Residential air-conditioner usage in China and efficiency standardization

International Nuclear Information System (INIS)

Wu, Jianghong; Liu, Chaopeng; Li, Hongqi; Ouyang, Dong; Cheng, Jianhong; Wang, Yuanxia; You, Shaofang

2017-01-01

Determining the real energy consumption and usage pattern of a room air-conditioner (RAC) are important issues from the point of view of both RAC design and evaluation of its energy efficiency. An air-conditioner's running time is fundamental data for the calculation of SEER and APF values. Therefore, in 2010, a nationwide investigation of RAC usage was conducted and 400 selected air-conditioning-units were monitored for a full year to obtain data on their cooling and heating usage. Two running time curves (cooling and heating) were obtained for the air-conditioners as a function of outdoor air temperatures using statistical analysis. The results show that the 27–30 °C temperature range accounts for more than 52% of the cooling time. Conversely, the 0–8 °C temperature range is associated with more than 75% of the heating time. The research presented in this paper has significantly contributed to China's new variable-speed RAC efficiency standard (GB21455-2013). It also has far-reaching implications for both the air-conditioner industry and energy policy in China due to its different method of calculating energy efficiency. - Highlights: • A nationwide survey to realize China's residential air-conditions usage behaviors. • Air-conditioner running time-environment temperature curves are obtained. • The peak heating demand and peak cooling demand happen at 28 °C and 4 °C, respectively. • The temperature of 27 °C–30 °C accounts for over 52% refrigeration time. • The temperature of 0 °C–8 °C occupies more than 75% heating time.

Viewpoint Mitigation of emissions through energy efficiency standards for room air conditioners in Malaysia

International Nuclear Information System (INIS)

Mahlia, T.M.I.; Masjuki, H.H.; Saidur, R.; Amalina, M.A.

2004-01-01

Malaysian economy has grown rapidly in the last two decades. This growth has increased the ownership of household electrical appliances including room air conditioners. The number of users of air conditioners is predicted to grow dramatically in Malaysian households in the future. To reduce energy consumption in the residential sector, the Malaysia Energy Commission is considering implementing minimum energy efficiency standards for room air conditioners in early 2004. This paper attempts to predict the potential mitigation of emissions through energy efficiency standards for room air conditioners in Malaysia. The calculations were based on the growth of room air conditioners ownership data in Malaysian households. The study found that the energy efficiency standards for room air conditioners would mitigate a significant amount of emissions in this country

16 CFR 305.12 - Labeling for central air conditioners, heat pumps, and furnaces.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Labeling for central air conditioners, heat... (âAPPLIANCE LABELING RULEâ) Required Disclosures § 305.12 Labeling for central air conditioners, heat pumps, and furnaces. (a) Layout. All energy labels for central air conditioners, heat pumps, and...

Evaluation of environmental and physiological factors of a whole ceiling-type air conditioner using a salivary biomarker

Energy Technology Data Exchange (ETDEWEB)

Tahara, Yusuke; Yamaguchi, Masaki [Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Morito, Naomi; Nishimiya, Hajime; Yamagishi, Hideyuki [Asahi Kasei Homes Corporation, R and D Laboratories, 2-1 Samejima, Fuji, Shizuoka 416-8501 (Japan)

2009-06-15

In order to improve environmental condition such as humidity and airflow in living spaces, a whole ceiling-type air conditioner is proposed. This novel air conditioner exhaust dispersed airflow from the whole ceiling by using a 3-dimensional knit fabric. The purpose of this paper is to reveal the effects when controlling humidity and airflow using the whole ceiling-type air conditioner compared to a commercialized concentrated exhaust air conditioner (normal-type air conditioner) under the same temperature. Salivary {alpha}-amylase activity (SAA) was used as an index of sympathetic nervous activity. An acute experiment for a 15 min period was conducted using 12 healthy young female adults. No significant differences in room and skin temperatures were observed between the whole ceiling-type air conditioner and the normal-type air conditioner. The whole ceiling-type air conditioner showed 11.1% lower humidity than the normal-type air conditioner. The whole ceiling-type air conditioner showed one-thirteenth the airflow of the normal-type air conditioner. As a result, the PMV of the whole ceiling-type air conditioner was more comfortable level than the normal one. Moreover, subjective evaluation questionnaire revealed a significant difference was observed in wind perception (windy). The SAA of subjects under the whole ceiling-type air conditioner showed significantly low values compared with the normal-type air conditioner. It was found that the subject's sympathetic nervous activity has been inactivated under the conditions of the whole ceiling-type air conditioner. Thus, it was revealed that the whole ceiling-type air conditioner provides a more comfortable air environment by reducing physical stimulations to humans. (author)

77 FR 28519 - Test Procedure Guidance for Room Air Conditioners, Residential Dishwashers, and Residential...

Science.gov (United States)

2012-05-15

... Guidance for Room Air Conditioners, Residential Dishwashers, and Residential Clothes Washers: Public... procedures for room air conditioners, residential dishwashers, and residential clothes washers. DATES: DOE...'s existing test procedures for residential room air conditioners, residential dishwashers, and...

