium filiforme (Kuetz) were examined. The intrinsic tolerance of each seagrass to ultraviolet-B, the presence and effectiveness of photorepair mechanisms to ultraviolet-B-induced photosynthetic inhibition, and the role of epiphytic growth as a shield from ultraviolet-B were investigated. Halodule was found to possess the greatest photosynthetic tolerance for ultraviolet-B. Photosynthesis in Syringodium was slightly more sensitive to ultraviolet-B while Halophila showed relatively little photosynthetic tolerance. Evidence for a photorepair mechanism was found only in Halodule. Syringodium appeared to rely primarily on a thick epidermal cell layer to reduce photosynthetic damage. Halophila seemed to have no morphological or photorepair capabilities to deal with ultraviolet-B. This species appeared to rely on epiphytic and detrital shielding and the shade provided by other seagrasses to reduce ultraviolet-B irradiation to tolerable levels. The presence of epiphytes on leaf surfaces was found to reduce the extent of photosynthetic inhibition from ultraviolet-B exposure in all species. Halophila appears to obtain an increased photosynthetic tolerance to ultraviolet-B as an indirect benefit of chloroplast clumping to avoid photo-oxidation by intense levels of photosynthetically active radiation

  1. LARGE BUILDING HVAC SIMULATION

    Science.gov (United States)

    The report discusses the monitoring and collection of data relating to indoor pressures and radon concentrations under several test conditions in a large school building in Bartow, Florida. The Florida Solar Energy Center (FSEC) used an integrated computational software, FSEC 3.0...

  2. Disinfection Effect of Film Cassettes by Ultraviolet Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kweon, Dae Cheol; Park, Peom [Ajou Univ., Suwon (Korea, Republic of)

    2001-12-15

    A bacteria infection on film cassette contact surface was examined at the diagnostic radiology department. Studies have demonstrated a bactericidal effect of ultraviolet irradiation, and to assess the contamination level on film cassette contact surface as a predictor of patient prevent from nosocomial infection. The study showed that the laboratory result was identified non-pathologic and pathologic bacterial in the five different cassette size of the contact surface. Film cassettes were exposed to ultraviolet light for 1, 2 and 3 minutes. Ultraviolet light disinfection practices suitable for bacteria. The study concludes that presence of a bacterial infection will prevent a using antiseptic technique on film cassette contact surface. In conclusion, ultraviolet irradiate on film cassette over the surface more than 2 minutes. Ultraviolet dose of 1565 {mu}W {center_dot} s/cm{sup 2}Win in 30 second relative to ultraviolet dose in time.

  3. Disinfection Effect of Film Cassettes by Ultraviolet Irradiation

    International Nuclear Information System (INIS)

    Kweon, Dae Cheol; Park, Peom

    2001-01-01

    A bacteria infection on film cassette contact surface was examined at the diagnostic radiology department. Studies have demonstrated a bactericidal effect of ultraviolet irradiation, and to assess the contamination level on film cassette contact surface as a predictor of patient prevent from nosocomial infection. The study showed that the laboratory result was identified non-pathologic and pathologic bacterial in the five different cassette size of the contact surface. Film cassettes were exposed to ultraviolet light for 1, 2 and 3 minutes. Ultraviolet light disinfection practices suitable for bacteria. The study concludes that presence of a bacterial infection will prevent a using antiseptic technique on film cassette contact surface. In conclusion, ultraviolet irradiate on film cassette over the surface more than 2 minutes. Ultraviolet dose of 1565 μW · s/cm 2 Win in 30 second relative to ultraviolet dose in time

  4. Guidelines for the application of upper-room ultraviolet germicidal irradiation for preventing transmission of airborne contagion -- Part 2: Design and operation guidance

    Energy Technology Data Exchange (ETDEWEB)

    First, M.W.; Nardell, E.A.; Chaisson, W.; Riley, R.

    1999-07-01

    Installations of ultraviolet germicidal irradiation (UVGI) have been stimulated recently by a sudden rise in the incidence of tuberculosis. Hospitals, jails, and homeless shelters have been the most frequently equipped facilities because they are places where many tuberculosis cases are found, the buildings housing them tend to be old and not suited for economical increases in air exchange rates, and the work staffs have been apprehensive about transmission to themselves and their families. The diversity in structures currently being equipped with UVGI installations, plus the introduction of new designs of lamps and fixtures, have made it clear that an updated review of equipment performance factors and practical installation guidelines will be useful to interested parties. Illustrative examples are given of installations that have been made in a diverse set of facilities. In addition, representative figures are given to compare the cost of HVAC installations and UVGI installations that give an equivalent number of air changes based on equal levels of reduction in airborne microorganisms.

  5. Inhibition of seagrass photosynthesis by ultraviolet-B radiation.

    Science.gov (United States)

    Trocine, R P; Rice, J D; Wells, G N

    1981-07-01

    Effects of ultraviolet-B radiation on the photosynthesis of seagrasses (Halophila engelmanni Aschers, Halodule wrightii Aschers, and Syringodium filiforme Kütz) were examined. The intrinsic tolerance of each seagrass to ultraviolet-B, the presence and effectiveness of photorepair mechanisms to ultraviolet-B-induced photosynthetic inhibition, and the role of epiphytic growth as a shield from ultraviolet-B were investigated.Halodule was found to possess the greatest photosynthetic tolerance for ultraviolet-B. Photosynthesis in Syringodium was slightly more sensitive to ultraviolet-B while Halophila showed relatively little photosynthetic tolerance. Evidence for a photorepair mechanism was found only in Halodule. This mechanism effectively attenuated photosynthetic inhibition induced by ultraviolet-B dose rates and dosages in excess of natural conditions. Syringodium appeared to rely primarily on a thick epidermal cell layer to reduce photosynthetic damage. Halophila seemed to have no morphological or photorepair capabilities to deal with ultraviolet-B. This species appeared to rely on epiphytic and detrital shielding and the shade provided by other seagrasses to reduce ultraviolet-B irradiation to tolerable levels. The presence of epiphytes on leaf surfaces was found to reduce the extent of photosynthetic inhibition from ultraviolet-B exposure in all species.Observations obtained in this study seem to suggest the possibility of anthocyanin and/or other flavonoid synthesis as an adaptation to long term ultraviolet-B irradiation by these species. In addition, Halophila appears to obtain an increased photosynthetic tolerance to ultraviolet-B as an indirect benefit of chloroplast clumping to avoid photo-oxidation by intense levels of photosynthetically active radiation.

  6. Ultraviolet spectrophotometer for measuring columnar atmospheric ozone from aircraft

    Science.gov (United States)

    Hanser, F. A.; Sellers, B.; Briehl, D. C.

    1978-01-01

    An ultraviolet spectrophotometer (UVS) to measure downward solar fluxes from an aircraft or other high altitude platform is described. The UVS uses an ultraviolet diffuser to obtain large angular response with no aiming requirement, a twelve-position filter wheel with narrow (2-nm) and broad (20-nm) bandpass filters, and an ultraviolet photodiode. The columnar atmospheric ozone above the UVS (aircraft) is calculated from the ratios of the measured ultraviolet fluxes. Comparison with some Dobson station measurements gives agreement to 2%. Some UVS measured ozone profiles over the Pacific Ocean for November 1976 are shown to illustrate the instrument's performance.

  7. In-orbit Calibrations of the Ultraviolet Imaging Telescope

    Science.gov (United States)

    Tandon, S. N.; Subramaniam, Annapurni; Girish, V.; Postma, J.; Sankarasubramanian, K.; Sriram, S.; Stalin, C. S.; Mondal, C.; Sahu, S.; Joseph, P.; Hutchings, J.; Ghosh, S. K.; Barve, I. V.; George, K.; Kamath, P. U.; Kathiravan, S.; Kumar, A.; Lancelot, J. P.; Leahy, D.; Mahesh, P. K.; Mohan, R.; Nagabhushana, S.; Pati, A. K.; Kameswara Rao, N.; Sreedhar, Y. H.; Sreekumar, P.

    2017-09-01

    The Ultra-Violet Imaging Telescope (UVIT) is one of the payloads in ASTROSAT, the first Indian Space Observatory. The UVIT instrument has two 375 mm telescopes: one for the far-ultraviolet (FUV) channel (1300-1800 Å), and the other for the near-ultraviolet (NUV) channel (2000-3000 Å) and the visible (VIS) channel (3200-5500 Å). UVIT is primarily designed for simultaneous imaging in the two ultraviolet channels with spatial resolution better than 1.″8, along with provisions for slit-less spectroscopy in the NUV and FUV channels. The results of in-orbit calibrations of UVIT are presented in this paper.

  8. In-orbit Calibrations of the Ultraviolet Imaging Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Tandon, S. N. [Inter-University Center for Astronomy and Astrophysics, Pune (India); Subramaniam, Annapurni; Sankarasubramanian, K.; Sriram, S.; Stalin, C. S.; Mondal, C.; Sahu, S.; Joseph, P.; Barve, I. V.; George, K.; Kamath, P. U.; Kathiravan, S.; Kumar, A.; Lancelot, J. P.; Mahesh, P. K. [Indian Institute of Astrophysics, Koramangala II Block, Bangalore-560034 (India); Girish, V. [ISRO Satellite Centre, HAL Airport Road, Bangalore 560017 (India); Postma, J.; Leahy, D. [University of Calgary, 2500 University Drive NW, Calgary, Alberta Canada (Canada); Hutchings, J. [National Research Council of Canada, Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Ghosh, S. K., E-mail: purni@iiap.res.in [National Centre for Radio Astrophysics, Pune (India); and others

    2017-09-01

    The Ultra-Violet Imaging Telescope (UVIT) is one of the payloads in ASTROSAT, the first Indian Space Observatory. The UVIT instrument has two 375 mm telescopes: one for the far-ultraviolet (FUV) channel (1300–1800 Å), and the other for the near-ultraviolet (NUV) channel (2000–3000 Å) and the visible (VIS) channel (3200–5500 Å). UVIT is primarily designed for simultaneous imaging in the two ultraviolet channels with spatial resolution better than 1.″8, along with provisions for slit-less spectroscopy in the NUV and FUV channels. The results of in-orbit calibrations of UVIT are presented in this paper.

