WorldWideScience

Sample records for room air conditioning

  1. Flow in air conditioned rooms

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    1974-01-01

    Flow in air conditioned r ooms is examined by means of model experiments . The different gearnetries giving unsteady, steady three- dimensional and steady twodimensional flow are determined . Velacity profiles and temperature profiles are measured in some of the geometries. A numerical solution...... of the flow equations is demonstrated and the flow in air conditioned rooms in case of steady two dimensional flow is predi cted. Compari son with measured results is shown i n the case of small Archimedes numbers, and predictions are shown at high Archimedes numbers. A numerical prediction of f low and heat...

  2. Design and Implementation of Air Conditioning System in Operating Room

    Directory of Open Access Journals (Sweden)

    Htet Htet Aung

    2014-10-01

    Full Text Available The system is air conditioning system in operating room. The main objective of the system was implemented to provide air balance and temperature necessary conditions and to control airflow system for ventilation units in operating room. The operation room can be controlled with fuzzy expert system and describes the desired outputs. Input parameters such as temperature, humidity, oxygen and particle are used and output parameters are chosen as air conditioning motor speed and exhaust motor speed. Input parameters of the system are taken into account optimal conditions based on oxygen as medium and other parameters are chosen minimum condition for operating room. The airflow control system is determined the two components: the airflow block and the thermal block for ventilation units in operating room. The mathematical modeling of each such system based on a computational procedure and to combine them together in an efficient manner. Whether it supports to the most suitable control for the system prototype was determined by simulating the operation with varying the number of personnel and duration of time. Finally, according to the combination of temperature and airflow regulations with PI controller, the results of simulation of the entire ventilation unit control system is obtained.

  3. Control of Computer Room Air Conditioning using IT Equipment Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Geoffrey C.; Storey, Bill; Patterson, Michael K.

    2009-09-30

    The goal of this demonstration was to show how sensors in IT equipment could be accessed and used to directly control computer room air conditioning. The data provided from the sensors is available on the IT network and the challenge for this project was to connect this information to the computer room air handler's control system. A control strategy was developed to enable separate control of the chilled water flow and the fans in the computer room air handlers. By using these existing sensors in the IT equipment, an additional control system is eliminated (or could be redundant) and optimal cooling can be provided saving significant energy. Using onboard server temperature sensors will yield significant energy reductions in data centers. Intel hosted the demonstration in its Santa Clara, CA data center. Intel collaborated with IBM, HP, Emerson, Wunderlich-Malec Engineers, FieldServer Technologies, and LBNL to install the necessary components and develop the new control scheme. LBNL also validated the results of the demonstration.

  4. Optimization of recirculating laminar air flow in operating room air conditioning systems

    Directory of Open Access Journals (Sweden)

    Enver Yalcin

    2016-04-01

    Full Text Available The laminar flow air-conditioning system with 100% fresh air is used in almost all operating rooms without discrimination in Turkey. The laminar flow device which is working with 100% fresh air should be absolutely used in Type 1A operating rooms. However, there is not mandatory to use of 100% fresh air for Type 1B defined as places performed simpler operation. Compared with recirculating laminar flow, energy needs of the laminar flow with 100 % fresh air has been emerged about 40% more than re-circulated air flow. Therefore, when a recirculating laminar flow device is operated instead of laminar flow system with 100% fresh air in the Type 1B operating room, annual energy consumption will be reduced. In this study, in an operating room with recirculating laminar flow, optimal conditions have been investigated in order to obtain laminar flow form by analyzing velocity distributions at various supply velocities by using computational fluid dynamics method (CFD.

  5. [Design, equipment, and management for air conditioning in operating room].

    Science.gov (United States)

    Fuji, Kumiko; Mizuno, Ju

    2011-11-01

    In order to maintain air cleanliness in the operating room (OR) permanently, air exchange rate in the OR should be more than 15 times x hr(-1), the laminar air flow should be kept, and the numbers of the persons in the OR and the numbers of opening and closing OR door should be limited. High efficiency particulate air (HEPA) filter is effective in collection and removal of airborne microbes, and is used in the biological clean room. We need to design, equip, and manage the OR environment according to Guideline for Design and Operation of Hospital HVAC Systems HEAS-02-2004 established by Healthcare Engineering Association of Japan and Guideline for Prevention of Surgical Site Infection (SSI) established by the Center for Disease Control and Prevention (CDC) in the USA.

  6. [Air conditioning units and warm air blankets in the operating room].

    Science.gov (United States)

    Kerwat, Klaus; Piechowiak, Karolin; Wulf, Hinnerk

    2013-01-01

    Nowadays almost all operating rooms are equipped with air conditioning (AC units). Their main purpose is climatization, like ventilation, moisturizing, cooling and also the warming of the room in large buildings. In operating rooms they have an additional function in the prevention of infections, especially the avoidance of postoperative wound infections. This is achieved by special filtration systems and by the creation of specific air currents. Since hypothermia is known to be an unambiguous factor for the development of postoperative wound infections, patients are often actively warmed intraoperatively using warm air blankets (forced-air warming units). In such cases it is frequently discussed whether such warm air blankets affect the performance of AC units by changing the air currents or whether, in contrast, have exactly the opposite effect. However, it has been demonstrated in numerous studies that warm air blankets do not have any relevant effect on the functioning of AC units. Also there are no indications that their use increases the rate of postoperative wound infections. By preventing the patient from experiencing hypothermia, the rate of postoperative wound infections can even be decreased thereby. © Georg Thieme Verlag Stuttgart · New York.

  7. Air conditioning management of huge rooms; Gestion climatique des locaux de grande dimension

    Energy Technology Data Exchange (ETDEWEB)

    Guitton, P. [Electricite de France (EDF), 78 - Chatou (France); Izard, J.L. [Ecole d`Architecture de Marseille-Luminy, 13 - Marseille-Luminy (France); Wurtz, E. [La Rochelle Universite, 17 - La Rochelle, LEPTAB (France)] [and others

    1999-09-01

    This conference was organized by the section `air-conditioning engineering` of the French society of thermal engineers (SFT). This document comprises the abridged versions of the communications and deals with: air-conditioning using displacement: experience feedback on tertiary applications and development of a dimensioning tool, thermal response of linear atria, application of the zonal method to the description of the temperature field and flows pattern inside an auditorium, theoretical and experimental study of air renewal inside industrial rooms, management of huge rooms, design of new optimized buildings and use of the TAS software, can TRNSYS and Comis codes be used for huge spaces?, experimental study of the thermal-aeraulic conditions generated by a displacement air-conditioning device. (J.S.)

  8. Thermal properties in phase change wallboard room based on air conditioning cold storage

    Institute of Scientific and Technical Information of China (English)

    陈其针; 刘鑫; 牛润萍; 王琳

    2009-01-01

    By comparing the thermal performance parameters of an ordinary wall room with a phase change wall (PCW) room,the effect of phase change wallboard on the fluctuation of temperature in air-conditioning room in summer was studied. And PCW room and an ordinary wall room,which are cooled by air-conditioner,were built up. Differential scanning calorimetry (DSC) was used to test the temperature field and heat flow fluctuation in these rooms. Through analyzing the data tested,it is found that the mean temperature of PCW is lower than that of ordinary wall room by 1-2 ℃,and PCW can lower the heat flow by 4.6 W/m2. Combining phase change material to building envelope can lower the indoor temperature,make the room thermal comfortable,and cut down the turn-on-and-off frequency of air-conditioner,the primary investment and operating costs. It alleviates urgent need of the electric power. Building envelope which contains phase change wallboard can improve the indoor thermal environment,and decrease energy consumption in buildings. Phase change wallboard can make impressive effect on energy efficiency of buildings.

  9. The Design of Research Laboratories. Part I: A General Assessment. Part II: Air Conditioning and Conditioned Rooms.

    Science.gov (United States)

    Legget, R. F.; Hutcheon, N. B.

    Design factors in the planning of research laboratories are described which include--(1) location, (2) future expansion, (3) internal flexibility, (4) provision of services, (5) laboratory furnishing, (6) internal traffic, (7) space requirements, and (8) building costs. A second part discusses air-conditioning and conditioned rooms--(1)…

  10. Benefits of Leapfrogging to Superefficiency and Low Global Warming Potential Refrigerants in Room Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area; Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area; Letschert, Virginie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area; Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area

    2015-10-01

    Hydrofluorocarbons (HFCs) emitted from uses such as refrigerants and thermal insulating foam, are now the fastest growing greenhouse gases (GHGs), with global warming potentials (GWP) thousands of times higher than carbon dioxide (CO2). Because of the short lifetime of these molecules in the atmosphere, mitigating the amount of these short-lived climate pollutants (SLCPs) provides a faster path to climate change mitigation than control of CO2 alone. This has led to proposals from Africa, Europe, India, Island States, and North America to amend the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) to phase-down high-GWP HFCs. Simultaneously, energy efficiency market transformation programs such as standards, labeling and incentive programs are endeavoring to improve the energy efficiency for refrigeration and air conditioning equipment to provide life cycle cost, energy, GHG, and peak load savings. In this paper we provide an estimate of the magnitude of such GHG and peak electric load savings potential, for room air conditioning, if the refrigerant transition and energy efficiency improvement policies are implemented either separately or in parallel. We find that implementing HFC refrigerant transition and energy efficiency improvement policies in parallel for room air conditioning, roughly doubles the benefit of either policy implemented separately. We estimate that shifting the 2030 world stock of room air conditioners from the low efficiency technology using high-GWP refrigerants to higher efficiency technology and low-GWP refrigerants in parallel would save between 340-790 gigawatts (GW) of peak load globally, which is roughly equivalent to avoiding 680-1550 peak power plants of 500MW each. This would save 0.85 GT/year annually in China equivalent to over 8 Three Gorges dams and over 0.32 GT/year annually in India equivalent to roughly twice India’s 100GW solar mission target. While there is some uncertainty associated with

  11. Auditing the European room air-conditioning systems and potential energy savings

    Energy Technology Data Exchange (ETDEWEB)

    Bory, Daniela; Adnot, Jerome; Greco, Carmelo; Marchio, Dominique [Ecole des Mines de Paris, Center for Energy and Processes (France)

    2007-07-01

    Nowadays, the European Community promotes the energy improvement of the air-conditioning (AC) systems through the compulsory inspection of these facilities in the frame of the Energy Performance of Buildings Directive [EPBD, 2002]. Inspection itself is just a motivating mean for the AC actors to improve the energy efficiency of the systems and reduce energy. Therefore, the aim of the inspection is to follow periodically the correct management of the facility through a quick visit of the plant and a study of the available documentation while the aim of the audit is the research of best efficiency improvements which requires further investigations to evaluate and quantify the savings. Audit differs from the common maintenance activities of the facilities, the aim of which is limited to guarantee the basic operation of the plant. There is an overall lack of methodologies specific for air-conditioning and the improvements proposed are seldom proven with scientific rigour. For room air conditioning systems, the impacts of defect during operation due to ageing and neglected maintenance are considered: fouled condenser, charge leaks, compressor performances reduced, fans degradation, filter fouling and additional pressure drop in liquid line are explored. The over consumption due to these defects is evaluated for different building types and French climates. The results allow to define simple methods that can be used by the auditors to estimate the energy savings due to the correction of the defects.

  12. Impact of surface disinfection and sterile draping of furniture on room air quality in a cardiac procedure room with a ventilation and air-conditioning system (extrusion airflow, cleanroom class 1b (DIN 1946-4)).

    Science.gov (United States)

    Below, Harald; Ryll, Sylvia; Empen, Klaus; Dornquast, Tina; Felix, Stefan; Rosenau, Heike; Kramer, Sebastian; Kramer, Axel

    2010-09-21

    In a cardiac procedure room, ventilated by a ventilation and air-conditioning system with turbulent mixed airflow, a protection zone in the operating area could be defined through visualization of airflows. Within this protection zone, no turbulence was detectable in the room air.Under the given conditions, disinfection of all surfaces including all furniture and equipment after the last operation and subsequent draping of furniture and all equipment that could not be removed from the room with sterile surgical drapes improved the indoor room air quality from cleanroom class C to cleanroom class B. This also allows procedures with elevated requirements to be performed in room class 1b.

  13. Benefits of Leapfrogging to Superefficiency and Low Global Warming Potential Refrigerants in Room Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Letschert, Virginie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Phadke, Amol A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-10-01

    Hydrofluorocarbons (HFCs) emitted from uses such as refrigerants and thermal insulating foam, are now the fastest growing greenhouse gases (GHGs), with global warming potentials (GWP) thousands of times higher than carbon dioxide (CO2). Because of the short lifetime of these molecules in the atmosphere,1 mitigating the amount of these short-lived climate pollutants (SLCPs) provides a faster path to climate change mitigation than control of CO2 alone. This has led to proposals from Africa, Europe, India, Island States, and North America to amend the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) to phase-down high-GWP HFCs. Simultaneously, energy efficiency market transformation programs such as standards, labeling and incentive programs are endeavoring to improve the energy efficiency for refrigeration and air conditioning equipment to provide life cycle cost, energy, GHG, and peak load savings. In this paper we provide an estimate of the magnitude of such GHG and peak electric load savings potential, for room air conditioning, if the refrigerant transition and energy efficiency improvement policies are implemented either separately or in parallel.

  14. Air Distribution in Rooms

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    The research on air distribution in rooms is often done as full-size investigations, scale-model investigations or by Computational Fluid Dynamics (CFD). New activities have taken place within all three areas and this paper draws comparisons between the different methods. The outcome of the l...

  15. Upgrading of the Air-conditioning of the Computer Room in the Computer Centre for the LHC era

    CERN Document Server

    Lindroos, J

    2001-01-01

    Built in the beginning of 1970's, the Computer Centre air-conditioning and cooling systems were designed to be modular and easily adaptable to the unpredictable future needs of computing. The infrastructure of LHC-computing that will be housed in the existing Computer Room with its five Computing farms and over 11000 PC's increases the requirements of cooling and air-conditioning power to a new level. The nominal thermal loads from the equipment rise from the current design maximum of 1MW to estimated maximum of 2MW in the future. This paper presents calculations and proposes solutions to meet the new nominal requirements. The air-conditioning system must also be able to cope with a situation of power cut in the main supply. A calculation of the temperature evolution during the power cut and a justified operation strategy for this scenario is also presented.

  16. Transient analysis and improvement of indoor thermal comfort for an air-conditioned room with thermal insulations

    Directory of Open Access Journals (Sweden)

    D. Prakash

    2015-09-01

    Full Text Available Thermal insulations over the building envelop reduce the heat gain due to solar radiation and may enhance good and uniform indoor thermal comfort for the occupants. In this paper, the insulation layer-wood wool is laid over the roof and exposed wall of an air-conditioned room and its performance on indoor thermal comfort is studied by computational fluid dynamics (CFD technique. From this study, 3% of indoor thermal comfort index-predicted mean vote (PMV is improved by providing wood wool layer. In addition, the optimum supply air temperature of air-conditioning unit for good thermal comfort is predicted as in the range of 299–300 K (26–27 °C.

  17. AN IMPACT OF THE EFFICIENT FUNCTIONING OF THE VENTILATION AND AIR-CONDITIONING SYSTEM ON THERMAL COMFORT OF THE MEDICAL STAFF IN THE OPERATING ROOM

    OpenAIRE

    Tomasz Jankowski; Magdalena Młynarczyk

    2016-01-01

    Ventilation and air conditioning systems are necessary for developing proper parameters of indoor envi-ronment in operating rooms. The main task of ventilation and air conditioning in those specific areas consists in creating desirable temperature, reducing the number of microorganisms and the concen-trations of hazardous gases and substances in the air, as well as ensuring the proper direction of airflow. In Poland, indoor environment in operating rooms has to comply with the requirements se...

  18. 下送风空调房间的数值模拟%Numerical Simulation of a under Floor Air Supply Air-conditioned Room

    Institute of Scientific and Technical Information of China (English)

    刘行安; 张国强; 何雪强

    2012-01-01

    A design method for under floor supply air conditioning system is introduced,and an air-conditioned room designed by the method was analyzed through numerical simulation with software Airpak.Three conclusions are drawn from the results: air in the under floor air supply air-conditioned room shows clear temperature stratification in the vertical direction with lower temperature in the working area beneath,which makes it possible to save more energy than conventional whole room air conditioning system;human thermal comfort is improved in the working area beneath;air quality in the working area is improved as a result of lower air age.Simulation results prove that this design method is efficient and reliable.%介绍了一种下送风空调系统的设计方法,利用Airpak软件对该设计方法下的空调房间进行数值模拟分析。通过模拟结果得到,下送风空调房间在垂直方向出现温度分层现象,下部工作区温度较低,这使得下送风空调比传统全室性空调系统节能;下送风空调在下部工作区具有较好的热舒适性;下部工作区空气龄较小,能够改善工作区的空气品质。模拟结果证实了该设计方法可靠有效。

  19. All air treatments are realisable energy efficiently. Room air conditioning based on membranes; Alle Luftbehandlungen energiesparend realisierbar. Membranbasierte Raumklimatisierung

    Energy Technology Data Exchange (ETDEWEB)

    Rosenbaum, Hannes [ILK Dresden gGmbH, Dresden (Germany). Hauptbereich Luft- und Klimatechnik

    2011-12-15

    Membrane elements for indirect liquid sorption processes enable a decentralized air conditioning. A suitable design of the heat transmitting and substance transmitting components needs to be developed yet. Then, membrane heat exchangers perform a hygienic, condensate-free dehumidification energy efficiently.

  20. On Air Shutter for Cold Storage Room

    Science.gov (United States)

    Fukuhara, Isamu; Tsuji, Katsuhiko

    Air curtains are frequently placed at doorway of cold storage room or freezing chamber. As an opening of jet flow in these air curtains is relatively narrow and speed of jet flow is fast, air entrained from surroundings increases in quantity. Therefore, we consider that jet flow with narrow opening can not effectively isolate inside air from the external atmosphere, but the one with relatively wide opening can decrease air entrained from surroundings. Then, when air curtain which has a wide opening (we call it air shutter) is installed at cold storage room, and isolating performances of air shutter are compared with the air curtain. First, as various conditions can be easily changed in numerical calculation, we compare a velocity and temperature field in cold storage room under these conditions when velocity of jet flow is changed by using numerical method. Second, we measure a temperature and velocity distribution in an actual cold storage room under three conditions (air shutter operates, air curtain operates and no operation). From these results, it was found that air shutter is more efficient than air curtain.

  1. Environmental impact of the programs of substitution of room type air conditioning equipment; Impacto ambiental de los programas de sustitucion de equipos de aire tipo cuarto

    Energy Technology Data Exchange (ETDEWEB)

    Alarcon Aleman, Jose Mauricio [OLADE, Quito (Ecuador)

    2002-09-01

    The present article approaches in a general way the relation that exists between the environment and the saving of electrical energy, especially in the Programs of Demand Side Management (DSM). In particular form the potential environmental impacts are described, derived of the use and the discard of the room type air conditioning equipment, goes deep into the characteristics of their cooling fluids, as well as in the relation that these keep with the protocols of Montreal and Kyoto. Finally, this article comments the incidence which have, the manufacturers as the institutions that implement DSM programs, on the environmental part of the programs of substitution of room type air conditioning equipment. In addition it is briefly described, the pilot program developed by Fideicomiso para el Ahorro de Energia Electrica (FIDE) as a successful case. [Spanish] En forma general, el presente articulo aborda la relacion que existe entre el medio ambiente y el ahorro de energia electrica, especialmente en los Programas de Administracion por el Lado de la Demanda (ALD). En forma particular se describen los impactos ambientales potenciales, derivados del uso y desecho de los equipos de aire acondicionado tipo cuarto, se ahonda en las caracteristicas de sus refrigerantes, asi como en la relacion que estos guardan con los protocolos de Montreal y Kioto. Finalmente, se comenta la incidencia que tienen, tanto los fabricantes como las instituciones que implementan programas de ALD, sobre la parte ambiental de los programas de sustitucion de equipos de aire acondicionado tipo cuarto. Ademas se describe brevemente, el programa piloto desarrollado por el Fideicomiso para el Ahorro de Energia Electrica (FIDE) como un caso exitoso.

  2. AN IMPACT OF THE EFFICIENT FUNCTIONING OF THE VENTILATION AND AIR-CONDITIONING SYSTEM ON THERMAL COMFORT OF THE MEDICAL STAFF IN THE OPERATING ROOM

    Directory of Open Access Journals (Sweden)

    Tomasz Jankowski

    2016-11-01

    Full Text Available Ventilation and air conditioning systems are necessary for developing proper parameters of indoor envi-ronment in operating rooms. The main task of ventilation and air conditioning in those specific areas consists in creating desirable temperature, reducing the number of microorganisms and the concen-trations of hazardous gases and substances in the air, as well as ensuring the proper direction of airflow. In Poland, indoor environment in operating rooms has to comply with the requirements set out in three regulations (Journal of Laws of 2002 No. 75, item 690, as amended, Journal of Laws of 2002 No. 217, item 1833, Journal of Laws of 2011 No. 31, item 158, as amended and the document entitled "Guidelines for the design of general hospitals". Given insufficient accuracy of the abovementioned national documents, it is a common practice to use foreign standards, i.e. ASHRAE Standard 170-2013, DIN 1946-4: 2008 and FprCEN TR 16244: 2011. When considering the conditions for thermal comfort, it is important to bear in mind a close link between air flow velocity and air temperature. Air in the zone occupied by patients and medical staff must not cause the sensation of draft. Furthermore, air velocity should be sufficient to eliminate interference caused by the presence of people and other sources of heat. It should also reduce the turbulence level in the air in the operating room. Efficient functioning of ventilation and air conditioning was tested during treatments and operations carried out on three wards of a Warsaw hospital. Tests were performed with the participation of medical staff from various surgical units. They were asked to perform minor manual tasks to simulate work on the op-erating table, and to complete a questionnaire on subjective thermal sensation. The applied methodology is widely used during testing of general and local ventilation in public buildings. Air temperature, relative humidity, air flow supply and exhaust air from the

  3. Controllability of room air temperature. Huonelaempoetilan saeaetoe

    Energy Technology Data Exchange (ETDEWEB)

    Laitila, P.; Katajisto, K.; Karjalainen, S.; Lassila, K. (Valtion Teknillinen Tutkimuskeskus, Espoo (Finland). LVI-tekniikan Laboratorio)

    1991-01-15

    At first, the control loop of room air temperature was studied as a unit process to find out the characteristic controllability factors of the process as well as possible. Step-response tests were made to the process. Furthermore, the choice of the control law, the adjustment of the controller parameters and the applicability of the controller parameters were analyzed. The results are based mainly on the simulation studies of the office building using the TRNSYS, HVACSIM{sup +} and PIPNET simulation programs. When making a step-change, e.g. to inlet air temperature, it takes a long time before the room air temperature achieves its final steady state. In addition, the gain of the process is slow. The time constant of the process is 30 min - 100 min. The steady state in terms of controllability is achieved in approximately four hours. The control difficulty of the process is significant below 0,1 independently of a heating or air conditioning system of the room space. The centralized and the distributed control of the room air temperature was studied as well. When the loads in different spaces differed greatly from one another, temperature conditions could not be controlled using centralized control. In that case the distributed temperature control based on room or zone space should be used. The integrated control of the air conditioning and heating systems proved to be quite difficult on the basis of the simulation studies especially when external loads vary a lot. The measurements made in a building in prevailing conditions did not support the integrated control of the air conditioning and heating systems. However, the heating system was under-dimensioned compared to the air conditioning system.

  4. Hydrogen peroxide vapour for decontaminating air-conditioning ducts and rooms of an emergency complex in northern India: time to move on.

    Science.gov (United States)

    Taneja, N; Biswal, M; Kumar, A; Edwin, A; Sunita, T; Emmanuel, R; Gupta, A K; Sharma, M

    2011-07-01

    Overcrowding and patient overload in emergency services areas often mean that inadequate attention is paid to thorough cleaning, disinfection of rooms and air-conditioning ducts, which would require closing the area concerned. Over a period of time, this leads to accumulation of lint, fibre, dust and fungal growth. This study assessed the effectiveness of hydrogen peroxide fog to decontaminate the air-conditioning ducts as well as for room disinfection without having to close down the area. The Postgraduate Institute of Medical Education and Research emergency complex, Chandigarh, is distributed over three floors housing nine air-handling units (AHUs) and seven wards. The work was carried out over a period of seven days and involved cleaning of air-conditioning ducts and wards, cleaning and disinfection of fittings and furniture, vacuuming and fogging of AHU, ducts and room air. Fogging was done with 20% Ecoshield fog, a complex formulation of stabilised hydrogen peroxide 11% w/v with 0.015% w/v silver nitrate. Pre- and post-fogging samples were taken for microbiological culture, and air samples were also collected. Hydrogen peroxide fogging was highly effective for disinfection of room air, furniture and other articles. It decontaminated the air-conditioning ducts effectively, was rapid and cheaper than formalin, and no adverse effects were noted. There was minimum disturbance to the patients and the treated areas were ready to be populated again after 5-6h. Hydrogen peroxide has the advantage of being safer, less irritating, and has shorter cycle times compared with formalin fumigation which is more commonly practised in India.

  5. High Efficiency Room Air Conditioner

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, Pradeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    This project was undertaken as a CRADA project between UT-Battelle and Geberal Electric Company and was funded by Department of Energy to design and develop of a high efficiency room air conditioner. A number of novel elements were investigated to improve the energy efficiency of a state-of-the-art WAC with base capacity of 10,000 BTU/h. One of the major modifications was made by downgrading its capacity from 10,000 BTU/hr to 8,000 BTU/hr by replacing the original compressor with a lower capacity (8,000 BTU/hr) but high efficiency compressor having an EER of 9.7 as compared with 9.3 of the original compressor. However, all heat exchangers from the original unit were retained to provide higher EER. The other subsequent major modifications included- (i) the AC fan motor was replaced by a brushless high efficiency ECM motor along with its fan housing, (ii) the capillary tube was replaced with a needle valve to better control the refrigerant flow and refrigerant set points, and (iii) the unit was tested with a drop-in environmentally friendly binary mixture of R32 (90% molar concentration)/R125 (10% molar concentration). The WAC was tested in the environmental chambers at ORNL as per the design rating conditions of AHAM/ASHRAE (Outdoor- 95F and 40%RH, Indoor- 80F, 51.5%RH). All these modifications resulted in enhancing the EER of the WAC by up to 25%.

  6. 空调机房的隔音降噪措施研究%The sound insulation and noise elimination measures research on air conditioning room

    Institute of Scientific and Technical Information of China (English)

    薛志飞

    2015-01-01

    Taking the Shanxi Library engineering as an example,analyzed the noise sources of air conditioning and ventilation system,from the layout,noise elimination,sound absorption and insulation three angles researched the noise elimination measures of air conditioning rooms,de-scribed in detail,so as to economy,effectively reduce the noise generated by the air conditioning system of large scale public buildings.%以山西省图书馆工程为例,分析了空调通风系统的噪声源,从布局、消声降噪、吸音隔音三个角度研究了空调机房降噪措施,并作了详细阐述,以经济、有效地降低大型公共建筑空调系统所产生的噪声。

  7. Historical and projected emissions of HCFC-22 and HFC-410A from China's room air conditioning sector

    Science.gov (United States)

    Wang, Ziyuan; Fang, Xuekun; Li, Li; Bie, Pengju; Li, Zhifang; Hu, Jianxin; Zhang, Boya; Zhang, Jianbo

    2016-05-01

    Recent decades witnessed the increase in production and uses of HCFC-22 (chlorodifluoromethane, CHClF2) and its alternative, HFC-410A (a blend of difluoromethane and pentafluoroethane), in China in response to the booming of room air conditioners (RACs) for both domestic use and exports. HCFC-22 is an ozone-depleting substance under the Montreal Protocol, while both HCFC-22 and HFC-410A are greenhouse gases (GHGs). This study provides a most comprehensive consumption and emission inventory of refrigerants emissions (HCFC-22 and HFC-410A) from RAC sector during 1995-2014, for the first time. Our estimates show that HCFC-22 emissions increased from 0.7 Gg/yr in 1995 to 48.2 Gg/yr in 2014. The accumulative emissions contributed to global total HCFCs emissions by 4.4% (3.3%-6.1%) CFC-11-equivalent (CFC-11-eq) and 5.4% (4.1%-7.5%) CO2-equivalent (CO2-eq) during 1995-2012. If left uncontrolled, accumulative emissions of HFC-410A will be12.4 (7.1-20.2) CO2-eq Pg during 2015-2050, which can offset the global climate benefits achieved by the Montreal Protocol. The HFC-410A emissions from China's RAC sector are estimated to be of importance to both global HFCs emissions and China's GHG emissions. Further, we probed the emission mitigation performances of the current 2014 North American Proposal scenario and a modified more ambitious scenario. The emissions of two mitigation scenarios are only 28% and 22% of the emissions without mitigation actions, respectively. This study is the first effort to map the transition of eliminated substance HCFC-22 and its alternative HFC-410A in RAC sector. Therefore, alternative chemicals should be scrutinized with cautions before they are promoted and applied.

  8. 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

  9. Mathematical Models for Room Air Distribution - Addendum

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    1982-01-01

    A number of different models on the air distribution in rooms are introduced. This includes the throw model, a model on penetration length of a cold wall jet and a model for maximum velocity in the dimensioning of an air distribution system in highly loaded rooms and shows that the amount of heat...

  10. Mathematical Models for Room Air Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    1982-01-01

    A number of different models on the air distribution in rooms are introduced. This includes the throw model, a model on penetration length of a cold wall jet and a model for maximum velocity in the dimensioning of an air distribution system in highly loaded rooms and shows that the amount of heat...

  11. Computational Fluid Dynamics and Room Air Movement

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    2004-01-01

    on the mass fraction transport equation. The importance of ?false? or numerical diffusion is also addressed in connection with the simple description of a supply opening. The different aspects of boundary conditions in the indoor environment as e.g. the simulation of Air Terminal Devices and the simulation...... of furnishings and occupants are discussed. The prediction of the flow in a room with a three dimensional wall by the use of different turbulence models as the - k e model, the   model and the Reynolds Stress model is addressed in the last chapter of the paper.  ...

  12. Design of Air Conditioning System and Automatic Control for Vaccine Hatch Room%疫苗孵房空调系统及自控设计

    Institute of Scientific and Technical Information of China (English)

    朱晔

    2015-01-01

    孵房是疫苗生产过程中重要的场所,其对环境的要求比较高。为生产水痘减毒活疫苗,根据该疫苗的生产条件要求,设计了一套空调系统及控制流程。该系统的运行特性表明,该系统的温度控制在(37±0.5)℃,湿度控制在45%~65%。孵房的净化级别可以达到C级,符合该疫苗的生产条件要求。%Hatch room is the important space for vaccine production, and demands a high quality of environment. In the present study, an air conditioning system and the automatic control process for the production of varicella attenuated live vaccine was designed based on requirement of the production conditions. The operation performance of this system shows that, the temperature is controlled within (37±0.5)oC and the humidity is controlled within 45%~65%. The purity of air can reach up to level C, which is in accordance with the requirement of production conditions.

  13. HISTORIC ENERGY STAR Certified Room Air Cleaners

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.2 ENERGY STAR Program Requirements for Room Air Cleaners that are effective as of July...

  14. REACH. Air Conditioning Units.

    Science.gov (United States)

    Garrison, Joe; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of air conditioning. The instructional units focus on air conditioning fundamentals, window air conditioning, system and installation, troubleshooting and…

  15. REACH. Air Conditioning Units.

    Science.gov (United States)

    Garrison, Joe; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of air conditioning. The instructional units focus on air conditioning fundamentals, window air conditioning, system and installation, troubleshooting and…

  16. Unitary and room air-conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.

    1977-09-01

    The scope of this technology evaluation on room and unitary air conditioners covers the initial investment and performance characteristics needed for estimating the operating cost of air conditioners installed in an ICES community. Cooling capacities of commercially available room air conditioners range from 4000 Btu/h to 36,000 Btu/h; unitary air conditioners cover a range from 6000 Btu/h to 135,000 Btu/h. The information presented is in a form useful to both the computer programmer in the construction of a computer simulation of the packaged air-conditioner's performance and to the design engineer, interested in selecting a suitably sized and designed packaged air conditioner.

  17. Experimental evaluation of air distribution in mechanically ventilated residential rooms

    DEFF Research Database (Denmark)

    Tomasi, R.; Krajčík, M.; Simone, A.

    2013-01-01

    The effect of low ventilation rates (1 or 0.5 air change per hour) on thermal comfort and ventilation effectiveness was experimentally studied in a simulated residential room equipped with radiant floor heating/cooling and mixing ventilation systems. The tests were performed for various positions...... removal effectiveness (CRE) and local air change index was measured in order to characterize ventilation effectiveness in the occupied zone. Acceptable thermal comfort was found in most experiments; however, air temperature differences higher than 3 °C occurred when floor cooling was combined...... with unconditioned outdoor air supply, i.e. at the supply air temperatures higher than the room air temperature. Moreover, low floor temperatures were needed to maintain the desired reference temperature in the stratified thermal environment. Mainly in cooling conditions the ventilation effectiveness depended...

  18. Healthy Buildings and Air Distribution in Rooms

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    Healthy buildings are to a great extent a question of indoor air quality. The processes involved in air quality can be looked upon as a number of links in a chain. Typical links will be emission from building materials, convection and diffusion in the room, local airflow around a person, personal...... exposure and at last the effect of the air quality on the occupant. The best results will obviously be obtained by using building materials with low emission. However, there will always exist some emission and the ventilation will consequently be an important link....

  19. Air distribution and ventilation effectiveness in an occupied room heated by warm air

    DEFF Research Database (Denmark)

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

    2012-01-01

    and at different simulated outside conditions, internal heat gains and air change rates. Floor heating was also simulated and compared with the warm air heating system. Vertical air temperature profiles, air velocity profiles and equivalent temperatures were derived in order to describe the thermal environment......Air distribution, ventilation effectiveness and thermal environment were experimentally studied in a simulated room in a low-energy building heated and ventilated by warm air supplied by a mixing ventilation system. Measurements were performed for various positions of the air terminal devices....... Contaminant removal effectiveness and air change efficiency were used to evaluate ventilation effectiveness. No significant risk of thermal discomfort due to vertical air temperature differences or draught was found. When the room was heated by warm air, buoyancy forces were important for ventilation...

  20. Assessment of performance of UV sterilizer for room air bacteria.

    Science.gov (United States)

    Joshi, P V

    2002-02-01

    Paper presents a technique for performance of UV sterilizer for room air bacteria. Patterns of decay of room air bacteria concentration during sterilization and build-up there after as a function of time is studied. Decay process seems to follow exponential pattern. Half-lives during decay are estimated. For single sterilizer unit with a dose of 16 W the decay half-life is around 8.6 min. For the dose of 32 W (2 sterilizers), half-life is estimated to be 6.18 min. The removal rates of room air bacteria due to sterilizer are compared with the natural decay of aerosols at steady state. The importance of decay half-life in the assessment has been stated. The bacteria concentration buildup process after putting off the sterilizers seems to be sigmoidal in nature. The buildup half-life is estimated to be around 53 min for present experimental conditions.

  1. Air Distribution in a Room with Ceiling-Mounted Diffusers

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Heby, Thomas; Moeller-Jensen, Bertil

    2006-01-01

    Experiments with air distribution in rooms generated by a radial ceiling-mounted diffuser and a diffuser generating flow with swirl are compared with the air distribution obtained by mixing ventilation from a wall-mounted diffuser, vertical ventilation and displacement ventilation. The air....... The characteristics of the air distribution systems are addressed by analysing the acceptable conditions for the supply flow rate and the temperature difference for the different systems. The paper shows that an air distribution system with ceiling-mounted air terminal units is able to generate comfortable velocity...... and temperature conditions at the same and at slightly higher loads as can be obtained by a vertical ventilation system, a mixing ventilation system with wall-mounted diffuser and a displacement ventilation system with a low velocity wall-mounted diffuser. The comparison is extended by considering both the local...

  2. No-reheat air-conditioning

    Science.gov (United States)

    Obler, H. D.

    1980-01-01

    Air conditioning system, for environmentally controlled areas containing sensitive equipment, regulates temperature and humidity without wasteful and costly reheating. System blends outside air with return air as dictated by various sensors to ensure required humidity in cooled spaces (such as computer room).

  3. Air-Conditioning Mechanic.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the skills needed by air conditioning mechanics. Addressed in the four chapters, or lessons, of the manual are the following topics: principles of air conditioning, refrigeration components as…

  4. Air bacterial counts in hundred-level laminar flow operating room under dynamic conditions%百级层流手术室动态条件下空气细菌数量的调查

    Institute of Scientific and Technical Information of China (English)

    张亚莉; 于芳; 周浩; 姚翠军; 汪能平; 孙树梅

    2012-01-01

    目的 探讨医院百级层流手术室在进行手术状态下,空气中沉降细菌数量监测结果,了解影响其因素和探讨改进层流手术室洁净度的措施.方法 测定百级层流手术室在进行手术状态下(即动态条件下)不同时段空气中沉降细菌菌落数.结果 静态条件下不同手术室之间比较,差异无统计学意义,动态条件下不同手术室之间亦差异无统计学意义;同一手术室动态条件下第一台手术开始时与结束前比较,1、3室沉降菌数量随手术时间延长而增加,差异有统计学意义(P<0.01),2室差异无统计学意义;在手术室内5~10人时,空气沉降菌数量为(10.978±7.275)CFU/平板,11~16人时,沉降菌数量为(23.399±17.334)CFU/平板,两组比较差异有统计学意义(P<0.01),即手术室动态条件下空气沉降菌数量与手术室人数呈正相关.结论 人员是层流手术室空气污染的主要因素,应严格限制手术室内人数,是保障手术中空气清净度的一项关键措施.%OBJECTIVE To evaluate results of the bacteria settlement in hundred-level laminar flow operating room of our hospital> and find out factors correlated with the number of bacteria settlement and measures to improve the clean level of the laminar flow operating room. METHODS The number of bacteria settlement in the air during the operation (under dynamic conditions) in the hundred-level laminar flow operating room was determined at different time points. RESULTS There was no significant difference in the number of bacteria settlement between the operating room under static and dynamic conditions; comparing the beginning (incision) and the end (suture) of the first operation in the same operating room under dynamic conditions, the numbers of bacteria settlement of room No. 1 and No, 3 significantly increased (P<0. 01) with operating time, but not in room No. 2. When there were 5-10 persons in the operating room, the number of bacteria settlement

  5. 室内空气净化器性能评价指标的试验研究%Experimental study of the evaluating indicators for the room-conditioning air cleaners

    Institute of Scientific and Technical Information of China (English)

    胡晓微; 张于峰; 谢朝国; 黄娟

    2012-01-01

    The present paper is engaged in a research for the evaluating indicators of the room-conditioning air cleaners. The current situation is that, although the room-conditional air quality control is very important, the air cleaning technology for the time being is far from being perfect because much remains to be improved in modern air conditioning systems. In addition , Due to the practical application of the limitations and complexity of air cleaning technology, there has not so far been systematic and comprehensive evaluation methods to air cleaners. Therefore, in order to further standardize the cleaning products, the markets concerned, it is necessary to promote healthy and orderly development of the standardized air cleaners, and carry out a series of research work on the air cleaners and the related materials, and advanced cleaner's performance evaluation methods. Cherishing this purpose, we have done a series of work in developing such materials as TiO2 photocata-lyst, activated carbon fiber( ACF)and composite materials TiO2/ACF through careful and conscientious comparison and selection. In reference to the relevant national standards, we have built up an air-cleaning performance test unit of air-conditioning systems. Corresponding measures of good air tightness have also been taken to ensure the desirable results during the standard performance tests and found that the room-conditioning interior air purification level is strongly influenced both by the natural attenuation and cleaning devices. Although the natural attenuation of contaminants inside the room is relatively weak, the cleaning performance test should be excluded as a rule, for its capacity can be acquired by testing the concentration change of such contaminants as the respirable paniculate matters and formal dehydrates passing through the cleaner. The other three indicators for air cleaners, that is, the cleaning capacity per u-nit area m, , the cleaning capacity per unit mt, and that per unit

  6. Carbon Emissions from air-Conditioning

    OpenAIRE

    Rajesh Kumar

    2013-01-01

    This paper explores electricity consumption and carbon emissions associated with air-conditioning. The total heat load of a room fitted with air conditioner of 1.5 ton capacity has been calculated by calculating conduction and ventilation losses. Solar heat gain and internal gain were taken as the other two parameters for the total heat calculation.

  7. Carbon Emissions from air-Conditioning

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2013-01-01

    Full Text Available This paper explores electricity consumption and carbon emissions associated with air-conditioning. The total heat load of a room fitted with air conditioner of 1.5 ton capacity has been calculated by calculating conduction and ventilation losses. Solar heat gain and internal gain were taken as the other two parameters for the total heat calculation.

  8. Storage and exchange thermal characteristic analysis of phase change wallboard room with different conditions

    Institute of Scientific and Technical Information of China (English)

    黄凯良; 冯国会; 陈其针; 牛润萍; 刘馨

    2009-01-01

    Based on the phase change material (PCM) thermal characteristic,some testing methods such as differential scanning calorimeter (DSC) etc were used to select the low melting mixture of capric and lauric acid as PCM of phase change wallboard (PCW). The PCW room was established,and some contrast analysis of the storage and exchange thermal characteristic of PCW room and ordinary wall room were made under different conditions. The results show that the fluctuation of indoor air temperature in PCW room is smaller than that in ordinary room obviously. The exchange energy of PCM room with outdoor is less than that of ordinary wall room. In the winter condition,PCW room utilizes valley period electricity to storage energy in the night,while releases at peak period electricity in daytime,which can divert 40% of peak load. In the summer condition,PCW room can reduce the peak cooling load by 25% compared with ordinary wall room.

  9. Energy savings from extended air temperature setpoints and reductions in room air mixing

    OpenAIRE

    Hoyt, Tyler; Lee, Kwang Ho; Zhang, Hui; Arens, Edward; Webster, Tom

    2005-01-01

    Large amounts of energy are consumed by air-conditioning systems to maintain tight control of air temperature in rooms--a narrow range of temperature excursion from neutral, and a uniform temperature in the ambient space. However, both field and lab studies are showing that neither narrow range nor uniformity is really necessary for providing occupant comfort. Data from several large field studies shows occupants accepting a much wider temperature range than is typically applied in practice (...

  10. The Contaminant Distribution in a Ventilated Room with Different Air Terminal Devices

    DEFF Research Database (Denmark)

    Heiselberg, Per; Nielsen, Peter V.

    of the jets and the comfort requirements applied to measured air velocities in the occupied zone. Normalized concentration distribution in the test room is determined along a vertical line through the middle of the room as a function of the air exchange rate and the density of the tracer gas. The relative......The room ventilation is investigated for three different air terminal devices under isothermal conditions. Velocity distribution in the occupied zone is measured for each air terminal device at different air exchange rates. The maximum air exchange rate is determined on the base of both the throw...... ventilation efficiency, , based on the room average concentration is also determined as a function of the air exchange rate and the density of the tracer gas. The influence from the position of the return opening on the relative ventilation efficiency is found for one air terminal device....

  11. Air regenerating and conditioning

    Science.gov (United States)

    Grishayenkov, B. G.

    1975-01-01

    Various physicochemical methods of regenerating and conditioning air for spacecraft are described with emphasis on conditions which affect efficiency of the system. Life support systems used in closed, hermetically sealed environments are discussed with references to actual application in the Soviet Soyuz and Voskhod manned spacecraft. Temperature and humidity control, removal of carbon dioxide, oxygen regeneration, and removal of bacteria and viruses are among the factors considered.

  12. Air conditioning boxes

    Energy Technology Data Exchange (ETDEWEB)

    1981-11-01

    Technical data, layout and function of air conditioning boxes by 6 German producers are described. The boxes cover a volume flow range of 1000 to 100000 m/sup 3//h. All boxes are equipped with heat exchangers, moisturizers, filters, and control elements.

  13. Preliminary Study of the Influence of Mosquito-repellent Incense on Radon Progeny Concentration in the Air-conditioned Room%蚊香对空调房内氡子体浓度影响的初步研究

    Institute of Scientific and Technical Information of China (English)

    李雯

    2012-01-01

    本文采用专业氡测量仪AlphaGUARD PQ2000PRO及其子体附件AlphaPM监测空调房内普通盘式蚊香及电热蚊香产生的气溶胶颗粒对氡子体浓度变化的影响。通过对比测量,可以看出普通盘式蚊香和电热蚊香产生的亚微米级气溶胶均会使得空调房内氡子体浓度增高,且前者导致的增加趋势更明显。建议开空调时室内使用电热蚊香,并且应定时开窗通风十几分钟,以降低室内氡子体浓度,减少其对人体的危害。%In this paper, the influence of aerosol particles produced by mosquito-repellent incense and electric heating mosquito-repellent incense on radon progeny concentration in the air-conditioned room was measured by professional radon monitor AlphaGUARD PQ2000PRO and its accessory AlphaPM. By comparing the measurements, it can be seen that the submicron aerosols produced by both mosquito-repellent incense and electric heating mosquito-repellent incense will make radon progeny concentration in the air-conditioned room increase, and the increasing trend caused by the former one is more obvious. The electric heating mosquito-repellent incense is recommended to be used in the air-conditioned room and windows should be open at the fixed time to reduce radon progeny concentration indoor, thereby reducing its harm to the human body.

  14. Exposure to aerosol and gaseous pollutants in a room ventilated with mixing air distribution

    DEFF Research Database (Denmark)

    Bivolarova, Mariya Petrova; Ondráček, Jakub; Ždímal, Vladimír

    2016-01-01

    The present study investigates the aerosol and gas dispersal in a mechanically ventilated room and the personal exposure to these contaminants. The study was performed in a full-scale climate chamber. The room was air conditioned via mixing total volume ventilation system. The room occupancy...... of the thermal manikin were measured. The results showed higher exposure to the contaminants measured at the breathing zone than at the ambient air. The behaviour of the tracer gas and the aerosols was similar....

  15. 一种通信机房空调节能降耗技术方案设计%Design of Energy Saving Technology for Air Conditioning System in Communication Room

    Institute of Scientific and Technical Information of China (English)

    魏三强; 朱军

    2012-01-01

    设计了一种通信机房空调节能降耗技术方案。智能通风技术适用于室内温度高于室外温度的场合,利用空气对流交换的原理及室内温度按高低梯度分布的规律,引入室外低温空气,并强制排出室内的热空气,从而达到降温的效果。通信机房空调节能降耗技术方案的设计,即对通信机房空调系统进行全方位的节能降耗改造,把不同节能性能的产品进行合理整合,在智能自控系统的调度下达到理想的节能降耗效果。%Intelligent ventilation technology is suitable for the occasions where indoor temperature is higher than the temperature outside, using principle of air convection exchange and discipline of in- door temperature gradient distribution, introducing outdoor low temperature air, and forcing out of hot air from indoor to achieve cooling effect. The design of energy saving technology for air conditioning system in communication room, namely omnibearing energy saving reform for air conditioning system communication room, effectively integrates energy saving products of different characteristics. It ob- tains best energy conservation effect in reasonable scheduling of intelligent automatic control system, will be able to improve the economic benefit of enterprise, and has a good market application value

  16. Air conditioning for data processing system areas

    Directory of Open Access Journals (Sweden)

    Hernando Camacho García

    2011-06-01

    Full Text Available The appropiate selection of air conditioners for data processing system areas requires the knowledge of the environmental desing conditions, the air conditioning systems succssfully used computer and the cooling loads to handle. This work contains information about a wide variety of systems designed for computer room applications. a complete example of calculation to determine the amount of heat to be removed for satisfactory operation, is also included.

  17. Research on a compact adsorption room air conditioner

    Energy Technology Data Exchange (ETDEWEB)

    Yang, G.Z.; Xia, Z.Z.; Wang, R.Z.; Keletigui, Daou; Wang, D.C. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030 (China); Dong, Z.H.; Yang, X. [Panasonic R and D Center, Suzhou Co., Ltd., Suzhou 215000 (China)

    2006-09-15

    A novel compact adsorption room air conditioner with a cooling capacity of 1kW has been designed, and two prototypes have been built. A two bed, continuous adsorption refrigeration cycle with heat recovery and mass recovery is adopted. Micropore spherical silica gel and water are selected as the working pair. A gravity heat pipe with methanol as working medium is designed to output the cooling. Experimental investigations have indicated that under typical air conditioning conditions, for the first prototype, a cooling capacity of 687W and a COP (coefficient of performance) of 0.307 can be obtained. However, for the improved one, a cooling capacity of 790W and a COP of 0.446 can be reached. It is also proved that the operating temperatures have strong influences on the performance. The designed room air conditioner can be driven by a low grade heat source (<90{sup o}C) and has small dimensions of 300mm (depth), 500mm (width) and 950mm (height). (author)

  18. Thermal conditions and perceived air quality in an air-conditioned auditorium

    Science.gov (United States)

    Polednik, Bernard; Guz, Łukasz; Skwarczyński, Mariusz; Dudzińska, Marzenna R.

    2016-07-01

    The study reports measurements of indoor air temperature (T) and relative humidity (RH), perceived air quality (PAQ) and CO2, fine aerosol particle number (PN) and mass (PM1) concentrations in an air conditioned auditorium. The measurements of these air physical parameters have been carried out in the unoccupied auditorium with the air conditioning system switched off (AC off mode) and in the unoccupied and occupied auditorium with the air conditioning system switched off during the night and switched on during the day (AC on/off mode). The average indoor air thermal parameters, CO2 concentration and the PAQ value (in decipols) were elevated, while average PM1 concentration was lower in the AC on/off mode. A statistically significant (p quality deteriorates along with the variation of the indoor air microclimate and room occupation. This, in turn, may adversely affect the comfort and productivity of the users of air conditioned premises.

  19. Simulation of particle distribution in a room with air cleaner

    DEFF Research Database (Denmark)

    Ardkapan, Siamak Rahimi; Afshari, Alireza; Nielsen, Peter V.

    2012-01-01

    gas and particles with different sizes.The proper turbulence model was selected after comparing the results with the behaviour of the gass in the test room. The simulations showed the effect that the location of an air cleaner had on the particle level. The results showed that the location of the air...... and particle phase model for simulating an air cleaner in a room. In addition, the aim is to study the impact of location of an air cleaner in a room. The dynamics of the particle inside a room was simulated by computational fluid dynamics software. Furthermore, the air change rate was measured by both tracer...... cleaner in relation to inlet, outlet and particle source had a significant effect on the effectiveness of the air cleaner....

  20. Perceived Air Quality in a Displacement Ventilated Room

    DEFF Research Database (Denmark)

    Brohus, Henrik; Knudsen, Henrik Nellemose; Nielsen, Peter V.

    In a displacement ventilated room the non-uniform contaminant distribution causes an improved indoor air quality in the occupied zone compared with conventional mixing ventilation. This has been demonstrated in numerous studies by chemical measurements. In this study the air quality...... in a displacement ventilated room was determined directly by asking humans about how they perceived the air quality. A trained sensory panel comprising 12 subjects assessed the perceived air quality immediately after entering a climate chamber. The experiments showed that the perceived air quality...... in the displacement ventilated chamber was substantially better than in the case of mixing ventilation....

  1. Concentration Distribution in a Ventilated Room under Isothermal Conditions

    DEFF Research Database (Denmark)

    Heiselberg, Per

    This paper contributes to the work in the lEA - Annex 20 "Air Flow Patterns within Buildings", subtask 1 "Room Air and Contaminant Flow". One of the objectives of subtask 1 is to acquire experimental data for the evaluation of the performance of air flow models in predicting air velocity, tempera...

  2. Air Distribution in Rooms with a Fan-Driven Convector

    DEFF Research Database (Denmark)

    Larsen, Tine Steen; Bindels, Rob H.W.; Michalak, Lukasz

    2007-01-01

    Experiments with a fan-driven convector used for both heating and cooling are de.scribed in this paper. Only the cooling situation is considered. The convector is positioned in the upper corner ofthe room, and from there the cold air is let out through the device along the ceiling. The airflow...... coming from the dijfuser is partly controlled by the momentum flow and partly from gravity forces, where the thermal load in the room and the temperature difference between room air and supply air affect the airflow from the convector. The convector system was tested in the same test room in which many...... regular ventilation systems were tested earlier to be ahle to compare airflow from the convector .system with regular ventilation ,systems at a later stage of this research. The heat load in the room consists of a thermal manikin sitting at a desk, a computer, and a desk lamp producing a total heat load...

  3. Vertical Distribution of Air Temperatures in Heated Dwelling Rooms

    OpenAIRE

    Šikula, Ondřej

    2007-01-01

    The paper presents an experimental and theoretic research on one of factors influencing the indoor climate in dwelling rooms heated by heating systems, the vertical distribution of temperatures. The paper summarizes results from simulation of the room heated by a gas space heater and a plate radiator. Among main factors causing unfavorable distribution of temperatures in a room belong insufficient elimination of cold dropping airflows and high temperature of heating air. The paper presents...

  4. Recent air conditioning systems of shopping buildings

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, Hironori

    1988-11-05

    In the air conditioning system in the shopping building, both the distributed air conditioning and DDC control methods have been increasingly adopted. The distributed air conditioning method, with a microcomputer mounted thereon, has attained the level sufficiently corresponding to the large scale building. While, the DDC control method, like the distributed air conditioning method, is considerably effective on the system having many surveillance control items. To engineer the energy conservation of air conditioning system in the shopping building, the utilization of atmospheric air as natural energy and control method for the ambient room condition reexamined must be studied. For the former, the atmospheric air intake quantity control to dilute CO and CO/sub 2/, and atmospheric air purge system prior to the air cooling are useful. While for the latter, the control method aiming at the comfort range, so called zero energy band control method is recommendable. Further for the temperature and humidity control, the DDC control by local controller is useful. 6 figures, 1 table.

  5. 洁净手术室不同状态空气质量的对比性研究%Contrastive research about air quality of cleanliness operation room in different condition

    Institute of Scientific and Technical Information of China (English)

    刘蕊; 杨瑾茹; 杨聚才; 周扬

    2009-01-01

    Objective To know the changes of air quality and kinds of bacterial in cleanliness operation room in vary conditions, and then make out proper countenneasues to prevent infection. Methods The air quality was detected dynamicly three times respectively when purification equipment was used for 30 minutes, in the lOth minute and 2nd hour of operation in Class 1000 and Class 10000 cleanliness oper-ation room, and then an average was taken to make a statistics1 compare and to analyze the bacteria classifica-tion. Results There were statistics significances among the datum of conditions above. The air quality when purification equipment was used for 30 minutes was better than that in the 10th minute and 2nd hour of opera-tion, and there was no significance in the 10th minute and 2nd hour of operation. Conclusions Scientific and regulated management is quite important to exert the advantage and function of clean-liness operation room adequately.%目的 探讨洁净手术室不同状态中空气质量的变化及细菌分类的不同,分析空气质量变化的原因,寻求有效预防手术伤口感染的措施.方法 对千级和万级洁净手术室在净化设备运行30 min时、手术开始10 min时、手术进行2 h时不同状态中的空气质量进行动态监测,取3次监测的均值,并对各项数据进行统计分析比较,分析统计细菌分类.结果 在3种状态中各项数据比较有差异;净化设备运行30 min即静态时和手术开始10 min时及手术2 h时细菌分类比较有显著差异,手术开始10 min时和手术2 h时比较无显著差异.结论 要充分发挥洁净手术室的优势和作用,科学规范管理尤为重要.

  6. Experimental Study on Thermal Performance of Externally Insulated Walls of Intermittent Air-Conditioned Rooms in Summer in Hot Summer and Cold Winter Region, China

    Directory of Open Access Journals (Sweden)

    Yong Ding

    2014-01-01

    Full Text Available Now requirements for the thermal performance of building walls are based on the assumption that heat flux transfers in one direction through the wall. However, in Hot Summer and Cold Winter Region of China, the direction of heat flow in the wall not only changes with the seasons, but also changes in the same period of using. In this paper, dynamic thermal process of externally insulated walls in different air-conditioner’s running state in summer in Chongqing, China, was tested. The distribution characteristics of the outdoor and indoor air temperature and the surface and inner temperatures of the wall were analyzed and demonstrated. Based on the unsteady-state heat transfer theory, the study calculated and analyzed the distribution characteristics of the direction of the heat flux in the thermal process. Also the characteristics of insulation and heat preservation for walls under different air-conditioner’s running state were analyzed. It is shown that, in any air-conditioner’s running state, the direction of the heat flux through the wall is obviously dynamically changing. There is obvious difference in the thermal performance needs of the wall; that is, it has strong demand for thermal insulation in daytime and strong demand for heat dissipation during night time in summer.