16 CFR Appendix E to Part 305 - Room Air Conditioners

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Room Air Conditioners E Appendix E to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE... Appendix E to Part 305—Room Air Conditioners Range Information Manufacturer's rated cooling capacity in Btu...

Ventilation-air conditioner system in nuclear power plant

International Nuclear Information System (INIS)

Kubota, Ryuji; Sugisaki, Toshihiko.

1989-01-01

This invention concerns a ventilation-air conditioner system which enables, upon occurrence of accidents in a nuclear power plant, continuous operation for other adjacent nuclear power plants with no effect of accidents. Air supply system and exhaust system are operated during usual operaiton. If loss of coolants accidents should occur in an adjacent nuclear power plants, operation is switched from ventilation operaiton to the operation of re-cycling system based on an AND logic of three signals, that is, a pressure HIGH signal for the reactor container, a water level LOW signal for the reactor and a radioactivity signal of the ventilation-air conditioner sytem on the side of air supply in the nuclear power plant. Thus, nuclear reactor buildings of the nuclear power plant are from the external atmosphere. Therefore, the radioactivity HIGH signal for switching to the emergency air conditioner system of the nuclear power plant is not actuated due to the loss of coolant accidents in the adjacent nuclear power plant. In addition, since the atmospheric temperature in the nuclear reactor building can be maintained by a cooling device disposed to the recycling system, reactor shutdown can be prevented. (I.S.)

Active Participation of Air Conditioners in Power System Frequency Control Considering Users’ Thermal Comfort

Directory of Open Access Journals (Sweden)

Rongxiang Zhang

2015-09-01

Full Text Available Air conditioners have great potential to participate in power system frequency control. This paper proposes a control strategy to facilitate the active participation of air conditioners. For each air conditioner, a decentralized control law is designed to adjust its temperature set point in response to the system frequency deviation. The decentralized control law accounts for the user’s thermal comfort that is evaluated by a fuzzy algorithm. The aggregation of air conditioners’ response is conducted by using the Monte Carlo simulation method. A structure preserving model is applied to the multi-bus power system, in which air conditioners are aggregated at certain load buses. An inner-outer iteration scheme is adopted to solve power system dynamics. An experiment is conducted on a test air conditioner to examine the performance of the proposed decentralized control law. Simulation results on a test power system verify the effectiveness of the proposed strategy for air conditioners participating in frequency control.

ENERGY STAR Certified Room Air Conditioners

Data.gov (United States)

U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Room Air Conditioners that are effective as of...

The life cycle rebound effect of air-conditioner consumption in China

International Nuclear Information System (INIS)

Liu, Jingru; Sun, Xin; Lu, Bin; Zhang, Yunkun; Sun, Rui

2016-01-01

Highlights: • Develop a life cycle rebound effect model. • Assess the life cycle rebound effect of Chinese room air conditioners. • Conduct a questionnaire to assess the consumption behavior of Chinese room air conditioners. • Rebound effect should be considered by energy policy makers. - Abstract: Governments worldwide are attempting to reduce energy consumption and environmental pollution by confronting environmental problems and adopting more energy-efficient products. However, because of the rebound effect, energy-saving targets cannot always be fully achieved, and sometimes greater energy consumption is generated. Research on the rebound effect from the perspective of industrial ecology considers not only direct energy consumption but also its life cycle negative impacts on the environment with China’s rapid economic development and simultaneously improving quality of life, the ownership of room air conditioners (RACs) has increased more than three hundred times, and air conditioners’ energy consumption has increased one thousand times over the last twenty years. The Air Conditioner Energy Efficiency Standard is one of the most important measures in China for reducing the amount of energy consumed by RACs. This paper introduces a life cycle based method to estimate the rebound effect of Chinese RACs consumption. This model provides a product’s life-cycle view to assess the rebound effect, considering the contribution of both producer and consumer. Based on the established life cycle rebound effect model, we compared urban household RAC consumption behaviour before and after the launch of the Air Conditioner Energy Efficiency Standard. A rebound effect in RAC consumption was found that there was a longer daily usage period in the household as air conditioner efficiency levels improved. The life cycle rebound effect of household air-conditioner consumption was calculated to be 67%. The main conclusion obtained from this study is that policies and

77 FR 8178 - Test Procedures for Central Air Conditioners and Heat Pumps: Public Meeting

Science.gov (United States)

2012-02-14

.... EERE-2010-BT-TP-0038] Test Procedures for Central Air Conditioners and Heat Pumps: Public Meeting... methodologies and gather comments on testing residential central air conditioners and heat pumps designed to use... residential central air conditioners and heat pumps that are single phase with rated cooling capacities less...