  9. Ultraviolet air disinfection for protection against influenza

    International Nuclear Information System (INIS)

    Riley, R.L.

    1977-01-01

    Three converging lines of evidence support the belief that it may be possible, under appropriate circumstances, to interrupt the airborne transmission of influenza by ultraviolet (UV) air disinfection. These lines of evidence are: (a) that influenza is airborne; (b) that UV irradiation of the upper air of a room can provide safe and effective disinfection of air in the lower part of the room; and (c) that epidemic spread of airborne viral infections in humans can be prevented if the population under consideration remains in the UV-protected environment

  10. Far ultraviolet spectrophotometry of BD +28 4211

    Science.gov (United States)

    Cook, Timothy A.; Cash, Webster; Green, James C.

    1991-01-01

    The results are reported of a November 1989 rocket flight which recorded a flux-calibrated spectrum of BD +28 4211 from 912 to 1150 A with 1A resolution. BD +28 4211, an SdO-type star, is commonly used as an ultraviolet calibration source in the IUE wavelength band. The present work extends the useful range of this standard shortward of Lyman-alpha. Since previous experiments show marked disparity, this study can be useful in determining a standard in the 912 to 1216 A band.

  11. Probing nanoscale ferroelectricity by ultraviolet Raman spectroscopy.

    Science.gov (United States)

    Tenne, D A; Bruchhausen, A; Lanzillotti-Kimura, N D; Fainstein, A; Katiyar, R S; Cantarero, A; Soukiassian, A; Vaithyanathan, V; Haeni, J H; Tian, W; Schlom, D G; Choi, K J; Kim, D M; Eom, C B; Sun, H P; Pan, X Q; Li, Y L; Chen, L Q; Jia, Q X; Nakhmanson, S M; Rabe, K M; Xi, X X

    2006-09-15

    We demonstrated that ultraviolet Raman spectroscopy is an effective technique to measure the transition temperature (Tc) in ferroelectric ultrathin films and superlattices. We showed that one-unit-cell-thick BaTiO3 layers in BaTiO3/SrTiO3 superlattices are not only ferroelectric (with Tc as high as 250 kelvin) but also polarize the quantum paraelectric SrTiO3 layers adjacent to them. Tc was tuned by approximately 500 kelvin by varying the thicknesses of the BaTiO3 and SrTiO3 layers, revealing the essential roles of electrical and mechanical boundary conditions for nanoscale ferroelectricity.

  12. Ultraviolet Flux Variation of Epsilon Aurigae

    Directory of Open Access Journals (Sweden)

    Young Woon Kang

    1990-06-01

    Full Text Available The eighteen ultraviolet light curves of Epsilon Aurigae have been plotted using the integrated fluxes reduced from the 233 IUE low dispersion spectra taken between 1978 and 1986. The times of contacts and depth of eclipse have been determined from the light curves at the wavelength from 2550 Å to 3050 Å. The UV light curves show two brightenings during the totality, the downward slope of the variation from the second to the third contacts, and asymmetry of the eclipse light curve. The two selected spectra note that the energy density distribution is not changed between the totality of the eclipse and out-of-eclipse.

  13. Dynamical structure of extreme ultraviolet macrospicules

    Science.gov (United States)

    Karovska, Margarita; Habbal, Shadia Rifai

    1994-01-01

    We describe the substructures forming the macrospicules and their temporal evolution, as revealed by the application of an image enhancement algorithm to extreme ultraviolet (EUV) observations of macrospicules. The enhanced images uncover, for the first time, the substructures forming the column-like structures within the macrospicules and the low-lying arches at their base. The spatial and temporal evolution of macrospicules clearly show continuous interaction between these substructures with occasional ejection of plasma following a ballistic trajectory. We comment on the importance of these results for planning near future space observations of macrospicules with better temporal and spatial resolution.

  14. Impact of Ultraviolet Light on Vitiligo.

    Science.gov (United States)

    Singh, Rasnik K

    2017-01-01

    Vitiligo is a disorder of the melanocytes that results in a dynamic spectrum of skin depigmentation. Its etiology is complex and multifactorial, with data supporting several different hypotheses. Given its prominent phenotype, vitiligo has a significant negative impact on quality of life. Coupled with the chronic and incurable nature of the disease, this presents a formidable treatment challenge. Several treatment modalities have been instituted over the years, with varying efficacy. This chapter focuses on the use of ultraviolet light in vitiligo as an established therapeutic option.

  15. International Energy Agency Building Energy Simulation Test and Diagnostic Method for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST): Volume 2: Cases E300-E545.

    Energy Technology Data Exchange (ETDEWEB)

    Neymark J.; Judkoff, R.

    2004-12-01

    This report documents an additional set of mechanical system test cases that are planned for inclusion in ANSI/ASHRAE STANDARD 140. The cases test a program's modeling capabilities on the working-fluid side of the coil, but in an hourly dynamic context over an expanded range of performance conditions. These cases help to scale the significance of disagreements that are less obvious in the steady-state cases. The report is Vol. 2 of HVAC BESTEST Volume 1. Volume 1 was limited to steady-state test cases that could be solved with analytical solutions. Volume 2 includes hourly dynamic effects, and other cases that cannot be solved analytically. NREL conducted this work in collaboration with the Tool Evaluation and Improvement Experts Group under the International Energy Agency (IEA) Solar Heating and Cooling Programme Task 22.

  16. Technical and economic aspects of fuel cell applications in space HVAC systems; Technische und wirtschaftliche Aspekte zum Einsatz von Brennstoffzellen in der Gebaeudeversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Handke, J; Handschin, E

    1999-12-31

    There are two different types of fuel cells for small-scale applications, li.e. polymer electrolyte membrane fuel cells (PEMFC) and high-termperature fuel cells with ceramic solid electrolytes (SOFC). Both types of fuel cells have different advantages and shortcomings. One of the main problems, however, is the fact that research is still going on and that commercial fuel cell systems for space HVAC applications are still not available. (orig.) [Deutsch] Nach dem heutigen Stand werden zwei unterschiedliche Brennstoffzellen-Typen zum Einsatz in Kleinanlagen entwickelt. Neben der zu Klasse der Niedertemperatur-Brennstoffzellen gehoerenden Polymer-Elektrolyt-Membran-Brennstoffzelle (PEMFC) ist dies die Hochtemperatur-Brennstoffzelle auf der Basis eines keramischen Festelektrolyten (SOFC). Beide Brennstoffzellen-Typen haben unterschiedliche Vor- und Nachteile fuer den Einsatz zur Gebaeudeversorgung. Eines der Hauptprobleme, das allerdings beide Zellentypen gemeinsam haben, besteht in der noch nicht abgeschlossenen Entwicklung und - daraus resultierend - der fehlenden kommerziellen Verfuegbarkeit im Bereich der Gebaeudeversorgung. (orig./MM)

  17. High volume acupuncture clinic (HVAC) for chronic knee pain--audit of a possible model for delivery of acupuncture in the National Health Service.

    Science.gov (United States)

    Berkovitz, Saul; Cummings, Mike; Perrin, Chris; Ito, Rieko

    2008-03-01

    Recent research has established the efficacy, effectiveness and cost effectiveness of acupuncture for some forms of chronic musculoskeletal pain. However, there are practical problems with delivery which currently prevent its large scale implementation in the National Health Service. We have developed a delivery model at our hospital, a 'high volume' acupuncture clinic (HVAC) in which patients are treated in a group setting for single conditions using standardised or semi-standardised electroacupuncture protocols by practitioners with basic training. We discuss our experiences using this model for chronic knee pain and present an outcome audit for the first 77 patients, demonstrating satisfactory initial (eight week) clinical results. Longer term (one year) data are currently being collected and the model should next be tested in primary care to confirm its feasibility.

  18. FAINT NEAR-ULTRAVIOLET/FAR-ULTRAVIOLET STANDARDS FROM SWIFT/UVOT, GALEX, AND SDSS PHOTOMETRY

    International Nuclear Information System (INIS)

    Siegel, Michael H.; Hoversten, Erik A.; Roming, Peter W. A.; Brown, Peter

    2010-01-01

    At present, the precision of deep ultraviolet photometry is somewhat limited by the dearth of faint ultraviolet standard stars. In an effort to improve this situation, we present a uniform catalog of 11 new faint (u ∼ 17) ultraviolet standard stars. High-precision photometry of these stars has been taken from the Sloan Digital Sky Survey and Galaxy Evolution Explorer archives and combined with new data from the Swift Ultraviolet Optical Telescope to provide precise photometric measures extending from the near-infrared to the far-ultraviolet. These stars were chosen because they are known to be hot (20, 000 eff < 50, 000 K) DA white dwarfs with published Sloan spectra that should be photometrically stable. This careful selection allows us to compare the combined photometry and Sloan spectroscopy to models of pure hydrogen atmospheres to both constrain the underlying properties of the white dwarfs and test the ability of white dwarf models to predict the photometric measures. We find that the photometry provides good constraints on white dwarf temperatures, which demonstrates the ability of Swift/UVOT to investigate the properties of hot luminous stars. We further find that the models reproduce the photometric measures in all 11 passbands to within their systematic uncertainties. Within the limits of our photometry, we find the standard stars to be photometrically stable. This success indicates that the models can be used to calibrate additional filters to our standard system, permitting easier comparison of photometry from heterogeneous sources. The largest source of uncertainty in the model fitting is the uncertainty in the foreground reddening curve, a problem that is especially acute in the UV.