  7. EnerGuide room air conditioner directory 2004 : energy ratings for room air conditioners[Includes Energy Star qualified room air conditioners

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-04-01

    This guide lists all room air conditioners sold in Canada and offers advice on how to buy an energy efficient model as labelled under the EnerGuide rating system. The EnerGuide label is regulated under Canada's Energy Efficiency Regulations and is designed to help consumers estimate the annual electricity cost of running an appliance. The EnerGuide compares the energy consumption or energy efficiency of major household appliances and room air conditioners. The EnerGuide label displays a bar scale with an arrow that positions the model compared to the most energy-efficient and least energy efficient models in the same class. The EnerGuide concept uses standardized methods, in which all models of appliances sold in Canada are tested to determine their yearly energy use. The EnerGuide program was developed to protect the environment by reducing the demand for energy in Canada and to help consumers spend less money on energy. This simple guide allows consumers to determine the exact size of room air conditioner they need to meet their cooling needs. It was noted that the operating cost of a room air conditioner will vary depending on the climate, the energy efficiency rating of the air conditioner, temperature setting of the unit, fan operation and the local cost of electricity. The guide includes tables which reveal the energy consumption in kWh by province during the cooling season. tabs.

  8. Distribution and Room Air Mixing Risks to Retrofitted Homes

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-01

    An energy efficiency upgrade reduces a home’s heating and cooling load. If the load reduction is great enough and the heating, ventilation, and air conditioning system warrants replacement, that system is often upgraded with a more efficient, lower capacity system that meets the load of the upgraded house. For a single-story house with floor supply air diffusers, the ducts often are removed and upgraded. For houses with ducts that are embedded in walls, the cost of demolition precludes the replacement of ducts. The challenge with the use of existing ducts is that the reduced airflow creates a decreased throw at the supply registers, and the supply air and room air do not mix well, leading to potential thermal comfort complaints. This project investigates this retrofit scenario. The issues and solutions discussed here are relevant to all climate zones, with emphasis on climates that require cooling. In this project, IBACOS performed load calculations for a two-story 1960s house and characterized duct sizes and layouts based on industry “rules of thumb” (Herk et al. 2014). The team performed duct-sizing calculations for unaltered ducts and post-retrofit airflows and examined airflow velocities and pressure changes with respect to various factors. The team then used a mocked-up duct and register setup to measure the characteristics of isothermal air—to reduce the effects of buoyancy from the observations—passing through the duct and leaving the register.

  9. Laser sheet light flow visualization for evaluating room air flowsfrom Registers

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Claret, Valerie; Smith, Brian

    2006-04-01

    Forced air heating and cooling systems and whole house ventilation systems deliver air to individual rooms in a house via supply registers located on walls ceilings or floors; and occasionally less straightforward locations like toe-kicks below cabinets. Ideally, the air velocity out of the registers combined with the turbulence of the flow, vectoring of air by register vanes and geometry of register placement combine to mix the supply air within the room. A particular issue that has been raised recently is the performance of multiple capacity and air flow HVAC systems. These systems vary the air flow rate through the distribution system depending on the system load, or if operating in a ventilation rather than a space conditioning mode. These systems have been developed to maximize equipment efficiency, however, the high efficiency ratings do not include any room mixing effects. At lower air flow rates, there is the possibility that room air will be poorly mixed, leading to thermal stratification and reduced comfort for occupants. This can lead to increased energy use as the occupants adjust the thermostat settings to compensate and parts of the conditioned space have higher envelope temperature differences than for the well mixed case. In addition, lack of comfort can be a barrier to market acceptance of these higher efficiency systems To investigate the effect on room mixing of reduced air flow rates requires the measurement of mixing of supply air with room air throughout the space to be conditioned. This is a particularly difficult exercise if we want to determine the transient performance of the space conditioning system. Full scale experiments can be done in special test chambers, but the spatial resolution required to fully examine the mixing problem is usually limited by the sheer number of thermal sensors required. Current full-scale laboratory testing is therefore severely limited in its resolution. As an alternative, we used a water-filled scale model

  10. Air conditioning. Special issue; Luchtbehandeling. Themanummer

    Energy Technology Data Exchange (ETDEWEB)

    Montague, M.; Liew, R.; Daruwalla, H.; Wenzek, J. [AAF International, Amsterdam (Netherlands); De Lede, F. [Klimaatinstallaties Kats en Waalwijk, Gorinchem (Netherlands); Nuijten, O. [ISSO, Rotterdam (Netherlands); Van Pelt, J. [Skiw, Nieuwegein (Netherlands); Arts, J. [Imtech Utiliteit West, Capelle a/d IJssel (Netherlands); Vollebregt, R.; Hoeffnagel, R.; Smorenburg, P.; Bijman, J.

    2007-02-15

    In eight articles attention is paid to several aspects of air conditioning and related systems: the perfect filter case for gas filtration, innovative cooling for computer rooms, thermal comfort in offices, standardization of legionella prevention in climate installations and cooling towers, air quality and energy consumption of integrated units, new air conditioners in the Dutch market. [Dutch] In acht artikelen wordt aandacht besteed aan verschillende aspecten van luchtbehandeling en verwante systemen: de perfecte filtercassette vor gasfasefiltratie, innovatieve koeling in computerruimte, hoog comfort in bestaande kantoren, de in ontwikkeling zijn ISSO-publicatie 55.3 voor legionellapreventie in klimaatinstallaties, legionellapreventie bij comfortkoeling, luchtbehandeling met geintegreerde units, en nieuwe luchtbehandelingskasten voor de Nederlandse markt.

  11. Diffuse Ceiling Inlet Systems and the Room Air Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jensen, Rasmus Lund; Rong, Li

    2010-01-01

    A diffuse ceiling inlet system is an air distribution system which is supplying the air through the whole ceiling. The system can remove a large heat load without creating draught in the room. The paper describes measurements in the case of both cooling and heating, and CFD predictions are given ...

  12. Control Technologies for Room Air-conditioner and Packaged Air-conditioner

    Science.gov (United States)

    Ito, Nobuhisa

    Trends of control technologies about air-conditioning machineries, especially room or packaged air conditioners, are presented in this paper. Multiple air conditioning systems for office buildings are mainly described as one application of the refrigeration cycle control technologies including sensors for thermal comfort and heating/ cooling loads are also described as one of the system control technologies. Inverter systems and related technologies for driving variable speed compressors are described in both case of including induction motors and brushless DC motors. Technologies for more accurate control to meet various kind of regulations such as ozone layer destruction, energy saving and global warming, and for eliminating harmonic distortion of power source current, as a typical EMC problem, will be urgently desired.

  13. Air Conditioning Does Reduce Air Pollution Indoors

    Science.gov (United States)

    Healy, Bud

    1970-01-01

    Report of the winter meeting of the American Society of Heating, Refrigerating and Air-Conditioning Engineers. Subjects covered are--(1) title subject, (2) predictions for the human habitat in 1994, (3) fans, and (4) fire safety in buildings. (JW)

  14. Air Conditioning Does Reduce Air Pollution Indoors

    Science.gov (United States)

    Healy, Bud

    1970-01-01

    Report of the winter meeting of the American Society of Heating, Refrigerating and Air-Conditioning Engineers. Subjects covered are--(1) title subject, (2) predictions for the human habitat in 1994, (3) fans, and (4) fire safety in buildings. (JW)

  15. Cost-benefit analysis of different air change rates in an operating room environment.

    Science.gov (United States)

    Gormley, Thomas; Markel, Troy A; Jones, Howard; Greeley, Damon; Ostojic, John; Clarke, James H; Abkowitz, Mark; Wagner, Jennifer

    2017-09-08

    Hospitals face growing pressure to meet the dual but often competing goals of providing a safe environment while controlling operating costs. Evidence-based data are needed to provide insight for facility management practices to support these goals. The quality of the air in 3 operating rooms was measured at different ventilation rates. The energy cost to provide the heating, ventilation, and air conditioning to the rooms was estimated to provide a cost-benefit comparison of the effectiveness of different ventilation rates currently used in the health care industry. Simply increasing air change rates in the operating rooms tested did not necessarily provide an overall cleaner environment, but did substantially increase energy consumption and costs. Additionally, and unexpectedly, significant differences in microbial load and air velocity were detected between the sterile fields and back instrument tables. Increasing the ventilation rates in operating rooms in an effort to improve clinical outcomes and potentially reduce surgical site infections does not necessarily provide cleaner air, but does typically increase operating costs. Efficient distribution or management of the air can improve quality indicators and potentially reduce the number of air changes required. Measurable environmental quality indicators could be used in lieu of or in addition to air change rate requirements to optimize cost and quality for an operating room and other critical environments. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  16. Air Distribution in a Furnished Room Ventilated by Mixing Ventilation

    DEFF Research Database (Denmark)

    Nielsen, June Richter; Nielsen, Peter V.; Svidt, Kjeld

    Using isothermal full-scale experiments and two-dimensional isothermal CFD simulations it is investigated how normal office furniture influences the air movements in a room with mixing ventilation. Three different set-ups are made in the experiments and different sizes and locations of the furnit......Using isothermal full-scale experiments and two-dimensional isothermal CFD simulations it is investigated how normal office furniture influences the air movements in a room with mixing ventilation. Three different set-ups are made in the experiments and different sizes and locations...

  17. Air Conditioning Overflow Sensor

    Science.gov (United States)

    1996-01-01

    The Technology Transfer Office at Stennis Space Center helped a local inventor develop a prototype of an attachment for central air conditioners and heat pumps that helps monitor water levels to prevent condensation overflow. The sensor will indicate a need for drain line maintenance and prevent possible damage caused by drain pan water spillover. An engineer in the Stennis Space Center prototype Development Laboratory used SSC sensor technology in the development of the sensor.

  18. Air Conditioning Overflow Sensor

    Science.gov (United States)

    1996-01-01

    The Technology Transfer Office at Stennis Space Center helped a local inventor develop a prototype of an attachment for central air conditioners and heat pumps that helps monitor water levels to prevent condensation overflow. The sensor will indicate a need for drain line maintenance and prevent possible damage caused by drain pan water spillover. An engineer in the Stennis Space Center prototype Development Laboratory used SSC sensor technology in the development of the sensor.

  19. SOLAR AIR CONDITIONING OF BUILDING

    Directory of Open Access Journals (Sweden)

    Debrayan Bravo Hidalgo

    2015-04-01

    Full Text Available Air Conditioning with renewable energy is a key issue in the region's energy policy. The high temperatures usually attributed to climate change and the increase of the standard of living in society continues increasing energy demand in order to establish the conditions for thermal comfort in buildings. Solar air conditioning, although it contains a mature technology, its level of market introduction and acceptance by designers of buildings is exhaustive. This paper discusses the feasibility of these projects, identifies non-technological type barriers that hinders such use and implementation of solar energy for air conditioning systems, and finally, it approaches some criteria and recommendations to overcome these obstacles.

  20. Models for the Prediction of Room Air Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    The paper describes work on simplified design methods made in connection with the International Energy Agency programme" Air Flow Pattern within Buildings" , Annex 20, subtask 1. It is shown that simplified models are able to indicate design values as the maximum velocity in the occupied zone...... and penetration depth of a non-isothermal jet in a room....

  1. Fifty years of CFD for room air distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    2015-01-01

    , and to addressing situations with more steady-state solutions. The article finishes with a number of different case studies such as design of air supply openings, smoke management in buildings, cross-infection risks from the exhalation of particles and calculation of people moving in a room. The use of benchmark...

  2. Medical aspects of room air quality and CO/sub 2/ sensors

    Energy Technology Data Exchange (ETDEWEB)

    Ranscht-Froemsdorff, W.

    1987-05-01

    So far, CO/sub 2/ received only peripheral interest in the search for relevant factors and trace elements that are detrimental to comfort in living rooms and offices. Medically speaking, CO/sub 2/ is an analeptic substance, i.e. a substance that, given in small doses, stimulates like coffein; in larger doses, it has an alcohol-like effect, and overdoses are lethal as they arrest breathing. The author assumes that a rise in CO/sub 2/ in closed rooms will be accompanied by a rise in other trace elements, possibly with synergetic effects on the human organism. In the last few years, portable, light-weight sensors have become available. The use of CO/sub 2/ sensors is particularly important in air-conditioned rooms, where the fresh air supply exceeds the actual requirements, i.e. where an energy-saving effect could be achieved by combining the sensors with the air conditioning unit. (BWI).

  3. Locating air samplers inside a room using qualitative airflow studies

    Energy Technology Data Exchange (ETDEWEB)

    Kravchik, T.; Levinson, S.; German, U. [Nuclear Research Center Negev, Beer-Sheva (Israel); Haim, M. [Ben-Gurion University of the Negev, Beer-Sheva (Israel)

    2000-05-01

    The concentration of airborne radioactive materials inside a room can vary widely from one location to another, sometimes by orders of magnitude even for locations that are reactively close. Inappropriately placed air samplers can give misleading results and, therefore, the location of air samplers is important. Proper placement of samplers is not always obvious and cannot be determined simply by observing the position of room air supply and exhaust vents. Airflow studies, such as the release of smoke aerosols, should be used. The significance of airflow pattern studies depends on the purpose of sampling-for estimating worker intakes, warning of abnormally high concentrations, defining airborne radioactive areas, testing for confinement of sealed radioactive materials, etc. Qualitative smoke tests were conducted inside rooms using a 'KUPO Inc.' smoke tube (D5050 fog machine). Smoke was released at elevation of 1-2 meters and its path was recorded on worksheet drawings of the room. The tests revealed three types of airflow patterns inside the rooms: a) flow path with a definite stable direction, b) flow path which changes direction arbitrarily as a result of airflow vortices, and c) static/stagnant air. In some cases the airflow path direction was different from the expected one. This emphasizes the significance of conducting airflow studies for location of air samplers and not only relying on intuition. An airflow patterns comparison study between the qualitative smoke tests and computer simulation using a commercial finite element CFD code, FIDAP 8.01, was also conducted. The measured and the computed paths of the airflow were mostly in good agreement. The computer simulation indicated additional details which could not be observed when performing the smoke tests because of physical and visibility limitations. (author)

  4. Control room envelope unfiltered air inleakage test protocols

    Energy Technology Data Exchange (ETDEWEB)

    Lagus, P.L. [Lagus Applied Technology, San Diego, CA (United States); Grot, R.A. [Lagus Applied Technology, Olney, MD (United States)

    1997-08-01

    In 1983, the Advisory Committee on Reactor Safeguards (ACRS) recommended that the US NRC develop a control room HVAC performance testing protocol. To date no such protocol has been forthcoming. Beginning in mid-1994, an effort was funded by NRC under a Small Business Innovation Research (SBIR) grant to develop several simplified test protocols based on the principles of tracer gas testing in order to measure the total unfiltered inleakage entering a CRE during emergency mode operation of the control room ventilation system. These would allow accurate assessment of unfiltered air inleakage as required in SRP 6.4. The continuing lack of a standard protocol is unfortunate since one of the significant parameters required to calculate operator dose is the amount of unfiltered air inleakage into the control room. Often it is assumed that, if the Control Room Envelope (CRE) is maintained at +1/8 in. w.g. differential pressure relative to the surroundings, no significant unfiltered inleakage can occur it is further assumed that inleakage due to door openings is the only source of unfiltered air. 23 refs., 13 figs., 2 tabs.

  5. Impact of room fragrance products on indoor air quality

    Science.gov (United States)

    Uhde, Erik; Schulz, Nicole

    2015-04-01

    Everyday life can no longer be imagined without fragrances and scented products. For the consumer, countless products exists which are solely or partly intended to give off a certain scent in sufficient concentrations to odorize a complete room. Sprays, diffusers and evaporators, scented candles and automatic devices for the distribution of fragrance liquids are typical examples of such products. If the consumer uses such products, his consent to the release of certain chemicals in his home can be implied, however, he may not know what kind of fragrance substances and solvents will be present in which concentrations. In this study, we determined the volatile emissions of a number of fragrance products in detail. Measurements were carried out under controlled conditions in test chambers. The products were tested in a passive (unused) and an active state, wherever applicable. Following a defined test protocol, the release of volatile organic compounds, ultrafine particles and NOx was monitored for each product. The potential for forming secondary organic aerosols under the influence of ozone was studied, and for a selection of products the long-term emission behavior was assessed. A remarkable variety of fragrance substances was found and more than 100 relevant compounds were identified and quantified. While it is the intended function of such products to release fragrance substances, also considerable amounts of non-odorous solvents and by-products were found to be released from several air fresheners. Emissions rates exceeding 2 mg/(unit*h) were measured for the five most common solvents.

  6. The Influence of Furniture on Air Velocity in a Room

    DEFF Research Database (Denmark)

    Nielsen, J. R.; Nielsen, Peter V.; Svidt, Kjeld

    Using isothermal full-scale experiments and 3-dimensional CFD simulations it is investigated how normal office furniture influences the air movements in a mixing ventilated room. Two different types of inlets are used in the experiments and a set-up with normal office furniture is made. The set......-up is simulated with one of the inlets where a volume resistance represents the furniture....

  7. Equal autophonic level curves under different room acoustics conditions

    DEFF Research Database (Denmark)

    Pelegrin Garcia, David; Mendizábal, Oier Fuentes; Brunskog, Jonas

    2011-01-01

    The indirect auditory feedback from one’s own voice arises from sound reflections at the room boundaries or from sound reinforcement systems. The relative variations of indirect auditory feedback are quantified through room acoustic parameters such as the room gain and the voice support, rather...... than the reverberation time. Fourteen subjects matched the loudness level of their own voice (the autophonic level) to that of a constant and external reference sound, under different synthesized room acoustics conditions. The matching voice levels are used to build a set of equal autophonic level...... curves. These curves give an indication of the amount of variation in voice level induced by the acoustic environment as a consequence of the sidetone compensation or Lombard effect. In the range of typical rooms for speech, the variations in overall voice level that result in a constant autophonic level...

  8. Smart sensors enable smart air conditioning control.

    Science.gov (United States)

    Cheng, Chin-Chi; Lee, Dasheng

    2014-06-24

    In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants' information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans' intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be controlled accurately with errors of less than ±0.1 °C. Rapid cool down can be achieved within 2 min to the optimized indoor capacity after occupants enter a room. It's also noted that within two-hour operation the total compressor output of the smart air conditioner is 48.4% less than that of the one using On-Off control. The smart air conditioner with wearable devices could detect the human temperature and activity during sleep to determine the sleeping state and adjusting the sleeping function flexibly. The sleeping function optimized by the smart air conditioner with wearable devices could reduce the energy consumption up to 46.9% and keep the human health. The presented smart air conditioner could provide a comfortable environment and achieve the goals of energy conservation and environmental protection.

  9. Distribution and Room Air Mixing Risks to Retrofitted Homes

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-01

    Energy efficiency upgrades reduce heating and cooling loads on a house. With enough load reduction and if the HVAC system warrants replacement, the HVAC system is often upgraded with a more efficient, lower capacity system that meets the loads of the upgraded house. For a single-story house with ceiling supply air diffusers, ducts are often removed and upgraded. For houses with ducts that are embedded in walls, the cost of demolition precludes the replacement of ducts. The challenge with the use of existing ducts is that the reduced airflow creates a decreased throw at the supply registers, and the supply air and room air do not mix well, leading to potential thermal comfort complaints. This project investigates this retrofit scenario. The issues and solutions discussed here are relevant to all climate zones, with emphasis on climates that require cooling.

  10. Technical and economic analysis of energy efficiency of Chinese room air conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Fridley, David G.; Rosenquist, Gregory; Jiang, Lin; Li, Aixian; Xin, Dingguo; Cheng, Jianhong

    2001-02-01

    China has experienced tremendous growth in the production and sales of room air conditioners over the last decade. Although minimum room air conditioner energy efficiency standards have been in effect since 1989, no efforts were made during most of the 1990's to update the standard to be more reflective of current market conditions. In 1999, China's State Bureau of Technical Supervision (SBTS) included in their annual plan the development and revision of the 1989 room air conditioner standard, and experts from SBTS worked together with LBNL to analyze the new standards. Based on the engineering and life cycle-cost analyses performed, the most predominant type of room air conditioner in the Chinese market (split-type with a cooling capacity between 2500 and 4500 W (8500 Btu/h and 15,300Btu/h)) can have its efficiency increased cost-effectively to an energy efficiency ratio (EER) of 2.92 W/W (9.9 Btu/hr/W). If an EER standard of 2.92 W/W became effective in 2001, Chinese consumers would be estimated to save over 3.5 billion Yuan (420 million U.S. dollars) over the period of 2001-2020. Carbon emissions over the same period would be reduced by approximately 12 million metric tonnes.

  11. Low GWP Refrigerants Modelling Study for a Room Air Conditioner Having Microchannel Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Bhandari, Mahabir S [ORNL

    2016-01-01

    Microchannel heat exchangers (MHX) have found great successes in residential and commercial air conditioning applications, being compact heat exchangers, to reduce refrigerant charge and material cost. This investigation aims to extend the application of MHXs in split, room air conditioners (RAC), per fundamental heat exchanger and system modelling. For this paper, microchannel condenser and evaporator models were developed, using a segment-to-segment modelling approach. The microchannel heat exchanger models were integrated to a system design model. The system model is able to predict the performance indices, such as cooling capacity, efficiency, sensible heat ratio, etc. Using the calibrated system and heat exchanger models, we evaluated numerous low GWP (global warming potential) refrigerants. The predicted system performance indices, e.g. cooling efficiency, compressor discharge temperature, and required compressor displacement volume etc., are compared. Suitable replacements for R22 and R-410A for the room air conditioner application are recommended.

  12. Health effects of air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Molina, C.; Caillaud, D.

    The air conditioning used in residential or commercial buildings (offices, hotels, sterile areas of hospitals, computer and electronics industries) is responsible for a certain number of well identified ailments which can be classified in three groups: infections (legionnaires'disease, ornithosis), allergies (mainly respiratory) eg. rhinitis, asthma, alveolitis but also Monday morning illness or humidifier fever, various functional disorders grouped under the name Sick Building Syndrome. To avoid these problems, a certain number of recommendations may be made. They concern: installation of air conditioning, humidification which is the cause of bacterial and fungal contamination, filtration, monitoring of the installation by qualitative and quantitative measurements, maintenance. The legal problems relating to these illnesses, the responsibility for which is ultimately laid at the door of the installers, should also be mentioned. Allergies are recognized to be of professional origin in Table 66 of allergic illnesses issued by the Social Security.

  13. Solar air-conditioning. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Within the 3rd International Conference on solar air-conditioning in Palermo (Italy) at 30th September to 2nd October, 2009 the following lectures were held: (1) Removal of non-technological barriers to solar cooling technology across Southern European islands (Stefano Rugginenti); (2) The added economic and environmental value of solar thermal systems in microgrids with combined heat and power (Chris Marney); (3) Australian solar cooling interest group (Paul Kohlenbach); (4) Designing of a technology roadmap for solar assisted air conditioning in Austria (Hilbert Focke); (5) Solar cooling in the new context of renewable policies at European level (Raffaele Piria); (6) Prototype of a solar driven steam jet ejector chiller (Clemens Pollerberg); (7) New integrated solar air conditioning system (Joan Carlos Bruno); (8) Primary energy optimised operation of solar driven desiccant evaporative cooling systems through innovative control strategies; (9) Green chiller association (Uli Jakob); (10) Climate Well {sup registered} (Olof Hallstrom); (11) Low capacity absorption chillers for solar cooling applications (Gregor Weidner); (12) Solar cooling in residential, small scale commercial and industrial applications with adsorption technology (Walter Mittelbach); (13) French solar heating and cooling development programme based on energy performance (Daniel Mugnier); (14) Mirrox fresnel process heat collectors for industrial applications and solar cooling (Christian Zahler); (15) Modelling and analyzing solar cooling systems in polysun (Seyen Hossein Rezaei); (16) Solar cooling application in Valle Susa Italy (Sufia Jung); (17) Virtual case study on small solar cooling systems within the SolarCombi+Project (Bjoern Nienborg); (18) Design of solar cooling plants under uncertainty (Fernando Dominguez-Munoz); (19) Fast pre-design of systems using solar thermally driven chillers (Hans-Martin Henning); (20) Design of a high fraction solar heating and cooling plant in southern

  14. Hellish conditions at single-room occupancy hotels.

    Science.gov (United States)

    Foley, D

    1998-08-01

    Poor conditions exist in many of the commercial single-room occupancy (SRO) hotels for people who are HIV-positive. Living conditions are unsanitary, brutal, and dangerous, and occupants often experience harassment from the hotel owners and staff. Many of the occupants are drug abusers or are mentally incapacitated, and therefore may not have the ability to secure better housing. The situation in the California Suites, an SRO in Manhattan, is described.

  15. High Energy Efficiency Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Edward McCullough; Patrick Dhooge; Jonathan Nimitz

    2003-12-31

    This project determined the performance of a new high efficiency refrigerant, Ikon B, in a residential air conditioner designed to use R-22. The refrigerant R-22, used in residential and small commercial air conditioners, is being phased out of production in developed countries beginning this year because of concerns regarding its ozone depletion potential. Although a replacement refrigerant, R-410A, is available, it operates at much higher pressure than R-22 and requires new equipment. R-22 air conditioners will continue to be in use for many years to come. Air conditioning is a large part of expensive summer peak power use in many parts of the U.S. Previous testing and computer simulations of Ikon B indicated that it would have 20 - 25% higher coefficient of performance (COP, the amount of cooling obtained per energy used) than R-22 in an air-cooled air conditioner. In this project, a typical new R-22 residential air conditioner was obtained, installed in a large environmental chamber, instrumented, and run both with its original charge of R-22 and then with Ikon B. In the environmental chamber, controlled temperature and humidity could be maintained to obtain repeatable and comparable energy use results. Tests with Ikon B included runs with and without a power controller, and an extended run for several months with subsequent analyses to check compatibility of Ikon B with the air conditioner materials and lubricant. Baseline energy use of the air conditioner with its original R-22 charge was measured at 90 deg F and 100 deg F. After changeover to Ikon B and a larger expansion orifice, energy use was measured at 90 deg F and 100 deg F. Ikon B proved to have about 19% higher COP at 90 deg F and about 26% higher COP at 100 deg F versus R-22. Ikon B had about 20% lower cooling capacity at 90 deg F and about 17% lower cooling capacity at 100 deg F versus R-22 in this system. All results over multiple runs were within 1% relative standard deviation (RSD). All of these

  16. Improving efficiency of existing air-conditioning

    Science.gov (United States)

    Obler, H. D.

    1977-01-01

    Inexpensive duct work changes improves hot-and-cold deck air conditioning units. Energy cost of reheating cooled air can be eliminated by tying all cold air decks to one air-conditioning unit and all hot decks to another. Resultant energy savings are easily possible with two or more units.

  17. Human preference and acceptance of increased air velocity to offset warm sensation at increased room temperatures

    DEFF Research Database (Denmark)

    Cattarin, Giulio; Simone, Angela; Olesen, Bjarne W.

    . The present climatic chamber study examined energy performance and achievable thermal comfort of traditional and bladeless desk fans. Different effects of mechanical and simulated-natural airflow patterns were also investigated. 32 Scandinavians, performing office activities and wearing light clothes , were......Previous studies have demonstrated that in summertime increased air velocities can compensate for higher room temperatures to achieve comfortable conditions. In order to increase air movement, windows opening, ceiling or desk fans can be used at the expense of relatively low energy consumption...... exposed to a increased air movement generated by a personal desk fan. The subjects could continuously regulate the fans under three fixed environmental conditions (operative temperatures equal to 26 °C, 28 °C, or 30 °C, and same absolute humidity 12.2 g/m3). The experimental study showed that increased...

  18. Desiccant dehumidification in decentralized air conditioning systems; Einsatz der Sorptionstechnik in der dezentralen Klimatisierung von Gebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Busweiler, Ulrich [Fachhochschule Giessen-Friedberg (Germany)

    2009-01-15

    Dehumidification of supply air with adsorption wheels, which is known from desiccant cooling systems, is now applied to small air handling units which condition the air of one single room. There is an increase in comfort in winter by recovery of moisture. In summer, dehumidification and cooling of air are ensured by an absolutely dry process without any hygienic risk. (orig.)

  19. Management of air-conditioning systems in residential buildings by using fuzzy logic

    Directory of Open Access Journals (Sweden)

    Sohair F. Rezeka

    2015-06-01

    Full Text Available There has been a rising concern in reducing the energy consumption in buildings. Heating, ventilation and air-conditioning system is the biggest consumer of energy in buildings. In this study, management of the air-conditioning system of a building for efficient energy operation and comfortable environment is investigated. The strategy used in this work depends on classifying the rooms to three different groups: very important rooms, important rooms and normal rooms. The total mass flow rate is divided between all rooms by certain percentage using a fuzzy-logic system to get the optimum performance for each room. The suggested Building Management System (BMS was found capable of keeping errors in both temperature and humidity within the acceptable limits at different operating conditions. The BMS can save the chilled/hot water flow rate and the cooling/heating capacity of rooms.

  20. Fungal colonization of air-conditioning systems

    Directory of Open Access Journals (Sweden)

    Ljaljević-Grbić Milica

    2008-01-01

    Full Text Available Fungi have been implicated as quantitatively the most important bioaerosol component of indoor air associated with contaminated air-conditioning systems. rarely, indoor fungi may cause human infections, but more commonly allergenic responses ranging from pneumonitis to asthma-like symptoms. From all air conditioner filters analyzed, 16 fungal taxa were isolated and identified. Aspergillus fumigatus causes more lethal infections worldwide than any other mold. Air-conditioning filters that adsorb moisture and volatile organics appear to provide suitable substrates for fungal colonization. It is important to stress that fungal colonization of air-conditioning systems should not be ignored, especially in hospital environments.

  1. Passive inhalation of marijuana smoke: urinalysis and room air levels of delta-9-tetrahydrocannabinol

    Energy Technology Data Exchange (ETDEWEB)

    Cone, E.J.; Johnson, R.E.; Darwin, W.D.; Yousefnejad, D.; Mell, L.D.; Paul, B.D.; Mitchell, J.

    1987-05-01

    In two separate studies, 5 drug-free male volunteers with a history of marijuana use were passively exposed to the sidestream smoke of 4 and 16 marijuana cigarettes (2.8% delta-9-tetrahydrocannabinol (THC)) for 1 h each day for 6 consecutive days. A third study was similarly performed with 2 marijuana-naive subjects passively exposed to the smoke of 16 marijuana cigarettes. Passive smoke exposure was conducted in a small, unventilated room. Room air levels of THC and CO were monitored frequently. All urine specimens were collected and analyzed by EMIT d.a.u. assay, Abuscreen radioimmunoassay and GC/MS. The studies show that significant amounts of THC were absorbed by all subjects at the higher level of passive smoke exposure (eg., smoke from 16 marijuana cigarettes), resulting in urinary excretion of significant amounts of cannabinoid metabolites. However, it seems improbable that subjects would unknowingly tolerate the noxious smoke conditions produced by this exposure. At the lower level of passive marijuana-smoke exposure, specimens tested positive only infrequently or were negative. Room air levels of THC during passive smoke exposure appeared to be the most critical factor in determining whether a subject produced cannabinoid-positive urine specimens.

  2. Concentrated Solar Air Conditioning for Buildings Project

    Science.gov (United States)

    McLaughlin, Rusty

    2010-01-01

    This slide presentation reviews project to implement the use of solar power to provide air conditioning for NASA buildings. Included is an overall conceptual schematic, and an diagram of the plumbing and instrumentation for the project. The use of solar power to power air conditioning in buildings, particularly in the Southwest, could save a significant amount of money. DOD studies have concluded that air conditioning accounts for 30-60% of total energy expenditures.

  3. PWM、S-PAM及PHASE电压联动控制技术在变频空调上的应用%The PWM, S-PAM, PHASE and Voltage Linkage Control Technology Using in Inverter Room Air-conditioning

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

      目前,变频空调采用高效永磁同步(大发电常数Ke)压缩机已成趋势,且用于农村的低压地区。根据PWM、S-PAM以及PHASE电压联动控制技术,可使高效永磁同步(Ke值大)压缩机运行到更高的频率且损耗降低;在低压地区,使空调正常运行并保证输出足够的制冷制热能力;在同频率下,比以往的变频压缩机的电流更低,功耗小,更节能。此技术大幅的提高了变频机的运行效率以及降低了压缩机的功率,实现了高效节能的效果,是变频控制技术的节能效果又一次提升,是一种最合适的直流变频压缩机控制技术。%With inverter air conditioner using parmanent magnet synchronous motor, this technique is al-so used in the rural area of low voltage. Because of the technique which are PWM, S-PAM, PHASE and Link-age control, efficient parmanent magnet synchronous motor can run to a higher frequency an lower power con-sumption. And in low voltage area, this technique can make the normal operation of air conditioning and refrig-eration system output enough cool or heat. In the same frequency, the inverter technology is more outstanding than before, which are lower power consumption , lower motor current and more energy saving. The technolo-gy greatly improves the efficient of the frequency conversion air conditioner, and to reduce the motor power con-sumption, realized the high efficiency and energy saving effect. This is a promotion of energy saving effect of the inverter technology, which is one of the most appropriate inverter compressors drive technology.

  4. Temperature and Humidity Control in Air-Conditioned Buildings with lower Energy Demand and increased Indoor Air Quality

    DEFF Research Database (Denmark)

    Paul, Joachim; Martos, E. T.

    2003-01-01

    %. For indoor air temperature and humidity control, the use of an ice slurry (´Binary Ice´)was compared to conventional chilled water. The use of Binary Ice instead of chilled water makes the air handling and air distribution installation much simpler, recirculation of air becomes obsolete, and a higher portion....... Binary Ice as secondary refrigerant for air-conditioning purposes is an economical and technically feasible solution in any climate. Whatever chilled water can do in an air-conditioning installation ? Binary Ice can do it better....... of ambient air can be supplied, thus improving the indoor air quality still further. Reheating of air is not necessary when using Binary Ice. The introduction of chilled air into a room requires a different type of air outlet, however. When using Binary Ice, energy savings are high for climates with low...

  5. Evaluating The Operation Of Three Air Cleaners Working Individually In A Clean Room

    DEFF Research Database (Denmark)

    Ardkapan, Siamak Rahimi; Afshari, Alireza; Bergsøe, Niels Christian

    2011-01-01

    The use of portable air cleaners is becoming increasingly popular in many countries including Denmark. Portable air cleaners are known for not only removing but also generating particles and gases. To clarify this, three air cleaning technologies were evaluated. They were nonthermal plasma......, photochemical air purifier and corona discharge ionizer. The concentrations of ultrafine particles, ozone and total volatile organic compounds were measured both in a duct and in a clean room. It was found that the studied air cleaning technologies increased the ozone level in the clean room and the duct....... The increase of ozone level in the clean room was more than that was measured in the duct. Additionally, it was found that the number of ultrafine particles in the room increased due to the generated ozone. The number of generated particles changed with the season. The study leads to the recommendation...

  6. Performance and Effectiveness of Portable Air Cleaners in an Office Room

    DEFF Research Database (Denmark)

    Ardkapan, Siamak Rahimi; Afshari, Alireza; Bergsøe, Niels Christian

    2015-01-01

    Nowadays, many people work in an office environment. Air pollutants, including particles and gases, are generated by humans and by different devices that are used in offices. Pollutants can also enter an office room with the air supplied from outdoors. It has been established that air pollutants ...

  7. The Performance of Diffuse Ceiling Inlet and other Room Air Distribution Systems

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jakubowska, Ewa

    2009-01-01

    The paper analyses different room air distribution systems, and describes a design chart which can be used for the evaluation of variables as air quality, air velocity and temperature gradient as a function of flow rate and temperature difference in the supply system. The design chart can also be...

  8. Effect of room air recirculation delay on the decay rate of tracer gas concentration

    Energy Technology Data Exchange (ETDEWEB)

    Kristoffersen, A.R.; Gadgil, A.J.; Lorenzetti, D.M.

    2004-05-01

    Tracer gas measurements are commonly used to estimate the fresh air exchange rate in a room or building. Published tracer decay methods account for fresh air supply, infiltration, and leaks in ductwork. However, the time delay associated with a ventilation system recirculating tracer back to the room also affects the decay rate. We present an analytical study of tracer gas decay in a well-mixed, mechanically-ventilated room with recirculation. The analysis shows that failing to account for delays can lead to under- or over-estimates of the fresh air supply, depending on whether the decay rate calculation includes the duct volume.

  9. Air Conditioning. Performance Objectives. Intermediate Course.

    Science.gov (United States)

    Long, William

    Several intermediate performance objectives and corresponding criterion measures are listed for each of seven terminal objectives for an intermediate air conditioning course. The titles of the seven terminal objectives are Refrigeration Cycle, Job Requirement Skills, Air Conditioning, Trouble Shooting, Performance Test, Shop Management, and S.I.E.…

  10. HEATING AND AIR CONDITIONING EDUCATIONAL PROGRAM.

    Science.gov (United States)

    Lennox Industries, Inc., Marshalltown, IA.

    INCREASED MOTIVATION, INCREASED INITIAL COMPREHENSION, AND INCREASED RETENTION ARE THE PRIME GOALS OF THE LENNOX HEATING AND AIR CONDITIONING EDUCATION PROGRAM. IT IS A COMPLETE PROGRAM WITH ALL THE TEACHING TOOLS REQUIRED TO PRODUCE A KNOWLEDGEABLE HEATING AND AIR-CONDITIONING INSTALLER OR SERVICE MAN. THIS INSTRUCTIONAL PROGRAM IS DESIGNED…

  11. Air Conditioning and Heating Technology--II.

    Science.gov (United States)

    Gattone, Felix

    Twenty-eight chapters and numerous drawings provide information for instructors and students of air conditioning and heating technology. Chapter 1 lists the occupational opportunities in the field. Chapter 2 covers the background or development of the industry of air conditioning and heating technology. Chapter 3 includes some of the principle…

  12. Air Conditioning. FOS: Fundamentals of Service.

    Science.gov (United States)

    Employment and Training Administration (DOL), Washington, DC. Office of Youth Programs.

    This manual on air conditioning is one of a series of power mechanics texts and visual aids covering theory of operation, diagnosis, and repair. Information is presented for use by vocational students and teachers as well as shop servicemen and laymen. Focus is on air conditioning systems for mobile machines, but most of the information also…

  13. Air Conditioning. Performance Objectives. Intermediate Course.

    Science.gov (United States)

    Long, William

    Several intermediate performance objectives and corresponding criterion measures are listed for each of seven terminal objectives for an intermediate air conditioning course. The titles of the seven terminal objectives are Refrigeration Cycle, Job Requirement Skills, Air Conditioning, Trouble Shooting, Performance Test, Shop Management, and S.I.E.…

  14. Air Conditioning and Heating Technology--II.

    Science.gov (United States)

    Gattone, Felix

    Twenty-eight chapters and numerous drawings provide information for instructors and students of air conditioning and heating technology. Chapter 1 lists the occupational opportunities in the field. Chapter 2 covers the background or development of the industry of air conditioning and heating technology. Chapter 3 includes some of the principle…

  15. A novel summer air conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Al-Nimr, M.A.; Abu Nabah, B.A.; Naji, M. [Jordan Univ. of Science and Technology, Irbid (Jordan). Dept. of Mechanical Engineering

    2002-09-01

    A novel summer air conditioning system is proposed. The proposed system modifies the work of the classical evaporative summer air conditioning system. The performance of the proposed system is investigated quantitatively, and a comparison between the performance of the classical and the modified systems is conducted. It is found that the modified system improves the performance of the classical one by about 100%. (author)

  16. Stratified Flow in a Room with Displacement Ventilation and Wall-Mounted Air Terminal devices

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    This paper describes experiments with wall-mounted air terminal devices. The stratified flow in the room is analyzed, and the influence of stratification and the influence of room dimensions on the velocity level and on the length scale are proved. The velocity level in the occupied zone can be d...

  17. Air Distribution in Rooms with Ceiling-mounted Obstacles and Three-Dimensional Isothermal Flow

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Evensen, Louis; Grabau, Peter;

    The air supply openings in ventilated rooms are often placed close to the ceiling. A recirculating flow is generated in the room, and the region between the ceiling and the occupied zone serves as an entrainment and velocity decay area for the wall jets. Ceiling-mounted obstacles may disturb...

  18. Heat exchange studies on coconut oil cells as thermal energy storage for room thermal conditioning

    Science.gov (United States)

    Sutjahja, I. M.; Putri, Widya A.; Fahmi, Z.; Wonorahardjo, S.; Kurnia, D.

    2017-07-01

    As reported by many thermal environment experts, room air conditioning might be controlled by thermal mass system. In this paper we discuss the performance of coconut oil cells as room thermal energy storage. The heat exchange mechanism of coconut oil (CO) which is one of potential organic Phase Change Material (PCM) is studied based on the results of temperature measurements in the perimeter and core parts of cells. We found that the heat exchange performance, i.e. heat absorption and heat release processes of CO cells are dominated by heat conduction in the sensible solid from the higher temperature perimeter part to the lower temperature core part and heat convection during the solid-liquid phase transition and sensible liquid phase. The capability of heat absorption as measured by the reduction of air temperature is not influenced by CO cell size. Besides that, the application of CO as the thermal mass has to be accompanied by air circulation to get the cool sensation of the room’s occupants.

  19. Effects of supply air temperature and inlet location on particle dispersion in displacement ventilation rooms

    Institute of Scientific and Technical Information of China (English)

    Yanming Kang; Youjun Wang; Ke Zhong

    2011-01-01

    The effects of supply temperature and vertical location of inlet air on particle dispersion in a displacement ventilated (DV) room were numerically modeled with validation by experimental data from the literature.The results indicate that the temperature and vertical location of inlet supply air did not greatly affect the air distribution in the upper parts of a DV room,but could significantly influence the airflow pattern in the lower parts of the room,thus affecting the indoor air quality with contaminant sources located at the lower level,such as particles from working activities in an office.The numerical results also show that the inlet location would slightly influence the relative ventilation efficiency for the same air supply volume,but particle concentration in the breathing zone would be slightly lower with a low horizontal wall slot than a rectangular diffuser.Comparison of the results for two different supply temperatures in a DV room shows that,although lower supply temperature means less incoming air volume,since the indoor flow is mainly driven by buoyancy,lower supply temperature air could more efficiently remove passive sources (such as particles released from work activities in an office).However,in the breathing zone it gives higher concentration as compared to higher supply air temperature.To obtain good indoor air quality,low supply air temperature should be avoided because concentration in the breathing zone has a stronger and more direct impact on human health.

  20. CFD SIMULATION OF AIR ION REGIME IN WORK AREAS AT CONDITION OF ARTIFICIAL AIR IONIZATION

    Directory of Open Access Journals (Sweden)

    M. M. Biliaiev

    2016-02-01

    Full Text Available Purpose. The paper supposes creation of a CFD model for calculating the air ion regime in the premises and in work areas at artificial ionization of the air by the ionizer installation indoors with considering the most important physical factors that influence the formation of ions concentration field. Methodology. The proposed CFD model for calculation of the air ion regime in work areas at artificial ionization of the air by installing ionizer indoors is based on the application of aerodynamics, electrostatics and mass transfer equations. The mass transfer equation takes into account the interaction of different polarities of ions with each other and with the dust particles. The calculation of air flow rate in the room is realized on the basis of the potential flow model by using the Laplace equation for the stream function. Poisson equation for the electric potential is used for calculation of the charged particles drift in an electric field. At the simulation to take into account: 1 influence of the working area geometric characteristics; 2 location of the ventilation holes; 3 placement of furniture and equipment; 4 ventilation regime in the room; 5 presence of obstacles on the ions dispersion process; 6 specific location of dust particles emission and ions of different polarity, and their interaction in the room and in the working zones. Findings. The developed CFD model allows determining the concentration of negative ions in the room and in the area of the human respiratory organs. The distribution of the negative ions concentration is presented in the form of concentration field isolines. Originality. The 2D CFD model for calculating the air ion regime in working areas, providing the ability to determine the ions concentration in a given place in the room was created. The proposed model is developed taking into account: placement of furniture and equipment in the room; geometric characteristics of the room; location of dust emissions

  1. Research on influence law of capillary length on performance of room air conditioner in non-standard working condition%非标工况下毛细管长度对家用空调器性能影响规律的研究

    Institute of Scientific and Technical Information of China (English)

    段亮; 熊军; 陈绍林

    2012-01-01

    通过研究家用空调器的制冷量、能效比、排气温度、吸气温度等随室外温度和毛细管长度的变化规律,得出增加毛细管长度有利于提升高温工况下的制冷量,缩短毛细管长度有利于提升低温工况下的制冷量的结论,对于空调系统匹配有一定的指导意义.%The influence law of capillary length and outdoor temperature on cooling capacity, COP, exhaust temperature, suction temperature of room air conditioner are analyzed. The results show that increasing capillary length is benefit for cooling capacity under high temperature condition and decreasing length brings advantage to cooling capacity under low temperature condition. The study will provide reference for air-conditioning system matching.

  2. Room air temperature affects occupants' physiology, perceptions and mental alertness

    Energy Technology Data Exchange (ETDEWEB)

    Tham, Kwok Wai; Willem, Henry Cahyadi [Department of Building, School of Design and Environment, National University of Singapore, 4 Architecture Drive, Singapore 117566 (Singapore)

    2010-01-15

    Thermal environment that causes thermal discomfort may affect office work performance. However, the mechanisms through which occupants are affected are not well understood. This study explores the plausible mechanism linking room air temperature and mental alertness through perceptual and physiological responses in the tropics. Ninety-six young adults participated as voluntary subjects in a series of experiment conducted in the simulated office settings. Three room air temperatures, i.e. 20.0, 23.0 and 26.0 C were selected as the experimental conditions. Both thermal comfort and thermal sensation changed significantly with time under all exposures (P < 0.0001). Longer exposure at 20.0 C led to cooling sensations due to lower skin temperatures (P < 0.0001) and was perceived as the least comfortable. Nevertheless, this moderate cold exposure induced nervous system activation as demonstrated by the increase of {alpha}-Amylase level (P < 0.0001) and the Tsai-partington test (P < 0.0001). A mechanism linking thermal environment, occupants' responses and performance is proposed. (author)

  3. Nocturnal oxygen enrichment of room air at 3800 meter altitude improves sleep architecture.

    Science.gov (United States)

    Barash, I A; Beatty, C; Powell, F L; Prisk, G K; West, J B

    2001-01-01

    Sleep is known to be impaired at high altitude, and this may be a factor contributing to reduced work efficiency, general malaise, and the development of acute mountain sickness (AMS). Nocturnal room oxygen enrichment at 3800 m has been shown to reduce the time spent in periodic breathing and the number of apneas, to improve subjective quality of sleep, and to reduce the AMS score. The present study was designed to evaluate the effect of oxygen enrichment to 24% at 3800 m (lowering the equivalent altitude to 2800 m) on sleep architecture. Full polysomnography and actigraphy were performed on 12 subjects who ascended in 1 day to 3800 m and slept in a specially constructed room that allowed oxygen enrichment or ambient air conditions in a randomized, crossover, double-blind study. The results showed that subjects spent a significantly greater percentage of time in deep sleep (stages III and IV combined, or slow wave sleep) with oxygen enrichment versus ambient air (17.2 +/- 10.0% and 13.9 +/- 6.7%, respectively; p sleep quality or with subject's assessment of the extent to which they suffered from AMS. This study provides further objective evidence of improved sleep as a result of oxygen enrichment at 3800 m and suggests that alleviating hypoxia may improve sleep quality.

  4. A Well-Mixed Computational Model for Estimating Room Air Levels of Selected Constituents from E-Vapor Product Use

    Directory of Open Access Journals (Sweden)

    Ali A. Rostami

    2016-08-01

    Full Text Available Concerns have been raised in the literature for the potential of secondhand exposure from e-vapor product (EVP use. It would be difficult to experimentally determine the impact of various factors on secondhand exposure including, but not limited to, room characteristics (indoor space size, ventilation rate, device specifications (aerosol mass delivery, e-liquid composition, and use behavior (number of users and usage frequency. Therefore, a well-mixed computational model was developed to estimate the indoor levels of constituents from EVPs under a variety of conditions. The model is based on physical and thermodynamic interactions between aerosol, vapor, and air, similar to indoor air models referred to by the Environmental Protection Agency. The model results agree well with measured indoor air levels of nicotine from two sources: smoking machine-generated aerosol and aerosol exhaled from EVP use. Sensitivity analysis indicated that increasing air exchange rate reduces room air level of constituents, as more material is carried away. The effect of the amount of aerosol released into the space due to variability in exhalation was also evaluated. The model can estimate the room air level of constituents as a function of time, which may be used to assess the level of non-user exposure over time.

  5. Prediction of Air Flow and Temperature Distribution Inside a Yogurt Cooling Room Using Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    A Surendhar

    2015-01-01

    Full Text Available Air flow and heat transfer inside a yogurt cooling room were analysed using Computational Fluid Dynamics. Air flow and heat transfer models were based on 3D, unsteady state, incompressible, Reynolds-averaged Navier-Stokes equations and energy equations. Yogurt cooling room was modelled with the measured geometry using 3D design tool AutoCAD. Yogurt cooling room model was exported into the flow simulation software by specifying properties of inlet air, yogurt, pallet and walls of the room. Packing material was not considered in this study because of less thickness (cup-0.5mm, carton box-1.5mm and negligible resistance created in the conduction of heat. 3D Computational domain was meshed with hexahedral cells and governing equations were solved using explicit finite volume method. Air flow pattern inside the room and the temperature distribution in the bulk of palletized yogurt were predicted. Through validation, the variation in the temperature distribution and velocity vector from the measured value was found to be 2.0oC (maximum and 30% respectively. From the simulation and the measured value of the temperature distribution, it was observed that the temperature was non-uniform over the bulk of yogurt. This might be due to refrigeration capacity, air flow pattern, stacking of yogurt or geometry of the room. Required results were achieved by changing the location of the cooling fan.

  6. The operating room: architectural conditions and potential hazards.

    Science.gov (United States)

    Koneczny, Sonja

    2009-01-01

    Ergonomics is still not fully implemented in the design of operation rooms (ORs). The OR staff has to deal with various ergonomic deficiencies which may be associated with potential hazards for the patient and/or the OR team.Three surveys were conducted among German OR staff at major conferences. Two of them dealt with the working conditions in the OR and were conducted among surgeons and OR nurses. The third survey queried OR nurses about the electrical safety in the OR.In addition, a specially developed checklist was used to evaluate the work place OR in five German OR units and the staff of these OR units were queried with questionnaires adapted from the surveys. For this article a few of the deficiencies found in the ORs were chosen to serve as examples for the plethora of results gathered.Findings showed that there was a high potential for ergonomic improvement and therefore an increase in safety and comfort. Many of these deficiencies may be eased by simple means such as the reduction of the number of different devices and mandatory training in the use of the devices since device operation is one of the main causes leading to potential hazards in the OR. Other deficiencies, such as the cable routing in the OR, require more extensive intervention and/or the implementation of new techniques, for example the "wireless" OR. All these deficiencies demonstrate the need for better implementation of ergonomics into the OR and for individual solutions, as there is no such thing as an 'one-size-fits-all' solution for OR units.

  7. Transmission of exhaled air between occupants in rooms with personalized and underfloor ventilation

    DEFF Research Database (Denmark)

    Cermak, Radim; Melikov, Arsen Krikor

    2004-01-01

    in rooms. The concentration of exhaled air from one occupant was measured in air inhaled by another occupant who used or did not use personalized ventilation. The results showed that the type of personalized ventilation, together with the throw height of underfloor ventilation, affects mixing...

  8. Reduced bleed air extraction for DC-10 cabin air conditioning

    Science.gov (United States)

    Newman, W. H.; Viele, M. R.; Hrach, F. J.

    1980-01-01

    It is noted that a significant fuel savings can be achieved by reducing bleed air used for cabin air conditioning. Air in the cabin can be recirculated to maintain comfortable ventilation rates but the quality of the air tends to decrease due to entrainment of smoke and odors. Attention is given to a development system designed and fabricated under the NASA Engine Component Improvement Program to define the recirculation limit for the DC-10. It is shown that with the system, a wide range of bleed air reductions and recirculation rates is possible. A goal of 0.8% fuel savings has been achieved which results from a 50% reduction in bleed extraction from the engine.

  9. Flow Conditions in a Mechanically Ventilated Room with a Convective Heat Source

    DEFF Research Database (Denmark)

    Heiselberg, Per; Nielsen, Peter V.

    1988-01-01

    The ventilation of a test room (LxWxH = 5.4x3.6x2.4 m) with a wall mounted heat source is investigated for two different air terminal devices.......The ventilation of a test room (LxWxH = 5.4x3.6x2.4 m) with a wall mounted heat source is investigated for two different air terminal devices....

  10. Heating, ventilation and air conditioning system modelling

    Energy Technology Data Exchange (ETDEWEB)

    Whalley, R.; Abdul-Ameer, A. [British University in Dubai (United Arab Emirates)

    2011-03-15

    Heating, ventilation and air conditioning modelling methods, for large scale, spatially dispersed systems are considered. Existing techniques are discussed and proposals for the application of novel analysis approaches are outlined. The use of distributed-lumped parameter procedures enabling the incorporation of the relatively concentrated and significantly dispersed, system element characteristics, is advocated. A dynamic model for a heating, ventilation and air conditioning system comprising inlet and exhaust fans, with air recirculation, heating/cooling and filtration units is presented. Pressure, airflow and temperature predictions within the system are computed following input, disturbance changes and purging operations. The generalised modelling advancements adopted and the applicability of the model for heating, ventilation and air conditioning system simulation, re-configuration and diagnostics is emphasised. The employment of the model for automatic, multivariable controller design purposes is commented upon. (author)

  11. A strategy for oxygen conditioning at high altitude: comparison with air conditioning.

    Science.gov (United States)

    West, John B

    2015-09-15

    Large numbers of people live or work at high altitude, and many visit to trek or ski. The inevitable hypoxia impairs physical working capacity, and at higher altitudes there is also cognitive impairment. Twenty years ago oxygen enrichment of room air was introduced to reduce the hypoxia, and this is now used in dormitories, hotels, mines, and telescopes. However, recent advances in technology now allow large amounts of oxygen to be obtained from air or cryogenic oxygen sources. As a result it is now feasible to oxygenate large buildings and even institutions such as hospitals. An analogy can be drawn between air conditioning that has improved the living and working conditions of millions of people who live in hot climates and oxygen conditioning that can do the same at high altitude. Oxygen conditioning is similar to air conditioning except that instead of cooling the air, the oxygen concentration is raised, thus reducing the equivalent altitude. Oxygen conditioning on a large scale could transform living and working conditions at high altitude, where it could be valuable in homes, hospitals, schools, dormitories, company headquarters, banks, and legislative settings. Copyright © 2015 the American Physiological Society.

  12. [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.

  13. Disinfection of indoor air microorganisms in stack room of university library using gaseous chlorine dioxide.

    Science.gov (United States)

    Hsu, Ching-Shan; Lu, Ming-Chun; Huang, Da-Ji

    2015-02-01

    As with all indoor public spaces in Taiwan, the stack rooms in public libraries should meet the air quality guidelines laid down by the Taiwan Environmental Protection Administration. Accordingly, utilizing a university library in Taiwan for experimental purposes, this study investigates the efficiency of gaseous chlorine dioxide (ClO2) as a disinfection agent when applied using three different treatment modes, namely a single-daily disinfection mode (SIM), a twice-daily disinfection mode (TWM), and a triple-daily disinfection mode (TRM). For each treatment mode, the ClO2 is applied using an ultrasonic aerosol device and is performed both under natural lighting conditions and under artificial lighting conditions. The indoor air quality is evaluated before and after each treatment session by measuring the bioaerosol levels of bacteria and fungi. The results show that for all three disinfection modes, the application of ClO2 reduces the indoor bacteria and fungi concentrations to levels lower than those specified by the Taiwan EPA (i.e., bacteria disinfection process is performed. For each disinfection mode, a better disinfection efficiency is obtained under natural lighting conditions since ClO2 readily decomposes under strong luminance levels. Among the three treatment modes, the disinfection efficiencies of the TWM and TRM modes are very similar under natural lighting conditions and are significantly better than that of the SIM mode. Thus, overall, the results suggest that the TWM treatment protocol represents the most cost-effective and efficient method for meeting the indoor air quality requirements of the Taiwan EPA.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-12-01

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

  15. Performance of radiant cooling ceiling combined with personalized ventilation in an office room: identification of thermal conditions

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Melikov, Arsen Krikor

    2014-01-01

    The paper compares thermal environment conditions created by four HVAC systems: mixing ventilation, chilled ceiling combined with mixing ventilation, chilled ceiling with mixing ventilation and personalized ventilation, and chilled ceiling combined with personalized ventilation only. Measurements...... were performed in a test room arranged as an office with 2 workstations and 2 seating occupants resembled by thermal manikins. Heat gain of 66-72 W/m2 was simulated in the room (occupants, computers, lighting, solar gain). The air temperature in the chamber was maintained at 26°C and 28°C. Personalized...