Capacity modulation of an inverter-driven multi-air conditioner using electronic expansion valves

International Nuclear Information System (INIS)

Choi, J.M.; Kim, Y.C.

2003-01-01

An inverter-driven multi-air conditioner provides the benefits of comfort, energy conservation and easy maintenance. Recently, the multi-air conditioner has been employed in small and medium-sized buildings. However, the performance data and control algorithm for multi-air conditioners are limited in literature due to complicated system parameters and operating conditions. In the present study, the performance of an inverter-driven multi-air conditioner having two indoor units with electronic expansion valves (EEV) was measured by varying indoor loads, EEV opening, and compressor speed. Based on the experimental results, the operating characteristics and capacity modulation of the inverter-driven multi-air conditioner are discussed. As a result, it is suggested that the superheats for both indoor units have to be maintained around 4 o C by utilizing the EEVs in this system, and consequently, the compressor speed needs to be adjusted to provide optimum cooling capacity for each indoor unit

Research on a Micro-Grid Frequency Modulation Strategy Based on Optimal Utilization of Air Conditioners

Directory of Open Access Journals (Sweden)

Qingzhu Wan

2016-12-01

Full Text Available With the proportion of air conditioners increasing gradually, they can provide a certain amount of frequency-controlled reserves for a micro-grid. Optimizing utilization of air conditioners and considering load response characteristics and customer comfort, the frequency adjustment model is a quadratic function model between the trigger temperature of the air conditioner compressor, and frequency variation is provided, which can be used to regulate the trigger temperature of the air conditioner when the micro-grid frequency rises and falls. This frequency adjustment model combines a primary frequency modulation method and a secondary frequency modulation method of the energy storage system, in order to optimize the frequency of a micro-grid. The simulation results show that the frequency modulation strategy for air conditioners can effectively improve the frequency modulation ability of air conditioners and frequency modulation effects of a micro-grid in coordination with an energy storage system.

Strategies for reducing the environmental impacts of room air conditioners in Europe

International Nuclear Information System (INIS)

Grignon-Masse, Laurent; Riviere, Philippe; Adnot, Jerome

2011-01-01

In Europe, buildings tend to be equipped with individual air conditioners, which constitute a fast growing electrical end-use. In this context, this study aims to assess the environmental impacts of European individual air conditioners and to analyse policy strategies to reduce these impacts. After analysing the European context concerning individual air conditioners, the environmental impacts of European air conditioners are assessed using a Life Cycle Analysis approach. The following step consists in studying, both technically and economically, different improvement options aiming at reducing the environmental impacts of these appliances. These results, obtained at the product level, are then generalised at the European level and different policy measures are defined and analysed. The main conclusion is that the implementation of a Minimum Energy Performance Standard based on Least Life Cycle Costs could save up to 49 TWh and 20 MtCO 2-eq in 2020 and be economically beneficial to the European end-user. - Research highlights: → A methodology based on Life Cycle Analysis is applied to European air conditioners. → Environmental impacts are mainly due to energy consumption. → There is a high potential for energy savings at very low costs for end users.

75 FR 7987 - Energy Conservation Standards for Residential Clothes Dryers and Room Air Conditioners: Public...

Science.gov (United States)

2010-02-23

... Conservation Standards for Residential Clothes Dryers and Room Air Conditioners: Public Meeting and... conservation standards for residential clothes dryers and room air conditioners; the analytical framework..., Mailstop EE-2J, Public Meeting for Residential Clothes Dryers and Room Air Conditioners, EERE-2007-BT-STD...

75 FR 14368 - Energy Conservation Standards for Residential Central Air Conditioners and Heat Pumps: Public...

Science.gov (United States)

2010-03-25

... Conservation Standards for Residential Central Air Conditioners and Heat Pumps: Public Meeting and Availability... conservation standards for residential central air conditioners and heat pumps; the analytical framework..., Mailstop EE-2J, Public Meeting for Residential Central Air Conditioners and Heat Pumps, EERE-2008-BT- STD...