  19. Ultraviolet and Infrared Correlation Studies in Orion

    Directory of Open Access Journals (Sweden)

    Bose Lakshmi S.

    2015-09-01

    Full Text Available We have studied the variation of diffuse ultraviolet (UV radiation in the northern part of the Orion constellation using a set of eight areas of the GALEX All-Sky Imaging Survey in the far and near UV. Different components of diffuse UV radiation, like dust scattered emission and H2 fluorescence, were quantified and separated after removing the point sources and the foreground emission in each of the fields. Then the dependence of the individual UV components on the infrared 100 μm dust emission was studied. We did not find any positive correlation between the diffuse-UV and IR-100 micron intensities, probably due to the high optical depth of the region or the entire dust column not contributing to the diffuse UV radiation. However, in the far UV we noticed the presence of an excess emission in addition to the dust scattered radiation, which is clearly absent in the near UV. This excess emission, identified as the H2 fluorescence, is produced by the Trapezium stars in the surrounding molecular clouds. We also compare our results with those of previous studies in the region, based on Far Ultraviolet Spectroscopic Explorer (FUSE observations.

  20. ULTRAVIOLET EXTINCTION AT HIGH GALACTIC LATITUDES

    Energy Technology Data Exchange (ETDEWEB)

    Peek, J. E. G.; Schiminovich, David, E-mail: jegpeek@gmail.com [Department of Astronomy, Columbia University, New York, NY (United States)

    2013-07-01

    In order to study the properties and effects of high Galactic latitude dust, we present an analysis of 373,303 galaxies selected from the Galaxy Evolution Explorer All-Sky Survey and Wide-field Infrared Explorer All-Sky Data Release. By examining the variation in aggregate ultraviolet colors and number density of these galaxies, we measure the extinction curve at high latitude. We additionally consider a population of spectroscopically selected galaxies from the Sloan Digital Sky Survey to measure extinction in the optical. We find that dust at high latitude is neither quantitatively nor qualitatively consistent with standard reddening laws. Extinction in the FUV and NUV is {approx}10% and {approx}35% higher than expected, with significant variation across the sky. We find that no single R{sub V} parameter fits both the optical and ultraviolet extinction at high latitude, and that while both show detectable variation across the sky, these variations are not related. We propose that the overall trends we detect likely stem from an increase in very small silicate grains in the interstellar medium.

  1. ULTRAVIOLET EXTINCTION AT HIGH GALACTIC LATITUDES

    International Nuclear Information System (INIS)

    Peek, J. E. G.; Schiminovich, David

    2013-01-01

    In order to study the properties and effects of high Galactic latitude dust, we present an analysis of 373,303 galaxies selected from the Galaxy Evolution Explorer All-Sky Survey and Wide-field Infrared Explorer All-Sky Data Release. By examining the variation in aggregate ultraviolet colors and number density of these galaxies, we measure the extinction curve at high latitude. We additionally consider a population of spectroscopically selected galaxies from the Sloan Digital Sky Survey to measure extinction in the optical. We find that dust at high latitude is neither quantitatively nor qualitatively consistent with standard reddening laws. Extinction in the FUV and NUV is ∼10% and ∼35% higher than expected, with significant variation across the sky. We find that no single R V parameter fits both the optical and ultraviolet extinction at high latitude, and that while both show detectable variation across the sky, these variations are not related. We propose that the overall trends we detect likely stem from an increase in very small silicate grains in the interstellar medium.

  2. Inhibition of DNA replication by ultraviolet light

    International Nuclear Information System (INIS)

    Edenberg, H.J.

    1976-01-01

    DNA replication in ultraviolet-irradiated HeLa cells was studied by two different techniques: measurements of the kinetics of semiconservative DNA synthesis, and DNA fiber autoradiography. In examining the kinetics of semiconservative DNA synthesis, density label was used to avoid measuring the incorporation due to repair replication. The extent of inhibition varied with time. After doses of less than 10 J/m 2 the rate was initially depressed but later showed some recovery. After higher doses, a constant, low rate of synthesis was seen for at least the initial 6 h. An analysis of these data indicated that the inhibition of DNA synthesis could be explained by replication forks halting at pyrimidine dimers. DNA fiber autoradiography was used to further characterize replication after ultraviolet irradiation. The average length of labeled segments in irradiated cells increased in the time immediately after irradiation, and then leveled off. This is the predicted pattern if DNA synthesis in each replicon continued at its previous rate until a lesion is reached, and then halted. The frequency of lesions that block synthesis is approximately the same as the frequency of pyrimidine dimers

  3. Photomorphogenic responses to ultraviolet-B light.

    Science.gov (United States)

    Jenkins, Gareth I

    2017-11-01

    Exposure to ultraviolet B (UV-B) light regulates numerous aspects of plant metabolism, morphology and physiology through the differential expression of hundreds of genes. Photomorphogenic responses to UV-B are mediated by the photoreceptor UV RESISTANCE LOCUS8 (UVR8). Considerable progress has been made in understanding UVR8 action: the structural basis of photoreceptor function, how interaction with CONSTITUTIVELY PHOTOMORPHOGENIC 1 initiates signaling and how REPRESSOR OF UV-B PHOTOMORPHOGENESIS proteins negatively regulate UVR8 action. In addition, recent research shows that UVR8 mediates several responses through interaction with other signaling pathways, in particular auxin signaling. Nevertheless, many aspects of UVR8 action remain poorly understood. Most research to date has been undertaken with Arabidopsis, and it is important to explore the functions and regulation of UVR8 in diverse plant species. Furthermore, it is essential to understand how UVR8, and UV-B signaling in general, regulates processes under natural growth conditions. Ultraviolet B regulates the expression of many genes through UVR8-independent pathways, but the activity and importance of these pathways in plants growing in sunlight are poorly understood. © 2017 John Wiley & Sons Ltd.

  4. STELLAR ACTIVITY IN THE BROADBAND ULTRAVIOLET

    International Nuclear Information System (INIS)

    Findeisen, K.; Hillenbrand, L.; Soderblom, D.

    2011-01-01

    The completion of the GALEX All-Sky Survey in the ultraviolet allows activity measurements to be acquired for many more stars than is possible with the limited sensitivity of ROSAT or the limited sky coverage of Chandra, XMM, or spectroscopic surveys for line emission in the optical or ultraviolet. We have explored the use of GALEX photometry as an activity indicator, using stars within 50 pc as a calibration sample representing the field and in selected nearby associations representing the youngest stages of stellar evolution. We present preliminary relations between UV flux and the optical activity indicator R' HK and between UV flux and age. We demonstrate that far-UV (FUV, 1350-1780 A) excess flux is roughly proportional to R' HK . We also detect a correlation between near-UV (NUV, 1780-2830 A) flux and activity or age, but the effect is much more subtle, particularly for stars older than ∼0.5-1 Gyr. Both the FUV and NUV relations show large scatter, ∼0.2 mag when predicting UV flux, ∼0.18 dex when predicting R' HK , and ∼0.4 dex when predicting age. This scatter appears to be evenly split between observational errors in current state-of-the-art data and long-term activity variability in the sample stars.

  5. Pollen and spores as biological recorders of past ultraviolet irradiance

    NARCIS (Netherlands)

    Jardine, P.E.; Fraser, W.T.; Lomax, B.H.; Sephton, M.A.; Shanahan, T.M.; Miller, C.S.; Gosling, W.D.

    2016-01-01

    Solar ultraviolet (UV) irradiance is a key driver of climatic and biotic change. Ultraviolet irradiance modulates stratospheric warming and ozone production, and influences the biosphere from ecosystem-level processes through to the largest scale patterns of diversification and extinction. Yet our

  6. Ultraviolet radiation, human health, and the urban forest

    Science.gov (United States)

    Gordon M. Heisler; Richard H. Grant

    2000-01-01

    Excess exposure to ultraviolet (UV) radiation from the sun, particularly the ultraviolet B (UVB) portion, has been linked with adverse effects on human health ranging from skin cancers to eye diseases such as cataracts. Trees may prevent even greater disease rates in humans by reducing UV exposure. Tree shade greatly reduces UV irradiance when both the sun and sky are...

  7. An assessment of ultraviolet radiation components of light emitted ...

    African Journals Online (AJOL)

    An assessment of ultraviolet radiation components of light emitted from electric arc and their possible exposure risks. ... The study of Ultraviolet Radiation has of recent become interesting because of the health hazards it poses to human. Apart from its intensity reaching the earth from the sun, other man-made sources have ...

  8. 21 CFR 872.6070 - Ultraviolet activator for polymerization.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultraviolet activator for polymerization. 872.6070 Section 872.6070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ultraviolet radiation intended to polymerize (set) resinous dental pit and fissure sealants or restorative...

  9. 21 CFR 880.6500 - Medical ultraviolet air purifier.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical ultraviolet air purifier. 880.6500 Section 880.6500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... to ultraviolet radiation. (b) Classification. Class II (performance standards). ...