  16. Validation of Boundary Conditions for CFD Simulations on Ventilated Rooms

    DEFF Research Database (Denmark)

    Topp, Claus; Jensen, Rasmus Lund; Pedersen, D.N.;

    2001-01-01

    of full-scale experiments in a room ventilated by the mixing principle have been performed for validation of the models. The experimental results include measurements of temperature as well as measurements of velocity and turbulence by Laser Doppler Anemometry (LDA). A simple model of the complex inlet...

  17. Simulation study on the impact of air distribution on formaldehyde pollutant distribution in room

    Science.gov (United States)

    Wu, Jingtao; Wang, Jun; Cheng, Zhu

    2017-01-01

    In this paper, physical and mathematical model of a room was established based on the Airpak software. The velocity distribution, air age distribution, formaldehyde concentration distribution and Predicted Mean Vote(PMV), Predicted Percentage Dissatisfied(PPD) distribution in the ward of a hospital were simulated. In addition, the air volume was doubled, the change of indoor pollutant concentration distribution was simulated. And further, the change of air age was simulated. Through the simulation, it can help arrange the position of the air supply port, so it is very necessary to increase the comfort of the staff in the room. Finally, through the simulation of pollutant concentration distribution, it can be seen that when concentration of indoor pollutants was high, the supply air flow rate should be increased appropriately. Indoor pollutant will be discharged as soon as possible, which is very beneficial to human body health.

  18. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System.

    Science.gov (United States)

    Zhao, Baiwang; Peng, Na; Liang, Canzeng; Yong, Wai Fen; Chung, Tai-Shung

    2015-11-16

    In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18-22 g/m³ to a range of 13.5-18.3 g/m³. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  19. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Baiwang Zhao

    2015-11-01

    Full Text Available In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18–22 g/m3 to a range of 13.5–18.3 g/m3. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  20. Local Air Quality Conditions and Forecasts

    Science.gov (United States)

    ... Monitor Location Archived Maps by Region Canada Air Quality Air Quality on Google Earth Links A-Z About AirNow AirNow International Air Quality Action Days / Alerts AirCompare Air Quality Index (AQI) ...

  1. The Effect of Computers on School Air-Conditioning.

    Science.gov (United States)

    Fickes, Michael

    2000-01-01

    Discusses the issue of increased air-conditioning demand when schools equip their classrooms with computers that require enhanced and costlier air-conditioning systems. Air-conditioning costs are analyzed in two elementary schools and a middle school. (GR)

  2. The Effect of Computers on School Air-Conditioning.

    Science.gov (United States)

    Fickes, Michael

    2000-01-01

    Discusses the issue of increased air-conditioning demand when schools equip their classrooms with computers that require enhanced and costlier air-conditioning systems. Air-conditioning costs are analyzed in two elementary schools and a middle school. (GR)

  3. Prizes awarded in fiscal 1999 by the Minister for International Trade and Industry on factories having applied excellent energy management. Energy conservation by installing fuel cell power generation facilities utilizing methane gas generated from waste water treatment plants / Improvements toward a clean room and energy saving air conditioning system; 1999 nendo energy kanri yuryo kojo tsusho sangyo daijin hyosho jusho. 1999 nendo shigen energy sho chokan hyosho jusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-04-01

    In order to achieve energy conservation in a waste water treatment plant in a brewery factories, an anaerobic treatment facility was introduced, and a fuel cell power generation facility effectively utilizing methane gas generated from the anaerobic waste water treatment plant was installed. This has resulted in large reduction in the operating number of blowers in the waste water treatment facility of activated sludge system. In addition, electric power, steam, and hot water generated from the fuel cells are effectively utilized as the factory utility. In energy conservation in an optical communication device manufacturing factory, the fan filter unit system was adopted, having been changed from the circulation air conditioner, a conventional type air conditioning system. The present system is a circulation system integrating the fan with the filter, making it possible to circulate air in the room to perform control of temperature, humidity, and dust in a clean room. Thus, the system has eliminated the circulating air conditioner, and reduced the air conditioner capacity by 42% and power consumption by 58.6% compared with those in the conventional circulation system. (NEDO)

  4. Air Conditioning and Refrigeration. Book Two.

    Science.gov (United States)

    Wantiez, Gary W.

    This curriculum guide (book II), along with book I, is designed to provide students with the basic skills for an occupation in air conditioning and refrigeration. Six major areas are included, each consisting of one or more units of instruction. These areas and their respective units are titled as follows: Electricity (fundamentals of electricity,…

  5. Air Conditioning and Refrigeration Supplementary Units.

    Science.gov (United States)

    Winston, Del; And Others

    This document contains supplemental materials for special needs high school students intended to facilitate their mainstreaming in regular air conditioning and refrigeration courses. Teacher's materials precede the materials for students and include general notes for the instructor, additional suggestions, two references, a questionnaire on the…

  6. Air Conditioning and Refrigeration Book IV.

    Science.gov (United States)

    Eckes, William; Fulkerson, Dan

    This publication is the concluding text in a four-part curriculum for air conditioning and refrigeration. Materials in Book 4 are designed to complement theoretical and functional elements in Books 1-3. Instructional materials in this publication are written in terms of student performance using measurable objectives. The course includes six…

  7. Fundamentals of Air Conditioning and Refrigeration.

    Science.gov (United States)

    Clemons, Mark

    This set of instructional materials provides secondary and postsecondary students with a state-of-the-art curriculum for the air conditioning and refrigeration industry that includes the many changes brought by new Environmental Protection Agency (EPA) regulations. Introductory materials explain the use of this publication and provide the…

  8. Readings in Air Conditioning and Refrigeration.

    Science.gov (United States)

    Uberto, Jeffrey A.

    Designed to encourage vocational high school students to read by offering reading materials relevant to their vocational goals, this document contains thirty-seven articles related to air conditioning and refrigeration which have been selected from trade journals, magazines, and newspapers and adapted to the students' reading capabilities. A…

  9. Air Conditioning and Refrigeration. Book One.

    Science.gov (United States)

    Wantiez, Gary W.

    Designed to provide students with the basic skills for an occupation in air conditioning and refrigeration, this curriculum guide includes seven major areas, each consisting of one or more units of instruction. These areas and their respective units are titled as follows: Orientation (history and development, and job opportunities), Safety…

  10. Effects of ambient room temperature on cold air cooling during laser hair removal.

    Science.gov (United States)

    Ram, Ramin; Rosenbach, Alan

    2007-09-01

    Forced air cooling is a well-established technique that protects the epidermis during laser heating of deeper structures, thereby allowing for increased laser fluences. The goal of this prospective study was to identify whether an elevation in ambient room temperature influences the efficacy of forced air cooling. Skin surface temperatures were measured on 24 sites (12 subjects) during cold air exposure in examination rooms with ambient temperatures of 72 degrees F (22.2 degrees C) and 82 degrees F (27.8 degrees C), respectively. Before cooling, mean skin surface temperature was 9 degrees F (5 degrees C) higher in the warmer room (P cooling (within 1 s), the skin surface temperature remained considerably higher (10.75 degrees F, or 5.8 degrees C, P cooling in a room with an ambient temperature of 82 degrees F (27.8 degrees C) is not as effective as in a room that is at 72 degrees F (22.2 degrees C).

  11. Urban air pollution and emergency room admissions for respiratory symptoms: a case-crossover study in Palermo, Italy.

    Science.gov (United States)

    Tramuto, Fabio; Cusimano, Rosanna; Cerame, Giuseppe; Vultaggio, Marcello; Calamusa, Giuseppe; Maida, Carmelo M; Vitale, Francesco

    2011-04-13

    Air pollution from vehicular traffic has been associated with respiratory diseases. In Palermo, the largest metropolitan area in Sicily, urban air pollution is mainly addressed to traffic-related pollution because of lack of industrial settlements, and the presence of a temperate climate that contribute to the limited use of domestic heating plants. This study aimed to investigate the association between traffic-related air pollution and emergency room admissions for acute respiratory symptoms. From January 2004 through December 2007, air pollutant concentrations and emergency room visits were collected for a case-crossover study conducted in Palermo, Sicily. Risk estimates of short-term exposures to particulate matter and gaseous ambient pollutants including carbon monoxide, nitrogen dioxide, and sulfur dioxide were calculated by using a conditional logistic regression analysis. Emergency departments provided data on 48,519 visits for respiratory symptoms. Adjusted case-crossover analyses revealed stronger effects in the warm season for the most part of the pollutants considered, with a positive association for PM10 (odds ratio = 1.039, 95% confidence interval: 1.020 - 1.059), SO2 (OR = 1.068, 95% CI: 1.014 - 1.126), nitrogen dioxide (NO2: OR = 1.043, 95% CI: 1.021 - 1.065), and CO (OR = 1.128, 95% CI: 1.074 - 1.184), especially among females (according to an increase of 10 μg/m3 in PM10, NO2, SO2, and 1 mg/m3 in CO exposure). A positive association was observed either in warm or in cold season only for PM10. Our findings suggest that, in our setting, exposure to ambient levels of air pollution is an important determinant of emergency room (ER) visits for acute respiratory symptoms, particularly during the warm season. ER admittance may be considered a good proxy to evaluate the adverse effects of air pollution on respiratory health.

  12. Urban air pollution and emergency room admissions for respiratory symptoms: a case-crossover study in Palermo, Italy

    Directory of Open Access Journals (Sweden)

    Calamusa Giuseppe

    2011-04-01

    Full Text Available Abstract Background Air pollution from vehicular traffic has been associated with respiratory diseases. In Palermo, the largest metropolitan area in Sicily, urban air pollution is mainly addressed to traffic-related pollution because of lack of industrial settlements, and the presence of a temperate climate that contribute to the limited use of domestic heating plants. This study aimed to investigate the association between traffic-related air pollution and emergency room admissions for acute respiratory symptoms. Methods From January 2004 through December 2007, air pollutant concentrations and emergency room visits were collected for a case-crossover study conducted in Palermo, Sicily. Risk estimates of short-term exposures to particulate matter and gaseous ambient pollutants including carbon monoxide, nitrogen dioxide, and sulfur dioxide were calculated by using a conditional logistic regression analysis. Results Emergency departments provided data on 48,519 visits for respiratory symptoms. Adjusted case-crossover analyses revealed stronger effects in the warm season for the most part of the pollutants considered, with a positive association for PM10 (odds ratio = 1.039, 95% confidence interval: 1.020 - 1.059, SO2 (OR = 1.068, 95% CI: 1.014 - 1.126, nitrogen dioxide (NO2: OR = 1.043, 95% CI: 1.021 - 1.065, and CO (OR = 1.128, 95% CI: 1.074 - 1.184, especially among females (according to an increase of 10 μg/m3 in PM10, NO2, SO2, and 1 mg/m3 in CO exposure. A positive association was observed either in warm or in cold season only for PM10. Conclusions Our findings suggest that, in our setting, exposure to ambient levels of air pollution is an important determinant of emergency room (ER visits for acute respiratory symptoms, particularly during the warm season. ER admittance may be considered a good proxy to evaluate the adverse effects of air pollution on respiratory health.

  13. Saving energy in the make-up air unit (MAU) for semiconductor clean rooms in subtropical areas

    Energy Technology Data Exchange (ETDEWEB)

    Tsao, Jhy-Ming; Hu, Shih-Cheng [Department of Energy and Refrigerating Air-Conditioning Engineering, National Taipei University of Technology. 1, Sec. 3, Chung-Hsiao E. Rd. Taipei 106 (China); Chan, David Yih-Liang; Hsu, Rich Tsung-Chi; Lee, Jane Car-Cheng [Energy and Environment Research Labs, Industrial Technology Research Institute Bldg 51, 195, Sec. 4, Chung Hsing Rd, Chutung, Hinchu 106 Taiwan (China)

    2008-07-01

    The energy requirements to cool, dehumidify, preheat and/or humidify outdoor air are significant in the make-up air unit (MAU) of clean room air-conditioning systems, and can represent 30% to 65% of the total thermal energy required to maintain a clean room environment. Because of these high-energy requirements, cost-effective means to reduce energy costs can influence unit production costs. Reducing or displacing mechanical cooling or electrical heating requirements can achieve the greatest opportunity for significant energy savings. This paper, therefore, aims to improve the energy performance of the MAU system by properly arranging compositions of components of a typical MAU applied in a semiconductor clean room. Explicitly, we investigated the influence of various factors including the fan location (draft-through type vs. push-through type), chilled water system (single-chilled water temperature system vs. two chilled water temperature system) and reheating scheme (electrical heating vs. hot water provided by heat recovery chiller). The result shows that the draw-through type accompanied by two chilled water temperature system with heat recovery function exhibits the lowest electrical power consumption. (author)

  14. Evaporative Condensers in Comfortable Air Conditioning System

    Institute of Scientific and Technical Information of China (English)

    YIN Ying-de; ZHU Dong-sheng; DU Gui-mei; LI Yuan-xi; SUN He-jing; LIU Qing-ming

    2009-01-01

    The operating theory of an evaporative condenser was expatiated.The difference between an e-vaporative condensing refrigeration system and a general refrigeration system was analyzed.Compared with the air-cooled and the water-cooled,the virtues of energy-conservation and water-conservation of evaporative con-densers were analyzed.Some questions existing in the application of evaporative condensers were pointed out,the corresponding solving methods were analyzed accordingly,and the development trend of evaporative con-densing technique in mechanical refrigeration system field and the applied foreground of evaporative condensers in comfortable air conditioning were prospected.

  15. Air Conditioning System using Rankine Cycle

    Science.gov (United States)

    Nagatomo, Shigemi; Yamaguchi, Hiroichi; Hattori, Hitoshi; Futamura, Motonori

    Natural gas is used as the energy source to cope with the recent situation of increasing demand for electricity especially in summer. In this paper, the performance of a Rankine cycle air conditioning system driven by natural gas was studied. The following results were obtained : (1) Basic equations of performance, refrigerant mass flow rate and expander volume were developed by using the values of heating efficiency, regeneration efficiency, expander efficiency and compressor efficiency. (2) R134a refrigerant has been considered to be suitable for the Rankine cycle air conditioning system, compared with other refrigerants. (3)A Rankine cycle cooling system using R134a refrigerant as a single working fluid was developed. System COP of 0.47 was attained at typical operating condition.

  16. Reduced exposure to coughed air by a novel ventilation method for hospital patient rooms

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho Dimitrov; Melikov, Arsen Krikor; Brand, Marek

    2012-01-01

    A novel hospital bed integrated ventilation and cleaning unit (HBIVCU) for local airflow control and cleansing, limiting the airborne spread of contagious air coughed from a sick patient in a hospital room, was developed. The performance efficiency of the unit, to successfully reduce occupants......’ exposure to coughed air, was studied in a full-scale, two-bed hospital room mock-up, 4.65 m x 4.65 m x 2.60 m (W x L x H), with two patients and a doctor. Four units were placed along the two sides of both beds close to the head. The room was ventilated by overhead mixing air distribution at 22 °C room air...... beside the bed and facing the coughing patient. The generated cough consisted of 100% CO2. The mouth was simulated by a circular opening of 0.021 m diameter. The characteristics of the cough were: peak flow - 10 L/s, cough volume - 2.5 L, duration - 0.5 s and maximum velocity - 28.9 m/s. The performance...

  17. Application of FMEA-DEA (Failure Modes and Effect Analysis - Data Envelopment Analysis) to the air conditioning system of the control room a nuclear power plant; Aplicacao de FMEA-DEA ao sistema de ar condicionado da sala de controle de uma usina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa Junior, Gilberto Varanda

    2007-03-15

    This dissertation presents the FMEA-DEA analysis application to the air conditioning system of the control room of a nuclear power plant. After obtaining the failure modes, the index associated to the occurrence probability, the severity of the effects and the potential of detention, a priority order is established for the failure modes or deviations. This number is obtained by multiplying the three mentioned index that vary in a natural scale from 1 to 10, where the higher the index, the more critical the situation will be. In this work, it is intended to use a model based on the data envelopment analysis, DEA jointly with the FMEA, to identify the current efficiency of the system and which failure modes or deviations are considered more critical, and by means of the weights attributed for the mathematical modeling to identify which index are contributing more for these deviations. From this identification, improvements can be set, which may consider administrative changes, operator training and so on, thus adding value to the final product. (author)

  18. 10 CFR Appendix F to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Room Air Conditioners

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Uniform Test Method for Measuring the Energy Consumption of Room Air Conditioners F Appendix F to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY... Appendix F to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Room Air...

  19. Numerical simulation and nasal air-conditioning

    Directory of Open Access Journals (Sweden)

    Keck, Tilman

    2010-01-01

    Full Text Available Heating and humidification of the respiratory air are the main functions of the nasal airways in addition to cleansing and olfaction. Optimal nasal air conditioning is mandatory for an ideal pulmonary gas exchange in order to avoid desiccation and adhesion of the alveolar capillary bed. The complex three-dimensional anatomical structure of the nose makes it impossible to perform detailed in vivo studies on intranasal heating and humidification within the entire nasal airways applying various technical set-ups. The main problem of in vivo temperature and humidity measurements is a poor spatial and time resolution. Therefore, in vivo measurements are feasible only to a restricted extent, solely providing single temperature values as the complete nose is not entirely accessible. Therefore, data on the overall performance of the nose are only based on one single measurement within each nasal segment. In vivo measurements within the entire nose are not feasible. These serious technical issues concerning in vivo measurements led to a large number of numerical simulation projects in the last few years providing novel information about the complex functions of the nasal airways. In general, numerical simulations merely calculate predictions in a computational model, e.g. a realistic nose model, depending on the setting of the boundary conditions. Therefore, numerical simulations achieve only approximations of a possible real situation. The aim of this review is the synopsis of the technical expertise on the field of in vivo nasal air conditioning, the novel information of numerical simulations and the current state of knowledge on the influence of nasal and sinus surgery on nasal air conditioning.

  20. Innovative Air Conditioning and Climate Control

    Science.gov (United States)

    Graf, John

    2015-01-01

    NASA needed to develop a desiccant wheel based humidity removal system to enable the long term testing of the Orion CO2 scrubber on the International Space Station. In the course of developing that system, we learned three things that are relevant to energy efficient air conditioning of office towers. NASA developed a conceptual design for a humidity removal system for an office tower environment. We are looking for interested partners to prototype and field test this concept.

  1. Low Energy Air Conditioning for Hot Climates

    OpenAIRE

    Almutairi, Hamad Hhn

    2012-01-01

    Fossil fuels are the major sources of electrical power generation in the world. Among all fossil fuels, oil is considered as the most sought-after fuel. The burden on countries that provide subsidized electricity produced from oil-fired power plants is noteworthy. Kuwait is a notable example of these countries. Electricity in Kuwait is heavily consumed by residential air conditioning, which comprises 60% of the total electricity generated at peak times on a hot summer day. From this perspecti...

  2. Influence of the inlet air in efficiency of photocatalytic devices for mineralization of VOCs in air-conditioning installations.

    Science.gov (United States)

    Jimenez-Relinque, E; Castellote, M

    2014-10-01

    Nowadays, a large proportion of photocatalytic oxidation (PCO) devices are being implemented in heating, ventilation and air-conditioning systems. However, no systematic studies have been carried out regarding the influence of inlet air preconditioning. To analyse the impact of the inlet air-conditions into photocatalytic efficiency, a simulated air-conditioning duct with flowing gas through inside was designed. Isobutylene was chosen as the target VOCs. The concentration in the gas phase was monitored using a photoionization detector. The influence of flow rate, relative humidity and temperature on the VOC removal efficiency was analysed. Experimental results were presented in terms of gas-removal efficiency (η) and clean air delivery rate (CADR) and analysed on a kinetic basis. From them, the weight of each parameter in the global process has been determined, from bigger to smaller contribution, flow>temperature>relative humidity. Also, the relevance of the inlet air conditions has been illustrated in a model room in order to determinate the time necessary to obtain a threshold value accomplishing with enough air quality and the energy consumption of the device. Additionally, the photocatalytic decontamination has been assimilated to the "air exchange rate", a parameter commonly used in indoor air quality studies. The results show that preconditioning of air can improve the efficiency of photocatalytic devices and bring important energy savings.

  3. Seminar 14 - Desiccant Enhanced Air Conditioning: Desiccant Enhanced Evaporative Air Conditioning (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Kozubal, E.

    2013-02-01

    This presentation explains how liquid desiccant based coupled with an indirect evaporative cooler can efficiently produce cool, dry air, and how a liquid desiccant membrane air conditioner can efficiently provide cooling and dehumidification without the carryover problems of previous generations of liquid desiccant systems. It provides an overview to a liquid desiccant DX air conditioner that can efficiently provide cooling and dehumidification to high latent loads without the need for reheat, explains how liquid desiccant cooling and dehumidification systems can outperform vapor compression based air conditioning systems in hot and humid climates, explains how liquid desiccant cooling and dehumidification systems work, and describes a refrigerant free liquid desiccant based cooling system.

  4. Modelling the impact of room temperature on concentrations of polychlorinated biphenyls (PCBs) in indoor air

    DEFF Research Database (Denmark)

    Lyng, Nadja; Clausen, Per Axel; Lundsgaard, Claus;

    2016-01-01

    Buildings contaminated with polychlorinated biphenyls (PCBs) are a health concern for the building occupants. Inhalation exposure is linked to indoor air concentrations of PCBs, which are known to be affected by indoor temperatures. In this study, a highly PCB contaminated room was heated to six...... temperature levels between 20 and 30 C, i.e. within the normal fluctuation of indoor temperatures, while the air exchange rate was constant. The steady-state air concentrations of seven PCBs were determined at each temperature level. A model based on Clausius–Clapeyron equation, ln(P) = −H/RT + a0, where...... changes in steady-state air concentrations in relation to temperature, was tested. The model was valid for PCB-28, PCB-52 and PCB-101; the four other congeners were sporadic or non-detected. For each congener, the model described a large proportion (R2>94%) of the variation in indoor air PCB levels...

  5. Condition-based Human Reliability Assessment for digitalized control room

    Energy Technology Data Exchange (ETDEWEB)

    Kang, H. G.; Jang, S. C.; Eom, H. S.; Ha, J. J

    2005-04-01

    In safety-critical systems, the generation failure of an actuation signal is caused by the concurrent failures of the automated systems and an operator action. These two sources of safety signals are complicatedly correlated. The failures of sensors or automated systems will cause a lack of necessary information for a human operator and result in error-forcing contexts such as the loss of corresponding alarms and indications. In the conventional analysis, the Human Error Probabilities (HEP) are estimated based on the assumption of 'normal condition of indications and alarms'. In order to construct a more realistic signal-generation failure model, we have to consider more complicated conditions in a more realistic manner. In this study, we performed two kinds of investigation for addressing this issue. We performed the analytic calculations for estimating the effect of sensors failures on the system unavailability and plant risk. For the single-parameter safety signals, the analysis result reveals that the quantification of the HEP should be performed by focusing on the 'no alarm from the automatic system and corresponding indications unavailable' situation. This study also proposes a Condition-Based Human Reliability Assessment (CBHRA) method in order to address these complicated conditions in a practical way. We apply the CBHRA method to the manual actuation of the safety features such as a reactor trip and auxiliary feedwater actuation in Korean Standard Nuclear Power Plants. In the case of conventional single HEP method, it is very hard to consider the multiple HE conditions. The merit of CBHRA is clearly shown in the application to the AFAS generation where no dominating HE condition exits. In this case, even if the HE conditions are carefully investigated, the single HEP method cannot accommodate the multiple conditions in a fault tree. On the other hand, the application result of the reactor trip in SLOCA shows that if there is a

  6. Air Distribution in a Room and Design Considerations of Mixing Ventilation by Flow Elements

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jensen, Rasmus Lund; Pedersen, D. N.

    2001-01-01

    The paper shows detailed measurements of the air distribution in a room ventilated by mixing ventilation according to the specifications given by the International Energy Agency work. (Energy Conservation in Buildings and Community Systems Programme, Annex 20). It describes a number of flow...... elements and how they are used as design tools. The flow elements are the throw of an isothermal jet and the change in jet velocity when the jet moves from the upper to the lower part of the room. A third flow element is the penetration length of a non-isothermal wall jet....

  7. Validation of Boundary Conditions for CFD Simulations on Ventilated Rooms

    DEFF Research Database (Denmark)

    Topp, Claus; Jensen, Rasmus Lund; Pedersen, D.N.

    2001-01-01

    The application of Computational Fluid Dynamics (CFD) for ventilation research and design of ventilation systems has increased during the recent years. This paper provides an investigation of direct description of boundary conditions for a complex inlet diffuser and a heated surface. A series of ...

  8. Performance Evaluation of Photovoltaic Solar Air Conditioning

    Science.gov (United States)

    Snegirjovs, A.; Shipkovs, P.; Lebedeva, K.; Kashkarova, G.; Migla, L.; Gantenbein, P.; Omlin, L.

    2016-12-01

    Information on the electrical-driven solar air conditioning (SAC) is rather scanty. A considerable body of technical data mostly concerns large-scale photo-voltaic solar air conditioning (PV-SAC) systems. Reliable information about the energy output has arisen only in recent years; however, it is still not easily accessible, and sometimes its sources are closed. Despite these facts, solar energy researchers, observers and designers devote special attention to this type of SAC systems. In this study, performance evaluation is performed for the PV-SAC technology, in which low-power (up to 15 kWp of cooling power on average) systems are used. Such a system contains a PV electric-driven compression chiller with cold and heat sensible thermal storage capacities, and a rejected energy unit used for preheating domestic hot water (DHW). In a non-cooling season, it is possible to partly employ the system in the reverse mode for DHW production. In this mode, the ambient air serves as a heat source. Besides, free cooling is integrated in the PV-SAC concept.

  9. Performance Evaluation of Photovoltaic Solar Air Conditioning

    Directory of Open Access Journals (Sweden)

    Snegirjovs A.

    2016-12-01

    Full Text Available Information on the electrical-driven solar air conditioning (SAC is rather scanty. A considerable body of technical data mostly concerns large-scale photo-voltaic solar air conditioning (PV-SAC systems. Reliable information about the energy output has arisen only in recent years; however, it is still not easily accessible, and sometimes its sources are closed. Despite these facts, solar energy researchers, observers and designers devote special attention to this type of SAC systems. In this study, performance evaluation is performed for the PV-SAC technology, in which low-power (up to 15 kWp of cooling power on average systems are used. Such a system contains a PV electric-driven compression chiller with cold and heat sensible thermal storage capacities, and a rejected energy unit used for preheating domestic hot water (DHW. In a non-cooling season, it is possible to partly employ the system in the reverse mode for DHW production. In this mode, the ambient air serves as a heat source. Besides, free cooling is integrated in the PV-SAC concept.

  10. Industrial air conditioning dossier; Dossier Clim industrielle

    Energy Technology Data Exchange (ETDEWEB)

    Nicolas, J.

    2004-04-01

    Because each industrial process is different and has its own specificities, the question of air conditioning in the industry must be considered in a global way and has to take into consideration the different steps of the process and the expectations of prime contractors which, today, pay more attention to the environmental and energy saving aspects. The cooling towers, even if much debated today, remain one of the most efficient solution for high power installations. This dossier presents three examples of realizations: a newspaper printing workshop which requires a precise regulation of temperature and hygrometry, the huge volume workshop of an aerospace company with important solar and internal heat loads, and the painting workshop of a car making company which requires a rigorous control of temperature, humidity and dust content of the ambient air. (J.S.)

  11. Simulation of the interaction between room air flow and human body using the Tanabe model; Simulation der Mensch-Raumklima-Wechselwirkung mit dem Tanabe-Modell

    Energy Technology Data Exchange (ETDEWEB)

    Bartsch, P.; Spille-Kohoff, A. [CFX Berlin Software GmbH, Berlin (Germany)

    2006-09-15

    The human body is a complex system which reacts upon the ambient conditions such as temperature, air speed and radiation intensity by sweating or shivering in order to control its heat balance. On the other hand, the ambient flow field is influenced by the heat and moisture released by the body. This interaction must be included in CFD simulations of room air flow in order to assess the comfort level. (orig.)

  12. Room Acoustic Conditions of Performers in AN Old Opera House

    Science.gov (United States)

    IANNACE, GINO; IANNIELLO, CARMINE; MAFFEI, LUIGI; ROMANO, ROSARIO

    2000-04-01

    Proposed objective criteria related to the acoustic conditions for instrumentalists and singers have not received a sufficiently wide consent yet. In spite of this situation, it is the opinion of the authors that the measurement of existing criteria is useful for analysis and comparison. This paper reports the results of various acoustic measurements carried out in the Teatro di San Carlo, Naples-Italy, with the aim of obtaining objective information about its acoustics for performers. A first set of measurements was carried out when the theater was fitted for a symphonic concert and a second one when it was fitted for an opera performance.

  13. The Effect of Ventilation, Filtration and Passive Sorption on Indoor Air Quality in Museum Storage Rooms

    DEFF Research Database (Denmark)

    Ryhl-Svendsen, M.; Clausen, Geo

    2009-01-01

    A study was conducted in five storage rooms at the National Museum of Denmark, in which the effect on indoor air quality of mechanical ventilation, filtration and passive sorption was investigated. Mechanical ventilation and recirculation/filtration was initiated by introducing new ventilation...... and filtration units. Passive sorption was initiated by hanging sheets of sorptive materials oil walls. The control strategies were evaluated in terms of their ability to lower the concentration of internally, generated pollutants, and the indoor-to-outdoor concentration ratio of outdoor pollutants. The overall...... environmental impact for each method was evaluated by the use of material dosimeters. It was found that passive sorption performed better in a small room compared to a large room. Mechanical ventilation and filtration with activated charcoal gave a high protection against ozone, but were less effective...

  14. The Influence of Office Furniture on the Air Movement in a Mixing Ventilated Room

    DEFF Research Database (Denmark)

    Nielsen, June Richther

    Isothermal and thermal experiments and simulations form the basis of the investigations in this thesis. It is mainly the isothermal case that is studied. The examinations concern how normal office furniture influences the air movements in a mixing ventilated room. Especially, the jet under...... the ceiling is affected by the furniture and by the heat load. The velocity decay and the width of the jet are both increased. The maximum velocity in the occupied zone is increased by the furniture with a thermal load. The changes in the air movements in the room are partly caused by the furniture and partly...... show that the jet under the ceiling is insignificantly influenced by the normal office furniture. The maximum velocity in the occupied zone is reduced by the furniture and this reduction is dependent on the total length of the furniture in the main flow direction. When the total length of the furniture...

  15. Modelling the impact of room temperature on concentrations of polychlorinated biphenyls (PCBs) in indoor air

    DEFF Research Database (Denmark)

    Lyng, Nadja; Clausen, Per Axel; Lundsgaard, Claus

    2016-01-01

    Buildings contaminated with polychlorinated biphenyls (PCBs) are a health concern for the building occupants. Inhalation exposure is linked to indoor air concentrations of PCBs, which are known to be affected by indoor temperatures. In this study, a highly PCB contaminated room was heated to six....... The results showed that one easured concentration of PCB at a known steady-state temperature can be used to predict the steady-state concentrations at other temperatures under circumstances where e.g. direct sunlight does not influence temperatures and the air exchange rate is constant. The model was also...

  16. Room air stratification in combined chilled ceiling and displacement ventilation systems.

    OpenAIRE

    Schiavon, Stefano; Bauman, Fred; Tully, Brad; Rimmer, Julian

    2012-01-01

    Radiant chilled ceilings (CC) with displacement ventilation (DV) represent a promising integrated system design that combines the energy efficiency of both sub-systems with the opportunity for improved ventilation performance resulting from the thermally stratified environment of DV systems. The purpose of this study was to conduct laboratory experiments for a typical U.S. interior zone office to investigate how room air stratification is affected by the ratio of cooling load removed by a chi...

  17. High Pressure Air Jet in the Endoscopic Preparation Room: Risk of Noise Exposure on Occupational Health

    OpenAIRE

    King-Wah Chiu; Lung-Sheng Lu; Cheng-Kun Wu

    2015-01-01

    After high-level disinfection of gastrointestinal endoscopes, they are hung to dry in order to prevent residual water droplets impact on patient health. To allow for quick drying and clinical reuse, some endoscopic units use a high pressure air jet (HPAJ) to remove the water droplets on the endoscopes. The purpose of this study was to evaluate the excessive noise exposure with the use of HPAJ in endoscopic preparation room and to investigate the risk to occupational health. Noise assessment w...

  18. Demonstration of Intelligent Control and Fan Improvements in Computer Room Air Handlers

    Energy Technology Data Exchange (ETDEWEB)

    Coles, Henry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Greenberg, Steve [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Vita, Corinne [Vigilent, Oakland, CA (United States)

    2012-11-30

    This report documents a demonstration of the energy-efficiency improvement provided by a new control system for computer room air handling devices. It also analyzes measured and reported air handling device fan power associated with changing the fan type. A 135,000 square foot commercial data center was used for the demonstration. All air handling units were upgraded with improved efficiency fans, and a control system that automatically adjusts the fan speed for the air handling units was added. Power measurements were collected for a baseline and for a period with the fan speed control system active. Changing the fan type resulted in a savings of 47 percent of energy used by the air handling equipment and associated chiller plant energy needed to cool the air handlers themselves. The addition of the fan speed control resulted in an additional 37 percent savings in the same two categories. The combined savings for the two improvements for the same categories was 66 percent compared to the data center fitted with the original fans without a control system. The energy use reduction provided by the complete air handling device improvement program for the whole data center site is estimated to be 2.9 million kilowatt hours per year—an overall data center site savings of 8.0 percent. The reduced electrical energy use at the site provides a 1.9 million pound yearly reduction of carbon dioxide emissions. This demonstration showed that fan upgrades and a control system addition provide cost-effective improvements for data centers, with a payback reported to be under two years without utility incentives. In addition to the control system providing energy savings, the data collection and visual analysis capabilities provided immediate and long-term benefits. It is recommended that data center operators consider investing in fan upgrades and/or adding fan speed control for computer room air handlers.

  19. Laparoscopy Using Room Air Insufflation in a Rural African Jungle Hospital: The Bongolo Hospital Experience, January 2006 to December 2013.

    Science.gov (United States)

    O'Connor, Zachary; Faniriko, Marco; Thelander, Keir; O'Connor, Jennifer; Thompson, David; Park, Adrian

    2017-06-01

    Carbon dioxide is the standard insufflation gas for laparoscopy. However, in many areas of the world, bottled carbon dioxide is not available. Laparoscopy offers advantages over open surgery and has been practiced using filtered room air insufflation since 2006 at Bongolo Hospital in Gabon, Africa. Our primary goal was to evaluate the safety of room air insufflation related to intraoperative and postoperative complications. Our secondary aim was to review the types of cases performed laparoscopically at our institution. This retrospective review evaluates laparoscopic cases performed at Bongolo Hospital between January 2006 and December 2013. Demographic and perioperative information for patients undergoing laparoscopic procedures was collected. Insufflation was achieved using a standard, oil-free air compressor using filtered air and a standard insufflation regulator. A total of 368 laparoscopic procedures were identified within the time period. The majority of cases were gynecologic (43%). There was a 2% (8/368) complication rate with one perioperative death. The 2 complications related to insufflation were episodes of hypotension responsive to standard corrective measures. No intracorporeal combustion events were observed in any cases in which the use of diathermy and room air insufflation were combined. The other complications and the death were unrelated to the use of insufflation with air. Insufflation complications with room air occurred in our study. However, the complications related to insufflation with room air in our study were no different than those described in the literature using carbon dioxide. As room air is less costly than carbon dioxide and readily available, confirming the safety of room air insufflation in prospective studies is warranted. Room air appears to be safe for establishing and maintaining pneumoperitoneum, making laparoscopic surgery more accessible to patients in low-resource settings.

  20. Automatic air flow control in air conditioning ducts

    Science.gov (United States)

    Obler, H. D.

    1972-01-01

    Device is designed which automatically selects air flow coming from either of two directions and which can be adjusted to desired air volume on either side. Device uses one movable and two fixed scoops which control air flow and air volume.

  1. Indoor air quality investigation at air-conditioned and non-air-conditioned markets in Hong Kong.

    Science.gov (United States)

    Guo, H; Lee, S C; Chan, L Y

    2004-05-05

    To characterize indoor air quality at the markets in Hong Kong, three non-air-conditioned and two air-conditioned markets were selected for this study. The indoor air pollutants measured included PM(10) (particulate matters with aerodynamic diameter less than 10 microm), total bacteria count (TBC), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO(2)) and sulfur dioxide (SO(2)). The indoor and outdoor concentrations of these target air pollutants at these markets were measured and compared. The effects of air conditioning, temperature/relative humidity variation and different stalls on the indoor air quality were also investigated. The results indicated that all of the average indoor concentrations of PM(10), TBC, CO and NO(2) at the markets were below the Hong Kong Indoor Air Quality Objectives (HKIAQO) standards with a few exceptions for PM(10) and TBC. The elevated PM(10) concentrations at Hung Hom, Ngau Tau Kok and Wan Chai markets were probably due to the air filtration of outdoor airborne particulates emitted from vehicular exhaust, whereas high concentrations of airborne bacteria at Sai Ying Pun and Tin Shing markets were linked to the use of air conditioning. Correlation analysis demonstrated that indoor bacteria concentrations were correlated with temperature and relative humidity. The operation of air conditioning did not significantly reduce the levels of air pollutants at the markets. However, the higher indoor/outdoor ratios demonstrated that the operation of air conditioning had influence on the levels of bacteria at the markets. It was found that average PM(10) concentration at poultry stalls was higher than the HKIAQO standard of 180 microg/m(3), and was over two times that measured at vegetable, fish and meat stalls. Furthermore, the concentration of airborne bacteria at the poultry stalls was as high as 1031 CFU/m(3), which was above the HKIAQO standard of 1000 CFU/m(3). The bacteria levels at other three stalls were all below the

  2. [Microbial air purity in hospitals. Operating theatres with air conditioning system].

    Science.gov (United States)

    Krogulski, Adam; Szczotko, Maciej

    2010-01-01

    The aim of this study was to show the influence of air conditioning control for microbial contamination of air inside the operating theatres equipped with correctly working air-conditioning system. This work was based on the results of bacteria and fungi concentration in hospital air obtained since 2001. Assays of microbial air purity conducted on atmospheric air in parallel with indoor air demonstrated that air filters applied in air-conditioning systems worked correctly in every case. To show the problem of fluctuation of bacteria concentration more precisely, every sequences of single results from successive measure series were examined independently.

  3. Emissions of indoor air pollutants from six user scenarios in a model room

    Science.gov (United States)

    Höllbacher, Eva; Ters, Thomas; Rieder-Gradinger, Cornelia; Srebotnik, Ewald

    2017-02-01

    In this study six common user scenarios putatively influencing indoor air quality were performed in a model room constructed according to the specifications of the European Reference Room given in the new horizontal prestandard prEN 16516 to gain further information about the influence of user activities on indoor air quality. These scenarios included the use of cleaning agent, an electric air freshener, an ethanol fireplace and cosmetics as well as cigarette smoking and peeling of oranges. Four common indoor air pollutants were monitored: volatile organic compounds (VOC), particulate matter (PM), carbonyl compounds and CO2. The development of all pollutants was determined during and after the test performance. For each measured pollutant, well-defined maximum values could be assigned to one or more of the individual user scenarios. The highest VOC concentration was measured during orange-peeling reaching a maximum value of 3547 μg m-3. Carbonyl compounds and PM were strongly elevated while cigarette smoking. Here, a maximum formaldehyde concentration of 76 μg m-3 and PM concentration of 378 μg m-3 were measured. CO2 was only slightly affected by most of the tests except the use of the ethanol fireplace where a maximum concentration of 1612 ppm was reached. Generally, the user scenarios resulted in a distinct increase of several indoor pollutants that usually decreased rapidly after the removal of the source.

  4. Ultraviolet germicidal irradiation inactivation of airborne fungal spores and bacteria in upper-room air and HVAC in-duct configurations

    Energy Technology Data Exchange (ETDEWEB)

    Kujundzic, E.; Hernandez, M. [Colorado Univ., Boulder, CO (United States). Dept. of Civil, Environmental and Architectural Engineering; Miller, S.L. [Colorado Univ., Boulder, CO (United States). Dept. of Mechanical Engineering

    2007-01-15

    This article presented an evaluation of the efficiency of ultraviolet germicidal irradiation (UVGI) for inactivating airborne fungal spores and bacterial vegetative cells under 3 configurations, namely intrinsic, upper-room air, and in-duct. Several experiments were conducted in a pilot-scale chamber fitted with 4 corner ultraviolet lamps that irradiated the entire chamber; a full-scale room fitted with a UVGI system that irradiated the top 30 cm of the room; and, the supply air duct of a heating ventilation and air-conditioning (HVAC) system. Fungal spores and vegetative cells of bacterium were aerosolized regularly such that their numbers and physiologic state were comparable both with and without the UVGI lamps operating. The article provided information on the materials and methods used including the experimental facilities (pilot-scale chamber, full-scale room, and in-duct UVGI system and ductwork) as well as the methods used for the three experimental studies. It also discussed the bioaerosol generation and sampling and quantification. These included culturing and direct microscopy. UV fluence rate was described. Last, the the results, discussion and conclusions from the studies were presented. It was shown that increasing the air stream velocity through the supply air duct reduces the residence time of bioaerosol being exposed to in-duct UVGI. 36 refs., 3 figs.

  5. Mixed air ceilings for surgical rooms with recirculating blowers; Mischluftdecke fuer OP-Raeume mit Umluftventilatoren

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-07-01

    Ceilings of modern surgery rooms must have a size of about 3,200 x 3,200 mm for a laminar displacement flow of 0.18 - 0.25 m/s. air volume flows of more than 9,000 cubic metres per hour are required. Not all surgical wards have the capacity for sufficiently large air ducts for central air supply. [German] Die moderne Chirurgie verlangt OP-Zuluftdecken mit Groessen von etwa 3 200 x 3 200 mm, die eine laminare Verdraengungsstroemung im Geschwindigkeitsbereich von etwa 0,18 bis 0,25 m/s sichern. Hierbei werden Zuluft-Volumenstroeme bis ueber 9 000 m{sup 3}/h erforderlich. Nicht alle OP-Abteilungen lassen die Verlegung der entsprechend grossen Luftleitungen fuer zentrale Luftversorgung zu. (orig.)

  6. Refrigeration, Heating & Air Conditioning. Post Secondary Curriculum Guide.

    Science.gov (United States)

    Garrison, Joe C.; And Others

    This curriculum guide was designed for use in postsecondary refrigeration, heating and air conditioning education programs in Georgia. Its purpose is to provide for the development of entry level skills in refrigeration, heating, and air conditioning in the areas of air conditioning knowledge, theoretical structure, tool usage, diagnostic ability,…

  7. Thermal comfort and indoor air quality in the lecture room with 4-way cassette air-conditioner and mixing ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Kwang-Chul; Jang, Jae-Soo; Oh, Myung-Do [Department of Mechanical and Information Engineering, University of Seoul, Seoul 130-743 (Korea, Republic of)

    2007-02-15

    We performed the experimental and the numerical studies on thermal comfort (TC) and indoor air quality (IAQ) in the lecture room with cooling loads when the operating conditions are changed. Predicted mean vote (PMV) value and CO{sub 2} concentration of the lecture room were measured and compared to the numerical results. Both of them showed a reasonable agreement with each other and then we applied the numerical model to analyze TC and IAQ for a couple of different operating conditions. From the results we found that the increment of the discharge angle of 4-way cassette air-conditioner makes uniformity of TC worse, but rarely affects IAQ. It turned out that TC and IAQ are hardly affected by the variation of the discharge airflow. Finally TC was merely affected by the increment of the ventilation rate, but when the ventilation rate is more than 800m{sup 3}/h, the average CO{sub 2} concentration can be satisfied with the standard limits of Japanese in our case studies. (author)

  8. MULTI - TRACER CONTROL ROOM AIR INLEAKAGE PROTOCOL AND SIMULATED PRIMARY AND EXTENDED MULTI - ZONE RESULTS.

    Energy Technology Data Exchange (ETDEWEB)

    DIETZ,R.N.

    2002-01-01

    The perfluorocarbon tracer (PFT) technology can be applied simultaneously to the wide range in zonal flowrates (from tens of cfms in some Control Rooms to almost 1,000,000 cfm in Turbine Buildings), to achieve the necessary uniform tagging for subsequent determination of the desired air inleakage and outleakage from all zones surrounding a plant's Control Room (CR). New types of PFT sources (Mega sources) were devised and tested to handle the unusually large flowrates in a number of HVAC zones in power stations. A review of the plans of a particular nuclear power plant and subsequent simulations of the tagging and sampling results confirm that the technology can provide the necessary concentration measurement data to allow the important ventilation pathways involving the Control Room and its air flow communications with all adjacent zones to be quantitatively determined with minimal uncertainty. Depending on need, a simple single or 3-zone scheme (involving the Control Room alone or along with the Aux. Bldg. and Turbine Bldg.) or a more complex test involving up to 7 zones simultaneously can be accommodated with the current revisions to the technology; to test all the possible flow pathways, several different combinations of up to 7 zones would need to be run. The potential exists that for an appropriate investment, in about 2 years, it would be possible to completely evaluate an entire power plant in a single extended multizone test with up to 12 to 13 separate HVAC zones. With multiple samplers in the Control Room near each of the contiguous zones, not only will the prevalent inleakage or outleakage zones be documented, but the particular location of the pathway's room of ingress can be identified. The suggested protocol is to perform a 3-zone test involving the Control Room, Aux. Bldg., and Turbine Bldg. to (1) verify CR total inleakage and (2) proportion that inleakage to distinguish that from the other 2 major buildings and any remaining untagged

  9. Performance of personalized ventilation combined with chilled ceiling in an office room: inhaled air quality and contaminant distribution

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Melikov, Arsen Krikor

    2014-01-01

    In a simulated two persons’ office room inhaled air quality and contaminant distribution provided with personalized ventilation combined with chilled ceiling, mixing ventilation only, chilled ceiling with mixing ventilation and chilled ceiling with mixing and personalized ventilation was studied...

  10. Bed-integrated local exhaust ventilation system combined with local air cleaning for improved IAQ in hospital patient rooms

    DEFF Research Database (Denmark)

    Bivolarova, Mariya Petrova; Melikov, Arsen Krikor; Mizutani, Chiyomi;

    2016-01-01

    The performance of a ventilated mattress (VM) used as a bed-integrated local exhaust ventilation system combined with air cleaning fabric (acid-treated activated carbon fibre (ACF) fabric) was developed and studied. The separate and combined effect of the VM and the local air cleaning for reducing...... micro-environment was exhausted. Two modes of operation were studied: 1) the exhausted polluted air was discharged out of the room and 2) the polluted air was cleaned by the ACF material installed inside the mattress and recirculated back into the room. Both modes of operation efficiently reduced...

  11. Methodology for uncertainty calculation of net total cooling effect estimation for rating room air conditioners and packaged terminal air conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Diaz, Nestor [Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica, Pereira (Colombia); University of Liege, Campus du Sart Tilman, Bat: B49, P33, B-4000 Liege (Belgium)

    2009-09-15

    This article presents the general procedure for uncertainty calculation of net total cooling effect estimation for rating room air conditioners and packaged terminal air conditioners, by means of measurements carried out in a test bench specially designed for this purpose. The uncertainty analysis presented in this work looks for establishing a confidence degree or certainty of experimental results. It is particularly important considering that international standards related to this type of analysis are too ambiguous when treating this subject. The uncertainty analysis is on the other hand an indispensable requirement to international standard ISO 17025 [ISO, 2005. International Standard. 17025. General Requirement to Test and Calibration Laboratories Competences. International Organization for Standardization, Geneva.], which must be applied to obtain the required quality levels according to the Word Trade Organization WTO. (author)

  12. Upper-room ultraviolet light and negative air ionization to prevent tuberculosis transmission.

    Directory of Open Access Journals (Sweden)

    A Roderick Escombe

    2009-03-01

    Full Text Available Institutional tuberculosis (TB transmission is an important public health problem highlighted by the HIV/AIDS pandemic and the emergence of multidrug- and extensively drug-resistant TB. Effective TB infection control measures are urgently needed. We evaluated the efficacy of upper-room ultraviolet (UV lights and negative air ionization for preventing airborne TB transmission using a guinea pig air-sampling model to measure the TB infectiousness of ward air.For 535 consecutive days, exhaust air from an HIV-TB ward in Lima, Perú, was passed through three guinea pig air-sampling enclosures each housing approximately 150 guinea pigs, using a 2-d cycle. On UV-off days, ward air passed in parallel through a control animal enclosure and a similar enclosure containing negative ionizers. On UV-on days, UV lights and mixing fans were turned on in the ward, and a third animal enclosure alone received ward air. TB infection in guinea pigs was defined by monthly tuberculin skin tests. All guinea pigs underwent autopsy to test for TB disease, defined by characteristic autopsy changes or by the culture of Mycobacterium tuberculosis from organs. 35% (106/304 of guinea pigs in the control group developed TB infection, and this was reduced to 14% (43/303 by ionizers, and to 9.5% (29/307 by UV lights (both p < 0.0001 compared with the control group. TB disease was confirmed in 8.6% (26/304 of control group animals, and this was reduced to 4.3% (13/303 by ionizers, and to 3.6% (11/307 by UV lights (both p < 0.03 compared with the control group. Time-to-event analysis demonstrated that TB infection was prevented by ionizers (log-rank 27; p < 0.0001 and by UV lights (log-rank 46; p < 0.0001. Time-to-event analysis also demonstrated that TB disease was prevented by ionizers (log-rank 3.7; p = 0.055 and by UV lights (log-rank 5.4; p = 0.02. An alternative analysis using an airborne infection model demonstrated that ionizers prevented 60% of TB infection and 51% of TB

  13. Upper-room ultraviolet light and negative air ionization to prevent tuberculosis transmission.

    Science.gov (United States)

    Escombe, A Roderick; Moore, David A J; Gilman, Robert H; Navincopa, Marcos; Ticona, Eduardo; Mitchell, Bailey; Noakes, Catherine; Martínez, Carlos; Sheen, Patricia; Ramirez, Rocio; Quino, Willi; Gonzalez, Armando; Friedland, Jon S; Evans, Carlton A

    2009-03-17

    Institutional tuberculosis (TB) transmission is an important public health problem highlighted by the HIV/AIDS pandemic and the emergence of multidrug- and extensively drug-resistant TB. Effective TB infection control measures are urgently needed. We evaluated the efficacy of upper-room ultraviolet (UV) lights and negative air ionization for preventing airborne TB transmission using a guinea pig air-sampling model to measure the TB infectiousness of ward air. For 535 consecutive days, exhaust air from an HIV-TB ward in Lima, Perú, was passed through three guinea pig air-sampling enclosures each housing approximately 150 guinea pigs, using a 2-d cycle. On UV-off days, ward air passed in parallel through a control animal enclosure and a similar enclosure containing negative ionizers. On UV-on days, UV lights and mixing fans were turned on in the ward, and a third animal enclosure alone received ward air. TB infection in guinea pigs was defined by monthly tuberculin skin tests. All guinea pigs underwent autopsy to test for TB disease, defined by characteristic autopsy changes or by the culture of Mycobacterium tuberculosis from organs. 35% (106/304) of guinea pigs in the control group developed TB infection, and this was reduced to 14% (43/303) by ionizers, and to 9.5% (29/307) by UV lights (both p < 0.0001 compared with the control group). TB disease was confirmed in 8.6% (26/304) of control group animals, and this was reduced to 4.3% (13/303) by ionizers, and to 3.6% (11/307) by UV lights (both p < 0.03 compared with the control group). Time-to-event analysis demonstrated that TB infection was prevented by ionizers (log-rank 27; p < 0.0001) and by UV lights (log-rank 46; p < 0.0001). Time-to-event analysis also demonstrated that TB disease was prevented by ionizers (log-rank 3.7; p = 0.055) and by UV lights (log-rank 5.4; p = 0.02). An alternative analysis using an airborne infection model demonstrated that ionizers prevented 60% of TB infection and 51% of TB

  14. The Mycobiota of Air Inside and Outside the Meju Fermentation Room and the Origin of Meju Fungi.

    Science.gov (United States)

    Kim, Dae-Ho; Kim, Sun-Hwa; Kwon, Soon-Wo; Lee, Jong-Kyu; Hong, Seung-Beom

    2015-09-01

    The fungi on Meju are known to play an important role as degrader of macromolecule of soybeans. In order to elucidate the origin of fungi on traditional Meju, mycobiota of the air both inside and outside traditional Meju fermentation rooms was examined. From 11 samples of air collected from inside and outside of 7 Meju fermentation rooms, 37 genera and 90 species of fungi were identified. In outside air of the fermentation room, Cladosporium sp. and Cladosporium cladosporioides were the dominant species, followed by Cladosporium tenuissimum, Eurotium sp., Phoma sp., Sistotrema brinkmannii, Alternaria sp., Aspergillus fumigatus, Schizophyllum commune, and Penicillium glabrum. In inside air of the fermentation room, Cladosporium sp., Aspergillus oryzae, Penicillium chrysogenum, Asp. nidulans, Aspergillus sp., Cla. cladosporioides, Eurotium sp., Penicillium sp., Cla. tenuissimum, Asp. niger, Eur. herbariorum, Asp. sydowii, and Eur. repens were collected with high frequency. The concentrations of the genera Aspergillus, Eurotium, and Penicillium were significantly higher in inside air than outside air. From this result and those of previous reports, the origin of fungi present on Meju was inferred. Of the dominant fungal species present on Meju, Lichtheimia ramosa, Mucor circinelloides, Mucor racemosus, and Scopulariopsis brevicaulis are thought to be originated from outside air, because these species are not or are rarely isolated from rice straw and soybean; however, they were detected outside air of fermentation room and are species commonly found in indoor environments. However, Asp. oryzae, Pen. polonicum, Eur. repens, Pen. solitum, and Eur. chevalieri, which are frequently found on Meju, are common in rice straw and could be transferred from rice straw to Meju. The fungi grow and produce abundant spores during Meju fermentation, and after the spores accumulate in the air of fermentation room, they could influence mycobiota of Meju fermentation in the following

  15. Effect of Air Stability on the Dispersal of Exhaled Contaminant in Rooms

    DEFF Research Database (Denmark)

    Xu, Chunwen; Gong, Guangcai; Nielsen, Peter V.

    2013-01-01

    Experiments are conducted in a full-scale chamber equipped with whole floor and whole ceiling supply or exhaust to form approximately zero and larger temperature gradients corresponding to unstable and stable air conditions. It can be observed that the air with smoke exhaled from a life-sized the......Experiments are conducted in a full-scale chamber equipped with whole floor and whole ceiling supply or exhaust to form approximately zero and larger temperature gradients corresponding to unstable and stable air conditions. It can be observed that the air with smoke exhaled from a life......-sized thermal manikin is locked and stratified at certain heights at stable condition while it mixes well with the ambient air and is diluted quickly through upper openings when the air is relatively unstable. The concentration of contaminant simulated by tracer gas (N2O) is measured both around and 0.35m from...... the manikin, indicating that the person who exhales the contaminant may not be polluted by himself as the protective effect of the thermal boundary layer around the body, especially in stable condition with two concentration zones and clean air drawn from the inlets. However, other persons facing...