Development of multiplexing network for air conditioner systems; Eakon yo LAN system no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, T; Nakazawa, Y; Nakase, M; Sato, Y [Nissan Motor Co. Ltd., Tokyo (Japan); Nomura, M; Okasato, Y; Sunaga, H [Calsonic Corp., Tokyo (Japan)

1997-10-01

Plural air flap actuators of the air conditioner system in a vehicle have been integrated into a single-type actuator using two newly developed technologies: super-low-cost multiplexing network technology and digital motor control technology with a 1-bit A/D converter. The number of harnesses and connectors and the handling load of the air conditioner control microcomputer are reduced, so that we succeeded in sharply reducing the cost of the air conditioner system. 9 figs., 2 tabs.

Development of a solar-powered residential air conditioner: System optimization preliminary specification

Science.gov (United States)

Rousseau, J.; Hwang, K. C.

1975-01-01

Investigations aimed at the optimization of a baseline Rankine cycle solar powered air conditioner and the development of a preliminary system specification were conducted. Efforts encompassed the following: (1) investigations of the use of recuperators/regenerators to enhance the performance of the baseline system, (2) development of an off-design computer program for system performance prediction, (3) optimization of the turbocompressor design to cover a broad range of conditions and permit operation at low heat source water temperatures, (4) generation of parametric data describing system performance (COP and capacity), (5) development and evaluation of candidate system augmentation concepts and selection of the optimum approach, (6) generation of auxiliary power requirement data, (7) development of a complete solar collector-thermal storage-air conditioner computer program, (8) evaluation of the baseline Rankine air conditioner over a five day period simulating the NASA solar house operation, and (9) evaluation of the air conditioner as a heat pump.

[Verification of bacteriological safety of PCM 40 air conditioner].

Science.gov (United States)

Dumas, J L; Ducel, G; Rouge, J C

1991-01-01

This study assessed the bacteriological safety of the bedside air conditioner PCM 40 (Howorth Airtech), used for prevention of intraoperative hypothermia, by blowing filtered warm air through a special mattress. The 3 microns bacterial filter of the device released 2,968 +/- 5,618 particles of diameter less than 3 microns per m3 of room air, containing 78,798 +/- 37,243 of such particles per m3. The amount of bacteries in the air pulsed from the mattress was 30 +/- 41 cfu/m3 vs 120 cfu/m3 in the ambient air and in the hot air supply tubing it reached 6 +/- 5 cfu/m3 vs 175 +/- 77 cfu/m3. It is concluded that bacteriological data do not contra-indicate the use of this air conditioner in the operating theater. The only limitations for use are the position (prone or lateral position) and type of surgery (neurosurgery).

Energy and economic analysis of a building air-conditioner with a phase change material (PCM)

International Nuclear Information System (INIS)

Chaiyat, Nattaporn

2015-01-01

Highlights: • Phase change material of Rubitherm20 was applied with the air-conditioner under the climate of Thailand. • PCM was used to reduce cooling load and electrical power of the air-conditioner. • Mathematical model of the packed ball bed of PCM was presented to predict the thermal performance. - Abstract: In this study, a concept of using phase change material (PCM) for improving cooling efficiency of an air-conditioner had been presented under Thailand climate. Rubitherm20 (RT-20) was selected to evaluate the thermal performance by reducing the air temperature entering the evaporating coil. The model of PCM celluloid balls had been performed with the air-conditioner. For the experiment, 2 TR of R-134a air-conditioner was chosen to test a pack bed of PCM balls with thickness 40 cm. The pressure drops of the air flowing through the bed were considered with and without a set of by-pass tubes along the height of the storage bed. The mathematical model of the air-conditioner with the PCM storage was developed and verified with the testing results. From the study results, it could be seen that pressure drops of the bed with and without bypass tubes were nearly the same results. Thus, PCM ball pack bed using RT-20 without bypass tubes was used to improve the cooling efficiency of the air-conditioner. The experimental result of the modified unit was compared and verified with the mathematical model, which agreed quite well with the simulation result. Finally, the model was used to analyze the economic result, which found that the electrical consumption of the modified air-conditioner could be decreased around 3.09 kW h/d. The saving cost from the PCM bed could be 9.10% of 170.03 USD/y and the payback period was around 4.15 y

Net private benefits of purchasing eco-labeled air conditioners and subsidization policies in China

International Nuclear Information System (INIS)

Sun, Junxiu; Yin, Haitao; Wang, Feng

2014-01-01

Built on a data set of 527 air conditioner models collected from an online retailer, this study investigates whether the savings that consumers realize on their private electricity bills from purchasing energy-efficient appliances compensate for the additional cost of the appliances on the market, and if not, the size of the gap between the savings and the cost. Our findings show that, except for the most energy-efficient category, the cost savings from using energy-efficient air conditioners does compensate for their higher price. Therefore, any government subsidy should be reserved for the most efficient products. For less energy-efficient appliances, the best policy may be to provide more effective information instead of a subsidy because the subsidy might attract consumers away from more energy-efficient air conditioners and result in an unwanted effect. - Highlights: • This paper analyses the net private benefits of purchasing eco-labeled air conditioners in China. • There is no need to subsidize less energy-efficient air conditioners. • The most recently proposed policy development in China is a reform headed in the right direction

Pulmonary function tests in air conditioner users | Vidya ...