  10. 21 CFR 878.4630 - Ultraviolet lamp for dermatologic disorders.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultraviolet lamp for dermatologic disorders. 878.4630 Section 878.4630 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... disorders is a device (including a fixture) intended to provide ultraviolet radiation of the body to...

  11. Ultraviolet microscopy aids in cytological and biomedical research

    Science.gov (United States)

    Schlenk, F.; Svihla, B.

    1967-01-01

    Ultraviolet microscopy is used by cytologists and biochemists to study the morphological and physiological changes in the living cell under varied culture conditions. The yeast cell is used because of its content of ultraviolet absorbing materials and its lack of motility.

  12. Ultraviolet solar radiation and the prevention of erythema

    International Nuclear Information System (INIS)

    Tena, F.; Martinez-Lozano, J.A.; Utrillas, M.P.

    1998-01-01

    An ultraviolet index appropriate for its use in Spain is studied on the basis of those already available in other countries. The suitability of this index to characterise ultraviolet solar radiation and, particularly, the potential risks to human health are discussed. Finally, the main factors affecting this index are identified and their influence is studied. (Author) 43 refs

  13. Does ultraviolet radiation affect the xanthophyll cycle in marine phytoplankton?

    NARCIS (Netherlands)

    van de Poll, W.H.; Buma, A.G.J.

    2009-01-01

    This Perspective summarizes the state of knowledge of the impact of ultraviolet radiation on the photoprotective xanthophyll cycle in marine phytoplankton. Excess photosynthetically active radiation (PAR; 400-700 nm) and ultraviolet radiation (UVR; 280-400 nm) affect various cellular processes and

  14. Ultraviolet radiation, cancer of the skin and immunology

    International Nuclear Information System (INIS)

    Suurmond, D.

    1984-01-01

    The effects of near and far ultraviolet radiation on the development of skin neoplasms are reviewed. Especially the role of ultraviolet radiation in immunosuppression is discussed as a possible working mechanism of the tumor promoting the effect of this radiation, beside effects on DNA-repair. (Auth.)

  15. Resveratrol anti-ultraviolet-induced guinea pig skin injury

    International Nuclear Information System (INIS)

    Li Wenxing; Zhao Ying

    2014-01-01

    Objective: To Estimate on the protection effect of Stilbene on skin damage induced by ultraviolet radiation. Methods: After the normal skin in guinea pig under the intervene of Resveratrol was irradiated with over- dose of ultraviolet rays (UVB and UVA), the samples in every group were matched and compared. Results: The skin tissue in the Resveratrol intervene group irradiated by ultraviolet rays didn't change obviously as compared with that in the self-control group. But, the damage skin tissue in the control group irradiated by ultraviolet did change significantly as compared with that in the Stilbene intervene group. Conclusion: Resveratrol is a good material to protect the skin from damage effect by ultraviolet radiation. (authors)

  16. High intensity vacuum ultraviolet and extreme ultraviolet production by noncollinear mixing in laser vaporized media

    Energy Technology Data Exchange (ETDEWEB)

    Todt, Michael A.; Albert, Daniel R.; Davis, H. Floyd, E-mail: hfd1@cornell.edu [Baker Laboratory, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301 (United States)

    2016-06-15

    A method is described for generating intense pulsed vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) laser radiation by resonance enhanced four-wave mixing of commercial pulsed nanosecond lasers in laser vaporized mercury under windowless conditions. By employing noncollinear mixing of the input beams, the need of dispersive elements such as gratings for separating the VUV/XUV from the residual UV and visible beams is eliminated. A number of schemes are described, facilitating access to the 9.9–14.6 eV range. A simple and convenient scheme for generating wavelengths of 125 nm, 112 nm, and 104 nm (10 eV, 11 eV, and 12 eV) using two dye lasers without the need for dye changes is described.

  17. Ultraviolet-visible spectroscopy of graphene oxides

    Directory of Open Access Journals (Sweden)

    Qi Lai

    2012-09-01

    Full Text Available Dispersions of few-layer (1-3 layers, multi-layer (4-10 layers and thick-layer (>10 layers graphene oxide (GO were prepared by a modified Hummers method with different mass ratios of KMnO4 to graphite. Ultraviolet-visible (UV-vis spectroscopic data show that few-layer GO dispersions can be distinguished from multi- and thick-layer dispersions by a more intense peak at 230 nm. Atomic force microscopy (AFM images of few-layer GO contain a single peak, those of multi-layer GO exhibit a shoulder and those of thick-layer GO do not contain a peak or shoulder. These findings allow qualitative analysis of GO dispersions. X-ray photoelectron spectra (XPS show that the change of UV-vis absorption intensity of GO is caused by a conjugative effect related to chromophore aggregation that influences the π-π* plasmon peak.

  18. Preoperative ultraviolet B inflammation in skin

    DEFF Research Database (Denmark)

    Lunn, T H; Dawes, J M; Denk, F

    2018-01-01

    BACKGROUND: Neuroimmune interactions play a vital role in many of the most common pain conditions, such as arthritis. There have been many attempts to derive clinically predictive information from an individual's inflammatory response in order to gauge subsequent pain perception. OBJECTIVES: Here......, we wanted to test whether this effort could be enhanced and complemented by the use of a model system which takes into account the function of not just circulating, but also tissue-resident immune cells: ultraviolet B (UVB) irradiation of the skin. METHODS: We conducted psychophysical...... in the skin might predict the degree of a patient's neuro-immune response and the extent of their postoperative pain after total knee arthroplasty....

  19. Recovery of phage lambda from ultraviolet damage

    International Nuclear Information System (INIS)

    Devoret, R.; Blanco, M.; George, J.; Radman, M.

    1975-01-01

    Recovery of phage lambda from ultraviolet damage can occur, in the dark, through three types of repair processes as defined by microbiological tests: host-cell reactivation, prophage reactivation, and uv reactivation. This paper reviews the properties of the three repair processes, analyzes their dependence on the functioning of bacterial and phage genes, and discusses their relationship. Progress in the understanding of the molecular mechanisms underlying the three repair processes has been relatively slow, particularly for uv reactivation. It has been shown that host-cell reactivation is due to pyrimidine dimer excision and that prophage reactivation is due to genetic recombination (prereplicative). We provide evidence showing that neither of these mechanisms accounts for uv reactivation of phage lambda. Furthermore, uv reactivation differs from the other repair processes in that it is inducible and error-prone. Whether uv-damaged bacterial DNA is subject to a similar repair process is still an open question

  20. Al nanogrid electrode for ultraviolet detectors.

    Science.gov (United States)

    Ding, G; Deng, J; Zhou, L; Gan, Q; Hwang, J C M; Dierolf, V; Bartoli, F J; Mazuir, C; Schoenfeld, W V

    2011-09-15

    Optical properties of Al nanogrids of different pitches and gaps were investigated both theoretically and experimentally. Three-dimensional finite-difference time-domain simulation predicted that surface plasmons at the air/Al interface would enhance ultraviolet transmission through the subwavelength gaps of the nanogrid, making it an effective electrode on GaN-based photodetectors to compensate for the lack of transparent electrode and high p-type doping. The predicted transmission enhancement was verified by confocal scanning optical microscopy performed at 365 nm. The quality of the nanogrids fabricated by electron-beam lithography was verified by near-field scanning optical microscopy and scanning electron microscopy. Based on the results, the pitch and gap of the nanogrids can be optimized for the best trade-off between electrical conductivity and optical transmission at different wavelengths. Based on different cutoff wavelengths, the nanogrids can also double as a filter to render photodetectors solar-blind.

  1. Some resistance mechanisms to ultraviolet radiation

    International Nuclear Information System (INIS)

    Alcantara D, D.

    2002-12-01

    The cyclical exposure of bacterial cells to the ultraviolet light (UV) it has as consequence an increment in the resistance to the lethal effects of this type of radiation, increment that happens as a result of a selection process of favorable genetic mutations induced by the same UV light. With object to study the reproducibility of the genetic changes and the associate mechanisms to the resistance to UV in the bacteria Escherichia coli, was irradiated cyclically with UV light five different derived cultures of a single clone, being obtained five stumps with different resistance grades. The genetic mapping Hfr revealed that so much the mutation events like of selection that took place during the adaptation to the UV irradiation, happened of random manner, that is to say, each one of the resistant stumps it is the result of the unspecified selection of mutations arisen at random in different genes related with the repair and duplication of the DNA. (Author)

  2. Phototherapy cabinet for ultraviolet radiation therapy

    International Nuclear Information System (INIS)

    Horwitz, S.N.; Frost, P.

    1981-01-01

    A newly designed cabinet can be used for the treatment of psoriasis with fluorescent ultraviolet (UV) lamps. the new design provides more uniform distribution of UV radiation in both the horizontal and vertical axes, and several safety features have been added. The distribution and uniformity of UV output in this and in a previously described cabinet are compared. The UV output at the vertical center of the older UV light cabinet was six times greater than that at either the top or bottom, while the design of the present cabinet provides uniform UV radiation except for a slight increase at head height and at the level of the lower legs compared with the middle third of the cabinet. The variation in output of the older cabinet may, in part, explain the commonly encountered difficulty in the phototherapy of psoriasis of the scalp and lower extremities

  3. Ultraviolet-laser ablation of skin

    Energy Technology Data Exchange (ETDEWEB)

    Lane, R.J.; Linsker, R.; Wynne, J.J.; Torres, A.; Geronemus, R.G.