  16. Forced-air warming: a source of airborne contamination in the operating room?

    Directory of Open Access Journals (Sweden)

    David Leaper

    2009-12-01

    Full Text Available Forced-air-warming (FAW is an effective and widely used means for maintaining surgical normothermia, but FAW also has the potential to generate and mobilize airborne contamination in the operating room. We measured the emission of viable and non-viable forms of airborne contamination from an arbitrary selection of FAW blowers (n=25 in the operating room. A laser particle counter measured particulate concentrations of the air near the intake filter and in the distal hose airstream. Filtration efficiency was calculated as the reduction in particulate concentration in the distal hose airstream relative to that of the intake. Microbial colonization of the FAW blower’s internal hose surfaces was assessed by culturing the microorganisms recovered through swabbing (n=17 and rinsing (n=9 techniques. Particle counting revealed that 24% of FAW blowers were emitting significant levels of internally generated airborne contamination in the 0.5 to 5.0 mm size range, evidenced by a steep decrease in FAW blower filtration efficiency for particles 0.5 to 5.0 mm in size. The particle size-range-specific reduction in efficiency could not be explained by the filtration properties of the intake filter. Instead, the reduction was found to be caused by size-range-specific particle generation within the FAW blowers. Microorganisms were detected on the internal air path surfaces of 94% of FAW blowers. The design of FAW blowers was found to be questionable for preventing the build-up of internal contamination and the emission of airborne contamination into the operating room. Although we did not evaluate the link between FAW and surgical site infection rates, a significant percentage of FAW blowers with positive microbial cultures were emitting internally generated airborne contamination within the size range of free floating bacteria and fungi (<4 mm that could, conceivably, settle onto the surgical site.

  17. Research of the Temperature and Humidity Processes in the Air Conditioning Apparatus Varying Air Ion Concentration

    Directory of Open Access Journals (Sweden)

    Marchenko V. G.

    2015-12-01

    Full Text Available To create comfortable conveniences for people in the room, we have to process the indoor air in the AC apparatus. Depending on given air parameters in the room, the air processing comprises the next steps: heating, cooling, wetting, drying. Except the compliance of the temperature and humidity parameters of air, we must control its ionic composition. Thereby, the experimental analysis of the air preparing in the AC apparatus is given in this article. Thank to that analysis, we can estimate the ionic and deionic impact on the air space in the specific processes of the air preparing. According to the results of experiments, we have identified, that the air temperature varying does not have significant effect on the ionic concentration. The ionic increasing after electric heater is not associated with air temperature. It is the consequence of the electron extrication from the surface of the heating element. Reducing ion moving the high air humidity decreases the concentration of the lightweight ions. The increasing of the ions in the spray-type air washers is explained by ballo-electric effect of spraying water drops, but not the air humidity rising.

  18. The effect of air-conditioning parameters and deposition dust on microbial growth in supply air ducts

    Energy Technology Data Exchange (ETDEWEB)

    Li, Angui; Liu, Zhijian; Zhu, Xiaobin; Liu, Ying [School of Environmental and Municipal Engineering, Xi' an University of Architecture and Technology, Xi' an, Shannxi 710055 (China); Wang, Qingqin [China Academy of Building Research, Beijing 100013 (China)

    2010-04-15

    To investigate the effect of air-conditioning parameters (including temperature, relative humidity and air velocity) and deposition dust on microbial growth in supply air duct, a complete test facility according to ASHRAE Standard 62.1-2007 was constructed. A series of experiments for testing microbial concentration (including bacteria and fungus) were conducted under different working conditions (such as different temperatures and relative humidity). The air velocity was constantly kept at 2.0 m/s. Orthogonal design was employed for the analysis of test data. The results indicated that air velocity attenuation down the direction of the supply air affected dust distribution at the bottom of duct, to some extent, and the number of microorganisms was positively correlated with the quantity of dust. In the range of temperature 22-32 C and relative humidity (RH) 40-90%, microbial growth significantly accelerated with higher temperature and RH increasing. The organic compounds composing the dust also had great impact on microbial growth. The basic researches are contributed to control the growth of microorganism and improve the indoor microenvironment in the air-conditioning room. (author)

  19. Air- conditioner Energy Saving Renovation of Gaokai District IDC Telecom Room in Tangshan%IDC机房空调节能改造工程

    Institute of Scientific and Technical Information of China (English)

    刘婷婷; 田浩

    2011-01-01

    本文介绍了中国联通唐山分公司高开区IDC(互联网数据中心)机房空调的节能改造工程,根据改造后空调机组耗电量的实测数据,对节能型机房空调与普通型机房空调的能耗进行了对比,证实了改造后机房空调方案具有很好的节能效果,可为相似老旧通信机房的节能改造提供参考.%The air - conditioner energy saving renovation of Gaokai district IDC (Internet Data Center) telecom room of China Unicom Tangshan Branch was introduced in this paper. According to the measured power consumption of the air conditioning units after renovation, the energy consumption of energy - sav-ing telecom room air conditioners and common telecom room air conditioners were also compared in this paper. It was proved that the energy saving effect after renovation was extremely obvisus. This paper may be a reference for the energy saving renovation of similar old telecom rooms.

  20. Comparison between Different Air Distribution Systems

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    The aim of an air conditioning system is to remove excess heat in a room and replace room air with fresh air to obtain a high air quality. It is not sufficient to remove heat and contaminated air, it is also necessary to distribute and control the air movement in the room to create thermal comfort...

  1. Time-resolved LII signals from aggregates of soot particles levitated in room temperature air

    CERN Document Server

    Mitrani, James M

    2015-01-01

    We observed and modeled time-resolved laser-induced incandescence (LII) signals from soot aggregates. Time-resolved LII signals were observed from research-grade soot particles, levitated in room temperature air. We were able to measure sizes and structural properties of our soot particles ex situ, and use those measurements as input parameters when modeling the observed LII signals. We showed that at low laser fluences, aggregation significantly influences LII signals by reducing conductive cooling to the ambient air. At moderate laser fluences, laser-induced disintegration of aggregates occurs, so the effects of aggregation on LII signals are negligible. These results can be applied to extend LII for monitoring formation of soot and nanoparticle aggregates.

  2. Economical and environmental impact of room air conditioners energy labels in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Mahlia, T.M.I.; Masjuki, H.H.; Choudhury, I.A.; Ghazali, N.N.N. [University of Malaya, Kuala Lumpur (Malaysia). Dept. of Mechanical Engineering

    2002-12-01

    The usage of residential electrical appliances for the last two decades has increased rapidly in Malaysia together with the increasing income per capita. Like other developing countries with hot and humid climates, Malaysia has been experiencing dramatic growth in the number of use of air conditioners, and the usage will be higher in the future. In order to reduce energy consumption in the residential sector, the Department of Electricity and Gas Supply considers implementing energy labels for room air conditioners sometime in the coming year. This study attempts to calculate the economical and environmental impact of implementing this program in Malaysia. The study found the savings has exceeded the investment cost and the program has reduced the emissions caused by burning fossil fuel. (author)

  3. On the history of air conditioning; Zur Geschichte der Raumklimatechnik

    Energy Technology Data Exchange (ETDEWEB)

    Fitzner, Klaus; Finke, Ulrich [Klimakonzept Ingenieurgesellschaft, Berlin (Germany)

    2010-01-15

    The theoretical bases of indoor air conditioning originates from the time of enlightenment (Lavoisier 1792). For the first time air conditioning is applied 1836 in the House of Commons in London. Wide application begins in the USA in the 1930s, in Germany due to the war after the 1950s. Starting from 1970 there are advancements in Germany and Northern Europe, which make it possible not to only air-condition but to fulfil thermally comfortable conditions. (orig.)

  4. Air-conditioning vs. presence of pathogenic fungi in hospital operating theatre environment.

    Science.gov (United States)

    Gniadek, Agnieszka; Macura, Anna B

    2011-01-01

    Infections related to modern surgical procedures present a difficult problem for contemporary medicine. Infections acquired during surgery represent a risk factor related to therapeutical interventions. Eradication of microorganisms from hospital operating theatre environment may contribute to reduction of infections as the laminar flow air-conditioning considerably reduces the number of microorganisms in the hospital environment. The objective of the study was to evaluate the occurrence of fungi in air-conditioned operating theatre rooms. The study was carried out in one of the hospitals in Krak6w during December 2009. Indoor air samples and imprints from the walls were collected from five operating theatre rooms. A total of fifty indoor air samples were collected with a MAS-100 device, and twenty five imprints from the walls were collected using a Count Tact method. Fungal growth was observed in 48 air samples; the average numbers of fungi were within the range of 5-100 c.f.u. in one cubic metre of the air. Fungi were detected only in four samples of the wall imprints; the number of fungi was 0.01 c.f.u. per one square centimetre of the surface. The mould genus Aspergillus was most frequently isolated, and the species A. fumigatus and A. versicolor were the dominating ones. To ensure microbiological cleanness of hospital operating theatre, the air-conditioning system should be properly maintained. Domination of the Aspergillus fungi in indoor air as well as increase in the number of moulds in the samples taken in evenings (p < 0.05) may suggest that the room decontamination procedures were neglected.

  5. PROSPECTS FOR THE DEVELOPMENT OF TECHNOLOGY AIR CONDITIONING

    Directory of Open Access Journals (Sweden)

    O. V. Chernyshova

    2008-03-01

    Full Text Available In the article the evaporation cooling and spray (aqueous and air-to-water types of the air-conditioning systems are considered, their merits and demerits are analyzed; the new scheme of a conditioner is offered.

  6. Air Conditioner Charging. Automotive Mechanics. Air Conditioning. Instructor's Guide [and] Student Guide.

    Science.gov (United States)

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automobile air conditioning, consists of a student guide and an instructor guide dealing with air conditioning charging. Covered in the module are checking the air conditioning system for leaks, checking and adding refrigerant oil as needed, evacuating the system,…

  7. Air Conditioner Charging. Automotive Mechanics. Air Conditioning. Instructor's Guide [and] Student Guide.

    Science.gov (United States)

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automobile air conditioning, consists of a student guide and an instructor guide dealing with air conditioning charging. Covered in the module are checking the air conditioning system for leaks, checking and adding refrigerant oil as needed, evacuating the system,…

  8. The air-conditioning capacity of the human nose.

    Science.gov (United States)

    Naftali, Sara; Rosenfeld, Moshe; Wolf, Michael; Elad, David

    2005-04-01

    The nose is the front line defender of the respiratory system. Unsteady simulations in three-dimensional models have been developed to study transport patterns in the human nose and its overall air-conditioning capacity. The results suggested that the healthy nose can efficiently provide about 90% of the heat and the water fluxes required to condition the ambient inspired air to near alveolar conditions in a variety of environmental conditions and independent of variations in internal structural components. The anatomical replica of the human nose showed the best performance and was able to provide 92% of the heating and 96% of the moisture needed to condition the inspired air to alveolar conditions. A detailed analysis explored the relative contribution of endonasal structural components to the air-conditioning process. During a moderate breathing effort, about 11% reduction in the efficacy of nasal air-conditioning capacity was observed.

  9. Use of Recirculating Ventilation With Dust Filtration to Improve Wintertime Air Quality in a Swine Farrowing Room.

    Science.gov (United States)

    Anthony, T Renée; Altmaier, Ralph; Jones, Samuel; Gassman, Rich; Park, Jae Hong; Peters, Thomas M

    2015-01-01

    The performance of a recirculating ventilation system with dust filtration was evaluated to determine its effectiveness to improve the air quality in a swine farrowing room of a concentrated animal feeding operation (CAFO). Air was exhausted from the room (0.47 m(3) sec(-1); 1000 cfm), treated with a filtration unit (Shaker-Dust Collector), and returned to the farrowing room to reduce dust concentrations while retaining heat necessary for livestock health. The air quality in the room was assessed over a winter, during which time limited fresh air is traditionally brought into the building. Over the study period, dust concentrations ranged from 0.005-0.31 mg m(-3) (respirable) and 0.17-2.09 mg m(-3) (inhalable). In-room dust concentrations were reduced (41% for respirable and 33% for inhalable) with the system in operation, while gas concentrations (ammonia [NH3], hydrogen sulfide [H2S], carbon monoxide [CO], carbon dioxide [CO2]) were unchanged. The position of the exhaust and return air systems provided reasonably uniform contaminant distributions, although the respirable dust concentrations nearest one of the exhaust ducts was statistically higher than other locations in the room, with differences averaging only 0.05 mg m(-3). Throughout the study, CO2 concentrations consistently exceeded 1540 ppm (industry recommendations) and on eight of the 18 study days it exceeded 2500 ppm (50% of the ACGIH TLV), with significantly higher concentrations near a door to a temperature-controlled hallway that was typically often left open. Alternative heaters are recommended to reduce CO2 concentrations in the room. Contaminant concentrations were modeled using production and environmental factors, with NH3 related to the number of sow in the room and outdoor temperatures and CO2 related to the number of piglets and outdoor temperatures. The recirculating ventilation system provided dust reduction without increasing concentrations of hazardous gases.

  10. Air Distribution and Ventilation Effectiveness in a room with Floor/Ceiling Heating and Mixing/Displacement Ventilation

    OpenAIRE

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

    2014-01-01

    The present study investigated different combinations of floor/ceiling heating with mixing/displacement ventilation and their impacts on the indoor air distribution and ventilation effectiveness. Measurements were performed in a room during heating season in December. The results show that indoor vertical air temperature differences and air velocities for different hybrid systems are less than 3 C and 0.2 m/s when supply air temperature is 19 C, air change rate is 4.2 h-1, and heated surface ...

  11. Possible Economies in Air-Conditioning by Accepting Temperature Swings.

    Science.gov (United States)

    Loudon, A. G.; Petherbridge, P.

    Public building air conditioning systems, which use constant and varying heat and cooling loads, are compared and investigated. Experiments indicated that constant temperature controls based on outside air temperature alone were inefficient. Ventilating a building with outside air and the methods of doing so are cited as being the most economical…

  12. Vibration Analysis of Air Condition Unit on Subway

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2013-06-01

    Full Text Available Subway system has many merits including large passenger carrying ability, high speed, strong controllability and reliability of driving. Nevertheless, subways also have brought many disadvantages for human. In many subway systems, noisy environments are clearly observed and passengers are exposed to higher noise levels than permissible limit. This study presents a study of noise and vibration of subway air condition system, so as to grasp the vibration distribution laws of the air condition system. By the tested of noise and vibration, the researcher find the sound distribution rule of air condition is very important Based on the consequence of the testing, the acceleration of air condition has little to do with the subway speed and more to do with the vibration of fan; When the train driving on the viaduct bridge, the acceleration of air condition is biggish in 125 Hz and In 50-1000 Hz the vibration of air condition is obviously. When the train running underground line, as a result of the resonance of body, air condition’s vibration is biggish in 630 Hz and the vibration is obviously in 125-1250 Hz. With the increase of the speed, the influence of the ground’s second radiation on body vibration is enhanced. The superfine gross wool which is used to air condition can achieve good results for noise reduction. This research has higher reference for the vibration and noise reduction of the subway air condition system.

  13. Air conditioning and blowers. Special issue; Airconditioning en ventilatoren. Themanummer

    Energy Technology Data Exchange (ETDEWEB)

    Nekeman, H.E. [Multi Import, Rotterdam (Netherlands); Hol, M. [Aircool Klimaattechniek, Ridderkerk (Netherlands); Bassa, E. [ed.

    1997-06-01

    In four articles several aspects of air conditioners and blowers are discussed: the application of the newly developed electronically commutated direct current engine in high-efficiency boilers, air conditioners and cooling systems, the future for flexible synthetic cooling pipes, a description of a Mitsubishi-developed air conditioner: the Inverter Driven Multi-indoor unit, also known as the KX-system, and the importance of the private sector (houses, small businesses, cars) for the use of air conditioning installations. 8 figs.

  14. Neurological and Psychiatric Conditions: Hand in Hand in the Emergency Room – Neurologist’s Perspective

    Directory of Open Access Journals (Sweden)

    Cristina Costa

    2013-11-01

    Full Text Available Both neurologists and psychiatrists work under complex circumstances in the emergency department; these conditions may hinder diagnostic management of patients, especially when neurological and psychiatric disorders coexist. These two specialties frequently complement each other in their clinical approaches. In this paper, we will first address the psychiatric manifestations of neurological disorders, then the functional symptoms which mimic neuro- logical diseases. This latter group of symptoms constitutes the greatest challenge for the neurologist in the emergency room

  15. Analysis for SEER of variable speed room air conditioner in China. Paper no. IGEC-1-104

    Energy Technology Data Exchange (ETDEWEB)

    Yitai, M.; Shengchun, L.; Lirong, M. [Tianjin Univ., Thermal Energy Research Inst., Tianjin (China)]. E-mail: liushch@tju.edu.cn

    2005-07-01

    In this paper, the calculation method for seasonal energy efficiency ratio (SEER) given in Standard JRA4046-1999 is analyzed and further modified. Based on temperature zone map of U.S., Japan and China and detailed weather data of eight Chinese cities in last 30 years, regional seasonal energy efficiency ratio (RSEER) and energy saving percentage of variable speed room air conditioner are analyzed and compared with various geographical regions in China. It is concluded that RSEER presents the associated effect of season, climate and geography, and therefore should be taken as an evaluation standard for room air conditioner, especially variable speed room air conditioner. Experimental measurements are conducted in the analysis to investigate the effect of energy efficiency ratio (EER) on the improvement of energy saving percentage and SEER. (author)

  16. High pressure air jet in the endoscopic preparation room: risk of noise exposure on occupational health.

    Science.gov (United States)

    Chiu, King-Wah; Lu, Lung-Sheng; Wu, Cheng-Kun

    2015-01-01

    After high-level disinfection of gastrointestinal endoscopes, they are hung to dry in order to prevent residual water droplets impact on patient health. To allow for quick drying and clinical reuse, some endoscopic units use a high pressure air jet (HPAJ) to remove the water droplets on the endoscopes. The purpose of this study was to evaluate the excessive noise exposure with the use of HPAJ in endoscopic preparation room and to investigate the risk to occupational health. Noise assessment was taken during 7 automatic endoscopic reprocessors (AERs) and combined with/without HPAJ use over an 8-hour time-weighted average (TWA). Analytical procedures of the NIOSH and the ISO for noise-induced hearing loss were estimated to develop analytic models. The peak of the noise spectrum of combined HPAJ and 7 AERs was significantly higher than that of the 7 AERs alone (108.3 ± 1.36 versus 69.3 ± 3.93 dBA, P risk of hearing loss (HL > 2.5 dB) was 2.15% at 90 dBA, 11.6% at 95 dBA, and 51.3% at 100 dBA. The odds ratio was 49.1 (95% CI: 11.9 to 203.6). The noise generated by the HPAJ to work over TWA seriously affected the occupational health and safety of those working in an endoscopic preparation room.

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

    Science.gov (United States)

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

  18. Section 609 of the Clean Air Act: Motor Vehicle Air Conditioning

    Science.gov (United States)

    Fact sheet provides a general overview of EPA regulations under Section 609 of the Clean Air Act, which is focused on preventing the release of refrigerants during the servicing of motor vehicle air-conditioning systems and similar appliances.

  19. Mountain Plains Learning Experience Guide: Heating, Refrigeration, & Air Conditioning.

    Science.gov (United States)

    Carey, John

    This Heating, Refrigeration, and Air Conditioning course is comprised of eleven individualized units: (1) Refrigeration Tools, Materials, and Refrigerant; (2) Basic Heating and Air Conditioning; (3) Sealed System Repairs; (4) Basic Refrigeration Systems; (5) Compression Systems and Compressors; (6) Refrigeration Controls; (7) Electric Circuit…

  20. Energy Efficiency for Heating, Ventilating, Air-Conditioning Instructors.

    Science.gov (United States)

    Scharmann, Larry, Ed.; Lay, Gary, Ed.

    Intended primarily but not solely for use at the postsecondary level, this curriculum guide contains five units on energy efficiency that were designed to be incorporated into an existing program in heating, ventilating, and air-conditioning. The following topics are examined: how energy conservation pays, heating, ventilation, air-conditioning,…

  1. Thermal Environment for Classrooms. Central System Approach to Air Conditioning.

    Science.gov (United States)

    Triechler, Walter W.

    This speech compares the air conditioning requirements of high-rise office buildings with those of large centralized school complexes. A description of one particular air conditioning system provides information about the system's arrangement, functions, performance efficiency, and cost effectiveness. (MLF)

  2. Application of solar energy to air-conditioning

    Science.gov (United States)

    Harstad, A. J.; Nash, J. M.

    1978-01-01

    Results of survey of application of solar energy to air-conditioning systems are summarized in report. Survey reviewed air-conditioning techniques that are most likely to find residential applications and that are compatible with solar-energy systems being developed.

  3. Thermal Environment for Classrooms. Central System Approach to Air Conditioning.

    Science.gov (United States)

    Triechler, Walter W.

    This speech compares the air conditioning requirements of high-rise office buildings with those of large centralized school complexes. A description of one particular air conditioning system provides information about the system's arrangement, functions, performance efficiency, and cost effectiveness. (MLF)

  4. Energy Efficiency for Heating, Ventilating, Air-Conditioning Instructors.

    Science.gov (United States)

    Scharmann, Larry, Ed.; Lay, Gary, Ed.

    Intended primarily but not solely for use at the postsecondary level, this curriculum guide contains five units on energy efficiency that were designed to be incorporated into an existing program in heating, ventilating, and air-conditioning. The following topics are examined: how energy conservation pays, heating, ventilation, air-conditioning,…

  5. Air Conditioning and Refrigeration Program Articulation, 1981-1982.

    Science.gov (United States)

    Dallas County Community Coll. District, TX.

    Based on a survey of high school programs and courses in the Dallas County Community College District (DCCCD), this articulated program is designed to prepare students for entry-level employment in the air conditioning and refrigeration industry, including residential and commercial air conditioning and commercial refrigeration. The skills and…

  6. Hospital-acquired infections associated with poor air quality in air-conditioned environments

    OpenAIRE

    Daniela Pinheiro da Silva

    2014-01-01

    Backgound and Objectives: Individuals living in cities increasingly spend more time indoors in air-conditioned environments. Air conditioner contamination can be caused by the presence of aerosols from the external or internal environment, which may be associated with disease manifestations in patients present in this type of environment. Therefore, the aim of this review was to assess the air quality in air-conditioned hospital environments as a risk factor for hospital-acqui...

  7. Solar-powered air-conditioning

    Science.gov (United States)

    Clark, D. C.; Rousseau, J.

    1977-01-01

    Report focuses on recent study on development of solar-powered residential air conditioners and is based on selected literature through 1975. Its purposes are to characterize thermal and mechanical systems that might be useful in development of Rankine-cycle approach to solar cooling and assessment of a Lithium Bromide/Water absorption cycle system.

  8. Experimental studies on improvement of coefficient of performance of window air conditioning unit

    Directory of Open Access Journals (Sweden)

    Tharves Mohideen Sheik Ismail

    2017-01-01

    Full Text Available This paper presents the performance analysis of a window air conditioner unit incorporated with wick less loop heat pipes (WLHP. The WLHP are located on the evaporator side of the air conditioning unit. The working medium for the WLHP is R134a refrigerant gas, an alternate refrigerant. The supply and return humidity of room air, the heat removal rat, and the coefficient of performance of the unit are analyzed for various ambient and room temperatures before and after incorporation of WLHP. The performance curves are drawn by comparing the power consumption and humidity collection rates for various room and ambient temperatures. The results show that coefficient of performance of the unit is improved by 18% to 20% after incorporation of WLHP due to pre-cooling of return air by WLHP, which reduces the thermal load on compressor. Similarly, the energy consumption is reduced by 20% to 25% due to higher thermostat setting and the humidity collection is improved by 35% due to pre-cooling effect of WLHP. The results are tabulated and conclusion drawn is presented based on the performance.

  9. Energy consumption in air-conditioning; Improvement and Reduction

    Directory of Open Access Journals (Sweden)

    Yacoub Yousef Ahmad Alotaibi

    2015-06-01

    Full Text Available Anew technique to reduce latent heat to improve energy consumption in air-conditioning is by using Desiccant . The aim of dehumidification process is to remove the water vapor from the processed air to liquid desiccants. Dehumidification is considered as a key feature of HVAC systems for thermal comfort. Chemical dehumidification is remove the water vapour from the air by transferring it towards a desiccant material (adsorption or absorption. Results illustrate that the application of liquid desiccant in air conditioning can improve indoor air quality, reduce energy consumption and bring environmentally friendly products, also. Lewis number increased rapidly with the increase of solution concentration Therefore liquid desiccant air conditioning systems are drawing more and more attention in recent years.

  10. Air conditioning system and component therefore distributing air flow from opposite directions

    Science.gov (United States)

    Obler, H. D.; Bauer, H. B. (Inventor)

    1974-01-01

    The air conditioning system comprises a plurality of separate air conditioning units coupled to a common supply duct such that air may be introduced into the supply duct in two opposite flow directions. A plurality of outlets such as registers or auxiliary or branch ducts communicate with the supply duct and valve means are disposed in the supply duct at at least some of the outlets for automatically channelling a controllable amount of air from the supply duct to the associated outlet regardless of the direction of air flow within the supply duct. The valve means comprises an automatic air volume control apparatus for distribution within the air supply duct into which air may be introduced from two opposite directions. The apparatus incorporates a freely swinging movable vane in the supply duct to automatically channel into the associated outlet only the deflected air flow which has the higher relative pressure.

  11. Low energy air conditioning of shelters for telecommunication networks

    Energy Technology Data Exchange (ETDEWEB)

    Romagnoni, P. [Ist. Univ. di Architettura, Venezia (Italy); Scattolin, M. [Liebert Hiross, Piove di Sacco (PD) (Italy); Zecchin, R. [Dipt. di Fisica Tecnica, Padova (Italy)

    2000-07-01

    The control of the air temperature in a shelter for telecommunication networks is an important task for the correct operation of its electronic equipment. Different technical solutions have been studied in order to improve the energy performances of air conditioning plants: for this purpose direct free cooling allows to reduce the energy consumption to maintain the internal air temperature below the prescribed values. Nowadays the internal air temperature may rise up to 60 C, due to the high technology of the electronic equipment, and new solutions for the air temperature control can be proposed. This paper analyses the dynamic thermal performances of a shelter used in telecommunication networks, fitted up with an ''air - to air'' plate heat exchanger without mixing between internal and external air flows. Useful information, concerning the thermal and energy performances of this system is given for design purposes. (orig.)

  12. Does air conditioning impact on hygienic quality of indoor air on seagoing vessels?

    Science.gov (United States)

    Meyer, Gabriele; Schepers, Bernd-Fred

    2007-01-01

    According to observations by occupational health physicians, nearly 50 % of the seamen on German vessels will get diseases of the upper respiratory tract. An impact of the air-conditioning systems on these diseases has been suggested. To examine the hygienic quality of indoor air on seagoing vessels, a pilot study was initiated by the See-Berufsgenossenschaft. Air samples were taken on-site at different sampling sites and analysed for the occurrence of microorganisms. Bacteria showed the highest cell numbers and the highest distribution in indoor air on vessels, whereby the maximum level was determined in the air of crew cabins. The identification of bacteria showed that beside common airborne species, pathogens existed. Air-conditioning seems to influence the quality of indoor air on seagoing vessels. Interim results of the study indicate that regular maintenance of air-conditioning systems is essential.

  13. Air-conditioning in the human nasal cavity.

    Science.gov (United States)

    Elad, David; Wolf, Michael; Keck, Tilman

    2008-11-30

    Healthy humans normally breathe through their nose even though its complex geometry imposes a significantly higher resistance in comparison with mouth breathing. The major functional roles of nasal breathing are defense against infiltrating particles and conditioning of the inspired air to nearly alveolar conditions in order to maintain the internal milieu of the lung. The state-of-the-art of the existing knowledge on nasal air-conditioning will be discussed in this review, including in vivo measurements in humans and computational studies on nasal air-conditioning capacity. Areas where further studies will improve our understanding and may help medical diagnosis and intervention in pathological states will be introduced.

  14. Dual gas-diffusion membrane- and mediatorless dihydrogen/air-breathing biofuel cell operating at room temperature

    Science.gov (United States)

    Xia, Hong-qi; So, Keisei; Kitazumi, Yuki; Shirai, Osamu; Nishikawa, Koji; Higuchi, Yoshiki; Kano, Kenji

    2016-12-01

    A membraneless direct electron transfer (DET)-type dihydrogen (H2)/air-breathing biofuel cell without any mediator was constructed wherein bilirubin oxidase from Myrothecium verrucaria (BOD) and membrane-bound [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F (MBH) were used as biocatalysts for the cathode and the anode, respectively, and Ketjen black-modified water proof carbon paper (KB/WPCC) was used as an electrode material. The KB/WPCC surface was modified with 2-aminobenzoic acid and p-phenylenediamine, respectively, to face the positively charged electron-accepting site of BOD and the negatively charged electron-donating site of MBH to the electrode surface. A gas-diffusion system was employed for the electrodes to realize high-speed substrate supply. As result, great improvement in the current density of O2 reduction with BOD and H2 reduction with MBH were realized at negatively and postively charged surfaces, respectively. Gas diffusion system also suppressed the oxidative inactivation of MBH at high electrode potentials. Finally, based on the improved bioanode and biocathode, a dual gas-diffusion membrane- and mediatorless H2/air-breathing biofuel cell was constructed. The maximum power density reached 6.1 mW cm-2 (at 0.72 V), and the open circuit voltage was 1.12 V using 1 atm of H2 gas as a fuel at room temperature and under passive and quiescent conditions.

  15. Air Conditioning Compressor Air Leak Detection by Image Processing Techniques for Industrial Applications

    Directory of Open Access Journals (Sweden)

    Pookongchai Kritsada

    2015-01-01

    Full Text Available This paper presents method to detect air leakage of an air conditioning compressor using image processing techniques. Quality of air conditioning compressor should not have air leakage. To test an air conditioning compressor leak, air is pumped into a compressor and then submerged into the water tank. If air bubble occurs at surface of the air conditioning compressor, that leakage compressor must be returned for maintenance. In this work a new method to detect leakage and search leakage point with high accuracy, fast, and precise processes was proposed. In a preprocessing procedure to detect the air bubbles, threshold and median filter techniques have been used. Connected component labeling technique is used to detect the air bubbles while blob analysis is searching technique to analyze group of the air bubbles in sequential images. The experiments are tested with proposed algorithm to determine the leakage point of an air conditioning compressor. The location of the leakage point was presented as coordinated point. The results demonstrated that leakage point during process could be accurately detected. The estimation point had error less than 5% compared to the real leakage point.

  16. Air Conditioning Systems from a 2nd Law Perspective

    Directory of Open Access Journals (Sweden)

    Luigi Marletta

    2010-04-01

    Full Text Available In this paper exergy analysis is used to assess the performance of the three most common air conditioning plant schemes: all-air, dual-duct and fan-coil systems. The results are presented in terms of flow diagrams to provide a clear picture of the exergy flow across the systems. The most relevant outcomes are that the air cooling and dehumidification is the process most responsible for the exergy loss and that the exergy efficiency of the overall systems is rather low; thus the quest for more appropriate technologies. Solar-assisted air-conditioning is also discussed, outlining the possibilities and the constraints.

  17. Techno-Economic Analysis of Indian Draft Standard Levels for RoomAir Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    McNeil, Michael A.; Iyer, Maithili

    2007-03-01

    The Indian Bureau of Energy Efficiency (BEE) finalized its first set of efficiency standards and labels for room air conditioners in July of 2006. These regulations followed soon after the publication of levels for frost-free refrigerators in the same year. As in the case of refrigerators, the air conditioner program introduces Minimum Efficiency Performance Standards (MEPS) and comparative labels simultaneously, with levels for one to five stars. Also like the refrigerator program, BEE defined several successive program phases of increasing stringency. In support of BEE's refrigerator program, Lawrence Berkeley National Laboratory (LBNL) produced an analysis of national impacts of standards in collaboration with the Collaborative Labeling and Standards Program (CLASP). That analysis drew on LBNL's experience with standards programs in the United States, as well as many other countries. Subsequently, as part of the process for setting optimal levels for air conditioner regulations, CLASP commissioned LBNL to provide support to BEE in the form of a techno-economic evaluation of air conditioner efficiency technologies. This report describes the methodology and results of this techno-economic evaluation. The analysis consists of three components: (1) Cost effectiveness to consumers of efficiency technologies relative to current baseline. (2) Impacts on the current market from efficiency regulations. (3) National energy and financial impacts. The analysis relied on detailed and up-to-date technical data made available by BEE and industry representatives. Technical parameters were used in conjunction with knowledge about air conditioner use patterns in the residential and commercial sectors, and prevailing marginal electricity prices, in order to give an estimate of per-unit financial impacts. In addition, the overall impact of the program was evaluated by combining unit savings with market forecasts in order to yield national impacts. LBNL presented

  18. Experimental tests of a gas fired adsorption air conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Poyelle, F.; Guilleminot, J.J.; Meunier, F. [C.N.R.S.-L.I.M.S.I., Orsay Cedex (France); Canal, P.; Soide, I.; Klemsdal, E. [Gaz de Francer Saint Denis La Plaine (France)

    1997-10-01

    Over recent years, there has been growing interest for air conditioning systems, for commercial and offices buildings, transport and residential houses. Gaz de France promote natural gas powered air conditioning systems through the installation of commercial absorption machines, producing chilled and/or hot water. These machines cover loads from 70 kW to 5 MW. Gaz de France`s purpose is to develop a small scale natural gas fueled air conditioning system for residential applications and small commercials (5-20 kW). In order to study the feasibility of a small scale adsorption machine, a prototype has been studied, designed, constructed and tested. (au) 11 refs.

  19. Simulation technology for refrigeration and air conditioning appliances

    Institute of Scientific and Technical Information of China (English)

    DING Guoliang

    2006-01-01

    Simulation technology has been widely used for performance prediction and optimal design of refrigeration and air conditioning appliances. A brief history of simulation technology for refrigeration and air conditioning appliances is reviewed. The models for evaporator, condenser, compressor, capillary tube and thermal insulation layer are summarized, and a fast calculation method for thermodynamic properties of refrigerant is introduced in this paper. The model-based intelligent simulation technology and the simulation technology based on graph theory are also illustrated. Finally, an updated trend of simulation technology development for refrigeration and air conditioning appliances is discussed.

  20. Desiccant Enhanced Evaporative Air Conditioning: Parametric Analysis and Design; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Woods, J.; Kozubal, E.

    2012-10-01

    This paper presents a parametric analysis using a numerical model of a new concept in desiccant and evaporative air conditioning. The concept consists of two stages: a liquid desiccant dehumidifier and a dew-point evaporative cooler. Each stage consists of stacked air channel pairs separated by a plastic sheet. In the first stage, a liquid desiccant film removes moisture from the process (supply-side) air through a membrane. An evaporatively-cooled exhaust airstream on the other side of the plastic sheet cools the desiccant. The second-stage indirect evaporative cooler sensibly cools the dried process air. We analyze the tradeoff between device size and energy efficiency. This tradeoff depends strongly on process air channel thicknesses, the ratio of first-stage to second-stage area, and the second-stage exhaust air flow rate. A sensitivity analysis reiterates the importance of the process air boundary layers and suggests a need for increasing airside heat and mass transfer enhancements.

  1. Performance and evaluation of desiccant based air conditioning system.

    Directory of Open Access Journals (Sweden)

    Gaurav S. Wani

    2014-12-01

    Full Text Available This Project work presents study and experimental analysis of Desiccant based air conditioning system.The main purpose of this project is to increase the efficency of air conditioning system.In the convenstional air conditioning system cooling coli has two load latent load and sensible load. Cooling has to cool the air and simultaneously to dehumidify it.It increases load on cooling coil and affects performance to the system. To increase the efficiency the air conditioning system desiccant materials are used at the inlet of the air conditioning test rig. Desiccant materials attract moisture based on differences in vapor pressure. Due to their enormous affinity to absorb water and considerable ability to hold water. Due to use of desiccant material load on the cooling coil reduces since moisture is absorbed by desiccant; cooling coil has to take only sensible load. Analysis is done using different desiccant materials and based on the observation, power consumption before and after desiccant is calculated. From this conclusion is made that desiccant material improves the efficiency of air conditioning test rig

  2. Anaerobic digestion in mesophilic and room temperature conditions: Digestion performance and soil-borne pathogen survival.

    Science.gov (United States)

    Chen, Le; Jian, Shanshan; Bi, Jinhua; Li, Yunlong; Chang, Zhizhou; He, Jian; Ye, Xiaomei

    2016-05-01

    Tomato plant waste (TPW) was used as the feedstock of a batch anaerobic reactor to evaluate the effect of anaerobic digestion on Ralstonia solanacearum and Phytophthora capsici survival. Batch experiments were carried out for TS (total solid) concentrations of 2%, 4% and 6% respectively, at mesophilic (37±1°C) and room (20-25°C) temperatures. Results showed that higher digestion performance was achieved under mesophilic digestion temperature and lower TS concentration conditions. The biogas production ranged from 71 to 416L/kg VS (volatile solids). The inactivation of anaerobic digestion tended to increase as digestion performance improved. The maximum log copies reduction of R. solanacearum and P. capsici detected by quantitative PCR (polymerase chain reaction) were 3.80 and 4.08 respectively in reactors with 4% TS concentration at mesophilic temperatures. However, both in mesophilic and room temperature conditions, the lowest reduction of R. solanacearum was found in the reactors with 6% TS concentration, which possessed the highest VFA (volatile fatty acid) concentration. These findings indicated that simple accumulation of VFAs failed to restrain R. solanacearum effectively, although the VFAs were considered poisonous. P. capsici was nearly completely dead under all conditions. Based on the digestion performance and the pathogen survival rate, a model was established to evaluate the digestate biosafety.

  3. MARANGONI CONVECTION AROUND A VENTILATED AIR BUBBLE UNDER MICROGRAVITY CONDITIONS

    NARCIS (Netherlands)

    HOEFSLOOT, HCJ; JANSSEN, LPBM; HOOGSTRATEN, HW

    Under microgravity conditions in both parabolic and sounding rocket flights, the mass-transfer-induced Marangoni convection around an air bubble was studied. To prevent the bubble from becoming saturated, the bubble was ventilated. It turned out that the flow rate of the air through the bubble

  4. Effects of suspension of air-conditioning on airtight-type racks.

    Science.gov (United States)

    Kanzaki, M; Fujieda, M; Furukawa, T

    2001-10-01

    Although isolation racks are superior to open-type racks in terms of securing breeding conditions for laboratory animals, the contingency-proofing capability of the former has yet to be determined. Therefore, from the view of risk management, we studied the environmental change in isolation racks by forcibly suspending ventilation and air-conditioning and confirming the maximal time length for complete recovery to the original condition after restarting their operations. The isolation racks were placed in a room that was equipped with an independent air-conditioning system. When the inside condition of the racks reached 22-24 degrees C and 59-64% of relative humidity, the air-conditioning and ventilation were forcibly suspended and the subsequent temperature, relative humidity, ammonium and CO2 concentrations in the racks were measured over time. We found that after suspending the air-conditioning and ventilation, it took 40-60 min for temperature, and about 10 min for relative humidity to exceed the maximum values (temperature and relative humidity) referred to in the Showa 58 Nenban Guideline Jikken Doubutsu Shisetsu no Kenchiku oyobi Setsubi (Guidelines of buildings and facilities for experimental animals in Japan; Year 1983 edition). After 17 hr 25 min of the suspension of air-conditioning and ventilation, two rats were found dead. Then, the air-conditioning and ventilation were restarted. It took about 2 hr for temperature, and 50 min for relative humidity to regain the guideline values. The ammonium concentration stayed within the guideline value with a maximum concentration of 2 ppm in the experimental period, whereas the CO2 concentration was found to exceed 9% at the time of animal death.

  5. Performance Optimization of Alternative Lower Global Warming Potential Refrigerants in Mini-Split Room Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL

    2017-01-01

    Oak Ridge National laboratory (ORNL) recently conducted extensive laboratory, drop-in investigations for lower Global Warming Potential (GWP) refrigerants to replace R-22 and R-410A. ORNL studied propane, DR-3, ARM-20B, N-20B and R-444B as lower GWP refrigerant replacement for R-22 in a mini-split room air conditioner (RAC) originally designed for R-22; and, R-32, DR-55, ARM-71A, and L41-2, in a mini-split RAC designed for R-410A. We obtained laboratory testing results with very good energy balance and nominal measurement uncertainty. Drop-in studies are not enough to judge the overall performance of the alternative refrigerants since their thermodynamic and transport properties might favor different heat exchanger configurations, e.g. cross-flow, counter flow, etc. This study compares optimized performances of individual refrigerants using a physics-based system model tools. The DOE/ORNL Heat Pump Design Model (HPDM) was used to model the mini-split RACs by inputting detailed heat exchangers geometries, compressor displacement and efficiencies as well as other relevant system components. The RAC models were calibrated against the lab data for each individual refrigerant. The calibrated models were then used to conduct a design optimization for the cooling performance by varying the compressor displacement to match the required capacity, and changing the number of circuits, refrigerant flow direction, tube diameters, air flow rates in the condenser and evaporator at 100% and 50% cooling capacities. This paper compares the optimized performance results for all alternative refrigerants and highlights best candidates for R-22 and R-410A replacement.

  6. Measurement of Vehicle Air Conditioning Pull-Down Period

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, John F [ORNL; Huff, Shean P [ORNL; Moore, Larry G [ORNL; West, Brian H [ORNL

    2016-08-01

    Air conditioner usage was characterized for high heat-load summer conditions during short driving trips using a 2009 Ford Explorer and a 2009 Toyota Corolla. Vehicles were parked in the sun with windows closed to allow the cabin to become hot. Experiments were conducted by entering the instrumented vehicles in this heated condition and driving on-road with the windows up and the air conditioning set to maximum cooling, maximum fan speed and the air flow setting to recirculate cabin air rather than pull in outside humid air. The main purpose was to determine the length of time the air conditioner system would remain at or very near maximum cooling power under these severe-duty conditions. Because of the variable and somewhat uncontrolled nature of the experiments, they serve only to show that for short vehicle trips, air conditioning can remain near or at full cooling capacity for 10-minutes or significantly longer and the cabin may be uncomfortably warm during much of this time.

  7. Transitioning to Low-GWP Alternatives in Unitary Air Conditioning

    Science.gov (United States)

    This fact sheet provides current information on low-Global Warming Potential (GWP) refrigerant alternatives used in unitary air-conditioning equipment, relevant to the Montreal Protocol on Substances that Deplete the Ozone Layer.

  8. Persistence of Initial Conditions in Continental Scale Air Quality Simulations

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains the data used in Figures 1 – 6 and Table 2 of the technical note "Persistence of Initial Conditions in Continental Scale Air Quality...

  9. Poor weather conditions and flight operations: Implications for air ...

    African Journals Online (AJOL)

    Poor weather conditions and flight operations: Implications for air transport hazard ... Ethiopian Journal of Environmental Studies and Management ... fog, dust haze and line squall that affect flight operation such as flight delays, diversion and ...

  10. Application of Solar Energy to Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    M, Nash J; J, Harstad A

    1976-11-01

    The results of a survey of solar energy system applications of air conditioning are summarized. Techniques discussed are both solar powered (absorption cycle and the heat engine/ Rankine cycle) and solar related (heat pump). Brief descriptions of the physical implications of various air conditioning techniques, discussions of status, proposed technological improvements, methods of utilization and simulation models are presented, along with an extensive bibliography of related literature.

  11. Application of solar energy to air conditioning systems

    Science.gov (United States)

    Nash, J. M.; Harstad, A. J.

    1976-01-01

    The results of a survey of solar energy system applications of air conditioning are summarized. Techniques discussed are both solar powered (absorption cycle and the heat engine/Rankine cycle) and solar related (heat pump). Brief descriptions of the physical implications of various air conditioning techniques, discussions of status, proposed technological improvements, methods of utilization and simulation models are presented, along with an extensive bibliography of related literature.

  12. Circularly Polarized Persistent Room-Temperature Phosphorescence from Metal-Free Chiral Aromatics in Air.

    Science.gov (United States)

    Hirata, Shuzo; Vacha, Martin

    2016-04-21

    Circularly polarized room-temperature phosphorescence (RTP) with persistent emission characteristics was observed from metal-free chiral binaphthyl structures. Enantiomers of the binaphthyl compounds doped into an amorphous hydroxylated steroid matrix produced blue fluorescence and yellow persistent RTP in air. The lifetime and quantum yield of the yellow persistent RTP were 0.67 s and 2.3%, respectively. The dissymmetry factors of circular dichroism (CD) in the first absorption band, circularly polarized fluorescence (CPF), and circularly polarized persistent RTP were |1.1 × 10(-3)|, |4.5 × 10(-4)|, and |2.3 × 10(-3)|, respectively. A comparison between the experimental data and calculations by time-dependent density functional theory for transient CD spectra confirmed that the binaphthyl conformations in the lowest singlet excited state (S1) and the lowest triplet state (T1) were different. The large difference in the dissymmetry factors for the CPF and the circularly polarized persistent RTP was likely caused by this conformational change between S1 and T1.

  13. Microbiological air pollution of production room of the meat processing plant as a potential threat to the workers

    Directory of Open Access Journals (Sweden)

    Barbara Breza-Boruta

    2015-12-01

    Full Text Available Introduction. Production rooms of the meat plants are the specific environment that require constant monitoring of microbiological air purity. Bioaerosols pose a threat to the safety of produced food and a considerable risk to health of exposed workers. The aim of this study was to estimate the air microbiological pollution in production rooms of the meat processing plant and exposure of the workers to biological aerosol. Material and methods. Air samples were collected at 3 stands in production rooms during winter, with the compaction method using the impactor MAS-100. The total number of bacteria and moulds, Staphylococci and bacteria of the family Enterobacteriaceae were determined in the studied bioaerosol. The concentration of microorganisms was presented in the form of colony forming units in 1m3 of air. Results. The highest concentration of mesophylic bacteria was found at stand 1 – at the freezing tunnel; whereas the highest contamination with staphylococci and fungal aerosol was found in the room where several workers were employed at packing frozen food. Among determined fungi predominated moulds of the genera: Penicillium, Alternaria and Cladosporium. Also species of potentially pathogenic fungi which produce toxins and have allergizing properties were detected in the studied bioaerosol. Bacteria of the family Enterobacteriaceae, which also may cause many infavourable health effects in exposed people, occurred at all stands. Conclusion. The concentration level and microbial composition in the inhaled air make valuable information for determination of occupational risk and a potential threat to workers of their workstations. Potentially pathogenic microorganisms present in the studied air (staphylococci, bacteria of the family Enterobacteriaceae and some moulds according to the Directive 2000/54/EC l belong to the 2nd group of risk and threat of harmful biological agents. Identification of biological threats makes it easier for the

  14. Extreme conditions in a dissolving air nanobubble

    Science.gov (United States)

    Yasui, Kyuichi; Tuziuti, Toru; Kanematsu, Wataru

    2016-07-01

    Numerical simulations of the dissolution of an air nanobubble in water have been performed taking into account the effect of bubble dynamics (inertia of the surrounding liquid). The presence of stable bulk nanobubbles is not assumed in the present study because the bubble radius inevitably passes the nanoscale in the complete dissolution of a bubble. The bubble surface is assumed to be clean because attachment of hydrophobic materials on the bubble surface could considerably change the gas diffusion rate. The speed of the bubble collapse (the bubble wall speed) increases to about 90 m/s or less. The shape of a bubble is kept nearly spherical because the amplitude of the nonspherical component of the bubble shape is negligible compared to the instantaneous bubble radius. In other words, a bubble never disintegrates into daughter bubbles during the dissolution. At the final moment of the dissolution, the temperature inside a bubble increases to about 3000 K due to the quasiadiabatic compression. The bubble temperature is higher than 1000 K only for the final 19 ps. However, the Knudsen number is more than 0.2 for this moment, and the error associated with the continuum model should be considerable. In the final 2.3 ns, only nitrogen molecules are present inside a bubble as the solubility of nitrogen is the lowest among the gas species. The radical formation inside a bubble is negligible because the probability of nitrogen dissociation is only on the order of 10-15. The pressure inside a bubble, as well as the liquid pressure at the bubble wall, increases to about 5 GPa at the final moment of dissolution. The pressure is higher than 1 GPa for the final 0.7 ns inside a bubble and for the final 0.6 ns in the liquid at the bubble wall. The liquid temperature at the bubble wall increases to about 360 K from 293 K at the final stage of the complete dissolution.

  15. Exposure of health care workers and occupants to coughed air in a hospital room with displacement air distribution: impact of ventilation rate and distance from coughing patient

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Bolashikov, Zhecho Dimitrov; Kostadinov, Kamen

    The exposure of a doctor and a second patient to coughed air by an infected patient was studied in a simulated two-bed hospital patient room. The air temperature in the room, ventilated at two air change rates (3 h-1 and 6 h-1) was kept 22 oC. Thermal manikin with realistic body shape and surface...... temperature distribution was used as the doctor standing 0.55, 1.1 or 2.8 m downstream the cough. A coughing thermal dummy, lying in one bed and a second thermal manikin in the other bed (1.3 m away), were used as the “sick” and the “exposed” patients. The cough consisted of 100% CO2. The doctor...... hospital standards as minimum ventilation rate in hospital patient rooms, resulted in elevated exposure to coughed air for the doctor, suggesting increased risk from airborne cross-infection. Displacement air distribution does not reduce the risk from cross-infection....

  16. Sea water air conditioning : a cost effective alternative

    Energy Technology Data Exchange (ETDEWEB)

    Elsafty, A.F. [Arab Academy for Science, Technology and Maritime Transport, Alexandria (Egypt). Dept. of Mechanical Engineering, College of Engineering and Technology; Saeid, L. [National Gas Company, Cairo (Egypt). GIS and Design Section

    2009-07-01

    The 2 main types of air conditioning systems are vapor compression systems which are electrically operated, and absorption systems which are heat operated. This paper presented a new air conditioning technique for use in the Middle East. The Sea Water Air Conditioning (SWAC) system uses deep cold ocean and sea water as a renewable energy source to air-condition buildings. A technical and economical assessment was performed to determine the advantages of the SWAC system over conventional vapor compression systems to air-condition hotels and resorts at a new tourists resort in Egypt. Meteorological data for the region was used to estimate the gross cooling load for the hotels using the HVAC Load Explorer program. The major components of the SWAC system were sized and analyzed to the determine its operational performance and to estimate the probable costs. The economic analysis was based on two different methods, notably the net present value (NPV) and the simple pay back method. Three options were investigated in the economic study. The first was the use of a conventional air conditioning system to provide a baseline for the other options being investigated. The second option was the use of deep sea water only, and the third option involved the use of a hybrid system using both a sea water air conditioning system and a conventional chiller in series. The SWAC system was the preferred option for its minimum net present value as well as the short pay back period. The energy savings approached 80 per cent of conventional air-conditioners. It was concluded that in addition to reducing electricity use, the SWAC systems can contribute to a reduction in greenhouse gases. 11 refs., 7 tabs., 6 figs.

  17. Performance of personalized ventilation in a room with an underfloor air distribution system: transport of contaminants between occupants

    DEFF Research Database (Denmark)

    Cermak, Radim; Melikov, Arsen Krikor

    2003-01-01

    the workplaces has not been studied in detail. This paper presents a study on the performance of a personalized ventilation system installed in a full-scale test room with an underfloor air distribution system. Transport of human-produced airborne pollutants (in real life they can be infectious agents) between...... by the exposed manikin. The main conclusion is that the design of the personalised ventilation system and the interaction of personalized airflow and room airflow should be carefully considered in order to achieve minimal transport of pollution between occupants....

  18. AIR DISINFECTION EFFECT IN THE OPERATING ROOM OF HOSPITAL BY USING THE LOCAL AIR PURIFICATION DEVICE%局部空气净化装置对手术室空气的消毒效果

    Institute of Scientific and Technical Information of China (English)

    陈英

    2012-01-01

    目的 观察空气消毒机对医院手术室空气消毒效果,以评价其实际应用效果.方法 采用平板沉降采样和细菌培养方法,评价该多因子组合空气净化装置对手术室空气中自然菌净化效果,并与紫外线灯照射消毒作平行比较.结果 启动YKX/Y型空气消毒机和紫外线灯作用30 min,5 min后采样,手术室空气中细菌总数<200cfu/m3,随着时间的延长,空气中菌数逐渐增加,15 min后细菌总数逐渐增加到200 cfu/m3以上.在手术室有6人工作的情况下,空气消毒机持续运行,可使空气细菌继续保持在<200 cfu/m3.结论 试验用空气消毒机可以在手术期间持续消毒,可以维持手术室内空气中细菌总数< 200 cfu/m3.%Objective To observe the air disinfection effect in the operating room of hospital by using the local air purification device and evaluate the practical application effect of the device. Methods By using the methods of tablet settlement sampling and bacterial culture, to evaluate and compare the effect of air purification in the operating room by the air purification device and ultraviolet light irradiation. Results 5 mins later after using the air disinfection device of YKX / Y - type and the ultraviolet ray lamp for 30 mins, the total number of bacteria in the air of operating room was less than 200 cfu/m3. As the time prolonged to 15 min, the bacteria number increased to more than 200 cfu/m3. Under the condition of six persons working and the air disinfection device running continuously in the operating room, the bacteria in the air maintained less than 200 cfu/m3. Conclusion The air purification device can continue disinfection during surgical operation and the number of bacteria can maintain less than 200 cfu/m3.

  19. Feasibility of a solar-assisted winter air-conditioning system using evaporative air-coolers

    Directory of Open Access Journals (Sweden)

    Mohamed M. El-Awad

    2011-03-01

    Full Text Available The paper presents a winter air-conditioning system which is suitable for regions with mildly cold but dry winters. The system modifies the evaporative air-cooler that is commonly used for summer air-conditioning in such regions by adding a heating process after the humidification process. The paper describes a theoretical model that is used to estimate the system's water and energy consumption. It is shown that a 150-LPD solar heater is adequate for air-conditioning a 500 ft3/min (14.4 m3/min air flow rate for four hours of operation. The maximum air-flow rate that can be heated by a single solar water-heater for four hours of operation is about 900-cfm, unless a solar water heater large than a 250-LPD heater is used. For the 500 ft3/min air flow rate the paper shows that the 150, 200, 250 and 300 LPD solar water-heaters can provide air-conditioning for 4, 6, 8 and 10 hours, respectively, while consuming less energy than the equivalent refrigerated-type air-conditioner.

  20. Feasibility of a solar-assisted winter air-conditioning system using evaporative air-coolers

    Energy Technology Data Exchange (ETDEWEB)

    El-Awad, Mohamed M. [Mechanical Engineering Department, the University of Khartoum, P.O. Box 321 Khartoum (Sudan)

    2011-07-01

    The paper presents a winter air-conditioning system which is suitable for regions with mildly cold but dry winters. The system modifies the evaporative air-cooler that is commonly used for summer air-conditioning in such regions by adding a heating process after the humidification process. The paper describes a theoretical model that is used to estimate the system's water and energy consumption. It is shown that a 150-LPD solar heater is adequate for air-conditioning a 500 ft3/min (14.4 m3/min) air flow rate for four hours of operation. The maximum air-flow rate that can be heated by a single solar water-heater for four hours of operation is about 900-cfm, unless a solar water heater large than a 250-LPD heater is used. For the 500 ft3/min air flow rate the paper shows that the 150, 200, 250 and 300 LPD solar water-heaters can provide air-conditioning for 4, 6, 8 and 10 hours, respectively, while consuming less energy than the equivalent refrigerated-type air-conditioner.