African Journals Online (AJOL)

Background: Modernization has been implicated in the pathogenesis of allergic airway diseases. House dust, mites, and indoor air pollutants have been reported to cause elevation of serum IgE levels and/or enhancement of eosinophil activity. A component of modern lifestyle is the intense use of air-conditioners (AC) that ...

Potential CO{sub 2} reduction by implementing energy efficiency standard for room air conditioner in Malaysia

Energy Technology Data Exchange (ETDEWEB)

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

2001-09-01

This study attempts to predict the environmental impact of implementing an energy efficiency standard for room air conditioners in Malaysia. The ownership of room air conditioners has increased tremendously in this country. At present, there are about 528,792 room air conditioners in Malaysian households. In the year 2020, it will be about 1,511,276. The potential carbon dioxide reduction is based on the predicted electricity savings from implementing a minimum energy efficiency standard for room air conditioners. The electricity savings are calculated based on the predicted electricity consumption by a single air conditioner in the Malaysian household. The replacement of less efficient units of this appliance is reflected in reduced electricity consumption and emissions from power plants. The energy efficiency provisions of this regulation and agreement provide targets to save money, energy and, most importantly, to protect the environment. (Author)

Energy reduction of building air-conditioner with phase change material in Thailand

Directory of Open Access Journals (Sweden)

Nattaporn Chaiyat

2014-11-01

Full Text Available In this study, a concept of using phase change material (PCM for improving cooling efficiency of an air-conditioner had been presented under Thai climate. Paraffin waxes melting point at around 20 °C was selected to evaluate the thermal performance by reducing the air temperature entering the evaporating coil. The model of PCM celluloid balls had been performed with the air-conditioner. Moreover, the mathematical model of the air-conditioner with the PCM storage was developed and verified with the testing results. From the study results, it could be seen that the simulated data agreed quite well with the experimental result at the discrepant around 2–4%. Finally, the model was used to analyze the economic result which was found that the electrical consumption of the modified air-conditioner could be decreased 3.09 kW h/d. The electrical power consumption of the modified unit was 36.27 kW h/d at the operating time 15 h/d compared with 39.36 kW h/d of the normal unit at the operating time 12 h/d. The saving cost of the PCM bed could be 9.10% or 170.03 USD and the payback period was 4.15 y.

Research on a compact adsorption room air conditioner

International Nuclear Information System (INIS)

Yang, G.Z.; Xia, Z.Z.; Wang, R.Z.; Keletigui, Daou; Wang, D.C.; Dong, Z.H.; Yang, X.

2006-01-01

A novel compact adsorption room air conditioner with a cooling capacity of 1 kW 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 687 W and a COP (coefficient of performance) of 0.307 can be obtained. However, for the improved one, a cooling capacity of 790 W 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 ( o C) and has small dimensions of 300 mm (depth), 500 mm (width) and 950 mm (height)

ENERGY STAR Certified Non-AHRI Central Air Conditioner Equipment and Air Source Heat Pump

Data.gov (United States)

U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Air Source Heat Pump and Central Air Conditioner...

Improvement of Cooling Performance of a Compact Thermoelectric Air Conditioner Using a Direct Evaporative Cooling System

Science.gov (United States)

Tipsaenporm, W.; Lertsatitthanakorn, C.; Bubphachot, B.; Rungsiyopas, M.; Soponronnarit, S.

2012-06-01

This paper presents the results of tests carried out to investigate the potential application of a direct evaporative cooling (DEC) system for improving the performance of a compact thermoelectric (TE) air conditioner. The compact TE air conditioner is composed of three TE modules. The cold and hot sides of the TE modules were fixed to rectangular fin heat sinks. The DEC system produced cooling air that was used to assist the release of heat from the heat sinks at the hot side of the TE modules. The results showed that the cooling air dry bulb temperature from the DEC system achieved drops of about 5.9°C in parallel with about a 33.4% rise in relative humidity. The cooling efficiency of the DEC system varies between 72.1% and 81.5%. It increases the cooling capacity of the compact TE air conditioner from 53.0 W to 74.5 W. The 21.5 W (40.6%) increase represents the difference between the compact air conditioner operating with ambient air flowing through the TE module's heat sinks, and the compact air conditioner operating with the cooler air from the DEC system flowing through the TE module's heat sinks. In both scenarios, electric current of 4.5 A was supplied to the TE modules. It also has been experimentally proven that the coefficient of performance (COP) of the compact TE air conditioner can be improved by up to 20.9% by incorporating the DEC system.