    1985-05-01

    The authors report on the use of pulsed ultraviolet-laser irradiation at 193 nm from an argon-fluoride laser and at 248 nm from a krypton-fluoride laser to ablate skin. In vitro, both wavelengths performed comparably, removing tissue precisely and cleanly, and leaving minimal thermal damage to the surrounding tissue. In vivo, the 193-nm laser radiation failed to remove tissue after bleeding began. The 248-nm radiation, however, continued to remove tissue despite bleeding and left a clean incision with only minimal thermal damage. The krypton-fluoride excimer laser beam at 248 nm, which should be deliverable through a quartz optical fiber, has great potential as a surgical instrument.

  4. Solar maximum ultraviolet spectrometer and polarimeter

    Science.gov (United States)

    Tandberg-Hanssen, E.; Woodgate, B. E.; Brandt, J. C.; Chapman, R. D.; Hyder, C. L.; Michalitsianos, A. G.; Shine, R. A.; Athay, R. G.; Beckers, J. M.; Bruner, E. C.

    1979-01-01

    The objectives of the UVSP experiment are to study solar ultraviolet radiations, particularly from flares and active regions, and to measure constituents in the terrestrial atmosphere by the extinction of sunlight at satellite dawn and dusk. The instrument is designed to observe the Sun at a variety of spectral and spatial resolutions in the range from 1150 to 3600 A. A Gregorian telescope with effective focal length of 1.8 m is used to feed a 1 m Ebert-Fastie spectrometer. A polarimeter containing rotatable magnesium fluoride waveplates is included behind the spectrometer entrance slit and will allow all four Stokes parameters to be determined. Velocities on the Sun can also be measured. The instrument is controlled by a computer which can interact with the data stream to modify the observing program. The observing modes, including rasters, spectral scans, velocity measurements, and polarimetry, are also described along with plans for mission operations, data handling, and analysis of the observations.

  5. Ultraviolet reflectance by the cere of raptors

    Science.gov (United States)

    Mougeot, François; Arroyo, Beatriz E

    2006-01-01

    Ultraviolet (UV) signals have been shown to play key roles in social and sexual signalling in birds. Using a spectrophotometer, we analysed the colour of the cere (skin above the beak) of a diurnal raptor, the Montagu's harrier (Circus pygargus), and show that it reflects in the UV part of the spectrum. The cere is a well-known sexual signal in raptors, with carotenoid based pigmentation being indicative of quality. We thus hypothesized that UV reflectance also signals quality. Accordingly, we found that in our sample of wild males, the location of the UV peak was related to the orangeness of cere and correlated with male body mass and condition (mass corrected for size). Also, males with brighter UV were mated to females that laid earlier, as expected if UV reflectance relates to a male's quality and attractiveness. Future studies should investigate the relationships between UV reflectance and carotenoid pigmentation of cere, and test how UV reflectance influences mate choice. PMID:17148356

  6. Free-electron lasers in ultraviolet photobiology

    International Nuclear Information System (INIS)

    Coohill, T.P.; Sutherland, J.C.

    1989-01-01

    The potential uses for a free-electron laser (FEL), tunable in wavelength from 10 to 400 nm, for photobiological experiments is discussed. Inherent problems of cell and molecular absorption, especially in certain regions of the ultraviolet (UV), are addressed. Absorption values for living cells and viruses at selected wavelengths in the UV are tabulated, and a calculation of the flux needed to inactivate mammalian cells is included. A comparison is made of the UV output of a proposed rf-linac FEL with those of a monochromator, a tunable dye laser, and a synchrotron. The advantages of a UV FEL are apparent, especially in the wavelength regions where the cross section for absorption by biological molecules is low, i.e., 300 to 400 nm and 10 to 200 nm. It is apparent that a UV FEL would be an ideal source for a variety of biological studies that use both intact organisms and isolated cells and viruses

  7. Protection from solar ultraviolet radiation by clothing

    Energy Technology Data Exchange (ETDEWEB)

    Pailthorpe, M. [New South Wales Univ., Kensington, NSW (Australia)

    1996-12-31

    The recently published Australia/New Zealand Standard AS/NZS 4399: l996 `Sun Protective Clothing - Evaluation and Classification` specifies an in vitro spectrophotometric method for the measurement of the ultraviolet (WR) transmission of textiles. Ultraviolet Protection Factors (UPF) are then calculated by convolving the UVR transmission data with standard CIE erythemal response data and ARL solar irradiance data. At the present time the scope of the standard is limited to loose fitting dry clothing. Virtually every textile parameter has an influence on the UPF of the finished garment and hence on the protection afforded to skin from the harmful effects of solar UVR radiation. Textile parameters such as fibre type, the method of spinning the yarn, fabric structure, cover factor, colorant, UVR absorbers and finishing methods determine the UPF of the fabric and hence must be controlled from batch to batch. Since garments generally shrink when washed, multiple wearing and washing cycles usually cause an increase in fabric UPF. Adventitious soiling of fabrics and the absorption of certain components of domestic laundry formulations, e g fluorescent whitening agents, increase fabric UPF ratings. Garments with a high degree of elasticity, e g nylon/lycra sportswear, that are stretched on to fit, will obviously have lower UPFs when stretched than when relaxed. In general fabrics worn in a wet state provide lower protection than when worn dry. On Australia`s most extreme summer day it has been estimated that there are 30 MEDs (minimal erythemal doses) in a dawn to dusk exposure. Thus outdoor workers should be provided with UPF 30 clothing, or better. Results from recent experiments using SK-II hairless mice dressed in UPF 50 `sunsuits` have shown that the mice developed no sun induced skin cancers on the skin areas protected by the UPF 50 fabric whereas multiple tumours developed on the unprotected skin.

  8. Ultraviolet A1 phototherapy: One center's experience

    Directory of Open Access Journals (Sweden)

    Sasi Kiran Attili

    2017-01-01

    Full Text Available Background: Ultraviolet A1(UVA1 phototherapy is increasingly being used in the treatment of morphea, atopic dermatitis, lupus and some other recalcitrant dermatoses. We present a retrospective review of our experience with this modality. Aim: To evaluate the treatment response rates for various dermatoses and adverse effects of UVA1 phototherapy. Methods: We reviewed phototherapy notes along with electronic and/or paper case records for all patients treated with UVA1 phototherapy from October 1996 to December 2008. Results: A total of 269 patients (outcomes available for 247 had 361 treatment courses (treatment data available for 317 courses over this period. We found phototherapy to be beneficial in 28 (53% of 53 patients with atopic dermatitis and 19 (51% of 37 patients with morphea. A beneficial outcome was recorded in all six (100% cases of urticaria and six (85.7% of seven patients treated for a polymorphic light eruption. Benefit was also recorded in systemic lupus erythematosus (8 (44.4% of 18, lichen sclerosus (6 (42.9% of 14, mastocytosis (2 (33.3% of 6, necrobiosis lipoidica (4 (30.8% of 13, granuloma annulare (2 (25% of 8, scleroderma (2 (22.2% of 9 and keloids (1 (7.7% of 13. Overall, treatment was well tolerated with no patients having to stop treatment due to adverse effects. Limitations: This is a retrospective study with no control group. Subjective/recall bias is quite possible as a number of patients were followed up over the phone. Conclusions: Our data suggest that ultraviolet A1 can be considered for the treatment of selected dermatoses. However, long-term malignancy risk is as yet unknown.

  9. Protection from solar ultraviolet radiation by clothing

    International Nuclear Information System (INIS)

    Pailthorpe, M.

    1996-01-01

    The recently published Australia/New Zealand Standard AS/NZS 4399: l996 'Sun Protective Clothing - Evaluation and Classification' specifies an in vitro spectrophotometric method for the measurement of the ultraviolet (WR) transmission of textiles. Ultraviolet Protection Factors (UPF) are then calculated by convolving the UVR transmission data with standard CIE erythemal response data and ARL solar irradiance data. At the present time the scope of the standard is limited to loose fitting dry clothing. Virtually every textile parameter has an influence on the UPF of the finished garment and hence on the protection afforded to skin from the harmful effects of solar UVR radiation. Textile parameters such as fibre type, the method of spinning the yarn, fabric structure, cover factor, colorant, UVR absorbers and finishing methods determine the UPF of the fabric and hence must be controlled from batch to batch. Since garments generally shrink when washed, multiple wearing and washing cycles usually cause an increase in fabric UPF. Adventitious soiling of fabrics and the absorption of certain components of domestic laundry formulations, e g fluorescent whitening agents, increase fabric UPF ratings. Garments with a high degree of elasticity, e g nylon/lycra sportswear, that are stretched on to fit, will obviously have lower UPFs when stretched than when relaxed. In general fabrics worn in a wet state provide lower protection than when worn dry. On Australia's most extreme summer day it has been estimated that there are 30 MEDs (minimal erythemal doses) in a dawn to dusk exposure. Thus outdoor workers should be provided with UPF 30 clothing, or better. Results from recent experiments using SK-II hairless mice dressed in UPF 50 'sunsuits' have shown that the mice developed no sun induced skin cancers on the skin areas protected by the UPF 50 fabric whereas multiple tumours developed on the unprotected skin

  10. Exposure to ultraviolet radiation: recommendations for cosmetic use

    International Nuclear Information System (INIS)

    Dias, C.; Carvalho, F.R.S.