  1. A simplified method for the calculation of the influence of the room mass on the indoor thermal climate in buildings under summer conditions

    NARCIS (Netherlands)

    Euser, P.; Knorr, K.T.; Nicolaas, H.J.; Velde, A. van der

    1984-01-01

    Simplified methods and design aids for the calculation of cooling loads and room air temperatures are described. The complicated influence of the room mass is approximated by introducing the 'thermal effective mass' of the room. This quantity accounts for the restricted penetration of the fluctuatin

  2. Study of Air Velocity and Temperature Gradient in Lecture Room Through Mixed and Displacement Ventilation Systems to Improve the Thermal Comfort

    Directory of Open Access Journals (Sweden)

    Bambang Iskandriawan

    2010-05-01

    Full Text Available Air ventilation system is considered crucial in the target of maintaining clean and fresh room air at all times. It will improve the thermal comfort and indoor air quality along with the activities of occupant. This investigation explores the influence of fresh air diffuser location to the thermal comfort factor especially in the lecture room. It will contrast two types of ventilation: the mixed and the displacement ventilation. The thermal comfort factor is represented by means of air velocity and temperature. Using Fluent 6.2 as CFD (Computational Fluid Dynamics simulation program, all the variables will be exploited. The specific boundary type’s room model is verified in GAMBIT software generating such a specific lecture room. The finding shows that the displacement ventilation system has benefit in the propensity of controlling the heat and air velocity compare to the mixed ventilation

  3. Applicability of sewage heat pump air-conditioning system

    Institute of Scientific and Technical Information of China (English)

    陈金华; 刘猛; 刘勇; 靳鸣; 陈洁

    2009-01-01

    A sewage heat pump system and its application based on a project in Chongqing,China,were discussed. Based on the sewage conditions,a feasibility analysis of the sewage heat pump air conditioning system was conducted. The theoretical and quantitative calculations indicate that sewage flux in the city sewage main pipe in the project can satisfy heat exchange requirements,and taking water from the pipes has relatively small influence on the pipe net in summer and winter. The sewage heat pump air-conditioning system can save 21.5% operating cost in one year,which is energy efficient and environmentally friendly.

  4. Experimental and numerical investigation of optimum location for FCU in an all-water air conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Elsafty, A.F.; Hassan, A.A. [Arab Academy for Science and Technology and Marine Transport, Alexandria (Egypt). Dept. of Mechanical and Marine Engineering, College of Engineering and Technology

    2006-07-01

    In this study, an all-water air conditioning (AC) system was used to determine the optimum location of a fan cooling unit inside a room. The AC system consisted of a condensing unit; a storage tank; a fan coil unit; a circulating pump; and a direct digital control unit (DDC). Cooling loads were calculated using a software tool called HVAC Explorer. A series of flow pattern experiments were conducted in order to verify the optimal location of the fan coil. Velocity and temperature contour profiles were used to measure thermal comfort conditions. Two standard k-{epsilon} equation models were used to examine the effect of air flow turbulence. Experimental test results were then compared with computational fluid dynamics (CFD) results for the 3 positions of the fan coil unit inside the room. Values were measured using an air flow meter device. The 3-D geometry of the room model was generated using commercial software and a steady state analysis technique. It was concluded that the model accurately measured the air conditioning system's air flow patterns. 1 tab., 1 fig.

  5. Fuzzy logic control of air-conditioning system in residential buildings

    Directory of Open Access Journals (Sweden)

    Abdel-Hamid Attia

    2015-09-01

    Full Text Available There has been a rising concern in reducing the energy consumption in building. Heating ventilation and air condition system is the biggest consumer of energy in building. In this study, fuzzy logic control of the air conditioning system of building for efficient energy operation and comfortable environment is investigated. A theoretical model of the fan coil unit (FCU and the heat transfer between air and coolant fluid is derived. The controlled variables are the room temperature and relative humidity and control consequents are the percentage of chilled and hot water flow rates at summer and the percentage of hot water and steam injected flow rates at winter. A computer simulation has been conducted and fuzzy control results are compared with that of conventional Proportional-Integral-Derivative control. It was found that the proposed control strategy satisfies the space load and at the same time to achieve the comfort zone, as defined by the ASHRAE code. Meanwhile PID control fails to adjust the room temperature at part-load operations. It has been demonstrated that fuzzy controller operation is more efficient and consumes less energy than PID control.

  6. The microbiological quality of air improves when using air conditioning systems in cars.

    Science.gov (United States)

    Vonberg, Ralf-Peter; Gastmeier, Petra; Kenneweg, Björn; Holdack-Janssen, Hinrich; Sohr, Dorit; Chaberny, Iris F

    2010-06-01

    Because of better comfort, air conditioning systems are a common feature in automobiles these days. However, its impact on the number of particles and microorganisms inside the vehicle--and by this its impact on the risk of an allergic reaction--is yet unknown. Over a time period of 30 months, the quality of air was investigated in three different types of cars (VW Passat, VW Polo FSI, Seat Alhambra) that were all equipped with a automatic air conditioning system. Operation modes using fresh air from outside the car as well as circulating air from inside the car were examined. The total number of microorganisms and the number of mold spores were measured by impaction in a high flow air sampler. Particles of 0.5 to 5.0 microm diameter were counted by a laser particle counter device. Overall 32 occasions of sampling were performed. The concentration of microorganisms outside the cars was always higher than it was inside the cars. Few minutes after starting the air conditioning system the total number of microorganisms was reduced by 81.7%, the number of mold spores was reduced by 83.3%, and the number of particles was reduced by 87.8%. There were no significant differences neither between the types of cars nor between the types of operation mode of the air conditioning system (fresh air vs. circulating air). All parameters that were looked for in this study improved during utilization of the car's air conditioning system. We believe that the risk of an allergic reaction will be reduced during use also. Nevertheless, we recommend regular maintenance of the system and replacement of older filters after defined changing intervals.

  7. Experimental Investigation of Using Evaporative Air Cooler for Winter Air-Conditioning in Baghdad

    Directory of Open Access Journals (Sweden)

    Zainab Hasson Hassan

    2012-01-01

    Full Text Available This paper presents an efficient methodology to design modified evaporative air-cooler for winter air-conditioning in Baghdad city as well as using it for summer air-conditioning by adding a heating process after the humidification process. Laboratory tests were performed on a direct evaporative cooler (DEC followed by passing the air on hot water through heat exchanger placed in the coolers air duct exit. The tests were conducted on the 2nd of December /2011 when the ambient temperature was 8.1°C and the relative humidity was (68%. The air flow rate is assumed to vary between 0.069 to 0.209 kg/s with constant water flow rate of 0.03 kg/s in the heat exchanger. The performance is reported in terms of effectiveness of DEC, saturation efficiency of DEC, outlet temperature of air and cooling capacity. Heat transfer rate in heat exchanger mode is also estimated. The paper presents the mathematical development of the equations of thermal exchanges through DEC and HE. Prediction of air condition that exits o this system show that the present system could bring the air stream to a comfortable winter zone .

  8. Technology Equipment Rooms.

    Science.gov (United States)

    Day, C. William

    2001-01-01

    Examines telecommunications equipment room design features that allow for growth and can accommodate numerous equipment replacements and upgrades with minimal service disruption and with minimal cost. Considerations involving the central hub, power and lighting needs, air conditioning, and fire protection are discussed. (GR)

  9. Mesoporous Structure Control of Silica in Room-Temperature Synthesis under Basic Conditions

    Directory of Open Access Journals (Sweden)

    Jeong Wook Seo

    2015-01-01

    Full Text Available Various types of mesoporous silica, such as continuous cubic-phase MCM-48, hexagonal-phase MCM-41, and layer-phase spherical silica particles, have been synthesized at room temperature using cetyltrimethylammonium bromide as a surfactant, ethanol as a cosurfactant, tetraethyl orthosilicate as a silica precursor, and ammonia as a condensation agent. Special care must be taken both in the filtering of the resultant solid products and in the drying process. In the drying process, further condensation of the silica after filtering was induced. As the surfactant and cosurfactant concentrations in the reaction mixture increased and the NH3 concentration decreased, under given conditions, continuous cubic MCM-48 and layered silica became the dominant phases. A cooperative synthesis mechanism, in which both the surfactant and silica were involved in the formation of mesoporous structures, provided a good explanation of the experimental results.

  10. Detailed simulations of lighting conditions in office rooms lit by daylight and artificial light

    DEFF Research Database (Denmark)

    Iversen, Anne

    In this thesis the effect on the annual artificial lighting demand is investigated by employing detailed simulations of lighting conditions in office rooms lit by daylight and artificial. The simulations of the artificial lighting demand is accomplished through daylight simulations in Radiance....... The detailed simulations includes studies of the resolution of different weather data sets in climate-based daylight modeling. Furthermore, influence of the electrical lighting demand by simulating with dynamic occupancy patterns is studied. Finally the thesis explores the influence of obstructions in an urban...... canyon on the daylight availability within the buildings, and hence on the energy consumption for artificial lights. The results from the thesis demonstrates that the effect on the outcome of the daylight simulations when simulating with typical weather data files for the location of Copenhagen...

  11. Simulations of the impacts of building height layout on air quality in natural-ventilated rooms around street canyons.

    Science.gov (United States)

    Yang, Fang; Zhong, Ke; Chen, Yonghang; Kang, Yanming

    2017-08-30

    Numerical simulations were conducted to investigate the effects of building height ratio (i.e., HR, the height ratio of the upstream building to the downstream building) on the air quality in buildings beside street canyons, and both regular and staggered canyons were considered for the simulations. The results show that the building height ratio affects not only the ventilation fluxes of the rooms in the downstream building but also the pollutant concentrations around the building. The parameter, outdoor effective source intensity of a room, is then proposed to calculate the amount of vehicular pollutants that enters into building rooms. Smaller value of this parameter indicates less pollutant enters the room. The numerical results reveal that HRs from 2/7 to 7/2 are the favorable height ratios for the regular canyons, as they obtain smaller values than the other cases. While HR values of 5/7, 7/7, and 7/5 are appropriate for staggered canyons. In addition, in terms of improving indoor air quality by natural ventilation, the staggered canyons with favorable HR are better than those of the regular canyons.

  12. he Efficiency Analysis of Room Air Conditioners%房间空气调节器的效率分析

    Institute of Scientific and Technical Information of China (English)

    周子成

    2013-01-01

    本文介绍和论述房间空调器的效率现状及其提高的途径,如高效压缩机、高效换热器、变频驱动等。%The efficiency status of room air conditioners and its improving ways are introduced and discussed in this paper , such as high-efficiency compressors , high efficiency heat exchangers , and inverter drives etc..

  13. Nasal air conditioning in relation to acoustic rhinometry values.

    Science.gov (United States)

    Lindemann, Joerg; Tsakiropoulou, Evangelia; Keck, Tilman; Leiacker, Richard; Wiesmiller, Kerstin M

    2009-01-01

    Changes of nasal dimensions can influence the air-conditioning capacity of the nose because of alterations of airflow patterns. The goal of this study was to evaluate the correlation between intranasal temperature and humidity values and nasal dimensions, assessed by means of acoustic rhinometry. Eighty healthy volunteers (40 men and 40 women; median age, 51 years; range, 20-84 years) were enrolled in the study. In total, 160 nasal cavities were examined. All volunteers underwent a standardized acoustic rhinometry. Additionally, intranasal air temperature and humidity measurements at defined intranasal detection sites within the anterior nasal segment were performed. There was no statistically significant difference between the right and left side of the nose regarding air temperature, absolute humidity, and acoustic rhinometric values. A negative correlation was established between the rhinometric nasal volumes/minimal cross-sectional areas and air temperature and absolute humidity values at the three intranasal detection sites. According to our results, nasal volumes and cross- sectional areas relevantly influence nasal air conditioning. A healthy nasal cavity with smaller volumes and cross-sectional areas seems to present a more effective air-conditioning function than a too "wide" open nose because of changes in airflow patterns. This observation should be considered as a limitation for overly extensive nasal surgery especially of the turbinates.

  14. Intelligent Control System of Textile Mill's Air-conditioning

    Institute of Scientific and Technical Information of China (English)

    WU Fu-zhuan; ZHAO Fang

    2009-01-01

    This paper briefly analyzes the present situation of textile mill's air-conditioning system. Since it is difficult to establish detailed math model to control a textile mill's air-conditioning system because of the influence of various factors such as the differences in seasons, regions, etc., most air-conditioning equipment can not he controlled automatically. This paper suggests utilizing multi-function data acquisition card to collect the data about the temperature and humidity of a workshop, processing the data on a PC, comparing them with the expert database, and then using the 485 serial port expanding module to output the parameters, which are used to control the inverter, so that the purpose of adjusting the temperature and humidity of the workshop is achieved.

  15. Sustainable air-conditioning for the tropical buildings

    Directory of Open Access Journals (Sweden)

    Asrul Mahjuddin Ressang Aminuddin

    2008-12-01

    Full Text Available Tropical climates are thermally uncomfortable and are mostly unhealthy to the occupants of the modern skyscrapers. The temperatures are usually on the hot side coupled with high relative humidity. The population living in the tropics, especially in Malaysia, is getting affluent and can afford air-conditioning their residences and offices. This leads to increased electricity consumption in the buildings. However, switching off the air-conditioning is not an option for the modern buildings as it would affect the health of the people and their productivity. This paper proposes innovative indoor units that will contribute to energy conservation by utilising principles of partial air-conditioning. The outdoor units could be utilised for clothes drying or for providing hot water to the occupants of the building. This will successfully address the issues on sustainable building technologies and techniques. It will lead to considerable savings in energy consumption in buildings in the tropical climate.

  16. Room air quality as a challenge. Interview mit Bjarne W. Olesen about the 2008 Indoor Air Congress in Copenhagen; Raumluftqualitaet als Aufgabenstellung. Interview mit Bjarne W. Olesen zum Indoor Air Kongress 2008 in Kopenhagen

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, W.

    2008-01-15

    The upcoming Indoor Air - Eleventh International Conference on Room Air Quality and Climate from 17 to 22 August 2008 in Copenhagen in Denmark will for the first time feature a one-day event dedicated especially to architects. Wolfgang Schmid, a freelance journalist specialising in technical building equipment, spoke with Professor Bjarne Olesen, President of the 2008 Indoor Air, about the Congress agenda as well as about important trends of development in the area of well-being, health and indoor climate.

  17. AIR CONDITIONING IN MINES IN THE CZECH REPUBLIC AND UKRAINE

    Directory of Open Access Journals (Sweden)

    Pavel Zapletal

    2014-07-01

    Full Text Available The present-day micro-climatic conditions in black coal mines are of such nature that in no mine natural micro-climate conditioning is sufficient any more. The original temperature of rocks grows progressively in dependence on the increasing depth of the extracted seam, or more precisely, on the mining workplace, and this growth is much more significant than previously considered. The temperature of the surrounding rocks, but also high-performance continuous miners and conveyor belt drives heat up airflow, thus worsening microclimatic conditions. This article describes micro-climatic conditions the in Czech Republic and Ukraine and some methods of deep mines air conditioning.

  18. Effects of water nanodroplets on skin moisture and viscoelasticity during air-conditioning.

    Science.gov (United States)

    Ohno, Hideo; Nishimura, Naoki; Yamada, Kuniyuki; Shimizu, Yuuki; Iwase, Satoshi; Sugenoya, Junichi; Sato, Motohiko

    2013-11-01

    In air-conditioned rooms, dry air exacerbates some skin diseases, for example, senile xerosis, atopic dermatitis, and surface roughness. Humidifiers are used to improve air dryness, which often induces excess humidity and thermal discomfort. To address this issue, we investigated the effects of water nanodroplets (mist) on skin hydration, which may increase skin hydration by penetrating into the interstitial spaces between corneocytes of the stratum corneum (SC) without increasing air humidity. We examined biophysical parameters, including skin conductance and transepidermal water loss (TEWL), and biomechanical parameters of skin distension/retraction before and after suction at the forehead, lateral canthus, and cheek, with or without mist, in a testing environment (24°C, 35% relative humidity) for 120 min. In the group without mist, TEWL values significantly decreased at all the sites after 1 h compared with the initial values. However, in the presence of mist, TEWL values were maintained at the initial values through the test, yielding significant differences vs. the group without mist. There were no significant differences between mist and mist-free groups in terms of skin conductance. Skin distension was significantly increased in the group with mist compared with that in the group without mist at the forehead and cheek, suggesting a softening effect of mist. Skin deformation of the face was improved by mist, suggesting hydration of the SC by mist. The change in TEWL was influenced by mist, suggesting supply of water to the skin, particularly the SC, by mist. These data indicated that a mist of water nanodroplets played an important role in softening skin in an air-conditioned room without increasing excess humidity. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Air conditioning: Low-cost autonomous air conditioning systems for bionic buildings; Klimatechnik: Bezahlbare, autarke Klimatisierung von bionischen Gebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, H. [ARCADIS, Maastricht (Netherlands); Kutzker, A. [RUBITHERM GmbH, Hamburg (Germany)

    2005-05-01

    Termites in Africa construct buildings that are respectfully referred to as ''cathedrals'' by experts. Millions of insects inhabit these structures that are efficiently air conditioned: While the outside temperatures vary from 10 C at night to 45 C in daytime, the air inside has a constant temperature of 29 C +/- 1 C. The contribution presents a low-cost solution for human buildings. (orig.)

  20. Thermal stratification level of low sidewall air supply with air-conditioning system in large space

    Institute of Scientific and Technical Information of China (English)

    黄晨; 蔡宁; 高雪垒

    2009-01-01

    The thermal stratification level of low sidewall air supply system in large space was defined. Depending on the experiment of low sidewall air supply in summer 2008,the thermal stratification level was studied by simulation. Based on the simulation of experiment condition,the air velocity and vertical temperature distribution in a large space were simulated at different air-outlet velocities,and then the thermal stratification level line was obtained. The simulation results well match with the experimental ones and the average relative error is 3.4%. The thermal stratification level is heightened by increasing the air-outlet velocity with low sidewall air supply mode. It is concluded that when air-outlet velocity is 0.29 m/s,which is the experimental case,a uniform thermal environment in the higher occupied zone and a stable stratification level are formed. When the air-outlet velocity is low,such as 0.05 m/s,the thermal stratification level is too low and the air velocity is too small to meet the human thermal comfort in the occupied zone. So,it would be reasonable that the air-outlet velocity may be designed as 0.31 m/s if the height of the occupied zone is 2 m.

  1. Anthropogenic heating of the urban environment due to air conditioning

    Science.gov (United States)

    Salamanca, F.; Georgescu, M.; Mahalov, A.; Moustaoui, M.; Wang, M.

    2014-05-01

    This article investigates the effect of air conditioning (AC) systems on air temperature and examines their electricity consumption for a semiarid urban environment. We simulate a 10 day extreme heat period over the Phoenix metropolitan area (U.S.) with the Weather Research and Forecasting model coupled to a multilayer building energy scheme. The performance of the modeling system is evaluated against 10 Arizona Meteorological Network weather stations and one weather station maintained by the National Weather Service for air temperature, wind speed, and wind direction. We show that explicit representation of waste heat from air conditioning systems improved the 2 m air temperature correspondence to observations. Waste heat release from AC systems was maximum during the day, but the mean effect was negligible near the surface. However, during the night, heat emitted from AC systems increased the mean 2 m air temperature by more than 1°C for some urban locations. The AC systems modified the thermal stratification of the urban boundary layer, promoting vertical mixing during nighttime hours. The anthropogenic processes examined here (i.e., explicit representation of urban energy consumption processes due to AC systems) require incorporation in future meteorological and climate investigations to improve weather and climate predictability. Our results demonstrate that releasing waste heat into the ambient environment exacerbates the nocturnal urban heat island and increases cooling demands.

  2. An Assessment of Indoor Air Quality before, during and after Unrestricted Use of E-Cigarettes in a Small Room

    Directory of Open Access Journals (Sweden)

    Grant O'Connell

    2015-05-01

    Full Text Available Airborne chemicals in the indoor environment arise from a wide variety of sources such as burning fuels and cooking, construction materials and furniture, environmental tobacco smoke as well as outdoor sources. To understand the contribution of exhaled e-cigarette aerosol to the pre-existing chemicals in the ambient air, an indoor air quality study was conducted to measure volatile organic compounds (including nicotine and low molecular weight carbonyls, polycyclic aromatic hydrocarbons, tobacco-specific nitrosamines and trace metal levels in the air before, during and after e-cigarette use in a typical small office meeting room. Measurements were compared with human Health Criteria Values, such as indoor air quality guidelines or workplace exposure limits where established, to provide a context for potential bystander exposures. In this study, the data suggest that any additional chemicals present in indoor air from the exhaled e-cigarette aerosol, are unlikely to present an air quality issue to bystanders at the levels measured when compared to the regulatory standards that are used for workplaces or general indoor air quality.

  3. An Assessment of Indoor Air Quality before, during and after Unrestricted Use of E-Cigarettes in a Small Room.

    Science.gov (United States)

    O'Connell, Grant; Colard, Stéphane; Cahours, Xavier; Pritchard, John D

    2015-05-06

    Airborne chemicals in the indoor environment arise from a wide variety of sources such as burning fuels and cooking, construction materials and furniture, environmental tobacco smoke as well as outdoor sources. To understand the contribution of exhaled e-cigarette aerosol to the pre-existing chemicals in the ambient air, an indoor air quality study was conducted to measure volatile organic compounds (including nicotine and low molecular weight carbonyls), polycyclic aromatic hydrocarbons, tobacco-specific nitrosamines and trace metal levels in the air before, during and after e-cigarette use in a typical small office meeting room. Measurements were compared with human Health Criteria Values, such as indoor air quality guidelines or workplace exposure limits where established, to provide a context for potential bystander exposures. In this study, the data suggest that any additional chemicals present in indoor air from the exhaled e-cigarette aerosol, are unlikely to present an air quality issue to bystanders at the levels measured when compared to the regulatory standards that are used for workplaces or general indoor air quality.

  4. Effectiveness of different air disinfection methods for blood collection room%不同空气消毒方法对采血室消毒的效果

    Institute of Scientific and Technical Information of China (English)

    朱岷

    2014-01-01

    目的:比较不同空气消毒方法对采血室内空气消毒的效果。方法分别采用紫外线灯、三氧消毒机及空气净化消毒器对机采血小板献血环境进行空气消毒,并采用自然沉降法于消毒前、消毒后及工作人员工作时采样,检测消毒效果。结果3种方法消毒后与消毒前比较,均能明显降低采血室内空气菌落数,消毒后室内空气菌落数均符合Ⅲ类环境标准要求。三氧消毒机组和紫外线灯组在工作人员工作状态下,空气菌落数迅速升高,至4h时,分别达(7.53±1.28)CFU/5 min·Φ90皿、(8.16±1.57)CFU/5 min·Φ90皿;而空气净化消毒器在人员流动的采血环境消毒4 h,空气中菌落数始终<4.0 CFU/5 min·Φ90皿。结论使用空气净化消毒器对采血室内空气持续消毒,可持续维持工作状态下采血室内的空气洁净度。%Objective To compare disinfection efficacy of three different air disinfection methods on the air in blood collection room.Methods Air disinfection in blood collection room was conducted by ultraviolet (UV)light, ozone disinfector (OD)and air purification disinfector respectively ,natural sedimentation method was used to take air specimens before ,after disinfection ,and during working condition of staff ,air disinfection efficacy was detec-ted.Results All three methods could decrease air bacterial count after disinfection ,the total number of bacteria in indoor air after disinfection met the class Ⅲ environmental requirement.Under working condition of staff ,the num-ber of bacteria of OD and UV light group increased rapidly,at 4 hours was (7.53±1.28)CFU/5 min·Φ90petri dish and (8.16±1.57)CFU/5 min·Φ90petri dish respectively;air purification disinfector disinfected for 4 hours under the condition of movement of personnel in blood collection environment,bacteria count still remained <4.0 CFU/5 min·Φ90petri dish.Conclusion Disinfecting continuously by air purification disinfector can ensure the

  5. Enabling Smart Air Conditioning by Sensor Development: A Review.

    Science.gov (United States)

    Cheng, Chin-Chi; Lee, Dasheng

    2016-11-30

    The study investigates the development of sensors, in particular the use of thermo-fluidic sensors and occupancy detectors, to achieve smart operation of air conditioning systems. Smart operation refers to the operation of air conditioners by the reinforcement of interaction to achieve both thermal comfort and energy efficiency. Sensors related to thermal comfort include those of temperature, humidity, and pressure and wind velocity anemometers. Improvements in their performance in the past years have been studied by a literature survey. Traditional occupancy detection using passive infra-red (PIR) sensors and novel methodologies using smartphones and wearable sensors are both discussed. Referring to the case studies summarized in this study, air conditioning energy savings are evaluated quantitatively. Results show that energy savings of air conditioners before 2000 was 11%, and 30% after 2000 by the integration of thermo-fluidic sensors and occupancy detectors. By utilizing wearable sensing to detect the human motions, metabolic rates and related information, the energy savings can reach up to 46.3% and keep the minimum change of predicted mean vote (∆PMV→0), which means there is no compromise in thermal comfort. This enables smart air conditioning to compensate for the large variations from person to person in terms of physiological and psychological satisfaction, and find an optimal temperature for everyone in a given space. However, this tendency should be evidenced by more experimental results in the future.

  6. Enabling Smart Air Conditioning by Sensor Development: A Review

    Directory of Open Access Journals (Sweden)

    Chin-Chi Cheng

    2016-11-01

    Full Text Available The study investigates the development of sensors, in particular the use of thermo-fluidic sensors and occupancy detectors, to achieve smart operation of air conditioning systems. Smart operation refers to the operation of air conditioners by the reinforcement of interaction to achieve both thermal comfort and energy efficiency. Sensors related to thermal comfort include those of temperature, humidity, and pressure and wind velocity anemometers. Improvements in their performance in the past years have been studied by a literature survey. Traditional occupancy detection using passive infra-red (PIR sensors and novel methodologies using smartphones and wearable sensors are both discussed. Referring to the case studies summarized in this study, air conditioning energy savings are evaluated quantitatively. Results show that energy savings of air conditioners before 2000 was 11%, and 30% after 2000 by the integration of thermo-fluidic sensors and occupancy detectors. By utilizing wearable sensing to detect the human motions, metabolic rates and related information, the energy savings can reach up to 46.3% and keep the minimum change of predicted mean vote (∆PMV→0, which means there is no compromise in thermal comfort. This enables smart air conditioning to compensate for the large variations from person to person in terms of physiological and psychological satisfaction, and find an optimal temperature for everyone in a given space. However, this tendency should be evidenced by more experimental results in the future.

  7. [Air kerma transmission factors of Scattered X-rays in the maze of a Linac room for lead shield].

    Science.gov (United States)

    Kato, Hideki

    2005-01-20

    Spectra of scattered X-rays in the maze of a Linac (X-ray energies of 4, 6, and 10 MV) room were estimated by means of the Monte Carlo simulation, and air kerma transmission factors of the X-rays scattered through a lead shield were evaluated based on those spectra. Spectra of scattered X-rays showed a maximum in the energy area below 200 keV. The higher the accelerated electron energy, also, the smaller the scattering angle that tended to spread to the higher energy area of the distribution of spectra. The air kerma transmission factor of 120 degrees scattered X-rays of 4 MV X-rays obtained in this study was larger than the transmission factors of 124 degrees scattered photons of (60)Co gamma rays through a lead shield given in ICRP. The air kerma transmission factors of 120 degrees scattered X-rays of 6 MV X-rays were smaller than the transmission factors of 90 degrees scattered photons of (60)Co gamma rays. The air kerma transmission factors of 120 degrees scattered X-rays of 10 MV X-rays was slightly larger than transmission factors of 90 degrees scattered photons of (60)Co gamma rays. Therefore, in the case of a 4 MV X-ray Linac room, the calculation method given in the "Manual of Practical Shield Calculation of Radiation Facilities (2000)" causes underestimation of leakage doses.

  8. Ventilation and air-conditioning concept for CNGS underground areas

    CERN Document Server

    Lindroos, J

    2002-01-01

    The aim of the CNGS project is to prove the existence of neutrino oscillation by generating an intense neutrino beam from CERN in the direction of the Gran Sasso laboratory in Italy, where two large neutrino detectors are built to detect the neutrinos. All the components for producing the neutrino beam will be situated in the underground tunnels, service galleries and chambers. The ventilation and air-conditioning systems installed in these underground areas have multiple tasks. Depending on the operating mode and structure to be air-conditioned, the systems are required to provide fresh air, cool the machine, dehumidify areas housing sensible equipment or assure the smoke removal in a case of a fire. This paper presents the technical solutions foreseen to meet these requirements.

  9. Critical condition study of borehole stability during air drilling

    Institute of Scientific and Technical Information of China (English)

    Deng Jingen; Zou Linzhan; Tan Qiang; Yan Wei; Gao Deli; Zhang Hanlin; Yan Xiuliang

    2009-01-01

    The purpose of this paper is to establish the existence of the critical condition of borehole stability during air drilling.Rock Failure Process Analysis Code2D was used to set up a damage model of the borehole excavated in strain-softening rock.Damage evolution around the borehole was studied by tracking acoustic emission.The study indicates that excavation damaged zone (EDZ) is formed around borehole because of stress concentration after the borehole is excavated.There is a critical condition for borehole stability; the borehole will collapse when the critical damage condition is reached.The critical condition of underground excavation exists not only in elastic and ideal plastic material but in strain-softening material as well.The research is helpful to developing an evaluation method of borehole stability during air drilling.

  10. Hospital-acquired infections associated with poor air quality in air-conditioned environments

    Directory of Open Access Journals (Sweden)

    Daniela Pinheiro da Silva

    2014-04-01

    Full Text Available Backgound and Objectives: Individuals living in cities increasingly spend more time indoors in air-conditioned environments. Air conditioner contamination can be caused by the presence of aerosols from the external or internal environment, which may be associated with disease manifestations in patients present in this type of environment. Therefore, the aim of this review was to assess the air quality in air-conditioned hospital environments as a risk factor for hospital-acquired infections – HAI – as the air can be a potential source of infection, as well as assess the exposure of professionals and patients to different pollutants. Material and Methods: A literature review was performed in the LILACS, MEDLINE, SCIELO, SCIENCE DIRECT databases, CAPES thesis database and Ministry of Health – Brazil, including studies published between 1982 and 2008. The literature search was grouped according to the thematic focus, as follows: ventilation, maintenance and cleaning of systems that comprehend the environmental quality standard. Discussion and Conclusion: Outbreaks of hospital-acquired infections associated with Aspergillus, Acinetobacter, Legionella, and other genera such as Clostridium and Nocardia, which were found in air conditioners, were observed, thus indicating the need for air-conditioning quality control in these environments.

  11. Assessment of indoor air quality in comparison using air conditioning and fan system in printing premise

    Directory of Open Access Journals (Sweden)

    Ramlan Nazirah

    2017-01-01

    Full Text Available Printers contribute to various emissions consist with chemical contaminants. High concentration of the particulate matter can cause serious health problems. This study focuses on the indoor air quality in printing premise unit in Universiti Tun Hussein Onn, Malaysia. Field testing involving air sampling methods were taken from 900 hours to 1600 hours, for every 30 minutes using physical measurement which is Multi-Channel Air Quality Monitor (YESAIR, E-Sampler and Ozone Meter. Air sampling was recorded based on one sampling point and most suitable point for production. A comparison based on different ventilation using fan and air-conditioning were also taken and results is being compared based on OSHA and NIOSH standards. Besides that, the statistical analysis is being conducted in order to predict the effect on number of printers. From the result, the O3 concentrations show, 10% reduced for printing premise using fan ventilation compared to air-conditioning but remain the same value for PM2.5. The concentration of O3 increased when the number of printers decreased, while the concentration of PM2.5 increased the increase of printers number. Overall, the use of fan in printing premise is more suggested since the level is slightly lower than the printing premise using air-conditioning.

  12. Air Distribution and Ventilation Effectiveness in a room with Floor/Ceiling Heating and Mixing/Displacement Ventilation

    DEFF Research Database (Denmark)

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

    2014-01-01

    The present study investigated different combinations of floor/ceiling heating with mixing/displacement ventilation and their impacts on the indoor air distribution and ventilation effectiveness. Measurements were performed in a room during heating season in December. The results show that indoor...... combined with floor/ceiling heating systems is approximately equal to 1.0, and ventilation effectiveness of displacement ventilation system combined with floor/ceiling heating systems ranges from 1.0 to 1.2. The floor/ceiling heating systems combined with mixing ventilation system have more uniform indoor...... air distribution but smaller ventilation effectiveness compared with the floor/ceiling heating systems combined with displacement ventilation system. With regard to the building heat loss increased by non-uniform indoor air distribution and small ventilation effectiveness, there should be an optimal...

  13. An Analysis of the Air Conditioning, Refrigerating and Heating Occupation.

    Science.gov (United States)

    Frass, Melvin R.; Krause, Marvin

    The general purpose of the occupational analysis is to provide workable, basic information dealing with the many and varied duties performed in the air conditioning, refrigerating, and heating occupation. The document opens with a brief introduction followed by a job description. The bulk of the document is presented in table form. Six duties are…

  14. Air Conditioning, Heating, and Refrigeration. Competency-Based Curriculum Manual.

    Science.gov (United States)

    Gourley, Frank A., Jr.

    This manual was developed to serve as an aid to administrators and instructors involved with postsecondary air conditioning, heating, and refrigeration programs. The first of six chapters contains general information on program implementation, the curriculum design, facilities and equipment requirements, and textbooks and references. Chapter 2…

  15. Step response and frequency response of an air conditioning system

    NARCIS (Netherlands)

    Crommelin, R.D.; Jackman, P.J.

    1978-01-01

    A system of induction units of an existing air conditioning system has been analyzed with respect to its dynamic properties. Time constants were calculated and measured by analogue models. Comparison with measurements at the installation itself showed a reasonable agreement. Frequency responses were

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

    CERN Document Server

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

    2012-01-01

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

  17. State Skill Standards: Heating, Ventilation, Air Conditioning, and Refrigeration

    Science.gov (United States)

    Ball, Larry; Soukup, Dennis

    2006-01-01

    The Department of Education has undertaken an ambitious effort to develop statewide career and technical education skill standards. The standards in this document are for Heating, Ventilation, Air Conditioning and Refrigeration (HVAC&R) programs and are designed to clearly state what the student should know and be able to do upon completion of…

  18. Heating, Air-Conditioning, and Refrigeration Technician. National Skill Standards.

    Science.gov (United States)

    Vocational Technical Education Consortium of States, Decatur, GA.

    This guide contains information on the knowledge and skills identified by industry as essential to the job performance of heating, air-conditioning, and refrigeration technicians. It is intended to assist training providers in public and private institutions, as well as in industry, to develop and implement training that will provide workers with…

  19. Solar air conditioning researches and demonstrations in China

    Institute of Scientific and Technical Information of China (English)

    Wang Ruzhu

    2009-01-01

    This paper mainly shows the demonstration of solar air conditioning systems in China, which includes LiBr-H2O absorption cooling, silica gel-water adsorption chiller, desiccant cooling and hybrid integrated energy systems for buildings. The match of solar collector types and chiller types have been discussed and suggested.

  20. Modelling and simulation of air-conditioning cycles

    Science.gov (United States)

    Rais, Sandi; Kadono, Yoshinori; Murayama, Katsunori; Minakuchi, Kazuya; Takeuchi, Hisae; Hasegawa, Tatsuya

    2017-02-01

    The heat-pump cycle for air conditioning was investigated both numerically and experimentally by evaluating the coefficient of performance (COP) under Japanese Industrial Standard (JIS B 8619:1999) and ANSI/AHRI standard 750-2007 operating conditions. We used two expansion valve coefficients Cv_{(φ)} = 0.12 for standard operating conditions (Case 1) approaching 1.3 MPa at high pressure and 0.2 MPa at low pressure, and Cv_{(φ)} = 0.06 namely poor operating conditions (Case 2). To improve the performance of the air conditioner, we compared the performance for two outside air temperatures, 35 and 40 °C (Case 3). The simulation and experiment comparison resulted the decreasing of the COP for standard operating condition is equal to 14 %, from 3.47 to 2.95 and a decrease of the cooling capacity is equal to 18 %, from 309.72 to 253.53 W. This result was also occurred in poor operating condition which the COP was superior at 35 °C temperature.

  1. Experimental study of air distribution and ventilation effectiveness in a room heated by warm air and/or floor heating

    DEFF Research Database (Denmark)

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

    2010-01-01

    The levels of required ventilation depend on the criteria for indoor air quality in existing standards and guidelines. On top of that, the resulting ventilation in air changes per hour is depending on the ventilation effectiveness. In the standard CR 1752 the recommended values for ventilation...

  2. Thermal comfort and indoor air quality in rooms with integrated personalized ventilation and under-floor air distribution systems

    DEFF Research Database (Denmark)

    Li, Ruixin; Sekhar ., S. C.; Melikov, Arsen Krikor

    2011-01-01

    A comprehensive study comprising physical measurements and human subject experiments was conducted to explore the potential for improving occupants' thermal comfort and indoor air quality (IAQ) using a personalized ventilation (PV) system combined with an under-floor air distribution(UFAD) system...

  3. Feedback linearization based control of a variable air volume air conditioning system for cooling applications.

    Science.gov (United States)

    Thosar, Archana; Patra, Amit; Bhattacharyya, Souvik

    2008-07-01

    Design of a nonlinear control system for a Variable Air Volume Air Conditioning (VAVAC) plant through feedback linearization is presented in this article. VAVAC systems attempt to reduce building energy consumption while maintaining the primary role of air conditioning. The temperature of the space is maintained at a constant level by establishing a balance between the cooling load generated in the space and the air supply delivered to meet the load. The dynamic model of a VAVAC plant is derived and formulated as a MIMO bilinear system. Feedback linearization is applied for decoupling and linearization of the nonlinear model. Simulation results for a laboratory scale plant are presented to demonstrate the potential of keeping comfort and maintaining energy optimal performance by this methodology. Results obtained with a conventional PI controller and a feedback linearizing controller are compared and the superiority of the proposed approach is clearly established.

  4. Influence of a Cooled Ceiling on Indoor Air Quality in a Displacement Ventilated Room Examined by Means of Computational Fluid Dynamics

    DEFF Research Database (Denmark)

    Brohus, Henrik

    The influence of a cooled ceiling on the air quality in a displacement ventilated room is examined by means of CFD. The objective of the study is to examine how the flow field in a displacement ventilated room is influenced when a cooled ceiling removes a major part of the total heat I9ad...

  5. Nasal air-conditioning after partial turbinectomy: myths versus facts.

    Science.gov (United States)

    Tsakiropoulou, Evangelia; Vital, Victor; Constantinidis, Jannis; Kekes, George

    2015-01-01

    Turbinectomy, although a common procedure, is often accused of having a negative impact in all nasal functions. This study is the first in vivo study that evaluates objectively the effect of partial turbinectomy on nasal air-conditioning capacity. In total, 57 patients with prior partial inferior turbinectomy and 28 healthy controls were examined. Intranasal temperature and humidity values were measured at the level of the head of inferior and middle turbinate. Nasal patency was evaluated by means of acoustic rhinometry. The clinical assessment was completed with nasal endoscopy and the Nasal Obstruction Symptom Evaluation questionnaire for subjective evaluation of nasal patency. Significant changes of temperature were found in both detection sites with 13% reduced heating capacity of the air at the level of the inferior and 19% at the level of the middle turbinate, respectively. No similar results were found for humidity measurements. No correlations were found between air-conditioning values and acoustic rhinometry results for both study groups. Nasal endoscopy revealed normal healing in all patients. No major complications were reported by the patients. Their subjective ratings of nasal obstruction were similar to healthy controls. Partial turbinectomy seems to have a negative impact on intranasal air heating but not to humidification. This effect has no impact on clinical condition and subjective perception of surgical outcome.

  6. A survey of energy efficient strategies for effective air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rabghi, O.M.; Akyurt, M.M. [King Abdulaziz University, Jeddah (Saudi Arabia). Dept. of Mechanical Engineering

    2004-07-01

    Several methods are presented for lowering the energy consumed during air conditioning of buildings. Some of these strategies can be implemented during the design stage; others can be used to retrofit existing AC systems; and still others can be applied with hardly any changes on existing equipment. The methods that are discussed include heat recovery and utilization, absorption refrigeration systems, thermal cool storage, liquid (refrigerant) pressure amplification, reprogramming of the AC control systems, economical methods of removal of moisture from the air and initiation of awareness programs for the conservation of A/C energy. (author)

  7. Air conditioning and energy conservation. Improved space HVAC systems. Case studies: Office buildings, hotels, shopping centers, skyscrapers, industrial plants

    Energy Technology Data Exchange (ETDEWEB)

    Heiner, H.

    1988-08-01

    Rising energy prices and an increasing demand for comfortable rooms account for the importance attached to the windows and glass used for office buildings, hotels and industrial plants. Both windows and glass have a considerable influence on the thermal behavior and air conditioning of buildings. Among the latest developments are precious metal-coated insulating panes. Selected gases allow to reduce the total thickness of insulating glass and improve noise insulation. The case studies presented refer to the energy-saving air conditioning and space heating, heat recovery and cooling of rooms as well as to the respective control systems. Investigations into the specific energy consumption of building shells reveal the considerable space/tap water heating energy conservation potentials remaining to be utilized.

  8. Splashing phenomena of room temperature liquid metal droplet striking on the pool of the same liquid under ambient air environment

    CERN Document Server

    Li, Haiyan; Wang, Lei; Gao, Yunxia; Liu, Jing

    2013-01-01

    In this article, the fluid dynamics of room temperature liquid metal (RTLM) droplet impacting onto a pool of the same liquid in ambient air was investigated. A series of experiments were conducted in order to disclose the influence of the oxidation effect on the impact dynamics. The droplet shape and impact phenomenology were recorded with the aid of a high-speed digital camera. The impact energy stored in the splash structures was estimated via a theoretical model and several morphological parameters obtained from instantaneous images of the splash. It was observed that the droplet shape and the splashing morphology of RTLM were drastically different from those of water, so was the impact dynamics between room temperature LM pool and high temperature LM pool. The energy analysis disclosed that the height of the jet is highly sensitive to the viscosity of the fluid, which is subjected to the oxidation effect and temperature effect simultaneously, and thus perfectly explained the phenomena. These basic finding...

  9. Dispersal of Exhaled Air and Personal Exposure in Displacement Ventilated Rooms

    DEFF Research Database (Denmark)

    Bjørn, Erik; Nielsen, Peter Vilhelm

    2002-01-01

    The influence of the human exhalation on flow fields, contaminant distributions, and personal exposures in displacement ventilated rooms is studied together with the effects of physical movement. Experiments are conducted in full-scale test rooms with life-sized breathing thermal manikins...... of the exhalation flow is no acute problem in most normal ventilation applications. However, exhalation and local effects caused by movement may be worth considering if one wishes to contain contaminants in certain areas, as in the case of tobacco smoking, in hospitals and clinics, or in certain industries....

  10. Air distribution in a multi-occupant room with mixing or displacement ventilation with or without floor or ceiling heating

    DEFF Research Database (Denmark)

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

    2015-01-01

    This study performed a comparative analysis of the air distribution in a multi-occupant room with mixing or displacement ventilation and the effect of adding floor or ceiling heating to each of them. The vertical distribution of indoor air temperature and velocity in the occupied zone......; the mean local turbulence intensity varied from 12.0% to 14.1% with mixing ventilation with or without floor or ceiling heating, and the corresponding values were 1.5°C to 2.5°C and 7.3% to 9.8% with displacement ventilation with or without floor or ceiling heating. Mean air distribution effectiveness...... varied from 0.93 to 1.0 for mixing ventilation and from 1.06 to 1.14 for displacement ventilation with or without floor or ceiling heating. The results are relevant to the design and control of mixing and displacement ventilation with or without floor or ceiling heating in a multi-occupant room....

  11. Kerma rate evaluation in the air in a room interventional cardiology; Avaliacao da taxa de Kerma no ar em uma sala de cardiologia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Real, Jessica V.; Luz, Renata M. da, E-mail: jessica.real@pucrs.br, E-mail: renata.luz@pucrs.br [Hospital Sao Lucas (HSL/PUCRS), Porto Alegre, RS (Brazil); Fröhlich, Bruna D.; Silva, Ana Maria Marques da, E-mail: bruna.frohlich@acad.pucrs.br, E-mail: ana.marques@pucrs.br [Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil)

    2014-07-01

    In recent years, the number of interventional cardiology procedures is increasing. However, due to the long time of fluoroscopy in these procedures, care teams can receive high doses of radiation. The radiation scattered by the patient is not uniform, and their assessment is of utmost importance. This study aimed to estimate and map the kerma rate in the air at the time of the gonads, in an interventional cardiology room, seeking to optimize the dose absorbed by individuals occupationally exposed to ionizing radiation. For data collection, the room was divided into quadrants of 1m{sup 2}, totaling 40 collection points. The simulator was positioned so that its entry surface was located in the interventional reference point. Were chosen the conditions that simulate angiography and angioplasty procedures performed in the service. The data were obtained for height of 1 meter, gonad region. The results obtained for kerma rates in air, in quadrants, show that higher measured values was in the vicinity of the X-ray tube. Has been found that the medical staff are more exposed, because of its location during the procedure, around the table. The law of the inverse square distance of the farthest points of the X-ray tube were verified.

  12. Production and exploitation of thermoelectric air conditioning systems for vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Dudnik, Vladimir [Conditioner Ltd, Gagarin (Russian Federation); Skipidarov, Sergey [SCTB NORD, Moskau (Russian Federation); Rapp, Axel [Quick-Ohm Kupper und Co. GmbH, Wuppertal-Cronenberg (Germany)

    2011-07-01

    In the paper more than 10-year experience of thermoelectric devices batch manufacturing is described for the field of their obvious advantages. This field of application includes thermoelectric air conditioning systems which have shown their competitive advantage when used in vehicles of elevated vibration where compressor equipment application is difficult because of leakage of refrigerant. Energy characteristics of air conditioners for tractors, excavators, tanks, locomotive driver's cabins and cranes are described. Thermoelectric (TE) air conditioners mechanical test data as well as operation experience in vehicles are presented. It is shown that consumption of tellurium, which is a strategic component for thermoelectric materials manufacturing, may be lowered to 40 grams per 1 kW of cooling. (orig.)

  13. Effects of Air Pollution on Hospital Emergency Room Visits for Respiratory Diseases: Urban-Suburban Differences in Eastern China.

    Science.gov (United States)

    Liu, Peng; Wang, Xining; Fan, Jiayin; Xiao, Wenxin; Wang, Yan

    2016-03-19

    A study on the relationships between ambient air pollutants (PM2.5, SO₂ and NO₂) and hospital emergency room visits (ERVs) for respiratory diseases from 2013 to 2014 was performed in both urban and suburban areas of Jinan, a heavily air-polluted city in Eastern China. This research was analyzed using generalized additive models (GAM) with Poisson regression, which controls for long-time trends, the "day of the week" effect and meteorological parameters. An increase of 10 μg/m³ in PM2.5, SO₂ and NO₂ corresponded to a 1.4% (95% confidence interval (CI): 0.7%, 2.1%), 1.2% (95% CI: 0.5%, 1.9%), and 2.5% (95%: 0.8%, 4.2%) growth in ERVs for the urban population, respectively, and a 1.5% (95%: 0.4%, 2.6%), 0.8% (95%: -0.7%, 2.3%), and 3.1% (95%: 0.5%, 5.7%) rise in ERVs for the suburban population, respectively. It was found that females were more susceptible than males to air pollution in the urban area when the analysis was stratified by gender, and the reverse result was seen in the suburban area. Our results suggest that the increase in ERVs for respiratory illnesses is linked to the levels of air pollutants in Jinan, and there may be some urban-suburban discrepancies in health outcomes from air pollutant exposure.

  14. Magnetic Refrigeration Technology for High Efficiency Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Boeder, A; Zimm, C

    2006-09-30

    Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate

  15. Velocity Distribution in a Room Ventilated by Displacement Ventilation and Wall-Mounted Air Terminal Devices

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    2000-01-01

    The article describes experiments with wall-mounted air terminal devices. The airflow from an air terminal device influences the occupants' thermal comfort and, therefore, it is important to develop an expression for this flow in the occupied zone. The velocity at the floor is influenced by the f...

  16. Major differences observed in transcript profiles of blueberry during cold acclimation under field and cold room conditions.

    Science.gov (United States)

    Dhanaraj, Anik L; Alkharouf, Nadim W; Beard, Hunter S; Chouikha, Imed B; Matthews, Benjamin F; Wei, Hui; Arora, Rajeev; Rowland, Lisa J

    2007-02-01

    Our laboratory has been working toward increasing our understanding of the genetic control of cold hardiness in blueberry (Vaccinium section Cyanococcus) to ultimately use this information to develop more cold hardy cultivars for the industry. Here, we report using cDNA microarrays to monitor changes in gene expression at multiple times during cold acclimation under field and cold room conditions. Microarrays contained over 2,500 cDNA inserts, approximately half of which had been picked and single-pass sequenced from each of two cDNA libraries that were constructed from cold acclimated floral buds and non-acclimated floral buds of the fairly cold hardy cv. Bluecrop (Vaccinium corymbosum L.). Two biological samples were examined at each time point. Microarray data were analyzed statistically using t tests, ANOVA, clustering algorithms, and online analytical processing (OLAP). Interestingly, more transcripts were found to be upregulated under cold room conditions than under field conditions. Many of the genes induced only under cold room conditions could be divided into three major types: (1) genes associated with stress tolerance; (2) those that encode glycolytic and TCA cycle enzymes, and (3) those associated with protein synthesis machinery. A few of the genes induced only under field conditions appear to be related to light stress. Possible explanations for these differences are discussed in physiological context. Although many similarities exist in how plants respond during cold acclimation in the cold room and in the field environment, there are major differences suggesting caution should be taken in interpreting results based only on artificial, cold room conditions.

  17. Development of nanolubricant automotive air conditioning (AAC test rig

    Directory of Open Access Journals (Sweden)

    Redhwan A.A.M.

    2017-01-01

    Full Text Available Nanolubricant been introduced in compressor might improve the performance of automotive air conditioning system. Prior testing of the nanolubricant enhancement performance, an automotive air conditioning (AAC system test rig base on compact car has to be developed; therefore this paper presented the development process of AAC test rig. There are 15 thermocouples, 2 pressure gauges and power analyzer were assembled on the system in order to analyse its performance. The experiment was conducted with four different charged of refrigerant. The charging was based on initial weight charged. At each quantity of refrigerant charge, performance of the AAC system was evaluated by determining three important parameters which is cooling capacity, compressor work and coefficient of performance (COP. The maximum average COP is achieved at 900 RPM is 7.07. The average and maximum COP enhancement of 7.07 % and 13.34 % were achieved by applying SiO2 nanolubricant inside the compressor.

  18. Working fluid concentration measurement in solar air conditioning systems

    Energy Technology Data Exchange (ETDEWEB)

    Romero, R.J.; Basurto-Pensado, M.A. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001. Col. Chamilpa, C.P. 62210, Cuernavaca, Morelos (Mexico); Jimenez-Heredia, A.H.; Sanchez-Mondragon, J.J. [Departamento de Optica, Instituto Nacional de Astrofisica Optica y Electronica, Luis Enrique Erro No. 1, Tonantzintla, Apartado Postal 51 y 216, C.P. 72000, Puebla (Mexico)

    2006-02-15

    In order to evaluate on-line corrosive electrolyte concentration in solar air conditioning systems, an optical technique to determine the concentration is being proposed. With this optical sensing method, it is possible to measure the percentage concentration of the aqueous corrosive lithium bromide solution at temperatures ranging from 25{sup o}C to 70{sup o}C and a maximum concentration of 60%. The measurement system is based on the refractive index of the solution and the data correlation, at several temperature and concentration values. The results of this work present a direct method for concentration measurement of corrosive liquids and also show the correlation among the three parameters: refractive index, temperature and weight concentration. This correlation can be used to develop the optical device for solar air conditioning systems to control and improve efficiency. (author)

  19. Weather conditions and visits to the medical wing of emergency rooms in a metropolitan area during the warm season in Israel: a predictive model

    Science.gov (United States)

    Novikov, Ilya; Kalter-Leibovici, Ofra; Chetrit, Angela; Stav, Nir; Epstein, Yoram

    2012-01-01

    Global climate changes affect health and present new challenges to healthcare systems. The aim of the present study was to analyze the pattern of visits to the medical wing of emergency rooms (ERs) in public hospitals during warm seasons, and to develop a predictive model that will forecast the number of visits to ERs 2 days ahead. Data on daily visits to the ERs of the four largest medical centers in the Tel-Aviv metropolitan area during the warm months of the year (April-October, 2001-2004), the corresponding daily meteorological data, daily electrical power consumption (a surrogate marker for air-conditioning), air-pollution parameters, and calendar information were obtained and used in the analyses. The predictive model employed a time series analysis with transitional Poisson regression. The concise multivariable model was highly accurate ( r 2 = 0.819). The contribution of mean daily temperature was small but significant: an increase of 1°C in ambient temperature was associated with a 1.47% increase in the number of ER visits ( P electrical power consumption significantly attenuated the effect of weather conditions on ER visits by 4% per 1,000 MWh ( P forecasting the number of visits to ERs 2 days ahead. The marginal effect of temperature on the number of ER visits can be attributed to behavioral adaptations, including the use of air-conditioning.

  20. Solar air-conditioning-active, hybrid and passive

    Energy Technology Data Exchange (ETDEWEB)

    Yellott, J. I.

    1981-04-01

    After a discussion of summer air conditioning requirements in the United States, active, hybrid, and passive cooling systems are defined. Active processes and systems include absorption, Rankine cycle, and a small variety of miscellaneous systems. The hybrid solar cooling and dehumidification technology of desiccation is covered as well as evaporative cooling. The passive solar cooling processes covered include convective, radiative and evaporative cooling. Federal and state involvement in solar cooling is then discussed. (LEW)

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

    Science.gov (United States)

    2016-09-01

    Approved for public release: distribution unlimited TDS-NAVFAC-EXWC-PW-1603 Sep 2016 HVAC ; Heating, Ventilation, Air Conditioning - Aerosol...energy consumption, depending on the HVAC system type and the location of the ducts that were sealed. The cost effectiveness of the technology is...Although several studies have been done on the effectiveness of sealing leaky HVAC ductwork with aerosol duct sealant, few studies have been done on

  2. Control Techniques in Heating, Ventilating and Air Conditioning Systems

    OpenAIRE

    H. Mirinejad; Sadati, S.H.; M Ghasemian; H. Torab

    2008-01-01

    Problem statement: Heating, Ventilating and Air Conditioning (HVAC) systems are among the main installations in residential, commercial and industrial buildings. The purpose of the HVAC systems is normally to provide a comfortable environment in terms of temperature, humidity and other environmental parameters for the occupants as well as to save energy. Achieving these objectives requires a suitable control system design. Approach: In this overview, thermal comfort level and ISO comfort fiel...

  3. Initial proof-of-principle for near room temperature Xe and Kr separation from air with MOFs

    Energy Technology Data Exchange (ETDEWEB)

    Thallapally, Praveen K.; Strachan, Denis M.

    2012-06-06

    Materials were developed and tested in support of the U.S. Department of Energy, Office of Nuclear Energy, Fuel Cycle Technology Separations and Waste Forms Campaign. Specifically, materials are being developed for the removal of Xenon and krypton from gaseous products of nuclear fuel reprocessing unit operations. During FY 2012, Three Metal organic framework (MOF) structures were investigated in greater detail for the removal and storage of Xe and Kr from air at room temperature. Our breakthrough measurements on Nickel based MOF could capture and separate parts per million levels of Xe from Air (40 ppm Kr, 78% N2, 21% O2, 0.9% Ar, 0.03% CO2). Similarly, the selectivity can be changed from Xe > Kr to Xe < Kr simply by changing the temperature in another MOF. Also for the first time we estimated the cost of the metal organic frameworks in bulk.