Isolation and Identification of Pathogenic Fungi from Air Conditioners in Tutorial Rooms of the Faculty of Medicine, Universitas Padjadjaran

Directory of Open Access Journals (Sweden)

Gowre Govindasamy

2014-02-01

Full Text Available Background: Awareness about health problems caused by air conditioner is very important. Thus, it is crucial to have knowledge about proper maintenance of air conditioner. At the Faculty of Medicine, Universitas Padjadjaran, air conditioners are used in every tutorial rooms. This study was performed to provide adequate information on the fungi, such as Aspergillus, Penicillium and Mucor, found in air conditioners. Methods: A descriptive laboratory study was used to identify the presence and the type of pathogenic fungi from air conditioners in tutorial rooms. Thirty-four samples were collected from the air outlet grille of the air conditioners and cultured on Sabouraud agar at 27°C for 2 weeks. Fungi presence were then identified microscopically Results: The results showed that the majority of air conditioners in tutorial rooms of the Faculty of Medicine, University Padjadjaran contained many types of fungus that grew in Sabouraud agar. From 34 samples, thirty two samples were positive and 2 samples were negative. Various fungus have been identified, those were Penicillium (37.5%, Aspergillus (25%, Mucor (2.5% and unidentified (35% Conclusions : The majority of air conditioners in tutorial rooms of the Faculty of Medicine, University Padjadjaran contained many types of opportunistic fungus. [AMJ.2014;1(1:21–4

DEMONSTRATION AND TESTING OF AN EER OPTIMIZER SYSTEM FOR DX AIR-CONDITIONERS

Science.gov (United States)

2017-10-07

Conditioner and Any Web Connected Device Such as a Tablet, Phone, Laptop, or Desktop Computer. ............. 28  Figure 15. A Summary Screen Showing...efficiency specifications published by the Consortium for Energy Efficiency (CEEE) for new unitary air conditioning and heat pump systems5 establish Energy...Figure 14. Connection Diagram Showing Data Path between the Air Conditioner and Any Web Connected Device Such as a Tablet, Phone, Laptop, or Desktop

Noninvasive evaluation of the chronic influence of local air velocity from an air conditioner using salivary cortisol and skin caspase-14 as biomarkers of psychosomatic and environmental stress.

Science.gov (United States)

Yamaguchi, M; Nishimiya, H

2012-01-01

To demonstrate the possibility of evaluating the chronic influence of local air velocity from an air conditioner using noninvasive biomarkers. Over a consecutive 5-day period, 16 healthy young male adults were exposed to air flow from a whole ceiling-type air conditioner (low local air velocity) and from a commercial concentrated exhaust air conditioner (high local air velocity). Salivary cortisol was used as an index of the psychological effects and caspase-14, collected from the stratum corneum, was used as a marker of environmental stress on the skin. Local air velocity generated from the whole ceiling-type air conditioner where the subject's head was positioned was one-seventh that of the exhaust air conditioner. After exposure to the exhaust air conditioner for 5 days, salivary cortisol decreased significantly from morning to evening and skin caspase-14 gradually increased during the day. A significant increase in hydration index from the morning to the evening was found with the whole ceiling-type air conditioner. The effects of chronic exposure to air movement generated by an air conditioner may be quantified by measurement of salivary cortisol and skin caspase-14.

Influence of environmental characteristics and climatic factors on mites in the dust of air-conditioner filters.

Science.gov (United States)

Wu, J; Liu, Z G; Ran, P X; Wang, B

2009-12-01

To investigate mites in the dust of air-conditioner filters (MACF) in China, a total of 652 dust samples were collected from six cities: Guangzhou (n = 129), Nanchang (n = 127), Shanghai (n = 113), Xian (n = 93), Beijing (n = 93), and Shenyang (n = 79). Tarsonemus granarius was the most dominant species (87.2%). Dermatophagoides pteronyssinus and Dermatophagoides farinae only represented 7.0 and 3.0% of total mites, respectively. With latitude increasing, both mite occurrence rate (P air-conditioner age, utilization time and power. Wall and window type air-conditioner had higher risk of finding MACF than the floor type air-conditioner. As far as the cleaning interval time of ACF was concerned, higher risk ratio and the highest density of MACF were found in the time stage of >3, air-conditioner filters are potential indoor threat to asthma and allergy sufferers. In this study, we find that the storage mite Tarsonemus granarius is the predominant species of mites in the dust of air-conditioner filters (MACF). Thus, the possible clinical importance of T. granarius should cause more our attentions in the future. The abundance and distribution of MACF are also found significantly varied in different climatic regions of China. When we try to assess the possible risk of MACF, more attentions should be focused on subtropical region than temperate region. The influence analysis of environmental characteristics on the prevalence of MACF will shed light on the establishment of mite control strategy and the design of mite defense air-conditioner.