    2000-01-01

    The beginning of the so-called tanning industry made possible the acquisition of a tanned skin independently of the available solar radiation. The tan is produced by ultraviolet radiation and, as well as in solar exposure, there are additional risks on the use of the so-called sun-beds. The damaging effects of ultraviolet exposure are well documented and reasonably quantified. The objective of this paper is to inform the potential effects of ultraviolet radiation exposure in sun-beds and to provide recommendations in order to reduce the associated risks. These recommendations are adapted for cosmetics use only (author)

  11. Biological applications of ultraviolet free-electron lasers

    International Nuclear Information System (INIS)

    Sutherland, J.C.

    1997-10-01

    This review examines the possibilities for biological research using the three ultraviolet free-electron lasers that are nearing operational status in the US. The projected operating characteristics of major interest in biological research of the free-electron lasers at Brookhaven National Laboratory, the Thomas Jefferson National Accelerator Facility, and Duke University are presented. Experimental applications in the areas of far- and vacuum ultraviolet photophysics and photochemistry, structural biology, environmental photobiology, and medical research are discussed and the prospects for advances in these areas, based upon the characteristics of the new ultraviolet free-electron lasers, are evaluated

  12. Extreme ultraviolet spectral irradiance measurements since 1946

    Science.gov (United States)

    Schmidtke, G.

    2015-03-01

    In the physics of the upper atmosphere the solar extreme ultraviolet (EUV) radiation plays a dominant role controlling most of the thermospheric/ionospheric (T/I) processes. Since this part of the solar spectrum is absorbed in the thermosphere, platforms to measure the EUV fluxes became only available with the development of rockets reaching altitude levels exceeding 80 km. With the availability of V2 rockets used in space research, recording of EUV spectra started in 1946 using photographic films. The development of pointing devices to accurately orient the spectrographs toward the sun initiated intense activities in solar-terrestrial research. The application of photoelectric recording technology enabled the scientists placing EUV spectrometers aboard satellites observing qualitatively strong variability of the solar EUV irradiance on short-, medium-, and long-term scales. However, as more measurements were performed more radiometric EUV data diverged due to the inherent degradation of the EUV instruments with time. Also, continuous recording of the EUV energy input to the T/I system was not achieved. It is only at the end of the last century that there was progress made in solving the serious problem of degradation enabling to monitore solar EUV fluxes with sufficient radiometric accuracy. The data sets available allow composing the data available to the first set of EUV data covering a period of 11 years for the first time. Based on the sophisticated instrumentation verified in space, future EUV measurements of the solar spectral irradiance (SSI) are promising accuracy levels of about 5% and less. With added low-cost equipment, real-time measurements will allow providing data needed in ionospheric modeling, e.g., for correcting propagation delays of navigation signals from space to earth. Adding EUV airglow and auroral emission monitoring by airglow cameras, the impact of space weather on the terrestrial T/I system can be studied with a spectral terrestrial

  13. Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

    International Nuclear Information System (INIS)

    Thorseth, Trond Morten

    2000-01-01

    The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe

  14. Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

    Energy Technology Data Exchange (ETDEWEB)

    Thorseth, Trond Morten

    2000-07-01

    The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe.

  15. Photoprotective Effect of Tea and its Extracts against Ultraviolet ...

    African Journals Online (AJOL)

    Ultraviolet (UV) exposure induces photodamage of skin. It is a matter of ... to the skin as well as the photoprotective effects of tea and its extracts have been highlighted. ..... storage of skin cream supplemented with green tea catechins or EGCG ...

  16. Protective effect of (-)-epigallocatechin gallate on ultraviolet b ...

    African Journals Online (AJOL)

    Purpose: To investigate the protective effect of green tea (-)-epigallocatechin gallate (EGCg) on ultraviolet B (UV-B)-induced skin damages in hairless mice in order to develop a natural sunscreen ... hydrophilic cream has also showed high.

  17. High Data Rate Optical Wireless Communications Based on Ultraviolet Band

    KAUST Repository

    Sun, Xiaobin

    2017-01-01

    Optical wireless communication systems based on ultraviolet (UV)-band has a lot inherent advantages, such as low background solar radiation, low device dark noise. Besides, it also has small restrictive requirements for PAT (pointing, acquisition

  18. Ultraviolet and environmental stresses involved in the induction and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... regulating plant development and genes expression. Ultraviolet takes up 7% of ... Fax: 82-33-241-6480. fruits, vegetables, flowers, and other plant tissues or ... Structural classification of general anthocyanidin species (Tahara ...

  19. Photosynthetic carbon reduction by seagrasses exposed to ultraviolet A radiation

    Science.gov (United States)

    1979-01-01

    The seagrasses Halophila engelmannii, Halodule wrightii, and Syringodium filiforme were examined for their intrinsic sensitivity to ultraviolet-A-UV-A and ultraviolet-B-UV-B radiation. The effect of UV-A on photosynthetically active radiation (PAR) was also determined. Ultraviolet-A and ultraviolet-B were studied with emphasis on the greater respective environmental consequence in terms of seagrass distribution and abundance. Results indicate that an intrinsic sensitivity to UV-A alone is apparent only in Halophila, while net photosynthesis in Halodule and Syringodium seems unaffected by the level of UV-A provided. The sensitivity of Halophila to UV-A in the absense of (PAR) indicates that the photosynthetic reaction does not need to be in operation for damage to occur. Other significant results are reported.

  20. Polymer filters for ultraviolet-excited integrated fluorescence sensing

    International Nuclear Information System (INIS)

    Dandin, Marc; Abshire, Pamela; Smela, Elisabeth

    2012-01-01

    Optical filters for blocking ultraviolet (UV) light were fabricated by doping various polymer hosts with a UV absorbing chromophore. The polymers were polydimethylsiloxane (PDMS), a silicone elastomer frequently used in microfluidics, SU-8, a photopatternable epoxy, and Humiseal 1B66, an acrylic coating used for moisture protection of integrated circuits. The chromophore was 2-(2′-hydroxy-5′-methylphenyl) benzotriazole (BTA), which has a high extinction coefficient between 300 nm and 400 nm. We demonstrate filters 5 µm thick that exhibit high ultraviolet rejection (nearly −40 dB at 342 nm) yet pass visible light (near 0 dB above 400 nm), making them ideal for ultraviolet-excited fluorescence sensing within microsystems. The absorbance of the BTA depended on the host polymer. These filters are promising for integrated fluorescence spectroscopy in bioanalytical platforms because they can be patterned by dry etching, molding or exposure to ultraviolet light. (paper)

  1. Ultraviolet light in the use of water disinfection

    International Nuclear Information System (INIS)

    Dabbagh, R.

    1999-01-01

    Ultraviolet light is an effective method in the use of water disinfection for swimming pools, potable water and industry required water. For many reasons Ultraviolet light and Ultraviolet compounded with chlorine (Ultraviolet/chlorine) has been brought to attention ed in resent years. In this research, a swimming pool water disinfection was carried out by means of a system with the use of a reactor which was made of stainless steel (SS-304) and with many another standards required. Operation of system was carried out at first in the pilot plant and then installation in essential water treatment integrated. Inactivation of pollution index, E. Coli or Total coliform and Pseudomonas aeroginosa studies with 6000,16000 and 30000 μW.s/cm 2 Ultraviolet dose and then in presence of 0.3,0.6,0.9 and 1.2 mg/1 free chlorine (Ultraviolet/chlorine). In swimming pools minimum free chlorine residual usually is 1.5 mg/1. Optimum Ultraviolet dose was 16000 μW.s/cm 2 attention to 50 percent Ultraviolet absorption ca sued to TSS,TDS and turbidity. In the Ultraviolet/chlorine system suitable rate was 16000μW.s/cm 2 Ultraviolet dose/0.6 mg/1 chlorine in the 2.4 * 10 5 CFU/100 ml for Total coliform and 3600 CFU/100 ml for Pseudomonas aeroginosa. Most probable number (MPN) estimated multiple tube fermentation technique. In this way the flow rate for system indicated about 240 cm 3 /s or 0.9 m 3 /h. The samples polluted for secondary pollution with 54000 CFU/100 ml for E. Coli and 1800 CFU/100ml Pseudomonas aeroginosa. The number of microbes decreased to zero duration after 45 minutes contact time in presence of free chlorine residual in samples. In practical conditions which that disinfectant system was installed in essential water treatment circuit under 1.4 atm hydraulic pressure no growth was seen for pollution index in disinfected water with Ultraviolet in microbial density about 840 CFU/100 ml for Total coliform and 12 CFU/100 ml for pseudomonas aeroginosa. Attention to lower

  2. Ultraviolet and visible light penetration of epidermis

    International Nuclear Information System (INIS)

    Eggset, G.; Kavli, G.; Volden, G.; Krokan, H.

    1984-01-01

    Light penetration in untanned skin and skin tanned with UVB (middlewave ultraviolet light) or PUVA (Psoralen photochemotherapy) was compared. Transmission at different wavelengths was measured through sheets of intact epidermis isolated by a suction blister technique. Thick epidermis was collected from a newly formed palmar friction bulla. For these studies a monochromator was used and the range of wavelengths examined was 280-700 nm. The transmission was considerably lower in tanned skin and the difference was most pronounced in the UV range. In the UVB range (290-320 nm), transmission was 13-43% for untanned epidermis, 8-12% for UVB tanned and slightly lower for PUVA tanned epidermis. At wavelengths below 325 nm only a few per cent of light penetrate through thick palmar epidermis. Both UVB and PUVA induce increased melanin content and thickening of the epidermis. Our results indicate that melanin is the most efficient protection against UVA while thickening of epidermis may be as important as the increased melanin content for the protection of living basal cells against the harmful UVB rays. (Auth)

  3. Ultraviolet damage resistance of laser coatings

    International Nuclear Information System (INIS)

    Newnam, B.E.; Gill, D.H.