  4. Persistence of initial conditions in continental scale air quality ...

    Science.gov (United States)

    This study investigates the effect of initial conditions (IC) for pollutant concentrations in the atmosphere and soil on simulated air quality for two continental-scale Community Multiscale Air Quality (CMAQ) model applications. One of these applications was performed for springtime and the second for summertime. Results show that a spin-up period of ten days commonly used in regional-scale applications may not be sufficient to reduce the effects of initial conditions to less than 1% of seasonally-averaged surface ozone concentrations everywhere while 20 days were found to be sufficient for the entire domain for the spring case and almost the entire domain for the summer case. For the summer case, differences were found to persist longer aloft due to circulation of air masses and even a spin-up period of 30 days was not sufficient to reduce the effects of ICs to less than 1% of seasonally-averaged layer 34 ozone concentrations over the southwestern portion of the modeling domain. Analysis of the effect of soil initial conditions for the CMAQ bidirectional NH3 exchange model shows that during springtime they can have an important effect on simulated inorganic aerosols concentrations for time periods of one month or longer. The effects are less pronounced during other seasons. The results, while specific to the modeling domain and time periods simulated here, suggest that modeling protocols need to be scrutinized for a given application and that it cannot be assum

  5. High Technology Centrifugal Compressor for Commercial Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ruckes, John

    2006-04-15

    R&D Dynamics, Bloomfield, CT in partnership with the State of Connecticut has been developing a high technology, oil-free, energy-efficient centrifugal compressor called CENVA for commercial air conditioning systems under a program funded by the US Department of Energy. The CENVA compressor applies the foil bearing technology used in all modern aircraft, civil and military, air conditioning systems. The CENVA compressor will enhance the efficiency of water and air cooled chillers, packaged roof top units, and other air conditioning systems by providing an 18% reduction in energy consumption in the unit capacity range of 25 to 350 tons of refrigeration The technical approach for CENVA involved the design and development of a high-speed, oil-free foil gas bearing-supported two-stage centrifugal compressor, CENVA encompassed the following high technologies, which are not currently utilized in commercial air conditioning systems: Foil gas bearings operating in HFC-134a; Efficient centrifugal impellers and diffusers; High speed motors and drives; and System integration of above technologies. Extensive design, development and testing efforts were carried out. Significant accomplishments achieved under this program are: (1) A total of 26 builds and over 200 tests were successfully completed with successively improved designs; (2) Use of foil gas bearings in refrigerant R134a was successfully proven; (3) A high speed, high power permanent magnet motor was developed; (4) An encoder was used for signal feedback between motor and controller. Due to temperature limitations of the encoder, the compressor could not operate at higher speed and in turn at higher pressure. In order to alleviate this problem a unique sensorless controller was developed; (5) This controller has successfully been tested as stand alone; however, it has not yet been integrated and tested as a system; (6) The compressor successfully operated at water cooled condensing temperatures Due to temperature

  6. Room Acoustics

    Science.gov (United States)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  7. Average Air Temperature Inside a Room With a Semitransparent Wall With a Solar Control Film: Effect of The Emissivity

    Directory of Open Access Journals (Sweden)

    J. Xamán

    2012-06-01

    Full Text Available In this paper a theoretical study on conjugated heat transfer (natural convection, radiation and conduction in a squareroom (cavity with turbulent flow is presented, taking into account variation on the opaque wall emissivity. The room isformed by an isothermal vertical wall, two adiabatic horizontal walls and a semitransparent wall with and without acontrol solar radiation film. The governing equations for turbulent flow in 2D were solved using a finite volumeformulation and k- turbulent model. Results for an isothermal wall at 21°C and an external temperature of 35°C arepresented. The size of the room is 4.0 m length and height and the solar radiation falling directly on thesemitransparent wall was 750 W/m2 (AM2. The emissivity of the opaque walls was varied between 0.1 ≤ * ≤ 1.0.Results show that, based on the air average temperature and the effective heat flux inside the room, the solar controlfilm under study was advantageous for energy saving purposes, for emissivity values of * ≤ 0.46. A correlation onthis system for the heat transfer as a function of the emissivities was determined.

  8. Exposure to Exhaled Air from a Sick Occupant in a Two-Bed Hospital Room with Mixing Ventilation: Effect of Posture of Doctor and Air Change Rate

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho Dimitrov; Melikov, Arsen Krikor; Barova, Mariya

    2013-01-01

    Full-scale measurements were performed in a climate chamber set as a two-bed hospital room, ventilated at 3, 6 and 12 ACH with overhead mixing ventilation. Air temperature was kept constant at 22 °C. Two breathing thermal manikins were used to mimic a sick patient lying on one side in one...... of the beds and a doctor. A thermal dummy mimicked an exposed patient lying in the second bed. The doctor either stood up or sat in a chair 0.55 m facing the sick patient. The ‘sick patient’ was exhaling through the mouth and inhaling from the nose. Tracer gas (R 134A) was mixed with the exhaled air to mimic...

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

    Directory of Open Access Journals (Sweden)

    Rajagopalan Parameshwaran

    2008-01-01

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

  10. Effect of Intake Air Filter Condition on Vehicle Fuel Economy

    Energy Technology Data Exchange (ETDEWEB)

    Norman, Kevin M [ORNL; Huff, Shean P [ORNL; West, Brian H [ORNL

    2009-02-01

    The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy and the U.S. Environmental Protection Agency (EPA) jointly maintain a fuel economy website (www.fueleconomy.gov), which helps fulfill their responsibility under the Energy Policy Act of 1992 to provide accurate fuel economy information [in miles per gallon (mpg)] to consumers. The site provides information on EPA fuel economy ratings for passenger cars and light trucks from 1985 to the present and other relevant information related to energy use such as alternative fuels and driving and vehicle maintenance tips. In recent years, fluctuations in the price of crude oil and corresponding fluctuations in the price of gasoline and diesel fuels have renewed interest in vehicle fuel economy in the United States. (User sessions on the fuel economy website exceeded 20 million in 2008 compared to less than 5 million in 2004 and less than 1 million in 2001.) As a result of this renewed interest and the age of some of the references cited in the tips section of the website, DOE authorized the Oak Ridge National Laboratory (ORNL) Fuels, Engines, and Emissions Research Center (FEERC) to initiate studies to validate and improve these tips. This report documents a study aimed specifically at the effect of engine air filter condition on fuel economy. The goal of this study was to explore the effects of a clogged air filter on the fuel economy of vehicles operating over prescribed test cycles. Three newer vehicles (a 2007 Buick Lucerne, a 2006 Dodge Charger, and a 2003 Toyota Camry) and an older carbureted vehicle were tested. Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in

  11. Report of study 7.3: cooling and air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Russo, F.

    2000-07-01

    This report describes the results of the study carried out by the study group 7.3 in the triennium 1997-2000. The study was focused on industrial refrigeration and air conditioning for the large building utilising natural gas. The goal of this study, carried out in collaboration of the members of study group 7.3, was to analyse the markets of industrial refrigeration and air conditioning for large buildings to identify possibilities to increase the natural gas share in these sectors. The available technology in the two sectors of the market are described in a single section, i.e. the 'State of the art of the technology'. In this section, technical characteristics, applications, performances, new developments and others topics are discussed for absorbers, gas engines, gas turbines and fuel cells. In the 'Industrial Refrigeration' section an analysis of the present global market for the industrial sector is presented. Economics, advantages and barriers to gas units compared with the electrical units are discussed. Information on existing industrial plants, possible application options and new technology developments are described as well. The 'Air conditioning for the large building' section deals with offices, hotels, commercial buildings, hospitals and shopping centres with a cooling capacity of 350 kW or higher. It appears that the use of natural gas for cooling of large buildings has been increasing during the last decade, thanks to the greater availability of natural gas and the development of new technologies. A marketing survey of gas air-conditioning was carried out in cooperation with a group of Intergas Marketing. Based on the survey, the report describes the market position of natural gas relative to electricity. It provides the strategic prospects for further developing natural gas as a competitive option for air-conditioning of large buildings using a combination of state-of-the-art technologies. It is important to highlight

  12. A mixed air/air and air/water heat pump system ensures the air-conditioning of a cinema; Un systeme mixte PAC air/air et air/eau climatise un cinema

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-03-01

    This article presents the air conditioning system of a new cinema complex of Boulogne (92, France) which comprises a double-flux air processing plant and two heat pumps. Each heat pump has two independent refrigerating loops: one with a air condenser and the other with a water condenser. This system allows to limit the power of the loop and to reduce the size of the cooling tower and of the vertical ducts. This article describes the technical characteristics of the installation: thermodynamic units, smoke clearing, temperature control, air renewing. (J.S.)

  13. Membrane-based air conditioning. Decentral desiccant cooling; Membranbasierte Raumklimatisierung. Dezentrale sorptionsgestuetzte Klimatisierung

    Energy Technology Data Exchange (ETDEWEB)

    Rosenbaum, Hannes [Institut fuer Luft- und Kaeltetechnik gGmbH, Dresden (Germany)

    2012-04-15

    Semipermeable membranes have a considerable potential use in air conditioning systems due to their properties. As water resistant but water vapor permeable functional separation layers, they allow desiccant air-conditioning processes in decentral air conditioning systems and a condensate-free air dehumidification at cooling ceiling elements. (orig.)

  14. Subjective rating and objective evaluation of the acoustic and indoor climate conditions in video conferencing rooms

    DEFF Research Database (Denmark)

    Hauervig-Jørgensen, Charlotte; Jeong, Cheol-Ho; Toftum, Jørn

    2017-01-01

    Today, face-to-face meetings are frequently replaced by video conferences in order to reduce costs and carbon footprint related to travels and to increase the company efficiency. Yet, complaints about the difficulty of understanding the speech of the participants in both rooms of the video...... conference occur. The aim of this study is to find out the main causes of difficulties in speech communication. Correlation studies between subjective perceptions were conducted through questionnaires and objective acoustic and indoor climate parameters related to video conferencing. Based on four single......-room and three combined-room measurements, it was found that the traditional measure of speech, such as the speech transmission index, was not correlated with the subjective classifications. Thus, a correlation analysis was conducted as an attempt to find the hidden factors behind the subjective perceptions...

  15. Persistence of initial conditions in continental scale air quality simulations

    Science.gov (United States)

    Hogrefe, Christian; Roselle, Shawn J.; Bash, Jesse O.

    2017-07-01

    This study investigates the effect of initial conditions (IC) for pollutant concentrations in the atmosphere and soil on simulated air quality for two continental-scale Community Multiscale Air Quality (CMAQ) model applications. One of these applications was performed for springtime and the second for summertime. Results show that a spin-up period of ten days commonly used in regional-scale applications may not be sufficient to reduce the effects of initial conditions to less than 1% of seasonally-averaged surface ozone concentrations everywhere while 20 days were found to be sufficient for the entire domain for the spring case and almost the entire domain for the summer case. For the summer case, differences were found to persist longer aloft due to circulation of air masses and even a spin-up period of 30 days was not sufficient to reduce the effects of ICs to less than 1% of seasonally-averaged layer 34 ozone concentrations over the southwestern portion of the modeling domain. Analysis of the effect of soil initial conditions for the CMAQ bidirectional NH3 exchange model shows that during springtime they can have an important effect on simulated inorganic aerosols concentrations for time periods of one month or longer. The effects are less pronounced during other seasons. The results, while specific to the modeling domain and time periods simulated here, suggest that modeling protocols need to be scrutinized for a given application and that it cannot be assumed that commonly-used spin-up periods are necessarily sufficient to reduce the effects of initial conditions on model results to an acceptable level. What constitutes an acceptable level of difference cannot be generalized and will depend on the particular application, time period and species of interest. Moreover, as the application of air quality models is being expanded to cover larger geographical domains and as these models are increasingly being coupled with other modeling systems to better represent

  16. The Predictive Control Method of VAV Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Jiejia LI

    2013-09-01

    Full Text Available Aiming at the characteristics which variable air volume air conditioning system is multi-variable, nonlinear and uncertain system, normal fuzzy neural network is hard to meet the requirements which dynamic control of multi-variable. In this paper, we put forward a recursive neural network predictive control strategy based on wavelet neural network model. Through recursive wavelet neural network predictor on line established controlled object’s mathematical model, and using Elman neural network controller on line corrected information we get, thus to improve control effect. The simulation results show that recursive wavelet neural network predictive control has stronger robustness and adaptive ability, high control precision, better and reliable control effect and other advantages.

  17. Ecologic air-conditioning. A pilot plant for the geothermal and sorption supported air-conditioning in the HafenCity Hamburg; Oekologische Klimatisierung. Pilotanlage zur geothermisch- und sorptionsgestuetzten Klimatisierung in der HafenCity Hamburg

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xiaolong; Grabe, Juergen [Technische Univ. Hamburg-Harburg (Germany). Inst. fuer Geotechnik und Baubetrieb

    2011-10-24

    The relatively constant temperatures of the underground at a depth of 100 meters provide the opportunity to air-condition buildings with geothermal energy and economically. Currently, building air conditioning systems in Central Europe exhibit high growth rates. In summer, the task of an air conditioner is to cool and dehumidify air. Especially the dehumidification usually causes a high cooling demand, as the air is cooled below the dew point temperature of 12 C in order to condense out the water. The dew point is well below the demand for a comfortable room temperature of about 19 C. With this in mind, the authors of this contribution report on a principle of alternative dehumidification by means of a so-called sorption wheel. Sorption wheels use the hygroscopic properties of certain substances such as lithium chloride or silica gel in order to dehumidify the air. Thereby, the cooling demand significantly is reduced by the previous dehumidification. The regeneration of the sorption wheel requires heat. This heat can be provided by solar thermal plants and district heating. Since the air can no longer be dehumidified, rich supply temperatures between 16 and 19 C from. These temperatures can be achieved by means of near-surface temperature. Ground registers, geothermal energy probes or geothermal structures such as power poles are used as ground heat exchanger. The authors present the concept and the measurement results of the pilot plant in Hamburg's HafenCity.

  18. Speech intelligibility for normal hearing and hearing-impaired listeners in simulated room acoustic conditions

    DEFF Research Database (Denmark)

    Arweiler, Iris; Dau, Torsten; Poulsen, Torben

    Speech intelligibility depends on many factors such as room acoustics, the acoustical properties and location of the signal and the interferers, and the ability of the (normal and impaired) auditory system to process monaural and binaural sounds. In the present study, the effect of reverberation...... intelligibility and when binaural cues are effective. (Poster). Partly from HEARCOM project....

  19. An Experimental Study on Direct Load Control of Residential Air-conditioning Units from a Viewpoint of Short-period Controllability in Artificial Climate Chamber

    Science.gov (United States)

    Sugihara, Hideharu; Funaki, Tsuyoshi; Ueno, Kiyotaka

    Recently, much attention in Japan has been given to photovoltaic (PV) systems, which are being rapidly installed in ever greater numbers on homes. However, various concerns over potential adverse implications on the secure operation of the power systems that could result from large-scale installation of PV systems have been identified, such as large-scale PV causing frequency variations or causing voltage variations in distribution networks. This study presents findings on performing direct load control in an artificial climate chamber capable of constant outside air temperature control, and focuses on the potential for using load-variable residential Air-Conditioning (AC) units in order to promote the large-scale introduction of PV. Specifically, measurements were taken of power consumption, room temperature, suction air temperature, and blow air temperature while altering inside air temperature over several minute intervals, and the power consumption variability of AC unit was assessed, while also evaluating the effects on thermal comfort index inside the room.

  20. Thermo economical evaluation of retrofitting strategies in air conditioning systems

    Energy Technology Data Exchange (ETDEWEB)

    Tribess, Arlindo; Fiorelli, Flavio Augusto Sanzogo; Hernandez Neto, Alberto [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia Mecanica]. E-mail: atribess@usp.br; fiorelli@usp.br; ahneto@usp.br

    2000-07-01

    In a building project, several subsystems are designed, among them the air conditioning system. Electrical energy consumption profiles show that this subsystem is responsible for 40 to 50% of total consumption in a commercial building. Besides the study of technical aspects that should be considered in order to assure the thermal comfort of the occupants as well the temperature and humidity conditions for an efficient equipment operation, an economical evaluation of this subsystem should be also made. In retrofit projects, the economical aspect is also critical for such projects in order to assure bigger efficiency in an economically attractive way. This paper analyses some strategies that might be adopted in retrofitting an air conditioning system installed in a commercial building with mixed occupation. By mixed we mean that some floors have a typical office occupation profile and other floors are mainly occupied by electronic equipment. This analysis includes both technical and economical evaluation. The proposed solutions performance are compared to the old system, which allows to verify the retrofitting impact in energy consumption reduction and its economical feasibility. (author)

  1. Effect of air conditioning and chair cushion on scrotal temperature.

    Science.gov (United States)

    Song, Gook-Sup; Kim, Wonwoo; Seo, Ju Tae

    2008-08-01

    The hypothesis of this study is that the air conditioning temperature and thickness of the chair cushion affect a man's scrotal, and consequently testicular, temperature. Ten healthy male subjects volunteered for the study (age: 23.4 +/- 2.4 years; height: 173.8 +/- 5.09 cm; weight: 71.6 +/- 9.7 kg; body fat ratio: 18.6 +/- 4.1%). The air conditioning temperature was controlled at 18 degrees C to represent the heating season, and at 26 degrees C to represent the cooling season. The thickness of the chair cushions was varied from 0 to 8 cm at 2 cm intervals. The changes in the scrotal surface temperature (SST) and buttock skin temperature were measured for 120 min. At the ambient temperatures (t(a)) of 18 and 26 degrees C, the average SST were 33.76 +/- 1.28 and 35.02 +/- 0.54 degrees C for the chair cushion thickness (C(thk)) of 0 cm, 33.87 +/- 1.07 and 34.96 +/- 0.75 degrees C for C(thk) 2 cm, 33.91 +/- 0.84 and 35.03 +/- 0.85 degrees C for C(thk) 4 cm, 34.42 +/- 0.89 and 35.02 +/- 0.63 degrees C for C(thk) 6 cm, and 34.65 +/- 1.21 and 34.99 +/- 0.62 degrees C for C(thk) 8 cm respectively. SST was significantly affected by the air conditioning temperature (p < 0.001), but was not statistically correlated with the chair cushion thickness.

  2. Proposal for energy saving in air conditioning equipment; Propuesta para ahorro energetico en acondicionadores de aire

    Energy Technology Data Exchange (ETDEWEB)

    Solis Recendez, Daniel H [Division de Ingenieria Electrica, Universidad Nacional Autonoma de Mexico (Mexico)

    2008-10-15

    In the last decades, the air conditioning systems have become a crucial part in the search from comfort in extreme climates. Nevertheless, they have also become one of the greatest energy consumers. In this article it is proposed that the final conditions that the air conditioning equipment looks for not to be fixed, but variable in respect to a certain comfort zone. This zone is a variation of the used one in the bio-climatic chart of Olgyay that considers the rapidity whereupon the reached conditions tend to leave the comfort zone. It is analyzed how to choose the point on the zone that costs less energy in arriving to it. [Spanish] En las ultimas decadas, los sistemas de aire acondicionado se han vuelto una parte crucial en la busqueda de confort en climas extremosos. Sin embargo, tambien se han vuelto de los mayores consumidores de energia. En este articulo se propone que las condiciones finales que busquen lograr los acondicionadores no sean fijas, si no variables respecto a una determinada zona de confort. Dicha zona es una variacion de la utilizada en la carta bioclimatica de Olgyay, que considera la rapidez con que las condiciones alcanzadas tienden a abandonar la zona de confort. Se discute como elegir el punto sobre la zona que cueste menos energia en llegara el.

  3. Do-It-Yourself Additives Recharge Auto Air Conditioning

    Science.gov (United States)

    2010-01-01

    In planning for a return mission to the Moon, NASA aimed to improve the thermal control systems that keep astronauts comfortable and cool while inside a spacecraft. Goddard Space Flight Center awarded a Small Business Innovation Research (SBIR) contract to Mainstream Engineering Corporation, of Rockledge, Florida, to develop a chemical/mechanical heat pump. IDQ Inc., of Garland, Texas, exclusively licensed the technology and incorporates it into its line of Arctic Freeze products for automotive air conditioning applications. While working on the design, Mainstream Engineering came up with a unique liquid additive called QwikBoost to enhance the performance of the advanced heat pump design.

  4. Investigation of air cleaning system response to accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Andrae, R.W.; Bolstad, J.W.; Foster, R.D.; Gregory, W.S.; Horak, H.L.; Idar, E.S.; Martin, R.A.; Ricketts, C.I.; Smith, P.R.; Tang, P.K.

    1980-01-01

    Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported.

  5. Sea/Lake Water Air Conditioning at Naval Facilities.

    Science.gov (United States)

    1980-05-01

    r-AO89 262 CIVIL ENGINEERING LAS (NAVY) PONT HUJENEME CA F/6 13/1 SEA/LAKF WATER AIR CONDITIONING AT N4AVAL FACILITIES.u MAY S0 .J B CIAN...AROICC. Brooklyn NY: CO; C’ode (NP (LCDR ATJ Stewart): C’ode 10)28. RDT&ELO. Philadelphia PA: Code III (Castranovo) Philadelphia. PA: Design Div. (R...Governor’s Council On Energy) NEW MEXICO SOLAR ENERGY INST. Dr. Zwibcl Las Cruces NM NY CITY COMMUNITY COLLEGE BROOKLYN , NY (LIBRARY) NYS ENERGY OFFICE

  6. Human requirements in future air-conditioned environments

    DEFF Research Database (Denmark)

    Fanger, Povl Ole

    2001-01-01

    , even though existing standards and guidelines are met. A paradigm shift from rather mediocre to excellent indoor environments is foreseen in the 21st century. Based on existing information and on new research results, five principles are suggested as elements behind a new philosophy of excellence......Although air-conditioning has played a positive role for economic development in warm climates, its image is globally mixed. Field studies demonstrate that there are substantial numbers of dissatisfied people in many buildings, among them those suffering from Sick Building Syndrome (SBS) symptoms...... individual; individual control of the thermal environment should be provided. These principles of excellence are compatible with energy efficiency and sustainability....

  7. Simulation of Artificial Intelligence for Automotive Air-conditioning System

    Institute of Scientific and Technical Information of China (English)

    YUAN Xiao-mei; CHEN You-hua; CHEN Zhi-jiu

    2002-01-01

    The artificial intelligence is applied to the simulation of the automotive air-conditioning system ( AACS )According to the system's characteristics a model of AACS, based on neural network, is developed. Different control methods of AACS are discussed through simulation based on this model. The result shows that the neural- fuzzy control is the best one compared with the on-off control and conventional fuzzy control method.It can make the compartment's temperature descend rapidly to the designed temperature and the fluctuation is small.

  8. Engine-driven hybrid air-conditioning system

    Institute of Scientific and Technical Information of China (English)

    Chaokui QIN; Hongmei LU; Xiong LIU; Gerhard SCHMITZ

    2009-01-01

    A hybrid air-conditioning system that com-bines an engine-driven chiller with desiccant dehumidifi-cation was configured and experimentally tested to provide reliable data for energy consumption and operation cost. The engine performance and the desiccant wheel perfor-mance were measured and a numeric model previously set up for dehumidification capacity prediction was validated. For a reference building, the results based upon measured data show that under present electricity/gas price ratio, more than 40% of operation cost can be saved by the hybrid system.

  9. Heating control strategy in fresh air processor matched with variable refrigerant flow air conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Tu Qiu, E-mail: tuqiuky@163.co [Guangzhou Institute of Energy Conversion, Chinese Academy of Science, Guangzhou 510640 (China) and Key Laboratory of Renewable Energy and Gas Hydrate, Chinese Academy of Science, Guangzhou 510640 (China); Mao Shoubo; Feng Yuhai; Guo Defang [Haier Air-Conditioning Electronic Co. Ltd., Qingdao 266510 (China)

    2011-07-15

    Highlights: {yields} A set of fresh air processor matched with VRF AC has been designed. {yields} The heating control model of variable condensation temperature target has been presented {yields} The control strategy can realize reliable running, high control accuracy and energy-saving. {yields} The control model is universal for fresh air processors with different capacities. -- Abstract: The fresh air processor (FAP), matched with the variable refrigerant flow air conditioning system (VRF AC), has been developed. Two control methods were adopted to control the system running and air outlet temperature, contrastively. The first method is that the running frequency in heating mode is adjusted in terms of the ordinary control method of VRF, i.e., constant condensation temperature. The experiment demonstrates the control method is not feasible. For nominal heating under different static pressure and defrosting under 200 Pa static pressure, the system fluctuates frequently. And for high temperature heating, the air outlet temperature far exceeds the target temperature. Furthermore, the control model of variable condensation temperature target has been presented, and the heat transfer correction factor is introduced into the control model. And the control parameters in the model are determined by experiment. The control model is universal for FAPs with different capacities by identifying and choosing the heat transfer correction factor in the control program. For low temperature heating, the method of switching rotation speed of the motor can be adopted to enhance air outlet temperature to 22 {sup o}C. The control strategy can provide guide for the design and application of FAP.

  10. Distribution of Carbon Dioxide Produced by People in a Room:

    DEFF Research Database (Denmark)

    Naydenov, Kiril Georgiev; Baránková, Petra; Sundell, Jan

    2004-01-01

    Carbon dioxide exhaled by people can be used as a tracer gas for air change measurements in homes. Good mixing of tracer gas with room air is a necessary condition to obtain accurate results. However, the use of fans to ensure mixing is inconvenient. The natural room distribution of metabolic CO2...

  11. Bioaerosol deposition on an air-conditioning cooling coil

    Science.gov (United States)

    Wu, Yan; Chen, Ailu; Luhung, Irvan; Gall, Elliott T.; Cao, Qingliang; Chang, Victor Wei-Chung; Nazaroff, William W.

    2016-11-01

    This study is concerned with the role of a fin-and-tube heat exchanger in modifying microbial indoor air quality. Specifically, depositional losses of ambient bioaerosols and particles onto dry (not cooled) and wet (cool) coil surfaces were measured for different airspeeds passing through the test coil. Total, bacterial and fungal DNA concentrations in condensate water produced by a wet coil were also quantified by means of fluorescent dsDNA-binding dye and qPCR assays. Results revealed that the deposition of bioaerosols and total particles is substantial on coil surfaces, especially when wet and cool. The average deposition fraction was 0.14 for total DNA, 0.18 for bacterial DNA and 0.22 for fungal DNA on the dry coil, increasing to 0.51 for total DNA, 0.50 for bacterial DNA and 0.68 for fungal DNA on the wet coil. Overall, as expected, deposition fractions increased with increasing particle size and increasing airspeed. Deposited DNA was removed from the cooling coil surfaces through the flow of condensing water at a rate comparable to the rate of direct deposition from air. A downward trend of bacterial and fungal DNA measured in condensate water over time provides suggestive evidence of biological growth on heat exchangers during nonoperational times of a ventilation system. This investigation provides new information about bioaerosol deposition onto a conventional fin-and-tube cooling coil, a potentially important factor influencing indoor exposure to microbial aerosols in air-conditioned buildings.

  12. An effective silencer design for artificially air conditioned environment.

    Science.gov (United States)

    Fujiwara, Kyoji; Pang, Li Feng

    2004-11-01

    An effective silencer for an air conditioning duct is studied. A duct with an acoustically soft boundary is employed as an effective silencer. On the acoustically soft boundary the sound pressure is zero and it is impossible to realize such boundary in the air-borne sound field, because of the non-existence of a much lighter medium than the air. In this study, the arrangement of one-quarter wave-length acoustic tubes is employed as a soft boundary. This acoustic tube has frequency dependence, but the sound pressure becomes nearly zero at the tube mouth around the odd resonance frequency. The relation between the noise reduction efficiency and this acoustically soft boundary is examined experimentally and more than 40 dB noise reduction is obtained in a one-half octave band around the first resonance frequency. It is also made clear that more than one wave length of soft boundary is required to get enough reduction compared with the reduction obtained in the case of quite a long soft boundary.

  13. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Air conditioning environmental test... conditioning environmental test facility ambient requirements. The goal of an air conditioning test facility is..., within the test cell, during all phases of the air conditioning test sequence to 95 ±2 °F on average and...

  14. Rheological properties of boehmite sols during ageing at room temperature (30 ± 1°C) under closed condition

    Indian Academy of Sciences (India)

    M K Naskar; M Chatterjee; D Ganguli

    2002-04-01

    Boehmite sols were obtained by peptizing boehmite precipitates with glacial acetic acid. The sols were aged at room temperature (30 ± 1°C) under closed condition. Rheological properties of the sols were studied at different ageing times. The sol characteristics were interpreted by measuring their viscosity, areas of hysteresis of the flow curves and yield stress (y). Viscosity and the area of hysteresis of the flow curves increased with increasing ageing time of the sols. A sharp change of yield stress was observed during the ageing period from 15 to 36 days. The change in viscous to elastic nature and the appearance of gel point of the sol was observed by studying their oscillatory flow behaviour, i.e. by measuring loss modulus (''), elastic modulus ('), and loss tangent (tan ) of the sols. Gel point of boehmite sol was found at 36 days of ageing under closed condition at room temperature (30 ± 1°C).

  15. Speech intelligibility for normal hearing and hearing-impaired listeners in simulated room acoustic conditions

    DEFF Research Database (Denmark)

    Arweiler, Iris; Dau, Torsten; Poulsen, Torben

    , a classroom and a church. The data from the study provide constraints for existing models of speech intelligibility prediction (based on the speech intelligibility index, SII, or the speech transmission index, STI) which have shortcomings when reverberation and/or fluctuating noise affect speech......Speech intelligibility depends on many factors such as room acoustics, the acoustical properties and location of the signal and the interferers, and the ability of the (normal and impaired) auditory system to process monaural and binaural sounds. In the present study, the effect of reverberation...... on spatial release from masking was investigated in normal hearing and hearing impaired listeners using three types of interferers: speech shaped noise, an interfering female talker and speech-modulated noise. Speech reception thresholds (SRT) were obtained in three simulated environments: a listening room...

  16. Energy efficient air-conditioning technology for a healthier climate; Energieeffiziente Klimatechnik fuer ein gesundes Raumklima

    Energy Technology Data Exchange (ETDEWEB)

    Hartl, Thorsten [ebm-papst Motoren und Ventilatoren GmbH, St. Florian (Austria)

    2011-07-01

    Since climate and indoor air quality have a great impact on concentration, health and well being, it is important to provide good indoor air for example in classrooms. The use of air conditioning equipment enables an optimal air-conditioning, whether in new buildings or building alterations or renovations. Energy-saving EC fans in these air conditioning systems provide an efficient and quiet ventilation meeting the requirements. Thus, the contribution under consideration reports on centrifugal fans.

  17. Absorption and adsorption chillers applied to air conditioning systems

    Science.gov (United States)

    Kuczyńska, Agnieszka; Szaflik, Władysław

    2010-07-01

    This work presents an application possibility of sorption refrigerators driven by low temperature fluid for air conditioning of buildings. Thermodynamic models were formulated and absorption LiBr-water chiller with 10 kW cooling power as well as adsorption chiller with silica gel bed were investigated. Both of them are using water for desorption process with temperature Tdes = 80 °C. Coefficient of performance (COP) for both cooling cycles was analyzed in the same conditions of the driving heat source, cooling water Tc = 25 °C and temperature in evaporator Tevap = 5 °C. In this study, the computer software EES was used to investigate the performance of absorption heat pump system and its behaviour in configuration with geothermal heat source.

  18. Analysis of Alternative Refrigerants to R22 for Air-Conditioning Applications at Various Evaporating Temperatures

    Directory of Open Access Journals (Sweden)

    S. Venkataiah

    2014-03-01

    Full Text Available This paper presents the simulation results of a 1.5 ton capacity room air conditioning system with some selected refrigerants that have been assessed for their suitability as alternative refrigerants to R22 for air conditioning applications. The refrigerants with zero Ozone depletion potential only are selected in this study. The performance of selected refrigerants viz, R22, R134a, R404A, R407C, R410A, R507A, R290 and R600a is considered in the present analysis. The thermodynamic analysis of these refrigerants has been carried out on these selected refrigerants using COOLPACK software. The analysis mainly focuses on obtaining results of parameters with fixed condenser temperature but with variable evaporator temperatures. The parameters like heat rejection rate, mass flow rate of refrigerant, displacement volume, power input, discharge temperature, cop, saturation pressure and pressures ratio are analyzed. The thermodynamic analysis of eight selected refrigerants is carried out using the simulation software COOL PACK version 1.49 and a comparative study of the different refrigerants is made.

  19. Research on phase-change material building mass applied in the air-conditioning field

    Institute of Scientific and Technical Information of China (English)

    YANQuanying

    2003-01-01

    Phase-change material building mass contains phase-change matenals. It can decrease air-conditioning load and indoor temperature fluctuations, and improve comfort degree in summer because of thermal storage property of phase-change material. Thereby, the scale, initial investment and operational cost of air-conditioning system decrease effectively. The indoor surroundings improve. In this paper, suitable phase-change material used in architecture and combination mode between phase change material and architectural material were studied. By considering the properties of materials, such as phase-change temperature, phase-change latent heat, thermal conductivity and expansion coefficient, phase-change materials were selected and evaluated. Combination mode between phase-change material and architectural material were provided. The influence of phase-change material structure on thermal performance in room and energy-saving effect were analyzed and compared with traditional structure without phase-change material. It is proved that phase-change material structure is feasible in the practical engineenng. These provide the basis for developing phase-change material building mass.

  20. Air quality monitoring of the post-operative recovery room and locations surrounding operating theaters in a medical center in Taiwan.

    Science.gov (United States)

    Tang, Chin-Sheng; Wan, Gwo-Hwa

    2013-01-01

    To prevent surgical site infection (SSI), the airborne microbial concentration in operating theaters must be reduced. The air quality in operating theaters and nearby areas is also important to healthcare workers. Therefore, this study assessed air quality in the post-operative recovery room, locations surrounding the operating theater area, and operating theaters in a medical center. Temperature, relative humidity (RH), and carbon dioxide (CO2), suspended particulate matter (PM), and bacterial concentrations were monitored weekly over one year. Measurement results reveal clear differences in air quality in different operating theater areas. The post-operative recovery room had significantly higher CO2 and bacterial concentrations than other locations. Bacillus spp., Micrococcus spp., and Staphylococcus spp. bacteria often existed in the operating theater area. Furthermore, Acinetobacter spp. was the main pathogen in the post-operative recovery room (18%) and traumatic surgery room (8%). The mixed effect models reveal a strong correlation between number of people in a space and high CO2 concentration after adjusting for sampling locations. In conclusion, air quality in the post-operative recovery room and operating theaters warrants attention, and merits long-term surveillance to protect both surgical patients and healthcare workers.

  1. Air quality monitoring of the post-operative recovery room and locations surrounding operating theaters in a medical center in Taiwan.

    Directory of Open Access Journals (Sweden)

    Chin-Sheng Tang

    Full Text Available To prevent surgical site infection (SSI, the airborne microbial concentration in operating theaters must be reduced. The air quality in operating theaters and nearby areas is also important to healthcare workers. Therefore, this study assessed air quality in the post-operative recovery room, locations surrounding the operating theater area, and operating theaters in a medical center. Temperature, relative humidity (RH, and carbon dioxide (CO2, suspended particulate matter (PM, and bacterial concentrations were monitored weekly over one year. Measurement results reveal clear differences in air quality in different operating theater areas. The post-operative recovery room had significantly higher CO2 and bacterial concentrations than other locations. Bacillus spp., Micrococcus spp., and Staphylococcus spp. bacteria often existed in the operating theater area. Furthermore, Acinetobacter spp. was the main pathogen in the post-operative recovery room (18% and traumatic surgery room (8%. The mixed effect models reveal a strong correlation between number of people in a space and high CO2 concentration after adjusting for sampling locations. In conclusion, air quality in the post-operative recovery room and operating theaters warrants attention, and merits long-term surveillance to protect both surgical patients and healthcare workers.

  2. Air Quality Monitoring of the Post-Operative Recovery Room and Locations Surrounding Operating Theaters in a Medical Center in Taiwan

    Science.gov (United States)

    Tang, Chin-Sheng; Wan, Gwo-Hwa

    2013-01-01

    To prevent surgical site infection (SSI), the airborne microbial concentration in operating theaters must be reduced. The air quality in operating theaters and nearby areas is also important to healthcare workers. Therefore, this study assessed air quality in the post-operative recovery room, locations surrounding the operating theater area, and operating theaters in a medical center. Temperature, relative humidity (RH), and carbon dioxide (CO2), suspended particulate matter (PM), and bacterial concentrations were monitored weekly over one year. Measurement results reveal clear differences in air quality in different operating theater areas. The post-operative recovery room had significantly higher CO2 and bacterial concentrations than other locations. Bacillus spp., Micrococcus spp., and Staphylococcus spp. bacteria often existed in the operating theater area. Furthermore, Acinetobacter spp. was the main pathogen in the post-operative recovery room (18%) and traumatic surgery room (8%). The mixed effect models reveal a strong correlation between number of people in a space and high CO2 concentration after adjusting for sampling locations. In conclusion, air quality in the post-operative recovery room and operating theaters warrants attention, and merits long-term surveillance to protect both surgical patients and healthcare workers. PMID:23573296

  3. Calculation of Appropriate Minimum Size of Isolation Rooms based on Questionnaire Survey of Experts and Analysis on Conditions of Isolation Room Use

    Science.gov (United States)

    Won, An-Na; Song, Hae-Eun; Yang, Young-Kwon; Park, Jin-Chul; Hwang, Jung-Ha

    2017-07-01

    After the outbreak of the MERS (Middle East Respiratory Syndrome) epidemic, issues were raised regarding response capabilities of medical institutions, including the lack of isolation rooms at hospitals. Since then, the government of Korea has been revising regulations to enforce medical laws in order to expand the operation of isolation rooms and to strengthen standards regarding their mandatory installation at hospitals. Among general and tertiary hospitals in Korea, a total of 159 are estimated to be required to install isolation rooms to meet minimum standards. For the purpose of contributing to hospital construction plans in the future, this study conducted a questionnaire survey of experts and analysed the environment and devices necessary in isolation rooms, to determine their appropriate minimum size to treat patients. The result of the analysis is as follows: First, isolation rooms at hospitals are required to have a minimum 3,300mm minor axis and a minimum 5,000mm major axis for the isolation room itself, and a minimum 1,800mm minor axis for the antechamber where personal protective equipment is donned and removed. Second, the 15 ㎡-or-larger standard for the floor area of isolation rooms will have to be reviewed and standards for the minimum width of isolation rooms will have to be established.

  4. Inactivation of a 25.5 µm Enterococcus faecalis biofilm by a room-temperature, battery-operated, handheld air plasma jet

    Science.gov (United States)

    Pei, X.; Lu, X.; Liu, J.; Liu, D.; Yang, Y.; Ostrikov, K.; Chu, Paul K.; Pan, Y.

    2012-04-01

    Effective biofilm inactivation using a handheld, mobile plasma jet powered by a 12 V dc battery and operated in open air without any external gas supply is reported. This cold, room-temperature plasma is produced in self-repetitive nanosecond discharges with current pulses of ˜100 ns duration, current peak amplitude of ˜6 mA and repetition rate of ˜20 kHz. It is shown that the reactive plasma species penetrate to the bottom layer of a 25.5 µm-thick Enterococcus faecalis biofilm and produce a strong bactericidal effect. This is the thickest reported biofilm inactivated using room-temperature air plasmas.

  5. Cellulose sulphuric acid as a biodegradable catalyst for conversion of aryl amines into azides at room temperature under mild conditions

    Indian Academy of Sciences (India)

    Firouzeh Nesmati; Ali Elhampour

    2012-07-01

    This article describes simple and efficient method for the diazotization and azidation of different aromatic amines over cellulose sulphuric acid, sodium nitrite and sodium azide under mild conditions at room temperature. Various aryl amines possessing electron-withdrawing groups or electron-donating groups have been converted into the corresponding aryl azides with 71-99% yields. The use of mild reaction conditions, avoids the use of harmful acids and toxic solvents and short reaction times are advantages of this methodology. The selected catalyst is found to be highly efficient and recyclable.

  6. Comparison of two single-use scrub suits in terms of effect on air-borne bacteria in the operating room.

    Science.gov (United States)

    Tammelin, A; Blomfeldt, A-M

    2017-03-01

    A low level of air-borne bacteria in the operating room air can be achieved if all staff wear clothes made of low-permeability material (i.e. clean air suits). This study investigated if there was a difference in protective efficacy between two single-use scrubs made of polypropylene by testing them during routinely performed orthopaedic surgical procedures. No significant difference in the colony-forming unit count/m(3) air was found between the two scrubs, so the choice can be based on which scrub type is more comfortable for staff.

  7. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Science.gov (United States)

    2010-07-01

    ... Optional equipment and air conditioning for test vehicles. For test vehicles selected under §§ 86.1822-01... be expected to influence emissions include, but are not limited to: air conditioning, power steering...) Except for air conditioning, where it is expected that 33 percent or less of a car line, within a test...

  8. 24 CFR 3280.813 - Outdoor outlets, fixtures, air-conditioning equipment, etc.

    Science.gov (United States)

    2010-04-01

    ... Electrical Systems § 3280.813 Outdoor outlets, fixtures, air-conditioning equipment, etc. (a) Outdoor.../or air conditioning equipment located outside the manufactured home, shall have permanently affixed, adjacent to the outlet, a metal tag which reads: This Connection Is for Air Conditioning Equipment Rated at...

  9. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Science.gov (United States)

    2010-07-01

    ... alternative air conditioning test simulations. (a) Upon petition from a manufacturer or upon the Agency's own initiative, the Administrator will approve a simulation of the environmental cell for air conditioning test... the tailpipe emissions, air conditioning compressor load, and fuel economy. (2) For any simulation...

  10. 40 CFR 86.166-12 - Method for calculating emissions due to air conditioning leakage.

    Science.gov (United States)

    2010-07-01

    ... to air conditioning leakage. 86.166-12 Section 86.166-12 Protection of Environment ENVIRONMENTAL... for calculating emissions due to air conditioning leakage. This section describes procedures used to determine a refrigerant leakage rate in grams per year from vehicle-based air conditioning units. The...

  11. A review on test procedure, energy efficiency standards and energy labels for room air conditioners and refrigerator-freezers

    Energy Technology Data Exchange (ETDEWEB)

    Mahlia, T.M.I.; Saidur, R. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2010-09-15

    Air conditioners and refrigerator-freezers are major energy users in a household environment and hence efficiency improvement of these appliances can be considered as an important step to reduce their energy consumption along with environmental pollution prevention. Energy efficiency standards and labels are commonly used tools to reduce the energy uses for household appliances for many countries around the world. The first step towards adopting energy efficiency standards is to establish a test procedure for rating and testing of an appliance. It may be mentioned that an energy test procedure is the technical foundation for energy efficiency standards, energy labels, and other related programs. This paper reviews requirements and specifications of various international test standards for testing and rating of room air conditioners and refrigerators. A review on the development of the energy efficiency standards has been provided as well. Finally, energy labels that provide some useful information for identifying energy efficient products have been reviewed for these appliances. It may be stated that the review will be useful for the developing countries who wish to develop these energy savings strategies. It is also expected to be useful to revise the existing strategies for a few selected countries who already implemented these strategies earlier. (author)

  12. Voltage controller design for air conditioning; Diseno de controlador de voltaje para aire acondicionado

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Andrade, R; Lopez Villalobos, J.J; Valderrama Chairez, J; Ramirez, R.L. [Instituto Tecnologico de Nuevo Leon, Guadalupe, Nuevo Leon (Mexico)]. E-mails: roxana_garciaandrade@yahoo.com; xe2n@yahoo.com.mx; jose.valderrama@ieee.org

    2013-03-15

    This paper discusses the design of a voltage controller for an air conditioning system in order to generate additional power in activation or startup of the system, for which as a first stage is presented the modeling power generation of electric current through alternative means, such as solar energy. The results of this study will be the basis for development of the physical prototype of this system controller. [Spanish] El presente trabajo trata sobre el diseno de un controlador de voltaje para un sistema de aire acondicionado con el fin de generar energia adicional en la activacion o arranque de dicho sistema, para lo cual como primer fase se presenta el modelado de la generacion de corriente electrica mediante medios alternos, como lo es la energia solar. Los resultados de este trabajo seran la base para desarrollo del prototipo fisico de este sistema controlador.

  13. Risk Assessment of Heating, Ventilating, and Air-Conditioning Strategies in Low-Load Homes

    Energy Technology Data Exchange (ETDEWEB)

    Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

    2016-02-17

    "Modern, energy efficient homes conforming to the Zero Energy Ready Home standard face the challenge of meeting high customer expectations for comfort. Traditional heating, ventilation, and air conditioning (HVAC) sizing and control strategies may be insufficient to adequately condition each zone due to unique load patterns in each room caused by a number of factors. These factors include solar heat gains, occupant-related gains, and gains associated with appliances and electronics. Because of shrinking shell loads, these intermittent factors are having an increasingly significant impact on the thermal load in each zone. Consequently, occupant comfort can be compromised. To evaluate the impact of climate and house geometry, as well as HVAC system and control strategies on comfort conditions, IBACOS analyzed the results of 99 TRNSYS multiple-zone simulations. The results of this analysis indicate that for simple-geometry and single-story plans, a single zone and thermostat can adequately condition the entire house. Demanding house geometry and houses with multiple stories require the consideration of multiple thermostats and multiple zones.

  14. 8th International Symposium on Heating, Ventilation and Air Conditioning

    CERN Document Server

    Zhu, Yingxin; Li, Yuguo; Vol.1 Indoor and Outdoor Environment; Vol.2 HVAC&R Component and Energy System; Vol.3 Building Simulation and Information Management

    2014-01-01

    Proceedings of the 8th International Symposium on Heating, Ventilation and Air Conditioning is based on the 8th International Symposium of the same name (ISHVAC2013), which took place in Xi’an on October 19-21, 2013. The conference series was initiated at Tsinghua University in 1991 and has since become the premier international HVAC conference initiated in China, playing a significant part in the development of HVAC and indoor environmental research and industry around the world. This international conference provided an exclusive opportunity for policy-makers, designers, researchers, engineers and managers to share their experience. Considering the recent attention on building energy consumption and indoor environments, ISHVAC2013 provided a global platform for discussing recent research on and developments in different aspects of HVAC systems and components, with a focus on building energy consumption, energy efficiency and indoor environments. These categories span a broad range of topics, and the proce...

  15. Human requirements in future air-conditioned environments

    DEFF Research Database (Denmark)

    Fanger, Povl Ole

    2002-01-01

    though existing standards and guidelines are met. A paradigm shift from rather mediocre to excellent indoor environments is foreseen in buildings in the 21st century. Based on existing information and on new research results, five principles are suggested as elements behind a new philosophy of excellence......Air-conditioning of buildings has played a very positive role for economic development in warm climates. Still its image is globally mixed. Field studies demonstrate that there are substantial numbers of dissatisfied people in many buildings, among them those suffering from SBS symptoms, even...... to the breathing zone of each individual; individual control of the airflow and/or the thermal environment should be provided. These principles of excellence should be combined with energy efficiency and sustainability of future buildings....

  16. Experimental Research on Liquid Desiccant Air-conditioning Unit

    Directory of Open Access Journals (Sweden)

    Feng Yueyan

    2016-01-01

    Full Text Available An experimental device of liquid desiccant air conditioning system is established. Experimental tests about the temperature difference between diluted solution of inlet and concentrated solution of exit in the solution heat exchanger are carried on, and CaCl2 solution is used as desiccant. Results show that: the fluctuation range in the day at different times of the basic difference of the measured temperature does not exceed 1°C, and the temperature difference between diluted solution of inlet and concentrated solution of exit in solution heat exchanger appears the minimum value of 2.7°C and the maximum value of 10.2°C. Also, the percent of the additional load and the ratio of additional load to the evaporator load are analyzed.

  17. Automobile air-conditioning. Its energy and environmental impact

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-05-01

    Over the last three decades, automobile manufacturers have made a lot of progress in specific fuel consumption and engine emissions of pollutants. Yet the impact of these improvements on vehicle consumption has been limited by increased dynamic performances (maximum speed, torque), increased safety (power steering and power brakes) and increased comfort (noise and vibration reduction, electric windows and thermal comfort). Because of this, the real CO{sub 2}-emission levels in vehicles is still high in a context where road transport is a major factor in the balance sheet of greenhouse gas emissions, thus in complying with the international climate convention. Although European, Japanese and Korean manufacturers signed an important agreement with the European Commission for voluntarily reducing CO{sub 2} emissions from their vehicles, with a weighted average emission goal by sales of 140 grams per km on the MVEG approval cycle by 2008, it has to be noted that the European procedures for measuring fuel consumption and CO{sub 2} emissions do not take accessories into account, especially air-conditioning (A/C). The big dissemination of this equipment-recognized as a big energy consumer and as using a refrigerant with a high global warming potential-led ADEME to implement a set of assessments of A/C's energy and environmental impact. In particular these assessments include studies of vehicle equipment rates, analyses of impact on fuel consumption as well as regulated pollutant emissions in the exhaust, a characterization of the refrigerant leakage levels and an estimate of greenhouse gas emissions for all air-conditioned vehicles. This leaflet summarizes the results of these actions. (author)

  18. Cooling the Planet: Opportunities for Deployment of Superefficient Room Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Waide, Paul [Navigant Consulting Inc., Chicago, IL (United States); Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-04-01

    This report presents the results of an analysis, commissioned by the U.S. Department of Energy, of Air Conditioner (AC) efficiency in support of the Super-efficient Equipment and Appliance Deployment (SEAD) initiative.1 The International Energy Studies group at Lawrence Berkeley National Laboratory in collaboration with Navigant Consulting Inc. performed the analysis. SEAD aims to transform the global market by increasing the penetration of highly efficient equipment and appliances. SEAD partners work together in voluntary activities to: (1) “raise the efficiency ceiling” by pulling superefficient appliances and equipment into the market through cooperation on measures like incentives, procurement, awards, and research and development (R&D) investments; (2) “raise the efficiency floor” by working together to bolster national or regional policies like minimum efficiency standards; and (3) “strengthen the efficiency foundations” of programs by coordinating technical work to support these activities.2 The objective of this analysis is to provide the background technical information necessary to improve the efficiency of ACs and to provide a foundation for the activities of SEAD participating countries. We find that even the best currently available technology offers large efficiency improvement opportunities (35% to 50% reduction in energy consumption from the market average) in most SEAD countries. The cost effective efficiency improvements range from 20% to 30% reduction in energy consumption based on a consumer perspective.

  19. Quantitative assessment of mycological air pollution in selected rooms of residential and dormitory housing facilities.

    Science.gov (United States)

    Lonc, Elzbieta; Plewa, Kinga; Kiewra, Dorota; Szczepańska, Anna; Firling, Conrad E

    2013-01-01

    The qualitative and quantitative mycological composition of indoor areas of three private residencies and an academic dormitory in Wroclaw, Poland was investigated. Seasonal fungal samples were obtained using a MAS-100 air sampler. The samples were cultured on three different media: Sabouraud Agar (SAB), Dichloran Glycerol Selective Medium (DG18) and Malt Extract Agar (MEA). The number of colony forming unit (CFU) values ranged from 10 CFU/m3 to 490 CFU/m3 depending on the culture medium, season, and sampling site. The identification of the cultured fungi was performed using macro- and microscopic observations and diagnostic keys. Eleven fungal genera were identified. The most common fungi were members of genera Cladosporium, Penicillium, Aspergillus, Alternaria, and Fusarium; the least common fungi were members of genera Geotrichum and Paecilomyces. Seasonal variations in the concentration of fungi were observed with the highest concentration of fungi in the spring and the lowest concentration of fungi in the winter. There were no statistically significant correlations between fungal concentrations and the temperature or the relative humidity of the sample sites.

  20. Investigations of hydraulic operating conditions of air lift pump with three types of air-water mixers

    Directory of Open Access Journals (Sweden)

    Kalenik Marek

    2015-03-01

    Full Text Available Investigations of hydraulic operating conditions of air lift pump with three types of air-water mixers. The paper presents the analysis of results of the investigations concerning the influence of various constructive solutions of the air-water mixers on hydraulic operating conditions of the air lift pump. The scope of the investigations encompassed the determination of characteristics of delivery head and delivery rate for three types of air-water mixers applied in the constructed air lift pump. Using the obtained results, the efficiency of the three types of air-water mixers applied in this air lift pump was determined. The analysis was carried out and there was checked whether the improved analytical Stenning-Martin model can be used to design air lift pumps with the air-water mixers of these types. The highest capacity in the water transport was reached by the air lift pump with the 1st type air-water mixer, the lowest one – with the 3rd type air-water mixer. The water flow in the air lift pump increases along with the rise in the air flow. The lower are the hydraulic losses generated during flow of the air flux by the air-water mixer, the higher is the air lift pump capacity. Along with the rise in the water delivery head, the capacity of the air lift pump decreases. The highest efficiency is reached by the air lift pump with the 1st type air-water mixer, the lowest – with the 3st type air-water mixer. The efficiency of the air lift pump for the three investigated types of air-water mixers decreases along with the rise in air flow rate and water delivery head. The values of submergence ratio (h/L of the delivery pipe, calculated with the use of the improved analytical Stenning-Martin model, coincide quite well with the values of h/L determined from the measurements.

  1. Understanding the Dehumidification Performance of Air-Conditioning Equipment at Part-Load Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Don B. Shirey III; Hugh I. Henderson Jr; Richard A. Raustad

    2006-01-01

    Air conditioner cooling coils typically provide both sensible cooling and moisture removal. Data from a limited number of field studies (Khattar et al. 1985; Henderson and Rengarajan 1996; Henderson 1998) have demonstrated that the moisture removal capacity of a cooling coil degrades at part-load conditions--especially when the supply fan operates continuously while the cooling coil cycles on and off. Degradation occurs because moisture that condenses on the coil surfaces during the cooling cycle evaporates back into air stream when the coil is off. This degradation affects the ability of cooling equipment to maintain proper indoor humidity levels and may negatively impact indoor air quality. This report summarizes the results of a comprehensive project to better understand and quantify the moisture removal (dehumidification) performance of cooling coils at part-load conditions. A review of the open literature was initially conducted to learn from previous research on this topic. Detailed performance measurements were then collected for eight cooling coils in a controlled laboratory setting to understand the impact of coil geometry and operating conditions on transient moisture condensation and evaporation by the coils. Measurements of cooling coil dehumidification performance and space humidity levels were also collected at seven field test sites. Finally, an existing engineering model to predict dehumidification performance degradation for single-stage cooling equipment at part-load conditions (Henderson and Rengarajan 1996) was enhanced to include a broader range of fan control strategies and an improved theoretical basis for modeling off-cycle moisture evaporation from cooling coils. The improved model was validated with the laboratory measurements, and this report provides guidance for users regarding proper model inputs. The model is suitable for use in computerized calculation procedures such as hourly or sub-hourly building energy simulation programs (e

  2. Large Animal Model of Pumpless Arteriovenous Extracorporeal CO₂ Removal Using Room Air via Subclavian Vessels.

    Science.gov (United States)

    Witer, Lucas J; Howard, Ryan A; Trahanas, John M; Bryner, Benjamin S; Alghanem, Fares; Hoffman, Hayley R; Cornell, Marie S; Bartlett, Robert H; Rojas-Peña, Alvaro

    2016-01-01

    End-stage lung disease (ESLD) causes progressive hypercapnia and dyspnea and impacts quality of life. Many extracorporeal support (ECS) configurations for CO2 removal resolve symptoms but limit ambulation. An ovine model of pumpless ECS using subclavian vessels was developed to allow for ambulatory support. Vascular grafts were anastomosed to the left subclavian vessels in four healthy sheep. A low-resistance membrane oxygenator was attached in an arteriovenous (AV) configuration. Device function was evaluated in each animal while awake and spontaneously breathing and while mechanically ventilated with hypercapnia induced. Sweep gas (FiO2 = 0.21) to the device was increased from 0 to 15 L/min, and arterial and postdevice blood gases, as well as postdevice air, were sampled. Hemodynamics remained stable with average AV shunt flows of 1.34 ± 0.14 L/min. In awake animals, CO2 removal was 3.4 ± 1.0 ml/kg/min at maximum sweep gas flow. Respiratory rate decreased from 60 ± 25 at baseline to 30 ± 11 breaths per minute. In animals with induced hypercapnia, PaCO2 increased to 73.9 ± 15.1. At maximum sweep gas flow, CO2 removal was 3.4 ± 0.4 ml/kg/min and PaCO2 decreased to 49.1 ± 6.7 mm Hg. Subclavian AV access is effective in lowering PaCO2 and respiratory rate and is potentially an effective ambulatory destination therapy for ESLD patients.

  3. A randomized controlled study comparing room air with carbon dioxide for abdominal pain, distention, and recovery time in patients undergoing colonoscopy.