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

... of Room Air Conditioners F Appendix F to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY... Conditioners 1. Test method. The test method for testing room air conditioners shall consist of application of the methods and conditions in American National Standard (ANS) Z234.1-1972, “Room Air Conditioners...

16 CFR Appendix H to Part 305 - Cooling Performance and Cost for Central Air Conditioners

Science.gov (United States)

2010-01-01

... RULEâ) Pt. 305, App. H Appendix H to Part 305—Cooling Performance and Cost for Central Air Conditioners... Split System Units Central Air Conditioners (Cooling Only): All capacities 10.9 23.0 Heat Pumps (Cooling... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Cooling Performance and Cost for Central Air...

Dynamic performance of self-operated three-way valve used in a hybrid air conditioner

International Nuclear Information System (INIS)

Zhang, Penglei; Zhou, Dehai; Shi, Wenxing; Li, Xianting; Wang, Baolong

2014-01-01

A hybrid air conditioner combining a thermosyphon cycle with a vapor compression refrigeration cycle has a large energy saving potential compared with a common air conditioner for spaces requiring year-round cooling. The performance of the switch between the vapor compression mode and the thermosyphon mode largely impacts the safety and reliability of hybrid air conditioners. Therefore, a self-operated three-way valve is proposed. A thermodynamic model and a kinetic model are developed in this paper to evaluate the dynamic performance of the switch valve. The effects of the spring force constant, compressor discharging volume, fit clearance and piston length on the dynamic performance of the switch valve are analyzed. In conclusion, the proposed self-operated three-way valve can realize the switch operation accurately. - Highlights: •A self-operated three-way valve is proposed for hybrid air conditioners. •The thermodynamic model and kinetic model of the self-operated three-way valve are developed. •The validity of models is verified by experiments. •Effects of four main design parameters on the operating performance of the valve are researched

Performance curves of room air conditioners for building energy simulation tools

International Nuclear Information System (INIS)

Meissner, José W.; Abadie, Marc O.; Moura, Luís M.; Mendonça, Kátia C.; Mendes, Nathan

2014-01-01

Highlights: • Experimental characteristic curves for two room air conditioners are presented. • These results can be implemented in building simulation codes. • The energy consumption under different conditions can numerically determine. • The labeled higher energy efficiency product not always provides the best result. - Abstract: In order to improve the modeling of air conditioners in building simulation tools, the characteristic curves for total cooling capacity, sensible cooling capacity and energy efficiency ratio of two room units were determined. They were obtained by means of standard capacity tests on climatic chambers in a set of environmental conditions described by external dry- and internal wet bulb temperatures. Afterward, the performance of these two units and that of four other units, with and without taking into to account the thermodynamic variations of the surrounding environments on it, were compared using a whole building simulation program for simulating a conditioned space. The comparative analysis showed that the air conditioner with the higher energy efficiency rating not always provides the lowest power consumption in real conditions of use

Performance test of a grid-tied PV system to power a split air conditioner system in Surabaya

Science.gov (United States)

Tarigan, E.

2017-11-01

Air conditioner for cooling air is one of the major needs for those who live in hot climate area such as Indonesia. This work presents the performance test of a grid-tied PV system to power air conditioner under a hot tropical climate in Surabaya, Indonesia. A 800 WP grid-tied photovoltaic (PV) system was used, and its performance was tested to power a 0.5 pk of split air conditioner system. It was found that about 3.5 kWh daily energy was consumed by the tested air conditioner system, and about 80% it could be supplied from the PV system. While the other 20% was supplied by the grid during periods of low solar irradiation, 440 Wh of energy was fed into the grid during operation out of office hours. By using the grid-tied PV system, the energy production by PV system did not need to match the consumption of the air conditioner. However, a larger capacity of PV system would mean that a higher percentage of the load would be covered by PV system.

Development of a solar-powered residential air conditioner

Science.gov (United States)

1975-01-01

The initial objective of the program was the optimization (in terms of cost and performance) of a Rankine cycle mechanical refrigeration system which utilizes thermal energy from a flat solar collector for air conditioning residential buildings. However, feasibility investigations of the adsorption process revealed that a dessicant-type air conditioner offers many significant advantages. As a result, limited efforts were expended toward the optimization of such a system.

[Air-conditioner disease. Results of an industrial medicine survey (author's transl)].