    1978-01-01

    The damage resistance of several thin-film materials used in ultraviolet laser optics was measured at 266 and 355 nm. The coatings included single, quarterwave (QW) layers of NaF, LaF 3 , MgF 2 , ThO 2 , Al 2 O 3 , HfO 2 , ZrO 2 , Y 2 O 3 and SiO 2 , plus multilayer reflectors composed of some of these materials. The substrates were uv-grade fused silica. Single-shot thresholds were obtained with 22 ns and 27 ns (FWHM) pulses at 266 and 355 nm, respectively. One of the samples had previously been tested using 20-ps pulses, providing a pulsewidth comparison. At 266 nm the coating with the highest damage threshold was a QW layer of NaF at 10.8 J/cm 2 (450 MW/cm 2 ), whereas for a maximum reflector of Al 2 O 3 /NaF the value was 3.6 J/cm 2 (154 MW/cm 2 ), and the threshold of the maximum reflector was 12.2 J/cm 2 (470 MW/cm 2 ). The results were analyzed to determine correlations with standing-wave electric fields and linear and two-photon absorption. Scaling relationships for wavelength, refractive index and atomic density, and pulsewidth were found

  4. Ultraviolet and Visible Emission Mechanisms in Astrophysics

    Science.gov (United States)

    Stancil, Phillip C.; Schultz, David R.

    2003-01-01

    The project involved the study of ultraviolet (UV) and visible emission mechanisms in astrophysical and atmospheric environments. In many situations, the emission is a direct consequence of a charge transferring collision of an ion with a neutral with capture of an electron to an excited state of the product ion. The process is also important in establishing the ionization and thermal balance of an astrophysical plasma. As little of the necessary collision data are available, the main thrust of the project was the calculation of total and state-selective charge transfer cross sections and rate coefficients for a very large number of collision systems. The data was computed using modern explicit techniques including the molecular-orbital close-coupling (MOCC), classical trajectory Monte Carlo (CTMC), and continuum distorted wave (CDW) methods. Estimates were also made in some instances using the multichannel Landau-Zener (MCLZ) and classical over-the-barrier (COB) models. Much of the data which has been computed has been formatted for inclusion in a charge transfer database on the World Wide Web (cfadc.phy.ornl.gov/astro/ps/data/). A considerable amount of data has been generated during the lifetime of the grant. Some of it has not been analyzed, but it will be as soon as possible, the data placed on our website, and papers ultimately written.

  5. Hermite scatterers in an ultraviolet sky

    Science.gov (United States)

    Parker, Kevin J.

    2017-12-01

    The scattering from spherical inhomogeneities has been a major historical topic in acoustics, optics, and electromagnetics and the phenomenon shapes our perception of the world including the blue sky. The long wavelength limit of ;Rayleigh scattering; is characterized by intensity proportional to k4 (or λ-4) where k is the wavenumber and λ is the wavelength. With the advance of nanotechnology, it is possible to produce scatterers that are inhomogeneous with material properties that are functions of radius r, such as concentric shells. We demonstrate that with proper choice of material properties linked to the Hermite polynomials in r, scatterers can have long wavelength scattering behavior of higher powers: k8, k16, and higher. These ;Hermite scatterers; could be useful in providing unique signatures (or colors) to regions where they are present. If suspended in air under white light, the back-scattered spectrum would be shifted from blue towards violet and then ultraviolet as the higher order Hermite scatterers were illuminated.

  6. A private ultraviolet channel in visual communication.

    Science.gov (United States)

    Cummings, Molly E; Rosenthal, Gil G; Ryan, Michael J

    2003-01-01

    Although private communication is considered an important diversifying force in evolution, there is little direct behavioural evidence to support this notion. Here, we show that ultraviolet (UV) signalling in northern swordtails (Xiphophorus) affords a channel for communication that is not accessible to their major predator, Astyanax mexicanus, the Mexican tetra. Laboratory and field behavioural experiments with swordtails (X. nigrensis) and predators (A. mexicanus) demonstrate that male UV ornamentation significantly increases their attractiveness to females but not to this predator, which is less sensitive to UV. UV reflectance among swordtail species correlates positively with tetra densities across habitats, and visual contrast estimates suggest that UV signals are highly conspicuous to swordtails in their natural environment. Cross-species comparisons also support the hypothesis that natural selection drives the use of UV communication. We compared two species, one with high (X. nigrensis) and one with low (X. malinche) Mexican tetra densities. Xiphophorus nigrensis males reflect significantly more UV than X. malinche, exhibit significant UV sexual dimorphism, and UV is a salient component of the sexual communication system. In X. malinche, however, males reflect minimally in the UV, there is no UV sexual dimorphism, and UV does not play a part in its communication system. PMID:12803903

  7. Ultraviolet vision may be widespread in bats

    Science.gov (United States)

    Gorresen, P. Marcos; Cryan, Paul; Dalton, David C.; Wolf, Sandy; Bonaccorso, Frank

    2015-01-01

    Insectivorous bats are well known for their abilities to find and pursue flying insect prey at close range using echolocation, but they also rely heavily on vision. For example, at night bats use vision to orient across landscapes, avoid large obstacles, and locate roosts. Although lacking sharp visual acuity, the eyes of bats evolved to function at very low levels of illumination. Recent evidence based on genetics, immunohistochemistry, and laboratory behavioral trials indicated that many bats can see ultraviolet light (UV), at least at illumination levels similar to or brighter than those before twilight. Despite this growing evidence for potentially widespread UV vision in bats, the prevalence of UV vision among bats remains unknown and has not been studied outside of the laboratory. We used a Y-maze to test whether wild-caught bats could see reflected UV light and whether such UV vision functions at the dim lighting conditions typically experienced by night-flying bats. Seven insectivorous species of bats, representing five genera and three families, showed a statistically significant ‘escape-toward-the-light’ behavior when placed in the Y-maze. Our results provide compelling evidence of widespread dim-light UV vision in bats.

  8. Ultraviolet induced lysosome activity in corneal epithelium

    Energy Technology Data Exchange (ETDEWEB)

    Cullen, A.P.

    1980-01-01

    A 5.000 W Xe-Hg high pressure lamp and a double monochromator were used to produce a 3.3 nm half-bandpass ultraviolet radiation at 295 nm. Pigmented rabbit eyes were irradiated with radiant exposures from 140 Jm/sup -2/ to 10.000 Jm/sup -2/ and evaluated by slit-lamp biomicroscopy, light and electron microscopy. Corneal threshold (Hsub(c) was 200 Jm/sup -2/ and lens threshold (Hsub(L)) was 7.500 Jm/sup -2/. The most repeatable and reliable corneal response to these levels of UV was the development of corneal epithelial granules. Histological changes included a loss of superficial epithelial cells and selective UV induced autolysis of the wing cells. It is suggested that the biomicroscopically observed granules are the clinical manifestation of the secondary lysosomes revealed by light and electron microscopy. It is proposed that UV breaks down the primary lysosome membranes to release hydrolytic enzymes which in turn form the secondary lysosomes during autolysis. Extreme levels of radiant exposure at 295 nm result in indiscriminate destruction of all layers of the corneal epithelium, but the posterior cornea was spared.

  9. Ultraviolet induced lysosome activity in corneal epithelium

    International Nuclear Information System (INIS)

    Cullen, A.P.

    1980-01-01

    A 5.000 W Xe-Hg high pressure lamp and a double monochromator were used to produce a 3.3 nm half-bandpass ultraviolet radiation at 295 nm. Pigmented rabbit eyes were irradiated with radiant exposures from 140 Jm -2 to 10.000 Jm -2 and evaluated by slit-lamp biomicroscopy, light and electron microscopy. Corneal threshold (Hsub(c) was 200 Jm -2 and lens threshold (Hsub(L)) was 7.500 Jm -2 . The most repeatable and reliable corneal response to these levels of UV was the development of corneal epithelial granules. Histological changes included a loss of superficial epithelial cells and selective UV induced autolysis of the wing cells. It is suggested that the biomicroscopically observed granules are the clinical manifestation of the secondary lysosomes revealed by light and electron microscopy. It is proposed that UV breaks down the primary lysosome membranes to release hydrolytic enzymes which in turn form the secondary lysosomes during autolysis. Extreme levels of radiant exposure at 295 nm result in indiscriminate destruction of all layers of the corneal epithelium, but the posterior cornea was spared. (orig.) [de

  10. Pathways of ultraviolet mutability in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Lemontt, J.F.

    1977-01-01

    Non-allelic mutants of Saccharomyces cerevisiae with reduced capacity for ultraviolet light (UV)-induced forward mutation from CAN1 to can1 were assigned to seven distinct genetic loci, each with allele designations umr1-1, umr2-1, ..., umr7-1 to indicate UV mutation resistance. None conferred a great deal of UV sensitivity. When assayed on yeast extract-peptone-dextrose complex growth agar, umr1, umr3, and umr7 were the most UV-sensitive. When assayed on synthetic agar lacking arginine, however, umr3 was the most UV-sensitive. All strains carrying each of the seven umr genes exhibited varying degrees of defective UV mutability, compact with wild types. Normal UV revertibility of three different alleles was observed in strains carrying either umr4, umr5, umr6, or umr7. Five a/α homozygous umr diploids failed to sporulate. One of these, umr7, blocked normal secretion of alpha hormone in α segregants and could not conjugate with a strains. The phenotypes of umr mutants are consistent with the existence of branched UV mutation pathways of different specificity

  11. Low-energy QCD and ultraviolet renormalons

    International Nuclear Information System (INIS)

    Peris, S.