    Science.gov (United States)

    Chen, Yen-Ju; Lee, Jennifer; Puryear, Magaly; Wong, Roy K H; Lake, Jason M; Maydonovitch, Corrine L; Belle, Lavern; Moawad, Fouad J

    2014-01-01

    Colonoscopy remains the gold standard for colorectal cancer screening. Many barriers to the procedure exist including the possibility of abdominal discomfort that may occur with insufflation. Carbon dioxide (CO2), which is rapidly absorbed in the blood stream, is an alternate method used to distend the lumen during colonoscopy. The goal of this study was to compare patient discomfort, abdominal girth, and recovery time in 2 groups of patients randomized to CO2 versus room air insufflation during colonoscopy. Using a Wong-Baker score, we found statistical difference in postprocedural discomfort levels (CO2 Group: 1.15 ± 2.0 vs. room air: 0.41 ± 0.31, p = .015) and a significantly greater increase in abdominal girth over CO2 immediately postprocedure (room air: 1.06 ± 1.29 inches vs. CO2: 0.56 ± 0.73 inches, p = .054) girth immediately postprocedure; however, recovery time was similar between the 2 study arms (CO2: 9.1 ± 16.2 minutes vs. room air: 10.2 ± 18.6 minutes, p = .713). Further studies are needed to determine whether CO2 is cost-effective and improves patient satisfaction with colonoscopy.

  4. Study on the design schemes of the air-conditioning system in a gymnasium

    Science.gov (United States)

    Zhang, Yujin; Wu, Xinwei; Zhang, Jing; Pan, Zhixin

    2017-08-01

    In view of designing the air conditioning project for a gymnasium successfully, the cooling and heating source schemes are fully studied by analyzing the surrounding environment and energy conditions of the project, as well as the analysis of the initial investment and operating costs, which indicates the air source heat pump air conditioning system is the best choice for the project. The indoor air conditioning schemes are also studied systematically and the optimization of air conditioning schemes is carried out in each area. The principle of operating conditions for the whole year is followed and the quality of indoor air and energy-saving are ensured by the optimized design schemes, which provide references for the air conditioning system design in the same kinds of building.

  5. Human requirements in future air-conditioned environments

    DEFF Research Database (Denmark)

    Fanger, Povl Ole

    1999-01-01

    : better indoor air quality increases productivity and decreases SBS symptoms; unnecessary indoor pollution sources should be avoided; the air should be served cool and dry to the occupants; small amounts of clean air should be served gently, close to the breathing zone of each individual; individual...

  6. An efficient heterogeneous procedure for the catalytic acetalization and ketalization at room temperature under solvent-free condition

    Institute of Scientific and Technical Information of China (English)

    GAO Shan; LIANG XueZheng; CHENG WenPing; WANG Wen Juan; YANG JianGuo

    2008-01-01

    A novel carbon-based strong acid catalyst, methylnaphthalenesulfonic acid-formaldehyde condensate, has been synthesized successfully. The catalytic activity for acetalization and ketalization at room tem-perature under solvent-free condition was investigated. The results showed that the novel catalyst was very efficient for the reaction. Also the novel heterogeneous catalyst owned the advantages of high activity, wide applicability, strikingly simple work-up procedure, non-pollution, stability and reusability, which made the catalyst hold great potential for the "green process".

  7. Solar-aided air conditioning through sorption. Final report. Phase 2; Solar unterstuetzte Klimatisierung ueber Sorption. Endbericht zur Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Laevemann, E.; Kessling, W.; Peltzer, M.

    1996-09-24

    The present article reports on possibilities of using solar energy for cooling buildings. It contains the following chapters: Current state of research and development; room air conditioning; planning and results of the studies; theory; experimental studies on the sorption dehumidifier; development of exchange surfaces; development of solution distributors; cooling of exchange surfaces; construction of a sorption dehumidifier. (HW) [Deutsch] Die Arbeit berichtet ueber Moeglichkeiten der Anwendung von Solarenergie zur Kuehlung von Gebaeuden. Die Arbeit enthaelt folgende Kapitel: - Stand der Forschung und Entwicklung - Raumklimatisierung - Planung und Ergebnis der Untersuchungen - Theorie - Experimentelle Untersuchungen am Sorptionsentfeuchter - Entwicklung von Austauschflaechen - Entwicklung von Loesungsverteilern - Kuehlung von Austauschflaechen - Konstruktion eines Sorptionsentfeuchters. (HW)

  8. Intraoral air pressure and oral air flow under different bleed and bite-block conditions.

    Science.gov (United States)

    Putnam, A H; Shelton, R L; Kastner, C U

    1986-03-01

    Intraoral pressures and oral flows were measured as normal talkers produced /p lambda/ and /si/ under experimental conditions that perturbed the usual aeromechanical production characteristics of the consonants. A translabial pressure-release device was used to bleed off intraoral pressure during /p/. Bite-blocks were used to open the anterior bite artificially during /s/. For /p/, intraoral pressure decreased and translabial air leakage increased as bleed orifice area increased. For /s/, flow increased as the area of sibilant constriction increased, but differential pressure across the /s/ oral constriction did not vary systematically with changes in its area. Flow on postconsonantal vowels /lambda/ and /i/ did not vary systematically across experimental conditions. The data imply that maintenance of perturbed intraoral pressure was more effective when compensatory options included opportunity for increased respiratory drive and structural adjustments at the place of consonant articulation rather than increased respiratory drive alone.

  9. China Energy Efficiency Round Robin Testing Results for Room Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan; Fridley, David; Zheng, Nina; Pierrot, Andre

    2010-06-07

    consuming products has always been an important component of all countries energy strategies. As we all know, a very large amount of total energy consumption is due to energy consuming products and equipment, which account for about 50% of China's total energy consumption. However, the current average energy utilization efficiency of this sector is only about 60%, 10 percent lower than the international advanced level. Therefore, China's energy consuming products and equipment sector holds great energy-saving potential. On the other hand, the energy supplied to these products is mainly from fossil fuel combustion, a major source of greenhouse gas (GHG) emissions. Therefore, improving the energy efficiency and augmenting the market share of market-dominant energy consuming products is of significant importance to achieving China's energy saving and emission reduction target and is an effective means to deal with energy and environmental constraints and climate change issues. Main energy consuming products generally include widely-used home appliances, industrial equipment, office equipment, transportation vehicles, etc. China is one of the major manufacturers and exporters of energy end-using products such as air-conditioners, refrigerators, televisions, etc. Their overall energy efficiency is comparatively low and the products are poorly designed, leading to great energy-saving potential. For example, electricity consumption of air conditioners accounts for about 20% of China's total electricity consumption and 40% of the summer electricity peak load in large and medium cities. However, less than 5% of units sold in the domestic market in 2009 reached the standard's highly efficient level of grade 2 above. The electricity consumption of electric motors and their related drive systems accounts for about 60% of China's total electricity consumption; however, less than 2% of the domestic market share consists of energy-efficient electric motor

  10. Catalytic mechanism of cationic red GTL at wide pH using the Mo-Zn-Al-O nanocatalyst under room conditions.

    Science.gov (United States)

    Xu, Yin; Li, Xiaoyi; Sun, Dezhi

    2014-09-01

    Catalytic mechanism of cationic red GTL at wide pH using the Mo-Zn-Al-O nanocatalyst under room conditions was investigated. The experimental results indicate that initial pH significantly affected the removal of cationic red GTL, the removal of COD, the pH value and residual oxygen in the reaction. In the range of pH value from 4 to 10, decolorization of cationic red GTL was almost above 90%. COD removal efficiency was enhanced with the decrease of pH in CWAO process and 79% of the COD was removed at pH 4.0, whereas only 57% COD removal was observed at pH 10.0. The terminal pH was in the range of 5.0-6.0 and the highest terminal concentrations of aqueous oxygen with 5.5 mg/L were observed at pH = 4.0. The radical inhibition experiments also carried out and the generation of *OH and 1O2 in catalytic wet air oxidation process were detected. It was found that the degradation of cationic red GTL occurs mainly via oxidation by 1O2 radical generated by Mo-Zn-Al-O nanocatalyst under acid conditions and *OH radical under alkaline conditions.

  11. Experimental Investigation on Indoor Air Distribution in Low Temperature Air Supply Room%低温送风室内气流组织的实验研究

    Institute of Scientific and Technical Information of China (English)

    张瑞; 柳建华; 张良

    2015-01-01

    低温送风在空气调节系统的节能和提高体感舒适度上有着独特的优势。但同时,送风温度偏低也带来了冷风下坠、温度场不均匀、热舒适性下降的隐患。本文针对低温送风中存在的这些问题,首先确立了低温送风的气流组织评价标准,并设计了包含制冷系统、冰蓄冷系统和测量系统在内的一整套低温送风实验系统,最后对不同的送风温度下实验结果进行定性和定量的分析,从而得到了相应的解决方法和结论。%Low temperature air supply possesses unique advantages on energy conservation and thermal comfort improvement for the air conditioning system. However, the supply air with low temperature also brings possible defects of cold air draught, asymmetrical temperature field or thermal comfort reduction. Thus, in order to explore and solve the above problems, the evaluation standards on airflow distribution of the low temperature air are first defined, then the corresponding experimental system is designed and introduced, including its refrigeration system, ice storage system and measurement system. Finally, the qualitative and quantitative analysis on experiment results is carried out for different air supply temperatures, and the targeted solving methods and conclusions are acquired and presented.

  12. Numerical Modelling of Thermal Environment in a Displacement-Ventilated Room

    DEFF Research Database (Denmark)

    Jacobsen, Torsten V.; Nielsen, Peter V.

    It is the purpose of this paper to investigate the ability of a k-E turbulence model to predict air flow and comfort conditions in a displacement-ventilated room.......It is the purpose of this paper to investigate the ability of a k-E turbulence model to predict air flow and comfort conditions in a displacement-ventilated room....

  13. Early retinal blood vessel growth in normal and growth restricted rat pups raised in oxygen and room air.

    Science.gov (United States)

    Dhaliwal, C A; Wade, J; Gillespie, T; Aspinall, P; McIntosh, N; Fleck, B W

    2011-11-01

    Premature infants are born with incompletely vascularised retinas and are at a risk of developing retinopathy of prematurity (ROP). Rate of prenatal and postnatal body growth is important in the pathogenesis of ROP. The aim of this study was to develop a physiology-based rat model in order to study the effect of growth restriction and oxygen on early retinal vascular development. Rat mothers were fed either a normal (18% casein) or low (9% casein) protein diet (to cause pup growth restriction) from the last week of gestation. After birth, mother and pups were placed in either room air or a specialised oxygen chamber that delivered a rapidly fluctuating hyperoxic oxygen profile. The oxygen profile was based on that from a premature infant who developed severe ROP. On day 14, retinas were dissected, flat-mounted and stained using biotinylated lectin. Images were captured by confocal microscopy. The avascular areas of the retinas were measured and compared. Growth restricted rat pups had significantly larger retinal avascular areas than 'normally grown' rat pups (Mann-Whitney U test, pair (Mann-Whitney U test, p=0.001). The authors have developed a novel model for ROP that involves inducing both intrauterine and postnatal growth restriction and also exposes neonatal rat pups to fluctuating oxygen. This physiology-based model can be used to study the effects of growth, nutrition and oxygen on early retinal vascular development.

  14. Controllable Growth of Perovskite Films by Room-Temperature Air Exposure for Efficient Planar Heterojunction Photovoltaic Cells.

    Science.gov (United States)

    Yang, Bin; Dyck, Ondrej; Poplawsky, Jonathan; Keum, Jong; Das, Sanjib; Puretzky, Alexander; Aytug, Tolga; Joshi, Pooran C; Rouleau, Christopher M; Duscher, Gerd; Geohegan, David B; Xiao, Kai

    2015-12-01

    A two-step solution processing approach has been established to grow void-free perovskite films for low-cost high-performance planar heterojunction photovoltaic devices. A high-temperature thermal annealing treatment was applied to drive the diffusion of CH3NH3I precursor molecules into a compact PbI2 layer to form perovskite films. However, thermal annealing for extended periods led to degraded device performance owing to the defects generated by decomposition of perovskite into PbI2. A controllable layer-by-layer spin-coating method was used to grow "bilayer" CH3NH3I/PbI2 films, and then drive the interdiffusion between PbI2 and CH3NH3I layers by a simple air exposure at room temperature for making well-oriented, highly crystalline perovskite films without thermal annealing. This high degree of crystallinity resulted in a carrier diffusion length of ca. 800 nm and a high device efficiency of 15.6%, which is comparable to values reported for thermally annealed perovskite films.

  15. Cost-Benefit of Improving the Efficiency of Room Air Conditioners (Inverter and Fixed Speed) in India

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Abhyankar, Nikit [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Park, Won Young [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Diddi, Saurabh [Bureau of Energy Efficiency, Government of India (India); Ahuja, Deepanshu [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States); Mukherjee, P. K. [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States); Walia, Archana [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States)

    2016-06-01

    Improving efficiency of air conditioners (ACs) typically involves improving the efficiency of various components such as compressors, heat exchangers, expansion valves, refrigerant,and fans. We estimate the incremental cost of improving the efficiency of room ACs based on the cost of improving the efficiency of its key components. Further, we estimate the retail price increase required to cover the cost of efficiency improvement, compare it with electricity bill savings, and calculate the payback period for consumers to recover the additional price of a more efficient AC. The finding that significant efficiency improvement is cost effective from a consumer perspective is robust over a wide range of assumptions. If we assume a 50% higher incremental price compared to our baseline estimate, the payback period for the efficiency level of 3.5 ISEER is 1.1 years. Given the findings of this study, establishing more stringent minimum efficiency performance criteria (one-star level) should be evaluated rigorously considering significant benefits to consumers, energy security, and environment

  16. Cost-Benefit of Improving the Efficiency of Room Air Conditioners (Inverter and Fixed Speed) in India

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Division; Abhyankar, Nikit [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Division; Park, Won Young [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Division; Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Division; Diddi, Saurabh [Government of India, New Delhi (India). Bureau of Energy Efficiency; Ahuja, Deepanshu [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States); Mukherjee, P. K. [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States); Walia, Archana [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States)

    2016-06-30

    Improving efficiency of air conditioners (ACs) typically involves improving the efficiency of various components such as compressors, heat exchangers, expansion valves, refrigerant and fans. We estimate the incremental cost of improving the efficiency of room ACs based on the cost of improving the efficiency of its key components. Further, we estimate the retail price increase required to cover the cost of efficiency improvement, compare it with electricity bill savings, and calculate the payback period for consumers to recover the additional price of a more efficient AC. We assess several efficiency levels, two of which are summarized below in the report. The finding that significant efficiency improvement is cost effective from a consumer perspective is robust over a wide range of assumptions. If we assume a 50% higher incremental price compared to our baseline estimate, the payback period for the efficiency level of 3.5 ISEER is 1.1 years. Given the findings of this study, establishing more stringent minimum efficiency performance criteria (one star level) should be evaluated rigorously considering significant benefits to consumers, energy security and environment.

  17. [Bipolar ionisation of indoor air through ion generators mountable into inflow ventilation and conditioning].

    Science.gov (United States)

    Dudarev, A A; Spichkin, G L; Denisikhina, D M; Burtsev, S I

    2010-01-01

    Experimental studies and digital modelling of artificial indoor air ionisation through bipolar ionisers mountable into inflow ventilation and conditioning proved possible creation of continuous even bipolar ion background in indoor air, similar to the natural one.

  18. Application of Computer Model to Estimate the Consistency of Air Conditioning Systems Engineering

    Directory of Open Access Journals (Sweden)

    Amal El-Berry

    2013-04-01

    Full Text Available Reliability engineering is utilized to predict the performance and optimization of the design and maintenance of air conditioning systems. There are a number of failures associated with the conditioning systems. The failures of an air conditioner such as turn on, loss of air conditioner cooling capacity, reduced air conditioning output temperatures, loss of cool air supply and loss of air flow entirely are mainly due to a variety of problems with one or more components of an air conditioner or air conditioning system. To maintain the system forecasting for system failure rates are very important. The focus of this paper is the reliability of the air conditioning systems. The most common applied statistical distributions in reliability settings are the standard (2 parameter Weibull and Gamma distributions. Reliability estimations and predictions are used to evaluate, when the estimation of distributionsparameters is done. To estimate good operating condition in a building, the reliability of the air conditioning system that supplies conditioned air to the several companies’ departments is checked. This air conditioning system is divided into two systems, namely the main chilled water system and the ten air handling systems that serves the ten departments. In a chilled-water system the air conditioner cools water down to 40 - 45oF (4 - 7oC. The chilled water is distributed throughout the building in a piping system and connected to air condition cooling units wherever needed. Data analysis has been done with support a computer aided reliability software, with the application of the Weibull and Gamma distributions it is indicated that the reliability for the systems equal to 86.012% and 77.7% respectively . A comparison between the two important families of distribution functions, namely, the Weibull and Gamma families is studied. It is found that Weibull method has performed well for decision making .

  19. Control Techniques in Heating, Ventilating and Air Conditioning Systems

    Directory of Open Access Journals (Sweden)

    H. Mirinejad

    2008-01-01

    Full Text Available Problem statement: Heating, Ventilating and Air Conditioning (HVAC systems are among the main installations in residential, commercial and industrial buildings. The purpose of the HVAC systems is normally to provide a comfortable environment in terms of temperature, humidity and other environmental parameters for the occupants as well as to save energy. Achieving these objectives requires a suitable control system design. Approach: In this overview, thermal comfort level and ISO comfort field is introduced, followed by a review and comparison of the main existing control techniques used in HVAC systems to date. Results: The present overview shows that intelligent controllers which are based on the human sensation of thermal comfort have a better performance in providing thermal comfort as well as energy saving than the traditional controllers and those based on a model of the HVAC system. Conclusion: Such an overview provides an insight into current control methods in HVAC systems and can help scholars and HVAC learners to have the comprehensive information about a variety of control techniques in the field of HVAC and therefore to better design a proper controller for their work

  20. Assessing summertime urban air conditioning consumption in a semiarid environment

    Science.gov (United States)

    Salamanca, F.; Georgescu, M.; Mahalov, A.; Moustaoui, M.; Wang, M.; Svoma, B. M.

    2013-09-01

    Evaluation of built environment energy demand is necessary in light of global projections of urban expansion. Of particular concern are rapidly expanding urban areas in environments where consumption requirements for cooling are excessive. Here, we simulate urban air conditioning (AC) electric consumption for several extreme heat events during summertime over a semiarid metropolitan area with the Weather Research and Forecasting (WRF) model coupled to a multilayer building energy scheme. Observed total load values obtained from an electric utility company were split into two parts, one linked to meteorology (i.e., AC consumption) which was compared to WRF simulations, and another to human behavior. WRF-simulated non-dimensional AC consumption profiles compared favorably to diurnal observations in terms of both amplitude and timing. The hourly ratio of AC to total electricity consumption accounted for ˜53% of diurnally averaged total electric demand, ranging from ˜35% during early morning to ˜65% during evening hours. Our work highlights the importance of modeling AC electricity consumption and its role for the sustainable planning of future urban energy needs. Finally, the methodology presented in this article establishes a new energy consumption-modeling framework that can be applied to any urban environment where the use of AC systems is prevalent.

  1. Multivariate analysis comparing microbial air content of an air-conditioned building and a naturally ventilated building over one year

    Science.gov (United States)

    Parat, Sylvie; Perdrix, Alain; Fricker-Hidalgo, Hélène; Saude, Isabelle; Grillot, Renee; Baconnier, Pierre

    Heating, ventilation and air-conditioning (HVAC) may be responsible for the production and spread of airborne microorganisms in office buildings. In order to compare airborne microbiological flora in an air-conditioned building with that in a naturally ventilated building, eight sets of measurements were made over a 1-year period. Concurrently with other environmental measurements, air samples were collected in each building, from three offices and from the outdoor air, using the Andersen single-stage sampler. Three different media were used to culture fungi, staphylococci and mesophilic bacteria. Multivariate analysis revealed a group of offices more contaminated than others, and a marked seasonal variation in fungal concentrations. A comparison of mean levels of microorganisms measured in the two buildings showed that the air microbial content was significantly higher and more variable in the naturally ventilated building than in the air-conditioned building. Moreover, in the naturally ventilated building, the interior fungal content was strongly dependent on the outdoor content, while in the air-conditioned building fungal concentrations remained constant despite significant variations measured outside. This was confirmed by a statistical comparison of the correlation coefficients between indoor and outdoor concentrations. No difference was observed regarding gaseous pollutants and temperature, but relative humidity was significantly higher in the air-conditioned building. The effect of HVAC was to prevent the intake of outdoor particles and to dilute the indoor concentrations. These results are consistent with the presence of high-efficiency filters and a steam humidifier in the HVAC system under study.

  2. Hygiene guideline for the planning, installation, and operation of ventilation and air-conditioning systems in health-care settings – Guideline of the German Society for Hospital Hygiene (DGKH

    Directory of Open Access Journals (Sweden)

    Külpmann, Rüdiger

    2016-02-01

    Full Text Available Since the publication of the first “Hospital Hygiene Guideline for the implementation and operation of air conditioning systems (HVAC systems in hospitals” ( in 2002, it was necessary due to the increase in knowledge, new regulations, improved air-conditioning systems and advanced test methods to revise the guideline. Based on the description of the basic features of ventilation concepts, its hygienic test and the usage-based requirements for ventilation, the DGKH section “Ventilation and air conditioning technology” attempts to provide answers for the major air quality issues in the planning, design and the hygienically safe operation of HVAC systems in rooms of health care.

  3. Curvas de isodose no ar em uma sala de mamografia Air isodose curves in a mammography room

    Directory of Open Access Journals (Sweden)

    Maria Cecília Baptista Todeschini Adad

    2008-08-01

    Full Text Available OBJETIVO: O objetivo deste trabalho foi obter a distribuição da dose absorvida no ar numa sala de mamografia durante a simulação de um exame mamográfico, visando a reavaliar a necessidade do uso de barreiras de proteção radiológica nessas salas e a exposição das pacientes. MATERIAIS E MÉTODOS: Os dados da dose absorvida no ar foram coletados mediante simulação de exame mamográfico de um simulador de mama de BR12, em um equipamento Senograph 600T-Senix HF. Para tal, 158 pastilhas de CaSO4 foram distribuídas em malhas retangulares em torno do bucky, em três alturas distintas. RESULTADOS: O valor mais elevado da dose absorvida no ar, registrado no ponto central da superfície do simulador, centralizado no feixe primário, foi de 8,33 mGy, enquanto o menor valor registrado, devido exclusivamente ao espalhamento, foi de 0,008 mGy. CONCLUSÃO: Estes resultados indicam que o uso de blindagem adicional nas salas de mamografia pode não ser necessário na incidência crânio-caudal, desde que as distâncias consideradas neste trabalho sejam observadas. No entanto, eles enfatizam a necessidade de proteção da paciente.OBJECTIVE: The present study was aimed at evaluating the absorbed dose in air in a medical examination room during a mammography simulation, to re-evaluate the level of patients' exposure as well as the necessity of radiological protection barriers. MATERIALS AND METHODS: Data regarding absorbed dose in air were collected during mammography simulation with a BR12 breast phantom in a Senograph 600T-Senix HF mammograph. For this purpose, 158 CaSO4 dosimeters were distributed over rectangular grids around the bucky at three different heights. RESULTS: The highest value for absorbed dose in air recorded on the center of the phantom surface and centralized on the primary beam was 8.33 mGy, while the lowest value recorded exclusively due to radiation scattering was 0.008 mGy. CONCLUSION: These results indicate that the utilization

  4. Plant Leaf Imaging using Time of Flight Camera under Sunlight, Shadow and Room Conditions

    DEFF Research Database (Denmark)

    Kazmi, Wajahat; Foix, Sergi; Alenya, Guillem

    2012-01-01

    in order to optimize the camera calibration. Our analysis is based on several statistical metrics estimated from the ToF data. We explain the estimation of the metrics and propose a method of predicting the deteriorating behavior of the data in each condition using camera flags. Finally, we also propose...

  5. Experimental investigation of integrated air purifying technology for bioaerosol removal and inactivation in central air-conditioning system

    Institute of Scientific and Technical Information of China (English)

    ZHENG Xiaohong; LIU Hongmin; YE Xiaojiang; LI Kejun; WANG Ruzhu; ZHAO Liping; Lisa. X. Xu; CHEN Yazhu; JIN Xinqiao; GU Bo; BAI Jingfeng

    2004-01-01

    In this research, high voltage static electricity and ultraviolet technologies were integrated to an air purifying device which can be used to trap and kill airborne bacteria and viruses in central air-conditioning systems. An experimental platform was built to mimic the central air system, in which the efficacy of the newly built device was examined. In addition to the standard physical and chemical tests, bacteriophages were used to simulate airborne viruses in the experimental system. The bacteriophage suspension was aerosolized into the air with ultrasonic wave atomization. The result showed that more than 86% removal efficiency of micro-particles (<10 micron in diameter) were removed after the device was in operation in a building and more than 95% of bacteriophages in the experimental system. It is concluded that the integrated air purifier is suitable for controlling air quality and preventing virus transmission through the central air system.

  6. Analyses of an air conditioning system with entropy generation minimization and entransy theory

    Science.gov (United States)

    Yan-Qiu, Wu; Li, Cai; Hong-Juan, Wu

    2016-06-01

    In this paper, based on the generalized heat transfer law, an air conditioning system is analyzed with the entropy generation minimization and the entransy theory. Taking the coefficient of performance (denoted as COP) and heat flow rate Q out which is released into the room as the optimization objectives, we discuss the applicabilities of the entropy generation minimization and entransy theory to the optimizations. Five numerical cases are presented. Combining the numerical results and theoretical analyses, we can conclude that the optimization applicabilities of the two theories are conditional. If Q out is the optimization objective, larger entransy increase rate always leads to larger Q out, while smaller entropy generation rate does not. If we take COP as the optimization objective, neither the entropy generation minimization nor the concept of entransy increase is always applicable. Furthermore, we find that the concept of entransy dissipation is not applicable for the discussed cases. Project supported by the Youth Programs of Chongqing Three Gorges University, China (Grant No. 13QN18).

  7. Diffusion of Moisture in a Cigarette Tobacco Column at Room Conditions

    Directory of Open Access Journals (Sweden)

    Oh IH

    2014-12-01

    Full Text Available The moisture content of cigarettes has a significant impact on the shelf life and the taste of the products as well as various physical properties of cigarettes including loose ends, burning rate, hardness, and pressure drop. To prepare better products it would be helpful to develop proper mathematical models for the simulation of moisture diffusion characteristic dynamics in a cigarette. In this work, four mathematical models have been developed with appropriate assumptions adequate to analyze the dynamics of moisture diffusion in cigarettes. The simulation of the derived models was also carried out in this work. When the theoretical values produced from each model were compared with the corresponding experimental data, it was found that three models (I-II, II, III can be used to explain the behavior of moisture in cigarettes. Convective mass transfer coefficients and effective moisture diffusivities that fit best were obtained by a regression analysis of the model using the experimental values. The simulation of the models revealed that there is no significant positional dependence of moisture content inside a tobacco column because most of the moisture dries out radially through the cigarette wrapper. The drying rate of moisture in a tobacco column is rarely affected by effective moisture diffusivity, but strongly influenced by convective mass transfer. To prevent quality deterioration of the cigarettes during long-term storage, it is concluded that improvement of the cigarette wrapper and air tightness of the package, which are directly related to the convective mass transfer, is very important.

  8. Novel compact sorption generators for car air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Tamainot-Telto, Z.; Metcalf, S.J.; Critoph, R.E. [School of Engineering, University of Warwick, Gibet Hill Road, Coventry CV4 7AL (United Kingdom)

    2009-06-15

    A prototype compact generator using the activated carbon-ammonia pair based on the plate heat exchanger concept has been designed and built at Warwick University. The novel generator has low thermal mass and good heat transfer. The heat exchanger uses nickel-brazed shims and spacers to create adsorbent layers only 4 mm thick between pairs of liquid flow channels of very low thermal mass. The prototype sorption generator manufactured was evaluated under EU car air conditioning test conditions. The prototype sorption generator is described and its experimental performance reported. While driven with waste heat from the engine coolant water (at 90 C), a pair of the current prototype generators (loaded with about 1 kg of activated carbon) operating out of phase has produced an average cooling power 1.6 kW with about 2 kW peaks. The typical average COP obtained is 0.22. (author) [French] Un prototype du generateur compact, base sur le concept des echangeurs de chaleur a plaques et utilisant la paire charbon actif-ammoniac, a ete concu et construit a l'Universite de Warwick. Le nouveau generateur a une faible inertie thermique et un excellent transfert de chaleur. L' echangeur utilise des plaques ayant des micro-canaux et des intercalaires brases au Nickel pour creer des couches d'adsorbant de 4 mm d'epaisseur entre les paires de plaques a l'interieur desquelles circule le fluide liquide. Le prototype du generateur a sorption ainsi fabrique a ete teste suivant des conditions prescrites par la Norme Europeenne de la Climatisation Automobile. Le prototype du generateur a sorption est decrit et ses performances experimentales presentees. Une paire dudit prototype (contenant chacun 1 kg the charbon actif), operant avec dephasage et ulisant des pertes thermiques en provenance de l'eau de refroidissement de moteur (a 90 C), a produit une puissance frigorifique moyenne de 1.6 kW avec une valeur maximum de 2 kW. La valeur typique du COP moyen est de

  9. Analysis of air-conditioning and drying processes using spreadsheet add-in for psychrometric data

    Directory of Open Access Journals (Sweden)

    E.O. Diemuodeke

    2010-01-01

    Full Text Available A spreadsheet add-in for the psychrometric data at any barometric pressure and in the air-conditioning and drying temperatureranges was developed using appropriate correlations. It was then used to simulate and analyse air-conditioning and dryingprocesses in the Microsoft Excel environment by exploiting its spreadsheet and graphic potentials. The package allowsone to determine the properties of humid air at any desired state, and to simulate and analyse air-conditioning as well asdrying processes. This, as a teaching tool, evokes the intellectual curiosity of students and enhances their interest and abilityin the thermodynamics of humid-air processes.

  10. Does urban vegetation mitigate air pollution in northern conditions?

    Science.gov (United States)

    Setälä, Heikki; Viippola, Viljami; Rantalainen, Anna-Lea; Pennanen, Arto; Yli-Pelkonen, Vesa

    2013-12-01

    It is generally accepted that urban vegetation improves air quality and thereby enhances the well-being of citizens. However, empirical evidence on the potential of urban trees to mitigate air pollution is meager, particularly in northern climates with a short growing season. We studied the ability of urban park/forest vegetation to remove air pollutants (NO2, anthropogenic VOCs and particle deposition) using passive samplers in two Finnish cities. Concentrations of each pollutant in August (summer; leaf-period) and March (winter, leaf-free period) were slightly but often insignificantly lower under tree canopies than in adjacent open areas, suggesting that the role of foliage in removing air pollutants is insignificant. Furthermore, vegetation-related environmental variables (canopy closure, number and size of trees, density of understorey vegetation) did not explain the variation in pollution concentrations. Our results suggest that the ability of urban vegetation to remove air pollutants is minor in northern climates.

  11. Computerized Simulation of Automotive Air-Conditioning System: Development of Mathematical Model and Its Validation

    Directory of Open Access Journals (Sweden)

    Haslinda Mohamed Kamar

    2012-03-01

    Full Text Available A semi-empirical model for simulating thermal and energy performance of an automotive air-conditioning (AAC system in passenger vehicles has been developed. The model consists of two sections, namely empirical evaporator correlations and dynamic load simulation. The correlations used consider sensible and latent heat transfer performance of the evaporator coil. The correlations were obtained from the experimental data of actual air conditioning system for a compact size passenger car. The sensible heat transfer correlation relates the evaporator air off dry-bulb temperature to inlet air dry-bulb temperature, humidity ratio, evaporator air velocity, condenser inlet air dry-bulb temperature, condenser air velocity and compressor speed. The latent heat transfer correlation relates the coil air-off humidity ratio to the same six independent variables. The dynamic load simulation model was developed based on the z-transfer function method with a one-minute time step. The cooling load calculations were performed using heat gain weighting factors. Heat extraction rate and cabin air dry-bulb temperature calculations were carried out using air temperature weighting factors. The empirical evaporator sensible and latent heat transfer correlations were embedded in the loads calculation program to enable the determination of evaporator inlet and outlet air conditions, the cabin air temperature and relative humidity. Comparisons with road test data indicated that the program was capable of predicting the performance of the automotive air-conditioning system with reasonable accuracy.

  12. 75 FR 6338 - Protection of Stratospheric Ozone: New Substitute in the Motor Vehicle Air Conditioning Sector...

    Science.gov (United States)

    2010-02-09

    ... to use conditions as a substitute for CFC-12 in motor vehicle air conditioning. The proposed... AGENCY 40 CFR Part 82 Protection of Stratospheric Ozone: New Substitute in the Motor Vehicle Air Conditioning Sector Under the Significant New Alternatives Policy (SNAP) Program AGENCY: Environmental...

  13. Poaceae pollen in the air depending on the thermal conditions

    Science.gov (United States)

    Myszkowska, Dorota

    2014-07-01

    The relationship between the meteorological elements, especially the thermal conditions and the Poaceae pollen appearance in the air, were analysed as a basis to construct a useful model predicting the grass season start. Poaceae pollen concentrations were monitored in 1991-2012 in Kraków using the volumetric method. Cumulative temperature and effective cumulative temperature significantly influenced the season start in this period. The strongest correlation was seen as the sum of mean daily temperature amplitudes from April 1 to April 14, with mean daily temperature >15 °C and effective cumulative temperature >3 °C during that period. The proposed model, based on multiple regression, explained 57 % of variation of the Poaceae season starts in 1991-2010. When cumulative mean daily temperature increased by 10 °C, the season start was accelerated by 1 day. The input of the interaction between these two independent variables into the factor regression model caused the increase in goodness of model fitting. In 2011 the season started 5 days earlier in comparison with the predicted value, while in 2012 the season start was observed 2 days later compared to the predicted day. Depending on the value of mean daily temperature from March 18th to the 31st and the sum of mean daily temperature amplitudes from April 1st to the 14th, the grass pollen seasons were divided into five groups referring to the time of season start occurrence, whereby the early and moderate season starts were the most frequent in the studied period and they were especially related to mean daily temperature in the second half of March.

  14. The Future of Air Conditioning for Buildings - Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Young, J. [Navigant Consulting Inc., Burlington, MA (United States); Fuhrman, J. [Navigant Consulting Inc., Burlington, MA (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-07-01

    The Building Technologies Office (BTO), within the U.S. Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy, works with researchers and industry to develop and deploy technologies that can substantially reduce energy consumption and greenhouse gas (GHG) emissions in residential and commercial buildings. Air conditioning (A/C) systems in buildings contribute to GHG emissions both directly through refrigerant emissions, as well as indirectly through fossil fuel combustion for power generation. BTO promotes pre-competitive research and development (R&D) on next-generation HVAC technologies that support the phase down of hydrofluorocarbon (HFC) production and consumption, as well as cost-effective energy efficiency improvements. Over the past several decades, product costs and lifecycle cooling costs have declined substantially in many global markets due to improved, higher-volume manufacturing and higher energy efficiency driven by R&D investments and efficiency policies including minimum efficiency standards and labeling programs.1 This report characterizes the current landscape and trends in the global A/C market, including discussion of both direct and indirect climate impacts, and potential global warming impacts from growing global A/C usage. The report also documents solutions that can help achieve international goals for energy efficiency and GHG emissions reductions. The solutions include pathways related to low-global warming potential2 (GWP) refrigerants, energy efficiency innovations, long-term R&D initiatives, and regulatory actions. DOE provides, with this report, a fact-based vision for the future of A/C use around the world. DOE intends for this vision to reflect a broad and balanced aggregation of perspectives. DOE brings together this content in an effort to support dialogue within the international community and help keep key facts and objectives at the forefront among the many important discussions.

  15. Working conditions in the engine department - A qualitative study among engine room personnel on board Swedish merchant ships.

    Science.gov (United States)

    Lundh, Monica; Lützhöft, Margareta; Rydstedt, Leif; Dahlman, Joakim

    2011-01-01

    The specific problems associated with the work on board within the merchant fleet are well known and have over the years been a topic of discussion. The work conditions in the engine room (ER) are demanding due to, e.g. the thermal climate, noise and awkward working postures. The work in the engine control room (ECR) has over recent years undergone major changes, mainly due to the introduction of computers on board. In order to capture the impact these changes had implied, and also to investigate how the work situation has developed, a total of 20 engine officers and engine ratings were interviewed. The interviews were semi-structured and Grounded Theory was used for the data analysis. The aim of the present study was to describe how the engine crew perceive their work situation and working environment on board. Further, the aim was to identify areas for improvements which the engine crew consider especially important for a safe and effective work environment. The result of the study shows that the design of the ECR and ER is crucial for how different tasks are performed. Design which does not support operational procedures and how tasks are performed risk inducing inappropriate behaviour as the crew members' are compelled to find alternative ways to perform their tasks in order to get the job done. These types of behaviour can induce an increased risk of exposure to hazardous substances and the engine crew members becoming injured.

  16. Cooling Performance Characteristics on Mobile Air-Conditioning System for Hybrid Electric Vehicles

    OpenAIRE

    Ho-Seong Lee; Moo-Yeon Lee

    2013-01-01

    This study investigates the cooling performance characteristics of the mobile air-conditioning system using R744 (CO2) for the hybrid electric vehicle as an alternative to both the R-134a and the conventional air-conditioning system. The developed air-conditioning system is operated with an electric driven compressor in the battery driving mode and a belt driven compressor in the engine driving mode. The cooling performance characteristics of the developed system have been analyzed by experim...

  17. Degradation of cationic red GTL by catalytic wet air oxidation over Mo-Zn-Al-O catalyst under room temperature and atmospheric pressure.

    Science.gov (United States)

    Xu, Yin; Li, Xiaoyi; Cheng, Xiang; Sun, Dezhi; Wang, Xueye

    2012-03-06

    To overcome the drawback of catalytic wet air oxidation (CWAO) with high temperature and high pressure, the catalytic activity of Mo-Zn-Al-O catalyst for degradation of cationic red GTL under room temperature and atmospheric pressure was investigated. Mo-Zn-Al-O catalyst was prepared by coprecipitation and impregnation. XRD, TG-DTG, and XPS were used to characterize the resulting sample. Central composition design using response surface methodology was employed to optimize correlation of factors on the decolorization of cationic red GTL. The results show that the optimal conditions of pH value, initial concentration of dye and catalyst dosage were found to be 4.0, 85 mg/L and 2.72 g/L, respectively, for maximum decolorization of 80.1% and TOC removal of 50.9%. Furthermore, the reaction on the Mo-Zn-Al-O catalyst and degradation mechanism of cationic red GTL was studied by Electron spin resonance (ESR) and GC-MS technique. The possible reaction mechanism was that the Mo-Zn-Al-O catalyst can efficiently react with adsorbed oxygen/H(2)O to produce ·OH and (1)O(2) and finally induce the degradation of cationic red GTL. GC-MS analysis of the degradation products indicates that cationic red GTL was initiated by the cleavage of -N ═ N- and the intermediates were further oxidized by ·OH or (1)O(2).

  18. PRINCIPLES OF SAFETY MANAGEMENT OF AIR TRAFFIC FLOWS AND CAPACITY UNDER UNCERTAINTY CONDITIONS

    Directory of Open Access Journals (Sweden)

    Wang Bo

    2016-11-01

    Full Text Available Purpose: The aim of this study is to investigate the general principles of safety and capacity management in Aeronautical systems regarding air traffic flows operations under uncertainty conditions. In this work the theoretical framework assessing at the same time both the uncertainty model and flight plans model are proposed. Methods: To study features of safety of air traffic flows and capacity under uncertainty conditions were built the original probabilistic models including Bayesian Network for flight plan and air traffic control sector model based on Poisson Binomial Distribution. Results: We obtained models for safety management of air traffic flows and capacity under uncertainty conditions. We discussed appropriate approach for estimating the parameters of safety of air traffic flows and capacity under uncertainty and Markovian uncertainty model for the flight plan. Discussion: We developed the Bayesian Network for flight plan and air traffic control sector models for safety management of air traffic flows and capacity under uncertainty conditions.

  19. Solar thermal plant of air tube for solar air conditioning; Planta Solar Termica de tubos de vacio para aire acondicionado solar

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, J. C.; Lopez, J.; Coronas, A.

    2004-07-01

    The present implementation of refrigeration and air conditioning technologies driven by thermal solar energy is very limited although there is a great market demand for them for environmental reasons and security of energy supply. In this paper it is presented a detailed technical description of the solar plant installed at the technological Innovation Centre CREVER, and an example of a complete energy analysis of this plant working under the required conditions to be used for solar air conditioning applications. Also it is included a review of solar air conditioning systems state of the art. (Author)

  20. Human requirements in future air-conditioned environments

    DEFF Research Database (Denmark)

    Fanger, Povl Ole

    2002-01-01

    in the built environment: better indoor air quality increases productivity and decreases SBS symptoms; unnecessary indoor pollution sources should be avoided; the air should be served cool and dry to the occupants; personalized ventilation, i.e. small amounts of clean air, should be provided gently, close...... though existing standards and guidelines are met. A paradigm shift from rather mediocre to excellent indoor environments is foreseen in buildings in the 21st century. Based on existing information and on new research results, five principles are suggested as elements behind a new philosophy of excellence...

  1. Human requirements in future air-conditioned environments

    DEFF Research Database (Denmark)

    Fanger, Povl Ole

    1999-01-01

    : better indoor air quality increases productivity and decreases SBS symptoms; unnecessary indoor pollution sources should be avoided; the air should be served cool and dry to the occupants; small amounts of clean air should be served gently, close to the breathing zone of each individual; individual......, even though existing standards and guidelines are met. A paradigm shift from rather mediocre to excellent indoor environments is foreseen in the 21st century. Based on existing information and on new research results, five principles are suggested as elements behind a new philosophy of excellence...

  2. Assessing indoor low velocity measurements. Pt. 1: Effect of measuring method on quantifying room air flow - comparison LDA - thermal anemometers; Messtechnische Erfassung characteristischer Kenngroessen von Raumluftstroemungen. T. 1: Einfluss der Messmethode bei der Bewertung von Raumluftstroemungen - Vergleich LDA - thermische Anemometer

    Energy Technology Data Exchange (ETDEWEB)

    Sefker, T.; Wolters, T. [Gebr. Trox GmbH, Neukirchen-Vluyn (Germany)

    2004-03-01

    Within the scope of an EU research project, Thermal Anemometers (TA) from different manufacturers were compared by means of a 'Laser Doppler Anemometer' (LDA) under model room conditions. Comparisons were carried out with different kinds of aerodynamic room flows, air change rates and heat loads. This article presents the measuring principle of thermal and 'Laser Doppler Anemometers', it demonstrates the measurements in the scale 1:1, it also demonstrates how the measured air velocities for the estimation of the aerodynamic room flows by means of statistical methods are developed and it presents the results of these measurements. (orig.) [German] Im Rahmen eines EU-Forschungsprojekts wurden Thermische Anemometer (TA) verschiedener Hersteller unter Modellraumbedingungen mit einem Laser Doppler Anemometer (LDA) verglichen. Vergleiche wurden fuer verschiedene Raumstroemungsarten, Luftwechsel und Raumlasten durchgefuehrt. Dieser Beitrag stellt das Messprinzip von thermischen und Laser Doppler Anemometern vor, demonstriert die Messungen im Massstab 1:1, zeigt wie die gemessenen Luftgeschwindigkeiten zur Beurteilung der Raumstroemung mittels statistischen Methoden weiterverarbeitet wurden und praesentiert die Ergebnisse dieser Betrachtungen. (orig.)

  3. An AES Study of the Room Temperature Surface Conditioning of Technological Metal Surfaces by Electron Irradiation

    CERN Document Server

    Scheuerlein, C; Taborelli, M; Brown, A; Baker, M A

    2002-01-01

    The modifications to technological copper and niobium surfaces induced by 2.5 keV electron irradiation have been investigated in the context of the conditioning process occurring in particle accelerator ultra high vacuum systems. Changes in the elemental surface composition have been found using Scanning Auger Microscopy (SAM) by monitoring the carbon, oxygen and metal Auger peak intensities as a function of electron irradiation in the dose range 10-6 to 10-2 C mm-2. The surface analysis results are compared with electron dose dependent secondary electron and electron stimulated desorption yield measurements. Initially the electron irradiation causes a surface cleaning through electron stimulated desorption, in particular of hydrogen. During this period both the electron stimulated desorption and secondary electron yield decrease as a function of electron dose. When the electron dose exceeds 10-4 C mm-2 electron stimulated desorption yields are reduced by several orders of magnitude and the electron beam indu...

  4. Clean air with positive energy balance. Elisabeth hospital in Essen uses energy optimized air conditioning systems; Saubere Luft mit positiver Energiebilanz. Elisabeth-Krankenhaus in Essen nutzt energieoptimierte Lueftungsgeraete

    Energy Technology Data Exchange (ETDEWEB)

    Dunker, Ralf

    2009-02-15

    Thinking on a long-term basis, spontaneously acting - according to this slogan the Elizabeth hospital in Essen (Federal Republic of Germany) converts potentials of energy saving with the facility management. Parallel to the change of the endoscope department and the station Barbara with its 35 beds, the hospital had installed particularly energy-saving air conditioning systems which can be cleaned easily. A view behind the doors of the technology rooms.

  5. Impact of air conditioning system operation on increasing gases emissions from automobile

    Science.gov (United States)

    Burciu, S. M.; Coman, G.

    2016-08-01

    The paper presents a study concerning the influence of air conditioning system operation on the increase of gases emissions from cars. The study focuses on urban operating regimes of the automobile, regimes when the engines have low loads or are operating at idling. Are presented graphically the variations of pollution emissions (CO, CO2, HC) depending of engine speed and the load on air conditioning system. Additionally are presented, injection duration, throttle position, the mechanical power required by the compressor of air conditioning system and the refrigerant pressure variation on the discharge path, according to the stage of charging of the air conditioning system.

  6. Analysis on Thermodynamic Perfectibility of Room Air Conditioners%房间空调器的热力学完善度分析

    Institute of Scientific and Technical Information of China (English)

    李晓凤; 马一太; 闫秋辉

    2013-01-01

    According to analysis on the energy efficiency standards of the constant speed room air conditioner and the variable speed type, differences between the two kinds of air conditioners exist in division standard, grades of energy efficiency and outdoor temperature starting refrigeration. Therefore, a survey was made about cooling capacity and EER as well as energy efficiency grades of the constant and variable speed room air conditioners. The thermodynamic perfectibility of the two types of room air conditioners was calculated for the performance evaluation. The calculation results show that energy efficiency standard of variable speed room air conditioners in 2008 is lower than that of constant room air conditioners. A new energy efficiency standard of the variable speed air conditioner is suggested in accordance with the consistent thermodynamic perfectibility.%  通过对定速与转速可控房间空调器能效标准的分析,发现两类房间空调器的能效划分标准、划分等级以及制冷运行室外温度发生时间均有不同的规定。因此对国内市场上的定速房间空调器制冷量和制冷循环的能效比(EER)、转速可控房间空调器制冷量和制冷季节能效比(SEER)、以及定速房间空调器与转速可控房间空调器的能效等级现状等方面进行了调研统计。利用热力学完善度对两类房间空调器能效等级进行计算,发现2008版转速可控房间空气调节器的能效等级的热力学完善度偏低,根据热力学完善度相一致的原则,提出转速可控房间空调器新的能效标准等级的建议。

  7. COMPOSITION CHANGES IN REFRIGERANT BLENDS FOR AUTOMOTIVE AIR CONDITIONING

    Science.gov (United States)

    Three refrigerant blends used to replace CFC-12 in automotive air conditioners were evaluated for composition changes due to typical servicing and leakage. When recommended service procedures were followed, changes in blend compositions were relatively small. Small changes in b...

  8. 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.

  9. Air Filtration as Protection against Fouling of Ventilation and Air Conditioning Units

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Lajčíková, Ariana

    2005-01-01

    Currently, air filters are one of the most critical components of air treatment systems as they decontaminate the air delivered to living space. During the operation, however, the level of harmful surface deposits increases, and at certain times, an uncleaned filter can itself become a source...

  10. Noise control considerations for patient rooms

    Science.gov (United States)

    Davenny, Benjamin

    2005-09-01

    The patient room envelope is a path between outside noise sources and the patient receiver. Within the patient room there are several sources including televisions, clinical monitor alarms, medical pumps, etc. Noise control in patient rooms relies on a combination of the sound transmission loss of the patient room envelope and the level of background sound at the patient's head. Guidelines published by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), American Institute of Architects (AIA), and the U.S. Department of Defense for background noise and sound transmission loss in patient rooms will be discussed. Appropriate levels, spectra, and temporal characteristics of background sound at the patient head location may be helpful in raising the threshold of annoying sounds. Various means of personal hearing protection for patients will be discussed. Sound-pressure levels in patient rooms reported in previous literature will also be discussed.

  11. Development of residential solar air conditioning system for electricity power peak cut 3

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Gwon Jong [Korea Inst. of Energy and Resources, Daeduk (Korea, Republic of)

    1995-12-31

    In this research, the converter rectifier unit of the inverter air conditioner is substituted into the bidirectional PWM converter. The DC/DC power converter is established on the DC link between the photovoltaic array and the inverter air conditioner, and the photovoltaic air conditioning system which can be parallel driven which utility is developed. (author). 35 ref., 112 figs.

  12. Large Eddy Simulation of Air Escape through a Hospital Isolation Room Single Hinged Doorway--Validation by Using Tracer Gases and Simulated Smoke Videos.

    Science.gov (United States)

    Saarinen, Pekka E; Kalliomäki, Petri; Tang, Julian W; Koskela, Hannu

    2015-01-01

    The use of hospital isolation rooms has increased considerably in recent years due to the worldwide outbreaks of various emerging infectious diseases. However, the passage of staff through isolation room doors is suspected to be a cause of containment failure, especially in case of hinged doors. It is therefore important to minimize inadvertent contaminant airflow leakage across the doorway during such movements. To this end, it is essential to investigate the behavior of such airflows, especially the overall volume of air that can potentially leak across the doorway during door-opening and human passage. Experimental measurements using full-scale mock-ups are expensive and labour intensive. A useful alternative approach is the application of Computational Fluid Dynamics (CFD) modelling using a time-resolved Large Eddy Simulation (LES) method. In this study simulated air flow patterns are qualitatively compared with experimental ones, and the simulated total volume of air that escapes is compared with the experimentally measured volume. It is shown that the LES method is able to reproduce, at room scale, the complex transient airflows generated during door-opening/closing motions and the passage of a human figure through the doorway between two rooms. This was a basic test case that was performed in an isothermal environment without ventilation. However, the advantage of the CFD approach is that the addition of ventilation airflows and a temperature difference between the rooms is, in principle, a relatively simple task. A standard method to observe flow structures is dosing smoke into the flow. In this paper we introduce graphical methods to simulate smoke experiments by LES, making it very easy to compare the CFD simulation to the experiments. The results demonstrate that the transient CFD simulation is a promising tool to compare different isolation room scenarios without the need to construct full-scale experimental models. The CFD model is able to reproduce

  13. Tension-Tension Fatigue Behavior of Unidirectional C/Sic Ceramic-Matrix Composite at Room Temperature and 800 °C in Air Atmosphere

    Directory of Open Access Journals (Sweden)

    Longbiao Li

    2015-06-01

    Full Text Available The tension-tension fatigue behavior of unidirectional C/SiC ceramic-matrix composite at room temperature and 800 °C under air has been investigated. The fatigue hysteresis modulus and fatigue hysteresis loss energy corresponding to different number of applied cycles have been analyzed. The fatigue hysteresis loops models for different interface slip cases have been derived based on the fatigue damage mechanism of fiber slipping relative to matrix in the interface debonded region upon unloading and subsequent reloading. The fiber/matrix interface shear stress has been estimated for different numbers of applied cycles. By combining the interface shear stress degradation model and fibers strength degradation model with fibers failure model, the tension-tension fatigue life S-N curves of unidirectional C/SiC composite at room temperature and 800 °C under air have been predicted.

  14. Operative temperature and thermal sensation assessments in non-air-conditioned multi-storey hostels in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Dahlan, N.D. [Department of Architecture, Faculty of Design and Architecture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Jones, P.J.; Alexander, D.K. [Welsh School of Architecture, Cardiff University, Bute Building, King Edward VII Avenue, CF10 3NB (United Kingdom)

    2011-02-15

    This study assessed the influences of operative temperature on occupants' perceptions of indoor thermal condition in three non-air-conditioned multi-storey hostels in Klang Valley, Malaysia. The thermal conditions of 24 measured rooms were recorded with and without an operating ceiling fan from May until July 2007. Measurements were made simultaneously at three different floor levels, namely, at the first, fifth and top floor of each of the case study hostels. A questionnaire survey was completed by 298 female student occupants of the same case study hostels. The results suggested that even though a significance above p < 0.01 was recorded between the operative temperatures with and without fan operation, the temperature difference remained small, i.e., from 0.5 K to 1 K. The findings of the questionnaire survey showed that the occupants perceived the thermal conditions in rooms that were shaded with a projected balcony (shading ratio of 0.9), a long roof overhang (shading ratio of 1.6) and an operable window-to-wall ratio of 0.3 to be thermally comfortable. (author)

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  16. Francisella guangzhouensis sp. nov., isolated from air-conditioning systems.

    Science.gov (United States)

    Qu, Ping-Hua; Chen, Shou-Yi; Scholz, Holger C; Busse, Hans-Jürgen; Gu, Quan; Kämpfer, Peter; Foster, Jeffrey T; Glaeser, Stefanie P; Chen, Cha; Yang, Zhi-Chong

    2013-10-01

    Four strains (08HL01032(T), 09HG994, 10HP82-6 and 10HL1960) were isolated from water of air-conditioning systems of various cooling towers in Guangzhou city, China. Cells were Gram-stain-negative coccobacilli without flagella, catalase-positive and oxidase-negative, showing no reduction of nitrate, no hydrolysis of urea and no production of H2S. Growth was characteristically enhanced in the presence of l-cysteine, which was consistent with the properties of members of the genus Francisella. The quinone system was composed of ubiquinone Q-8 with minor amounts of Q-9. The polar lipid profile consisted of the predominant lipids phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, two unidentified phospholipids (PL2, PL3), an unidentified aminophospholipid and an unidentified glycolipid (GL2). The polyamine pattern consisted of the major compounds spermidine, cadaverine and spermine. The major cellular fatty acids were C10 : 0, C14 : 0, C16 : 0, C18 : 1ω9c and C18 : 1 3-OH. A draft whole-genome sequence of the proposed type strain 08HL01032(T) was generated. Comparative sequence analysis of the complete 16S and 23S rRNA genes confirmed affiliation to the genus Francisella, with 95 % sequence identity to the closest relatives in the database, the type strains of Francisella philomiragia and Francisella noatunensis subsp. orientalis. Full-length deduced amino acid sequences of various housekeeping genes, recA, gyrB, groEL, dnaK, rpoA, rpoB, rpoD, rpoH, fopA and sdhA, exhibited similarities of 67-92 % to strains of other species of the genus Francisella. Strains 08HL01032(T), 09HG994, 10HP82-6 and 10HL1960 exhibited highly similar pan-genome PCR profiles. Both the phenotypic and molecular data support the conclusion that the four strains belong to the genus Francisella but exhibit considerable divergence from all recognized Francisella species. Therefore, we propose the name Francisella guangzhouensis sp

  17. Audibility of dispersion error in room acoustic finite-difference time-domain simulation in the presence of absorption of air.

    Science.gov (United States)

    Saarelma, Jukka; Savioja, Lauri

    2016-12-01

    The finite-difference time-domain method has gained increasing interest for room acoustic prediction use. A well-known limitation of the method is a frequency and direction dependent dispersion error. In this study, the audibility of dispersion error in the presence of air absorption is measured. The results indicate that the dispersion error in the worst-case direction of the studied scheme gets masked by the air absorption at a phase velocity error percentage of 0.28% at the frequency of 20 kHz.

  18. Operator's Manual, Boiler Room Operations and Maintenance. Supplement A, Air Pollution Training Institute Self-Instructional Course SI-466.

    Science.gov (United States)

    Environmental Protection Agency, Research Triangle Park, NC. Air Pollution Training Inst.