    1997-01-01

    We discuss the contribution of ultraviolet (UV) renormalons in QCD to two-point functions of quark current operators. This explicitly includes effects due to the exchange of one renormalon chain as well as two chains. It is shown that, when the external Euclidean momentum of the two-point functions becomes smaller than the scale Λ L associated with the Landau singularity of the QCD one-loop running coupling constant, the positions of the UV renormalons in the Borel plane become true singularities in the integration range of the Borel transform. This introduces ambiguities in the evaluation of the corresponding two-point functions. The ambiguities associated with the leading UV renormalon singularity are of the same type as the contribution due to the inclusion of dimension d=6 local operators in a low-energy effective Lagrangian valid at scales smaller than Λ L . We then discuss the inclusion of an infinite number of renormalon chains and argue that the previous ambiguity hints at a plausible approximation scheme for low-energy QCD, resulting in an effective Lagrangian similar to the one of the extended Nambu-Jona-Lasinio (ENJL) model of QCD at large N c . (orig.)

  12. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Joong-Won, E-mail: jshin@govst.edu [Division of Science, Governors State University, University Park, Illinois 60484-0975 (United States); Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States); Bernstein, Elliot R., E-mail: erb@lamar.colostate.edu [Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States)

    2014-01-28

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5{sup ′}-monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results.

  13. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    International Nuclear Information System (INIS)

    Shin, Joong-Won; Bernstein, Elliot R.

    2014-01-01

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5 ′ -monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results

  14. Biological Sensors for Solar Ultraviolet Radiation

    Directory of Open Access Journals (Sweden)

    André P. Schuch

    2011-04-01

    Full Text Available Solar ultraviolet (UV radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage, mutagenesis, and cell death. In fact, the various UV-wavelengths evoke characteristic biological impacts that greatly depend on light absorption of biomolecules, especially DNA, in living organisms, thereby justifying the increasing importance of developing biological sensors for monitoring the harmful impact of solar UV radiation under various environmental conditions. In this review, several types of biosensors proposed for laboratory and field application, that measure the biological effects of the UV component of sunlight, are described. Basically, the applicability of sensors based on DNA, bacteria or even mammalian cells are presented and compared. Data are also presented showing that on using DNA-based sensors, the various types of damage produced differ when this molecule is exposed in either an aqueous buffer or a dry solution. Apart from the data thus generated, the development of novel biosensors could help in evaluating the biological effects of sunlight on the environment. They also emerge as alternative tools for using live animals in the search for protective sunscreen products.

  15. A private ultraviolet channel in visual communication.

    Science.gov (United States)

    Cummings, Molly E; Rosenthal, Gil G; Ryan, Michael J

    2003-05-07

    Although private communication is considered an important diversifying force in evolution, there is little direct behavioural evidence to support this notion. Here, we show that ultraviolet (UV) signalling in northern swordtails (Xiphophorus) affords a channel for communication that is not accessible to their major predator, Astyanax mexicanus, the Mexican tetra. Laboratory and field behavioural experiments with swordtails (X. nigrensis) and predators (A. mexicanus) demonstrate that male UV ornamentation significantly increases their attractiveness to females but not to this predator, which is less sensitive to UV. UV reflectance among swordtail species correlates positively with tetra densities across habitats, and visual contrast estimates suggest that UV signals are highly conspicuous to swordtails in their natural environment. Cross-species comparisons also support the hypothesis that natural selection drives the use of UV communication. We compared two species, one with high (X. nigrensis) and one with low (X. malinche) Mexican tetra densities. Xiphophorus nigrensis males reflect significantly more UV than X. malinche, exhibit significant UV sexual dimorphism, and UV is a salient component of the sexual communication system. In X. malinche, however, males reflect minimally in the UV, there is no UV sexual dimorphism, and UV does not play a part in its communication system.

  16. Ultraviolet disinfection of treated municipal wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Vander Laan, H; Cairns, B

    1993-12-31

    A wastewater disinfection system developed by a Canadian company, Trojan Technologies Inc., was discussed. Disinfection for pathogen reduction prior to discharge of treated municipal wastewater back into rivers and lakes has been either ignored or treated by the use of chemicals. In 1979 the first pilot ultraviolet (UV) wastewater disinfection system was established. Since then, over 500 municipal UV installations have been commissioned. The largest installation can process 212 million gallons of water per day. The advantages of UV as a disinfectant are: (1) It is more effective than chlorine. (2) There are no mutagenic/carcinogenic byproducts formed with UV. (3) No toxic chemical residuals are discharged. (4) UV is safe to both the operators and the public. (5) It is cost effective. Europe has not been as active in wastewater disinfection as has North America. One result of the absence of wastewater disinfection in Europe is that the Rhine River, for example, carries 50 million salmonella per second. Disinfection of wastewater effluents is, of course, indispensable in protecting our drinking water supply. 2 figs.

  17. Impact of ultraviolet radiation on humans

    International Nuclear Information System (INIS)

    Cesarini, J.P.

    2001-01-01

    Solar radiation, including its ultraviolet (UV) components is a key factor in life on Earth. While small quantities of UV are beneficial for people (for example, through the production of vitamin D), the considerable amount to which people sometimes expose themselves may have extremely noxious effects including actinic erythema, sunburn, photo-induced diseases, photo-worsened diseases, actinic ageing and skin cancers. Since the last century, human exposure to UV has increased either by social-behaviour modifications, or by anthropogenic disruption to the environment through, among other things, industrial development. The World Health Organisation's (WHO) INTERSUN programme has several components: action for reconstruction of the ozone layer through, for example, preventing dumping of chlorofluorocarbons; creation and popularisation of a global UV index; prevention campaigns underlining the risks from UV exposure including dissemination of information to daily newspapers. These are all aimed at reducing the amount of UV radiation that people receive. In addition the WHO advises against exposure to UV artificial sources to reduce overall the quantity of UV received. (author)

  18. Impact of ultraviolet radiation on humans

    Energy Technology Data Exchange (ETDEWEB)

    Cesarini, J.P. [Laboratoire de Recherche sur les Tumeurs de la Peau Humaine, INSERM, Paris (France)

    2001-07-01

    Solar radiation, including its ultraviolet (UV) components is a key factor in life on Earth. While small quantities of UV are beneficial for people (for example, through the production of vitamin D), the considerable amount to which people sometimes expose themselves may have extremely noxious effects including actinic erythema, sunburn, photo-induced diseases, photo-worsened diseases, actinic ageing and skin cancers. Since the last century, human exposure to UV has increased either by social-behaviour modifications, or by anthropogenic disruption to the environment through, among other things, industrial development. The World Health Organisation's (WHO) INTERSUN programme has several components: action for reconstruction of the ozone layer through, for example, preventing dumping of chlorofluorocarbons; creation and popularisation of a global UV index; prevention campaigns underlining the risks from UV exposure including dissemination of information to daily newspapers. These are all aimed at reducing the amount of UV radiation that people receive. In addition the WHO advises against exposure to UV artificial sources to reduce overall the quantity of UV received. (author)

  19. Extreme ultraviolet observations of coronal holes. II

    International Nuclear Information System (INIS)

    Bohlin, J.D.; Sheeley, N.R. Jr.

    1978-01-01

    Extreme-ultraviolet Skylab and ground-based solar magnetic field data have been combined to study the origin and evolution of coronal holes. It is shown that holes exist only within the large-scale unipolar magnetic cells into which the solar surface is divided at any given time. A well-defined boundary zone usually exists between the edge of a hole and the neutral line which marks the edge of its magnetic cell. This boundary zone is the region across which a cell is connected by magnetic arcades with adjacent cells of opposite polarity. Three pieces of observational evidence are offered to support the hypothesis that the magnetic lines of force from a hole are open. Kitt Peak magnetograms are used to show that, at least on a relative scale, the average field strengths within holes are quite variable, but indistinguishable from the field strengths in other quiet parts of the Sun's surface. Finally it is shown that the large, equatorial holes characteristic of the declining phase of the last solar cycle during Skylab (1973-74) were all formed as a result of the mergence of bipolar magnetic regions (BMR's), confirming an earlier hypothesis by Timothy et al. (1975). Systematic application of this model to the different aspects of the solar cycle correctly predicts the occurrence of both large, equatorial coronal holes (the 'M-regions' which cause recurrent geomagnetic storms) and the polar cap holes. (Auth.)

  20. Ultraviolet-Absorption Spectroscopic Biofilm Monitor

    Science.gov (United States)

    Micheels, Ronald H.

    2004-01-01

    An ultraviolet-absorption spectrometer system has been developed as a prototype instrument to be used in continuous, real-time monitoring to detect the growth of biofilms. Such monitoring is desirable because biofilms are often harmful. For example, biofilms in potable-water and hydroponic systems act as both sources of pathogenic bacteria that resist biocides and as a mechanism for deterioration (including corrosion) of pipes. Biofilms formed from several types of hazardous bacteria can thrive in both plant-growth solutions and low-nutrient media like distilled water. Biofilms can also form in condensate tanks in air-conditioning systems and in industrial heat exchangers. At present, bacteria in potable-water and plant-growth systems aboard the space shuttle (and previously on the Mir space station) are monitored by culture-plate counting, which entails an incubation period of 24 to 48 hours for each sample. At present, there are no commercially available instruments for continuous monitoring of biofilms in terrestrial or spaceborne settings.