    This Operator's Manual is a supplement to a self-instructional course prepared for the United States Environmental Protection Agency. This publication is the Boiler Room Handbook for operating and maintaining the boiler and the boiler room. As the student completes this handbook, he is putting together a manual for running his own boiler. The…

  19. A Comparison between Temperature-Controlled Laminar Airflow Device and a Room Air-Cleaner in Reducing Exposure to Particles While Asleep

    Science.gov (United States)

    Spilak, Michal P.; Sigsgaard, Torben; Takai, Hisamitsu; Zhang, Guoqiang

    2016-01-01

    People spend approximately one third of their life sleeping. Exposure to pollutants in the sleep environment often leads to a variety of adverse health effects, such as development and exacerbation of asthma. Avoiding exposure to these pollutants by providing a sufficient air quality in the sleep environment might be a feasible method to alleviate these health symptoms. We performed full-scale laboratory measurements using a thermal manikin positioned on an experimental bed. Three ventilation settings were tested: with no filtration system operated, use of portable air cleaner and use of a temperature-controlled laminar airflow (TLA) device. The first part of the experiment investigated the air-flow characteristics in the breathing zone. In the second part, particle removal efficiency was estimated. Measured in the breathing zone, the room air cleaner demonstrated high turbulence intensity, high velocity and turbulence diffusivity level, with a particle reduction rate of 52% compared to baseline after 30 minutes. The TLA device delivered a laminar airflow to the breathing zone with a reduction rate of 99.5%. During a periodical duvet lifting mimicking a subject’s movement in bed, the particle concentration was significantly lower with the TLA device compared to the room air cleaner. The TLA device provided a barrier which significantly reduced the introduction of airborne particles into the breathing zone. Further studies should be conducted for the understanding of the transport of resuspended particles between the duvet and the laying body. PMID:27898693

  20. Residential air-conditioning and climate change: voices of the vulnerable.

    Science.gov (United States)

    Farbotko, Carol; Waitt, Gordon

    2011-12-01

    Decreasing the risk of heat-stress is an imperative in health promotion, and is widely accepted as necessary for successful adaptation to climate change. Less well understood are the vulnerabilities that air-conditioning use exacerbates, and conversely, the need for the promotion of alternative strategies for coping with heat wave conditions. This paper considers these issues with a focus on the role of air-conditioning in the everyday life of elderly public housing tenants living alone, a sector of the population that has been identified as being at high risk of suffering heat stress. A vulnerability analysis of domestic air-conditioning use, drawing on literature and policy on air-conditioning practices and ethnographic research with households. Residential air-conditioning exacerbated existing inequities. Case studies of two specifically selected low-income elderly single person households revealed that such households were unlikely to be able to afford this 'solution' to increasing exposure to heat waves in the absence of energy subsidies. Residential air-conditioning use during heat waves caused unintended side-effects, such as system-wide blackouts, which, in turn, led to escalating electricity costs as power companies responded by upgrading infrastructure to cope with periods of excess demand. Air-conditioning also contributed to emissions that cause climate change. Residential air-conditioning is a potentially maladaptive technology for reducing the risk of heat stress.

  1. The system of thermoelectric air conditioning based on permeable thermoelements

    Directory of Open Access Journals (Sweden)

    Cherkez R. G.

    2009-04-01

    Full Text Available There is thermoelectric air conditioner unit on the basis of permeable cooling thermoelements presented. In thermoelectric air conditioner unit the thermoelectric effects and the Joule–Thomson effect have been used for the air stream cooling. There have been described the method of temperature distribution analysis, the determinations of energy conversion power characteristics and design style of permeable thermoelement with maximum coefficient of performance described. The results of computer analysis concerning the application of the thermoelement legs material on the basis of Bi2Te3 have shown the possibility of coefficient of performance increase by a factor of 1,6—1,7 as compared with conventional thermoelectric systems.

  2. The design of an embedded system for controlling humidity and temperature room

    Science.gov (United States)

    Dwi Teguh, R.; Didik Eko, S.; Laksono, Pringgo D.; Jamaluddin, Anif

    2016-11-01

    The aim of the system is to design an embedded system for maintenance confortable room. The confortable room was design by controlling temperature (on range 18 - 34 °C) and humidity (on range 40% - 70%.) of room condition. Temperature and humidity of room were maintained using four variable such as lamp for warm, water pump for distributing water vapour, a fan for air circullation and an exhaust-fan for air cleaner. The system was constucted both hardware (humidity sensor, microcontroller, pump, lamp, fan) and software (arduino IDE). The result shows that the system was perfectly performed to control room condition.

  3. Air Filtration as Protection against Fouling of Ventilation and Air Conditioning Units

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Lajčíková, Ariana

    2005-01-01

    Currently, air filters are one of the most critical components of air treatment systems as they decontaminate the air delivered to living space. During the operation, however, the level of harmful surface deposits increases, and at certain times, an uncleaned filter can itself become a source...... of undesirable contaminents influencing negatively the IAQ of a living space. This is the phenomenon that has been a subject of the current research. The article presents a new, alternative view on indoor air contaminents and filtration requirements. It describes alternative means of filtration and assesses...... issues of inadequate maintenance and/or long term use of applied air filters. An experimental method of evealuating the air quality by means of chemical analysis and state-of-the-art spectrometer is also described....

  4. [Sanitary and epidemiological evaluation of the ventilation and air-conditioning systems of public buildings].

    Science.gov (United States)

    Dvorianov, V V

    2012-01-01

    The microbial contamination of ventilation and air conditioning systems was examined in the administrative buildings. The author proposes a set of indicators, methods for determining the scope of investigations, as well as sampling tactics and criteria for evaluating the microbial contamination of the ventilation and air-conditioning systems. The content of yeasts and molds in the delivered air has been found to be of importance for evaluating the sanitary-and epidemiological state of ventilation systems.

  5. 2014 German refrigeration and air conditioning meeting. Proceedings; Deutsche Kaelte- und Klimatagung 2014. Tagungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The proceedings of the 2014 German refrigeration and air conditioning meeting contain contributions on the following topics: cryotechnology, fundamentals and materials for the refrigeration and heat pump technology, devices and components for the refrigeration and heat pump technology, applications of refrigeration technologies, air conditioning technology and heat pump applications, cryotechnology in biology and medicine, heat transfer and ventilation, guidelines and legal topics, refrigerant fluid - oil mixtures, control and surveillance, simulation and control, ambient air.

  6. Laminar flow operation room air quality on intraoperative equipment safety study%层流手术室动态空气质量对术中器械安全性的研究

    Institute of Scientific and Technical Information of China (English)

    白晓霞

    2013-01-01

    objective:Analyze the effect of laminar flow operation room air quality change on intraoperative equipment of bacterial colony growth ,take effective measures to ensure the air quality of laminar flow operation room , prevent intraoperative equipment pollution, improve the quality and safety of operation. Methods:Choose the area of 30M2, air cleanliness class of 100 laminar flow operation room to take 40 operations, operation time are more than 6 hours, the 40 operations were randomly divided into intervention group and control group. By monitoring the surface colony number of two groups of instruments, compare the bacterial colony number and intraoperative air colony number. Results:There is no bacterial growth in the intervention group or bacterial number was minimal, and no correlation with operation time. The gloves and intraoperative equipment of control group in 2 hours have bacterial growth, equipment covered have no bacterial growth. Conclusion:In the laminar flow purification air conditioning equipment running under good conditions, if we strictly control the operation flow and reduce the times of opening number in operation process ,we can ensure the air quality,and prevent equipment pollution.%目的:分析手术过程中细菌生长繁殖数量与手术时间的变化规律,采取有效措施减少各种感染因素,提高手术质量与安全。方法:通过空气培养监测手术过程中细菌菌落数,将细菌菌落数量与手术时间进行统计分析,得出两者之间的关系。结果:细菌数量与手术时间呈非线性关系,菌落数先增长后下降。结论:了解手术时间与细菌繁殖数量之间的规律对控制手术感染有较好的参考意义。

  7. The Effect of Air-Conditioning on Student and Teacher Performance.

    Science.gov (United States)

    Phoenix Union High School District, AZ. Dept. of Research and Planning.

    The literature is reviewed to see if research shows a relationship between student and teacher performance and air conditioning of classrooms. The benefits of air conditioning in promoting learning are substantiated by studies that are summarized but not cited. The relationship of the report to the Phoenix Union High School System Advisory…

  8. Automotive Air Conditioning and Heating; Automotive Mechanics (Advanced): 9047.04.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to provide the student with all the foundations necessary to become employable in the automotive air conditioning and heating trade. The course of study includes an orientation to the world of work, the elementary physics of air conditioning and heating, and laboratory experiments…

  9. Air-Puff Conditioning Audiometry: Extending Its Applicability with Multiply Handicapped Individuals.

    Science.gov (United States)

    Lancioni, G. E.; And Others

    1990-01-01

    This study examined the use of air-puff conditioning audiometry in the hearing assessment of 12 multiply handicapped (including severe/profound mental retardation) subjects, ages 9-32. Ten subjects reached criterion conditioning and then completed the hearing assessment with the air-puff procedure while one reached criterion with a modified…

  10. The Effect of Air-Conditioning on Student and Teacher Performance.

    Science.gov (United States)

    Phoenix Union High School District, AZ. Dept. of Research and Planning.

    The literature is reviewed to see if research shows a relationship between student and teacher performance and air conditioning of classrooms. The benefits of air conditioning in promoting learning are substantiated by studies that are summarized but not cited. The relationship of the report to the Phoenix Union High School System Advisory…

  11. Criterion-Referenced Test (CRT) Items for Air Conditioning, Heating and Refrigeration.

    Science.gov (United States)

    Davis, Diane, Ed.

    These criterion-referenced test (CRT) items for air conditioning, heating, and refrigeration are keyed to the Missouri Air Conditioning, Heating, and Refrigeration Competency Profile. The items are designed to work with both the Vocational Instructional Management System and Vocational Administrative Management System. For word processing and…

  12. 2015 German refrigeration and air conditioning meeting. Abstracts; Deutsche Kaelte- und Klimatagung 2015. Kurzfassungen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-07-01

    The volume contains the abstracts of the 2015 German refrigeration and air conditioning meeting in 5 chapters: cryo-technology, fundamentals of materials for refrigeration engineering and heat pump technology, facilities and components for the refrigeration and heat pump technology; application of refrigeration engineering; air conditioning technology and heat pump application.

  13. Retrofitting Air Conditioning and Duct Systems in Hot, Dry Climates

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.; Aldrich, R.; Arena, L.

    2012-07-01

    This technical report describes CARB's work with Clark County Community Resources Division in Las Vegas, Nevada, to optimize procedures for upgrading cooling systems on existing homes in the area to implement health, safety, and energy improvements. Detailed monitoring of five AC systems showed that three of the five systems met or exceeded air flow rate goals.

  14. Retrofitting Air Conditioning and Duct Systems in Hot, Dry Climates

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Aldrich, Robb [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Arena, Lois [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2012-07-01

    This technical report describes CARB's work with Clark County Community Resources Division in Las Vegas, Nevada, to optimize procedures for upgrading cooling systems on existing homes in the area to implement health, safety, and energy improvements. Detailed monitoring of five AC systems showed that three of the five systems met or exceeded air flow rate goals.

  15. 多功能空气消毒机在消毒供应室的消毒效果%Disinfection Effect of Multifunctional Air Disinfecting Machine in Disinfection Supply Room

    Institute of Scientific and Technical Information of China (English)

    栗娜娜

    2016-01-01

    目的:探讨多功能空气消毒机在消毒供应室的消毒效果.方法:将笔者所在医院消毒供应室进行消毒,采用多功能空气消毒机消毒的为实验组,采用紫外线消毒的为对照组,两组基本条件一致,消毒供应室面积30 m2,相对湿度60%~70%,环境温度18 ℃~26 ℃.对消毒前后的空气细菌菌落数分析比较.结果:消毒后,实验组平均菌数减少率明显高于紫外线消毒组(P<0.05).结论:多功能空气消毒机可以明显减少空气细菌菌落数,并可改善消毒供应室的空气质量,对于消毒供应室进行消毒具有重要价值.%Objective:To investigate the effect of multifunctional air disinfecting machine in disinfection supply room.Method:The supply room disinfection in our hospital was disinfected,by multifunctional air disinfector in disinfection was selected as the experimental group,by ultraviolet disinfection was selected as the control group,two groups of basic conditions,sterilization and supply room 30 m2,60%-70% relative humidity,environmental temperature 18 ℃-26 ℃. Analysis and comparison of bacterial colonies of air before and after disinfection.Result:After disinfection,the average reduction rate of the experimental group was significantly higher than that of the ultraviolet disinfection group (P<0.05).Conclusion:The multifunctional air disinfection machine can significantly reduce the number of bacteria colonies,and can improve the air quality of disinfection supply room,and it has important value for disinfection and disinfection.

  16. Partial air conditioning in the production hall of VW-Mechatronics. Part 2; Teilklima-Anlagen in der Fertigungshalle VW-Mechatronic. Teil 2

    Energy Technology Data Exchange (ETDEWEB)

    Stroeder, R. [BKI Brab und Kahl Ingenieurgesellschaft mbH, Aachen (Germany)

    2005-07-01

    While part 1 presented the technical facilities for mechanical production and air filtering, part 2 describes the assembly section with the clean room and the space HVAC systems for testing, measuring, and auxiliary rooms. (orig.)

  17. Application of Fuzzy Comprehensive Evaluation to Air-conditioning Competitive Power Analysis

    Institute of Scientific and Technical Information of China (English)

    LU Congda; LIU Gaojin; JIANG Shaofei; LV Chaoqun

    2006-01-01

    As the conceptual design of air-conditioning is done using the theory of Quality Function Deployment (QFD), customer requirements should be understood and the product competitive power be analyzed as exactly as possible for new product designing. Lots of information in the process of this research is fuzzy and uncertain, but traditional QFD can not deal with it well. Fuzzy theory can solve the problem. So a fuzzy model for analyzing product competitive power is formulated in this paper to improve traditional QFD, after that it is applied to analyze air-conditioning competitive power. When air-conditioning competitive power is analyzed using this model, firstly the importance weight of the customer requirements of air-conditioning is determined using the Analytic Hierarchy Process (AHP) weighting process, then air-conditioning competitive power is evaluated using fuzzy comprehensive evaluation. It is proved that the model is feasible and has good applicability.

  18. Study on Model of Indoor Air Pollution Forecast for Decoration Under Natural Ventilation Condition

    Institute of Scientific and Technical Information of China (English)

    YAN-FENG HONG; XUN CHEN; NING XU

    2005-01-01

    Objective To establish the model of indoor air pollution forecast for decoration. Methods The model was based on the balance model for diffusing mass. Results The data between testing concentration and estimating concentration were compared. The maximal error was less than 30% and average error was 14.6%. Conclusion The model can easily predict whether the pollution for decoration exceeds the standard and how long the room is decorated.

  19. Analysis and evaluation methods for chemical contaminants in clean room air; Kagaku osen no bunseki hyokaho clean room kukichu no kagaku osen busshitsu ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, T.

    1998-07-31

    As for, chemical contamination in a cleanroom air has taken up as a important problem. As the main source is building materials, after construction the execution of countermeasures is difficult. Out-gas evaluation and selection in building materials, chemical filters for removing specific organic matter and so on, are a large technical theme in the future and analytical techniques corresponding them become necessary. In this paper, analytical methods of airborne molecular contaminants (AMCs) are introduced. Main samples are AMCs in cleanroom atmosphere, on silicon wafer surface and out-gas from raw materials for cleanroom construction materials such as sealant, plastics and so on. Analytical methods consist of quantification of inorganic compounds, organic compounds and identification of abnormal spot with local/surface analysis. Various interesting findings with analytical data are obtained and investigated. 22 refs., 6 figs., 5 tabs.

  20. Low-Flow Liquid Desiccant Air Conditioning: General Guidance and Site Considerations

    Energy Technology Data Exchange (ETDEWEB)

    Kozubal, E.; Herrmann, L.; Deru, M.; Clark, J.

    2014-09-01

    Dehumidification or latent cooling in buildings is an area of growing interest that has been identified as needing more research and improved technologies for higher performance. Heating, ventilating, and air-conditioning (HVAC) systems typically expend excessive energy by using overcool-and-reheat strategies to dehumidify buildings. These systems first overcool ventilation air to remove moisture and then reheat the air to meet comfort requirements. Another common strategy incorporates solid desiccant rotors that remove moisture from the air more efficiently; however, these systems increase fan energy consumption because of the high airside pressure drop of solid desiccant rotors and can add heat of absorption to the ventilation air. Alternatively, liquid desiccant air-conditioning (LDAC) technology provides an innovative dehumidification solution that: (1) eliminates the need for overcooling and reheating from traditional cooling systems; and (2) avoids the increased fan energy and air heating from solid desiccant rotor systems.

  1. Reducing indoor air pollution by air conditioning is associated with improvements in cardiovascular health among the general population.

    Science.gov (United States)

    Lin, Lian-Yu; Chuang, Hsiao-Chi; Liu, I-Jung; Chen, Hua-Wei; Chuang, Kai-Jen

    2013-10-01

    Indoor air pollution is associated with cardiovascular effects, however, little is known about the effects of improving indoor air quality on cardiovascular health. The aim of this study was to explore whether improving indoor air quality through air conditioning can improve cardiovascular health in human subjects. We recruited a panel of 300 healthy subjects from Taipei, aged 20 and over, to participate in six home visits each, to measure a variety of cardiovascular endpoints, including high sensitivity-C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG), fibrinogen in plasma and heart rate variability (HRV). Indoor particles and total volatile organic compounds (VOCs) were measured simultaneously at the participant's home during each visit. Three exposure conditions were investigated in this study: participants were requested to keep their windows open during the first two visits, close their windows during the next two visits, and close the windows and turn on their air conditioners during the last two visits. We used linear mixed-effects models to associate the cardiovascular endpoints with individual indoor air pollutants. The results showed that increases in hs-CRP, 8-OHdG and fibrinogen, and decreases in HRV indices were associated with increased levels of indoor particles and total VOCs in single-pollutant and two-pollutant models. The effects of indoor particles and total VOCs on cardiovascular endpoints were greatest during visits with the windows open. During visits with the air conditioners turned on, no significant changes in cardiovascular endpoints were observed. In conclusion, indoor air pollution is associated with inflammation, oxidative stress, blood coagulation and autonomic dysfunction. Reductions in indoor air pollution and subsequent improvements in cardiovascular health can be achieved by closing windows and turning on air conditioners at home. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Cooling Performance Characteristics on Mobile Air-Conditioning System for Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Ho-Seong Lee

    2013-01-01

    Full Text Available This study investigates the cooling performance characteristics of the mobile air-conditioning system using R744 (CO2 for the hybrid electric vehicle as an alternative to both the R-134a and the conventional air-conditioning system. The developed air-conditioning system is operated with an electric driven compressor in the battery driving mode and a belt driven compressor in the engine driving mode. The cooling performance characteristics of the developed system have been analyzed by experiments under various operating conditions of inlet air temperature, air flow rates for the gas cooler side and evaporator side, and electric compressor revolution respectively. As a result, cooling performances of the tested air-conditioning system for the EDC driving mode (electricity driven compressor were better than those for the BDC driving mode (belt driven compressor. The cooling capacity and cooling COP of the tested air-conditioning system for both driving modes were over 5.0 kW and 2.0, respectively. The observed cooling performance of the tested air-conditioning system may be sufficient for the cabin cooling of hybrid electric vehicles.

  3. Avoiding 100 new power plants by increasing efficiency of room air conditioners in India: opportunities and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, Amol; Abhyankar, Nikit; Shah, Nihar; [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technology Division

    2013-10-15

    Electricity demand for room ACs is growing very rapidly in emerging economies such as India. We estimate the electricity demand from room ACs in 2030 in India considering factors such as weather and income growth using market data on penetration of ACs in different income classes and climatic regions. We discuss the status of the current standards, labels, and incentive programs to improve the efficiency of room ACs in these markets and assess the potential for further large improvements in efficiency and find that efficiency can be improved by over 40% cost effectively. The total potential energy savings from Room AC efficiency improvement in India using the best available technology will reach over 118 TWh in 2030; potential peak demand saving is found to be 60 GW by 2030. This is equivalent to avoiding 120 new coal fired power plants of 500 MW each. We discuss policy options to complement, expand and improve the ongoing programs to capture this large potential.

  4. Avoiding 100 New Power Plants by Increasing Efficiency of Room Air Conditioners in India: Opportunities and Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, Amol; Abhyankar, Nikit; Shah, Nihar

    2014-06-19

    Electricity demand for room ACs is growing very rapidly in emerging economies such as India. We estimate the electricity demand from room ACs in 2030 in India considering factors such as weather and income growth using market data on penetration of ACs in different income classes and climatic regions. We discuss the status of the current standards, labels, and incentive programs to improve the efficiency of room ACs in these markets and assess the potential for further large improvements in efficiency and find that efficiency can be improved by over 40percent cost effectively. The total potential energy savings from Room AC efficiency improvement in India using the best available technology will reach over 118 TWh in 2030; potential peak demand saving is found to be 60 GW by 2030. This is equivalent to avoiding 120 new coal fired power plants of 500 MW each. We discuss policy options to complement, expand and improve the ongoing programs to capture this large potential.

  5. [Assessment of the air quality improment of cleaning and disinfection on central air-conditioning ventilation system].

    Science.gov (United States)

    Liu, Hongliang; Zhang, Lei; Feng, Lihong; Wang, Fei; Xue, Zhiming

    2009-09-01

    To assess the effect of air quality of cleaning and disinfection on central air-conditioning ventilation systems. 102 air-conditioning ventilation systems in 46 public facilities were sampled and investigated based on Hygienic assessment criterion of cleaning and disinfection of public central air-conditioning systems. Median dust volume decreased from 41.8 g/m2 to 0.4 g/m2, and the percentage of pipes meeting the national standard for dust decreased from 17.3% (13/60) to 100% (62/62). In the dust, median aerobic bacterial count decreased from 14 cfu/cm2 to 1 cfu/cm2. Median aerobic fungus count decreased from 10 cfu/cm2 to 0 cfu/cm2. The percentage of pipes with bacterial and fungus counts meeting the national standard increased from 92.4% (171/185) and 82.2% (152/185) to 99.4% (165/166) and 100% (166/166), respectively. In the ventilation air, median aerobic bacterial count decreased from 756 cfu/m3 to 229 cfu/m3. Median aerobic fungus count decreased from 382 cfu/m3 to 120 cfu/m3. The percentage of pipes meeting the national standard for ventilation air increased from 33.3% (81/243) and 62.1% (151/243) to 79.8% (292/366) and 87.7% (242/276), respectively. But PM10 rose from 0.060 mg/m3 to 0.068 mg/m3, and the percentage of pipes meeting the national standard for PM10 increased from 74.2% (13/60) to 90.2% (46/51). The cleaning and disinfection of central air-conditioning ventilation systems could have a beneficial effect of air quality.

  6. Influence of Cooling to Heating Load Ratio on Optimal Supply Water and Air Temperatures in an Air Conditioning System

    Science.gov (United States)

    Karino, Naoki; Shiba, Takashi; Yokoyama, Ryohei; Ito, Koichi

    In planning an air conditioning system, supply water and air temperatures are important factors from the viewpoint of energy saving and cost reduction. For example, lower temperature supply water and air for space cooling reduce the coefficient of performance of a refrigeration machine, and increase the thickness of heat insulation material. However, they enable larger temperature differences, and reduce equipment sizes and power demand. It is also an important subject to evaluate the effect of the supply water and air temperatures on energy saving and cost reduction on the annual basis by considering not only cooling but also heating loads. The purposes of this paper are to propose an optimal planning method for an air conditioning system with large temperature difference, and to analyze the effect of supply water and air temperatures on the long-term economics through a numerical study for an office building. As a result, it is shown that the proposed method effectively determines supply water and air temperatures, and the influence of the cooling to heating load ratio on the long-term economics is clarified.

  7. Calculation of the Chilling Requirement for Air Conditioning in the Excavation Roadway

    Directory of Open Access Journals (Sweden)

    Yueping Qin

    2015-10-01

    Full Text Available To effectively improve the climate conditions of the excavation roadway in coal mine, the calculation of the chilling requirement taking air conditioning measures is extremely necessary. The temperature field of the surrounding rock with moving boundary in the excavation roadway was numerically simulated by using finite volume method. The unstable heat transfer coefficient between the surrounding rock and air flow was obtained via the previous calculation. According to the coupling effects of the air flow inside and outside air duct, the differential calculation mathematical model of air flow temperature in the excavation roadway was established. The chilling requirement was calculated with the selfdeveloped computer program for forecasting the required cooling capacity of the excavation roadway. A good air conditioning effect had been observed after applying the calculated results to field trial, which indicated that the prediction method and calculation procedure were reliable.

  8. Air entrainment by a plunging jet under intermittent vortex conditions

    OpenAIRE

    Kim, Kevin Jin; Corfman, Kyle; Li, Kevin; Kiger, Ken T.

    2011-01-01

    This fluid dynamic video entry to the 2011 APS-DFD Gallery of Fluid Motion details the transient evolution of the free surface surrounding the impact region of a low-viscosity laminar liquid jet as it enters a quiescent pool. The close-up images depict the destabilization and breakup of the annular air gap and the subsequent entrainment of bubbles into the bulk liquid.

  9. Combustion of Gaseous Fuels with High Temperature Air in Normal- and Micro-gravity Conditions

    Science.gov (United States)

    Wang, Y.; Gupta, A. K.

    2001-01-01

    The objective of this study is determine the effect of air preheat temperature on flame characteristics in normal and microgravity conditions. We have obtained qualitative (global flame features) and some quantitative information on the features of flames using high temperature combustion air under normal gravity conditions with propane and methane as the fuels. This data will be compared with the data under microgravity conditions. The specific focus under normal gravity conditions has been on determining the global flame features as well as the spatial distribution of OH, CH, and C2 from flames using high temperature combustion air at different equivalence ratio.

  10. Engine room cooling system using jet pump

    Energy Technology Data Exchange (ETDEWEB)

    Lim, J.W.; Lee, S.H. [Daewoo Heavy Industries Ltd. (Korea)

    2000-04-01

    Construction machinery includes an engine enclosure separated from a cooling system enclosure by a wall to reduce noise and advance cooling system performance. For this structure, however, the axial fan cannot be of benefit to the engine room, and so the temperature rise in the engine room makes several bad conditions. This paper proposes that hot air in engine room is evacuated by secondary pipe using jet pump. This paper demonstrates the structure and the effect of jet pump and useful guideline on design of area, length, and shape of secondary pipe to maximize the effect of jet pump. (author). 4 refs., 7 figs., 5 tabs.

  11. AUTOMATED SYSTEM OF OPERATIONAL CONTROL HEATING AND AIR CONDITIONING OF BUILDINGS

    Directory of Open Access Journals (Sweden)

    PETRENKO A. O.

    2016-08-01

    Full Text Available Statement of the problem. Health and human performance largely determined by the conditions of climate and air quality in residential, administrative and residential and public buildings. At that, in turn, is influenced by the external environment and the climate, and the geometric dimensions of the room, and thermal performance building envelopes, and the location of the premises (Orientation, and many other factors. The result is the formation of complex systems, which control decision-making in conditions of multifactor [1]. In hygienic purposes it is necessary to strive to create the best indoor microclimate conditions, regardless of changes in the factors that affect the climate in residential, administrative and residential and public buildings. Develop systems to ensure the necessary microclimate parameters – it is a complex and important task, which will depend entirely comfortable and cozy environment for the person. The problem of the present time, there is a steady increase in the energy consumption of these systems, due to the rise in price of non-renewable energy sources, and our job is, to simulate the work of software systems necessary microclimate for the changes in the factors that affect it and to minimize the use of non-renewable energy sources. Analysis of recent research and publications. Domestic and foreign hygienists [2, 3, 4] to establish a connection between the climate in the room and in the workplace and the state of human health. Formation of the indoor climate of residential, administrative and residential and public buildings is influenced by many factors that have already noted earlier [5, 6]. Study of the processes of influence of various factors on human health is of great complexity. If we consider each process separately, and in this case they are not currently amenable to theoretical description clearer. To simulate the effect of these factors studies were conducted, which showed that, with sufficient

  12. Cool storage time of phase change wallboard room in summer

    Institute of Scientific and Technical Information of China (English)

    冯国会; 陈其针; 黄凯良; 牛润萍; 王琳

    2009-01-01

    More and more attention was paid to phase change energy storage in air conditioning domain and construction energy conservation,and became the focus of the international research. Through the test and analysis of the parameters of the indoor thermal property in phase change wallboard room and ordinary room,the effects of using phase change wallboards on indoor temperature in summer and air conditioning are obtained. The combination of construct enclosure and phase change materials can stabilize indoor temperature,improve indoor thermal comfort,reduce the frequency of the operation of air conditioning facility,cut the initial investment and operation expense,and meanwhile play an practical role in "the power balancing between the peak period and the valley period" policy. Through the experiment and the test of the effects exerted by phase change wallboard room and ordinary room on the indoor thermal environment,it is obtained that the phase change wallboard can reduce the fluctuation range of indoor temperature and the heat flow from the outside into indoor environment in summer. According to the study,it is found that the effect of cool-storing for 5 h is obvious. Through the analysis of the phase change wallboard without air conditioning in daytime,it is obtained that the frequency of the operation of air conditioning in phase change wallboard room is smaller than that in the ordinary room,which can prolong the lifetime of the facility and reduce operation expense.

  13. Performance analysis of a liquid desiccant and membrane contactor hybrid air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Bergero, Stefano; Chiari, Anna [DIPARC, Faculty of Architecture, University of Genoa, Stradone S. Agostino 37, 16123 Genova (Italy)

    2010-11-15

    The present study examines the performances of a hybrid air-conditioning system in which a vapour-compression inverse cycle is integrated with an air dehumidification system working with hygroscopic solution and hydrophobic membrane. This model may be a valid alternative to traditional summertime air-conditioning system, in which the air is cooled to below its dew-point temperature and subsequently reheated. The proposed hybrid system involves simultaneously cooling and dehumidifying the air conveyed to the conditioned ambient in an air-solution membrane contactor. An LiCl solution is cooled by means of a vapour-compression inverse cycle using the refrigerant KLEA 407C. The solution is regenerated in another membrane contactor by exploiting the heat rejected by the condenser. A SIMULINK calculation programme was designed in order to simulate the system under examination in steady-state conditions. The performances of the system were analysed on varying a few significant operating parameters, and were compared with those of a traditional direct-expansion air-conditioning plant in typical summertime conditions. The results of the simulations revealed significant energy savings, which, in particular operating conditions, may exceed 50%. (author)

  14. Parametric Analysis of a Rotary Type Liquid Desiccant Air Conditioning System

    Directory of Open Access Journals (Sweden)

    M. Mujahid Rafique

    2016-04-01

    Full Text Available Now days, air conditioning systems are a must for almost every commercial and residential building to achieve comfortable indoor conditions. The increasing energy demand, and increasing oil prices and pollution levels raise the need for alternative air conditioning systems which can efficiently utilize renewable energy resources. The liquid desiccant-based air conditioning method is pollution free and thermal energy-based cooling techniques can use low grade thermal energy resources like solar energy, waste heat, etc. These systems have an additional advantage of cleaning bacteria and fungi from the air. In this paper, a newly proposed rotary liquid desiccant air conditioning system has been investigated theoretically. Most direct contact liquid desiccant cooling systems have the problem of desiccant carryover which can be eliminated using the proposed system. The effects of various key parameters and climatic conditions on the performance of the system have been evaluated. The results showed that if the key parameters of the system are controlled effectively, the proposed cooling system has the ability to achieve the desired supply air conditions. The system can achieve high coefficient of performance (COP under different conditions. The dehumidifier has a sensible heat ratio (SHR in the range of 0.3–0.6 for different design, climatic, and operating conditions. The system can remove latent load efficiently in applications which require good humidity control.

  15. Google SketchUp在通风空调工程施工中的应用%Application of Google SketchUp in ventilating and air conditioning engineering

    Institute of Scientific and Technical Information of China (English)

    刘明

    2012-01-01

    结合某援外工程实例,介绍了运用Google SketchUp进行空调机房、空调设备及其组件、风管、建筑结构图建模的方法.使用该方法绘制施工图有利于确保工程质量、缩短工期.%With an example of China's international aid project, presents the modeling methods for air conditioning machine room, air conditioning equipment and module, air duct and building structure with Google SketchUp. Its application is favorable for ensuring construction quality and reducing the construction time of the project.

  16. Impaired Air Conditioning within the Nasal Cavity in Flat-Faced Homo.

    Science.gov (United States)

    Nishimura, Takeshi; Mori, Futoshi; Hanida, Sho; Kumahata, Kiyoshi; Ishikawa, Shigeru; Samarat, Kaouthar; Miyabe-Nishiwaki, Takako; Hayashi, Misato; Tomonaga, Masaki; Suzuki, Juri; Matsuzawa, Tetsuro; Matsuzawa, Teruo

    2016-03-01

    We are flat-faced hominins with an external nose that protrudes from the face. This feature was derived in the genus Homo, along with facial flattening and reorientation to form a high nasal cavity. The nasal passage conditions the inhaled air in terms of temperature and humidity to match the conditions required in the lung, and its anatomical variation is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat. In this study, we used computational fluid dynamics (CFD) with three-dimensional topology models of the nasal passage under the same simulation conditions, to investigate air-conditioning performance in humans, chimpanzees, and macaques. The CFD simulation showed a horizontal straight flow of inhaled air in chimpanzees and macaques, contrasting with the upward and curved flow in humans. The inhaled air is conditioned poorly in humans compared with nonhuman primates. Virtual modifications to the human external nose topology, in which the nasal vestibule and valve are modified to resemble those of chimpanzees, change the airflow to be horizontal, but have little influence on the air-conditioning performance in humans. These findings suggest that morphological variation of the nasal passage topology was only weakly sensitive to the ambient atmosphere conditions; rather, the high nasal cavity in humans was formed simply by evolutionary facial reorganization in the divergence of Homo from the other hominin lineages, impairing the air-conditioning performance. Even though the inhaled air is not adjusted well within the nasal cavity in humans, it can be fully conditioned subsequently in the pharyngeal cavity, which is lengthened in the flat-faced Homo. Thus, the air-conditioning faculty in the nasal passages was probably impaired in early Homo members, although they have survived successfully under the fluctuating climate of the Plio-Pleistocene, and then they moved "Out of Africa" to explore the more severe climates of

  17. Impaired Air Conditioning within the Nasal Cavity in Flat-Faced Homo.

    Directory of Open Access Journals (Sweden)

    Takeshi Nishimura

    2016-03-01

    Full Text Available We are flat-faced hominins with an external nose that protrudes from the face. This feature was derived in the genus Homo, along with facial flattening and reorientation to form a high nasal cavity. The nasal passage conditions the inhaled air in terms of temperature and humidity to match the conditions required in the lung, and its anatomical variation is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat. In this study, we used computational fluid dynamics (CFD with three-dimensional topology models of the nasal passage under the same simulation conditions, to investigate air-conditioning performance in humans, chimpanzees, and macaques. The CFD simulation showed a horizontal straight flow of inhaled air in chimpanzees and macaques, contrasting with the upward and curved flow in humans. The inhaled air is conditioned poorly in humans compared with nonhuman primates. Virtual modifications to the human external nose topology, in which the nasal vestibule and valve are modified to resemble those of chimpanzees, change the airflow to be horizontal, but have little influence on the air-conditioning performance in humans. These findings suggest that morphological variation of the nasal passage topology was only weakly sensitive to the ambient atmosphere conditions; rather, the high nasal cavity in humans was formed simply by evolutionary facial reorganization in the divergence of Homo from the other hominin lineages, impairing the air-conditioning performance. Even though the inhaled air is not adjusted well within the nasal cavity in humans, it can be fully conditioned subsequently in the pharyngeal cavity, which is lengthened in the flat-faced Homo. Thus, the air-conditioning faculty in the nasal passages was probably impaired in early Homo members, although they have survived successfully under the fluctuating climate of the Plio-Pleistocene, and then they moved "Out of Africa" to explore the more

  18. Computerized Simulation of Automotive Air-Conditioning System: A Parametric Study

    Directory of Open Access Journals (Sweden)

    Haslinda Mohamed Kamar

    2013-01-01

    Full Text Available This paper presents results of a parametric study performed on an automotive air-conditioning (AAC system of a passenger car. The goals are to assess the effects of varying the volumetric flow rate of supply air, number of occupants, vehicle speed, and the fractional ventilation air intake (XOA, on the dry-bulb temperature and specific humidity of the air inside the passengers cabin, and on the evaporator coil cooling load of the AAC system. Results of the parametric study show that increasing the supply air flow rate reduces the dry-bulb temperature of the cabin air, increases both the specific humidity of the air and the evaporator coil load. Increasing the number of occupants in the passenger cabin causes the cabin air temperature, specific humidity and the evaporator coil load to increase. Increasing the vehicle speed causes the specific humidity of the cabin air and the evaporator coil cooling load to increase but the dry-bulb temperature of the air is not significantly affected. Increasing the fractional fresh air intake (XOA also increases the cabin air specific humidity and the evaporator coil cooling load.

  19. Accelerating Improvements in the Energy Efficiency of Room Air Conditioners (RACs) in India: Potential, Cost-Benefit, and Policies (Interim Assessment)

    Energy Technology Data Exchange (ETDEWEB)

    Abhyankar, Nikit [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Park, Won Young [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-06-01

    Falling AC prices, increasing incomes, increasing urbanization, and high cooling requirements due to hot climate are all driving increasing uptake of Room Air Conditioners (RACs) in the Indian market. Air conditioning already comprises 40-60% of summer peak load in large metropolitan Indian cities such as Delhi and is likely to contribute 150 GW to the peak demand in 2030. Standards and labeling policies have contributed to improving the efficiency of RACs in India by about 2.5% in the last 10 years (2.5% per year) while inflation adjusted RAC prices have continued to decline. In this paper, we assess the technical feasibility, cost-benefit, and required policy enhancements by further accelerating the efficiency improvement of RACs in India. We find that there are examples of significantly more accelerated improvements such as those in Japan and Korea where AC efficiency improved by more than 7% per year resulting in almost a doubling of energy efficiency in 7 to 10 years while inflation adjusted AC prices continued to decline. We find that the most efficient RAC sold on the Indian market is almost twice as efficient as the typical AC sold on the market and hence see no technology constraints in a similar acceleration of improvement of efficiency. If starting 2018, AC efficiency improves at a rate of 6% instead of 3%, 40-60 GW of peak load (equivalent to connected load of 5-6 billion LED bulbs), and over 75 TWh/yr (equivalent to 60 million consumers consuming 100 kWh/month) will be saved by 2030; total peak load reduction would be as high as 50 GW. The net present value (NPV) of the consumer benefit between 2018-2030 will range from Rs 18,000 Cr in the most conservative case (in which prices don’t continue to decline and increase based estimates of today’s cost of efficiency improvement) to 140,000 Cr in a more realistic case (in which prices are not affected by accelerated efficiency improvement as shown by historical experience). This benefit is achievable by

  20. System and method for conditioning intake air to an internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Sellnau, Mark C.

    2015-08-04

    A system for conditioning the intake air to an internal combustion engine includes a means to boost the pressure of the intake air to the engine and a liquid cooled charge air cooler disposed between the output of the boost means and the charge air intake of the engine. Valves in the coolant system can be actuated so as to define a first configuration in which engine cooling is performed by coolant circulating in a first coolant loop at one temperature, and charge air cooling is performed by coolant flowing in a second coolant loop at a lower temperature. The valves can be actuated so as to define a second configuration in which coolant that has flowed through the engine can be routed through the charge air cooler. The temperature of intake air to the engine can be controlled over a wide range of engine operation.

  1. The use of air-conditioning to improve performances of personnel; Airco inzet voor betere prestaties

    Energy Technology Data Exchange (ETDEWEB)

    Havenaar, D.

    2012-04-01

    The combination of temperature, air humidity, ventilation and air movement highly determines the comfort feeling of personnel. Moreover, these factors enable optimal performance. Air-conditioning, but particularly temperature control are important instruments in realizing such an optimal performance climate. [Dutch] De combinatie van temperatuur, luchtvochtigheid, luchtverversing en luchtbeweging bepaalt in hoge mate het behaaglijkheidsgevoel van personeel. Daarnaast zorgen deze factoren ervoor dat optimaal gepresteerd kan worden. Om dit optimale prestatieklimaat te realiseren is airconditioning maar vooral temperatuurbeheersing een belangrijk hulpmiddel.

  2. 基于SINDA/FLUINT平台的R290房间空调器仿真%R290 room air- conditioner simulation based on SINDA/FLUINT

    Institute of Scientific and Technical Information of China (English)

    梁杰荣; 李廷勋

    2011-01-01

    R290 is environment -friendly natural refrigerant, but it is flammable. According to IEC 60335 the charge is limited strictly in room air conditioner (RAC). In this paper, simulating models of R290 room air conditioner were developed based on SINDA/FLUINT, and the models were verified by comparing the simulated temperature distribution and system performance like COP and indoor air humidity with experiment results. With the models, the R290 mass distribution and pressure drop among the RAC components were calculated. It is found that refrigerant concentrates in condenser (62%), while pressure drop is mainly produced in evaporator, liquid line and vapor line.%R290制冷剂是环保自然工质,但具有可燃性,在空调中对充注量要求非常严格.基于SINDA/FLUINT仿真平台对R290系统进行建模,通过与温度和运行性能的实验数据对比,检验了模型的可靠性;计算分析了R290空调器内各部件的制冷剂分布及沿程压损.计算结果表明,冷媒主要集中在冷凝器(62%);沿程压损主要集中在蒸发器,液相管和气相管.

  3. Air Conditioning Stall Phenomenon Testing, Model Development, and Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Irminger, Philip [ORNL; Rizy, D Tom [ORNL; Li, Huijuan [ORNL; Smith, Travis [ORNL; Rice, C Keith [ORNL; Li, Fangxing [ORNL; Adhikari, Sarina [ORNL

    2012-01-01

    Electric distribution systems are experiencing power quality issues of extended reduced voltage due to fault-induced delayed voltage recovery (FIDVR). FIDVR occurs in part because modern air conditioner (A/C) and heat pump compressor motors are much more susceptible to stalling during a voltage sag or dip such as a sub-transmission fault. They are more susceptible than older A/C compressor motors due to the low inertia of these newer and more energy efficient motors. There is a concern that these local reduced voltage events on the distribution system will become more frequent and prevalent and will combine over larger areas and challenge transmission system voltage and ultimately power grid reliability. The Distributed Energy Communications and Controls (DECC) Laboratory at Oak Ridge National Laboratory (ORNL) has been employed to (1) test, (2) characterize and (3) model the A/C stall phenomenon.

  4. Microwave Disinfection in a Ventilation and Air-Conditioning System

    Institute of Scientific and Technical Information of China (English)

    LU Zhen; ZHANG Ji-li; MA Liang-dong; HE Juan

    2009-01-01

    Because of its broad spectrum and high efficiency,the microwave disinfection was used to control the airborne microbial contaminates in VAC system.Some microwave disinfection devices were developed com-bined with air filter,the design and calculation method was presented,and the disinfection effects on White staphylococcus,Staphylococcus aureus,Bacillus Subtilis,Escherichi coli were measured.The results show that the major influence factors on disinfection effect are microwave power,water-content of filter material,dis-infecting duration.After 15 min,the kill ratio is>90%,and the log value is>1.The microwave field is uni-form and the kill effect of bacteria on each surface of filter is the same,without statistically significant differ-ence.

  5. Impact of airflow interaction on inhaled air quality and transport of contaminants in rooms with personalized and total volume ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Cermak, Radim; Kovar, O.

    2003-01-01

    The impact of airflow interaction on inhaled air quality and transport of contaminants between occupants was studied in regard to pollution from floor covering, human bioeffluents and exhaled air, with combinations of two personalized ventilation systems (PV) with mixing and displacement ventilat......The impact of airflow interaction on inhaled air quality and transport of contaminants between occupants was studied in regard to pollution from floor covering, human bioeffluents and exhaled air, with combinations of two personalized ventilation systems (PV) with mixing and displacement...

  6. A Trnsys simulation of a solar-driven ejector air conditioning system with an integrated PCM cold storage

    Science.gov (United States)

    Allouche, Yosr; Varga, Szabolcs; Bouden, Chiheb; Oliveira, Armando

    2017-02-01

    In this paper, the development of a TRNSYS model, for the simulation of a solar driven ejector cooling system with an integrated PCM cold storage is presented. The simulations were carried out with the aim of satisfying the cooling needs of a 140 m3 space during the summer season in Tunis, Tunisia. The system is composed of three main subsystems, which include: a solar loop, an ejector cycle and a PCM cold storage tank. The latter is connected to the air-conditioned space. The influence of applying cold storage on the system performance was investigated. It was found that the system COP increased compared to a system without cold storage. An optimal storage volume of 1000 l was identified resulting in the highest cooling COP and highest indoor comfort (95% of the time with a room temperature below 26°C). The maximum COP and solar thermal ratio (STR) were 0.193 and 0.097, respectively.

  7. Low-cost fabrication of WO{sub 3} films using a room temperature and low-vacuum air-spray based deposition system for inorganic electrochromic device applications

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung-Ik [Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Kim, Sooyeun, E-mail: sooyeunk@u.washington.edu [Department of Mechanical Engineering, University of Washington, Seattle, WA (United States); Choi, Jung-Oh; Song, Ji-Hyeon [Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Taya, Minoru [Department of Mechanical Engineering, University of Washington, Seattle, WA (United States); Ahn, Sung-Hoon, E-mail: ahnsh@snu.ac.kr [Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Institute of Advanced Machines and Design, Seoul (Korea, Republic of)

    2015-08-31

    We report the deposition of tungsten oxide (WO{sub 3}) thin films on fluorine-doped tin oxide (FTO) and indium-doped tin oxide (ITO) glass substrates by using a room-temperature deposition system based on low-vacuum air-spray for the fabrication of inorganic electrochromic windows. The structure of the WO{sub 3} films was characterized using X-ray diffraction, and the surface morphology and film thickness were investigated using scanning electron microscopy and atomic force microscopy. The color of the prepared WO{sub 3} films changed from slight yellow to dark blue under applied voltages, demonstrating electrochromism. The WO{sub 3} film coated FTO glass exhibited a large electrochromic contrast of up to 50% at a wavelength of 800 nm. The electrochemical properties of the films were examined using cyclic voltammetry and chronocoulometry. - Highlights: • WO{sub 3} thin films were fabricated using an air-spray based deposition system at room temperature under low-vacuum conditions. • Dry WO{sub 3} particles were directly deposited on FTO and ITO glasses by using a low-cost deposition system. • The FTO glass based WO{sub 3} film showed the optical contrast of 50% at a wavelength of 800 nm.

  8. Desiccant Enhanced Evaporative Air-Conditioning (DEVap): Evaluation of a New Concept in Ultra Efficient Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Kozubal, E.; Woods, J.; Burch, J.; Boranian, A.; Merrigan, T.

    2011-01-01

    NREL has developed the novel concept of a desiccant enhanced evaporative air conditioner (DEVap) with the objective of combining the benefits of liquid desiccant and evaporative cooling technologies into an innovative 'cooling core.' Liquid desiccant technologies have extraordinary dehumidification potential, but require an efficient cooling sink. DEVap's thermodynamic potential overcomes many shortcomings of standard refrigeration-based direct expansion cooling. DEVap decouples cooling and dehumidification performance, which results in independent temperature and humidity control. The energy input is largely switched away from electricity to low-grade thermal energy that can be sourced from fuels such as natural gas, waste heat, solar, or biofuels.

  9. AN EXPERIMENTAL ANALYSIS OF THE EFFECT OF REFRIGERANT CHARGE LEVEL AND OUTDOOR CONDITION ON A WINDOW AIR CONDITIONER

    Directory of Open Access Journals (Sweden)

    M Herbert Raj

    2010-01-01

    Full Text Available R22 is an hydrochlorofluorocarbon widely used in refrigerant and air conditioning plants and although it has a low ozone depletion potential (0.05, it is necessary to consider the large amount that commonly escapes from commercial units to the atmosphere. This paper presents experimental investigation on the performance of a window air conditioner operated with R22 and the M20 (80% R407C and 20% HC blend by wt. refrigerant mixture tested under different refrigerant charge levels and outdoor conditions. Experiments were conducted in accordance with the Bureau of Indian standards procedure in a psychrometric test facility. Capillary and charge optimization tests were conducted for the both R22 and the M20 refrigerant mixture based on maximum coefficient of performance. Refrigerant charge in the air conditioner was systematically varied and the influences of refrigerant charge quantities and outdoor conditions on system performance are studied for both R22 and the M20 refrigerant mixture. At each charge levels, the outdoor room conditions were changed in accordance with Bureau of Indian standards. It is observed that R22 is more sensitive to deviations in charge levels as compared to the M20 refrigerant mixture. A decrease in charge level of about 7% reduced the system refrigerating capacity by 11.3% with R22 while with the M20 refrigerant mixture it reduces by 6.9% only. Similarly an over charge by 7% reduces the refrigerating capacity of the system by 13.8% with R22 while with M20 it reduces by 6.5% only.

  10. Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems

    Science.gov (United States)

    Ahearn, D. G.; Simmons, R. B.; Switzer, K. F.; Ajello, L.; Pierson, D. L.

    1991-01-01

    Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia. The colonies were tightly appressed to the metal surface and conidia were not readily detectable via standard air sampling procedures.

  11. Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems

    Science.gov (United States)

    Ahearn, D. G.; Simmons, R. B.; Switzer, K. F.; Ajello, L.; Pierson, D. L.

    1991-01-01

    Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia. The colonies were tightly appressed to the metal surface and conidia were not readily detectable via standard air sampling procedures.

  12. Temperature and Humidity Independent Control Research on Ground Source Heat Pump Air Conditioning System

    Science.gov (United States)

    Chen, G.; Wang, L. L.

    Taking green demonstration center building air conditioning system as an example, this paper presents the temperature and humidity independent control system combined with ground source heat pump system, emphasis on the design of dry terminal device system, fresh air system and ground source heat pump system.

  13. Method for acquiring part load distribution coefficient of air conditioning system

    Institute of Scientific and Technical Information of China (English)

    丁勇; 李百战; 谭颖

    2009-01-01

    This paper presents a method to acquire runtime distribution ratio of building air conditioning system under part load condition (part load coefficient of system) through practical energy consumption data. By utilizing monthly energy consumption data of the entire year as the analysis object,this paper identifies data distribution,verifies distribution characteristics and analyzes distribution probability density for the issue of running time distribution ratio of air conditioning system in part load zones in the whole operation period,thus providing a basic calculation basis for an overall analysis of energy efficiency of air conditioning system. In view of the general survey of public building energy consumption carried by the government of Chongqing,this paper takes the governmental office building as an example,the part load ratio coefficient corresponding to practical running of air conditioning system of governmental office building in Chongqing is obtained by utilizing the above probability analysis and the solving method of probability density function. By utilizing the ratio coefficient obtained using this method,the part load coefficient with any running ratio of air conditioning system can be obtained according to the requirement of analysis,which can be used in any load ratio for analyzing running energy efficiency of air conditioning system.

  14. Self-Assembling of Colloidal Particles Dispersed in Mixture of Ethanol and Water at the Air-Liquid Interface of Colloidal Suspension at Room Temperature

    Institute of Scientific and Technical Information of China (English)

    WANG Ai-Jun; CHEN Sheng-Li; DONG Peng; ZHOU Qian; YUAN Gui-Mei; SU Gu-Cong

    2009-01-01

    Self-assembling of colloidal particles dispersed in a mixture of ethanol and water at the air-liquid interface of the colloidal suspension at room temperature is investigated,and a method of rapidly assembling colloidal particles is proposed.By this method,a uniform colloidal crystal thin 61m over ten square centimeters in area can be fabricated in 10 min without special facilities and heating the suspension.SEM images and a normal incidence transmission spectrum of the sample show that the colloidal crystal film fabricated by this method is of high quality.In addition,this method is very suitable for fabricating colloidal crystal heterostructures.

  15. Effect of air conditioning installation position on indoor air distribution in duplex apartment%空调安装位置对复式住宅室内流场的影响

    Institute of Scientific and Technical Information of China (English)

    王晶; 史柏语; 戚译天; 吴国忠; 赵文凯; 李栋

    2012-01-01

    建立复式住宅的三维数理模型,利用CFD软件对复式住宅室内气流组织进行数值模拟,探讨室内温度场和速度场的变化关系,分析2种客厅内不同空调安装位置对复式住宅室内气流组织和热舒适性的影响.结果表明:客厅内空调送风只能同时保证客厅内主要活动区域,以及与其直接连接的相邻且无遮挡空间的空气温度满足要求;在送风时,位于客厅内上层卧室外墙上方空调比位于客厅内西墙墙壁上方的空调对室内气流的扰动作用更大,对室内风速及温度的影响也更大.这对于复式住宅内空调优化设计和节能具有指导意义.%Three-dimensional physical and mathematical models of duplex apartment were established in this paper. Indoor air distribution of the duplex apartment was simulated by using computational fluid dynamics software CFD, and the impact of the different installation position of air conditioning on indoor air distribution in summer were analyzed. By comparing the change relations of the indoor temperature field and velocity field in different circumstances, and the influence of two installation positions of air conditioning that meet the requirements of air distribution and thermal comfort in the duplex apartment were analyzed. Results show that air supply of air conditioning inside the drawing room only meet air temperature requirements of the main activity areas of drawing room and its' directly connected neighboring space without occlusion at the same time; and the disturbance effect of indoor air flow fluctuates more fiercely when air conditioning located in the indoor central position than the border, as well as the influence of indoor wind speed and temperature.

  16. A Comparative Study of Sound Speed in Air at Room Temperature between a Pressure Sensor and a Sound Sensor

    Science.gov (United States)

    Amrani, D.

    2013-01-01

    This paper deals with the comparison of sound speed measurements in air using two types of sensor that are widely employed in physics and engineering education, namely a pressure sensor and a sound sensor. A computer-based laboratory with pressure and sound sensors was used to carry out measurements of air through a 60 ml syringe. The fast Fourier…

  17. A Comparative Study of Sound Speed in Air at Room Temperature between a Pressure Sensor and a Sound Sensor

    Science.gov (United States)

    Amrani, D.

    2013-01-01

    This paper deals with the comparison of sound speed measurements in air using two types of sensor that are widely employed in physics and engineering education, namely a pressure sensor and a sound sensor. A computer-based laboratory with pressure and sound sensors was used to carry out measurements of air through a 60 ml syringe. The fast Fourier…

  18. Performance of personalized ventilation in a room with an underfloor air distribution system: transport of contaminants between occupants

    DEFF Research Database (Denmark)

    Cermak, Radim; Melikov, Arsen Krikor

    2003-01-01

    Studies have documented that personalized ventilation, which provides clean air at each office workplace, is able to improve substantially the quality of air inhaled by occupants. However, the interaction between the airflow generated by personalized ventilation and the airflow pattern outside th...

  19. Influence of cooling face masks on nasal air conditioning and nasal geometry.

    Science.gov (United States)

    Lindemann, J; Hoffmann, T; Koehl, A; Walz, E M; Sommer, F

    2017-06-01

    Nasal geometries and temperature of the nasal mucosa are the primary factors affecting nasal air conditioning. Data on intranasal air conditioning after provoking the trigeminal nerve with a cold stimulus simulating the effects of an arctic condition is still missing. The objective was to investigate the influence of skin cooling face masks on nasal air conditioning, mucosal temperature and nasal geometry. Standardized in vivo measurements of intranasal air temperature, humidity and mucosal temperature were performed in 55 healthy subjects at defined detection sites before and after wearing a cooling face mask. Measurements of skin temperature, rhinomanometry and acoustic rhinometry were accomplished. After wearing the face mask the facial skin temperature was significantly reduced. Intranasal air temperature did not change. Absolute humidity and mucosal temperature increased significantly. The acoustic rhinometric results showed a significant increase of the volumes and the cross-sectional areas. There was no change in nasal airflow. Nasal mucosal temperature, humidity of inhaled air, and volume of the anterior nose increased after application of a cold face mask. The response is mediated by the trigeminal nerve. Increased mucosal temperatures as well as changes in nasal geometries seem to guarantee sufficient steady intranasal nasal air conditioning.

  20. Greenhouse Gas Reporting Requirements Related to Stationary Refrigeration and Air Conditioning

    Science.gov (United States)

    Provides links to information about parts of the 2009 Mandatory Reporting of Greenhouse Gases Rule that are relevant to owners and importers of stationary refrigeration and air-conditioning equipment.