Science.gov (United States)

Molina, C; Aiache, J M; Bedu, M; Menaut, P; Wahl, D; Brestowski, J; Grall, Y

1982-07-03

The results of a survey conducted in a company employing 1850 persons working in air-conditioned premises are reported. One hundred and five persons were examined, including 790 who mostly complained of respiratory disorders and 20 controls. Regular check-ups during the last two years have failed to reveal any serious disease. The most frequent complaints were rhinitis and tracheitis, especially among female employees. No alveolitis was observed. The finding of Bacillus subtilis in samples of ambient air and air-conditioner filters in conjunction with the presence of precipitating antibodies against crude extracts from these samples, suggested that the respiratory disorders might have been due to this microorganism. A multifactorial analysis demonstrated a statistically significant correlation between clinical symptoms and immunological disorders. The air-conditioner disease, therefore, may present as a benign condition.

Technologies for high performance and energy saving in room air conditioners. Shoenegata kokoritsu eakon ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Kawai, N. (Toshiba Corp., Tokyo (Japan))

1994-05-31

An energy saving inverter type air-conditioner was introduced. It is important to increase the efficiency in the low capacity zone below the rated capacity to realize the energy saving. For the reduction of peak, improving the efficiency in the high capacity operation is also necessary. The power consumption in compressor and in inverter is about 90 % of the total power consumption in air-conditioner. The other 10 % are distributed to the fan motor and the control unit. For achieving the energy saving, the reduction of this 10 % part is also necessary because this 10 % part is constant regardless of the capacity of air-conditioner. The compressor motor was modified to the brushless DC motor with rotor position detecting device to improve the rotor structure and the position detection system. The heat exchanger was changed to a room heat exchanger with slit pattern. For the outdoor heat exchanger, the complex curvature blade fan was adopted. The control system of air-conditioner was changed. The PMV was previously learned and input in the microcomputer to calculate the data. Resultantly, the power consumption was reduced by about 20 % as compared with the conventional air-conditioner. 10 figs., 1 tab.

[Fungus microbiota in air conditioners in intensive care units in Teresina, Piauí].

Science.gov (United States)

Mobin, Mitra; do Amparo Salmito, Maria

2006-01-01

With the aim of identifying the fungus microbiota in air conditioners in intensive care units (ICUs) within public and private hospitals in Teresina, Piauí, solid material was collected from ten different ICUs. Thirty-three species of Moniliaceae and Dematiaceae were isolated, which was the first report of these in Piauí. High frequencies of Aspergillus niger Van Tieghem (60%), Aspergillus fumigatus Fres (50%), Trichoderma koningii Oudem (50%) and Aspergillus flavus Link: Fr. (40%) were recorded. The air conditioner cleanliness validity had expired in all the ICUs, and the quantity of colony-forming units exceeded the levels permitted by Law 176/00 from the Ministry of Health. It is important to provide individual protection equipment for professionals, adopt hospital infection control measures, raise the awareness of the presence of fungus infection, improve air circulation around the environment, periodically clean the air conditioners, and make health professionals alert to the importance of these fungi in the hospital environment.

Air conditioner with three stages of indirect regeneration

International Nuclear Information System (INIS)

Worthington, M.N.

1987-01-01

An air conditioner is described comprising: a cabinet defining an internal evaporation chamber and having an air inlet and an air outlet; a heat exchanger mounted in the cabinet and defining an air movement path between the air inlet and the air outlet; means for supplying air to be cooled to the air inlet of the cabinet of movement through the air movement path of the heat exchanger in a heat exchanger relationship; air diversion means for continuously diverting some of the air emerging from the air outlet of the cabinet; and means in the evaporation chamber of the cabinet for recirculating spraying water into the chiller tube of the heat exchanger for interacting with the diverted air moving therethrough to evaporatively cool the heat exchanger

16 CFR Appendix I to Part 305 - Heating Performance and Cost for Central Air Conditioners

Science.gov (United States)

2010-01-01

... RULEâ) Pt. 305, App. I Appendix I to Part 305—Heating Performance and Cost for Central Air Conditioners... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Heating Performance and Cost for Central Air Conditioners I Appendix I to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC...

Requirements of office air conditioners. Pt. 1

Energy Technology Data Exchange (ETDEWEB)

Radtke, W

1988-01-01

New building designs and experiences gained in the past are reponsible for the considerable changes the requirements of air conditioners have gone through in recent years. Details are given on an exemplary air conditioning system designed for the Colonia Insurances building complex located in the city of Cologne. The ventilation requirements and hygienic conditions set out for air conditioned rooms call for outside air supplies, the careful selection of air intakes, and the filtering of intake air. Details are given on the efficiency and limits of combined natural window ventilation/artificial ventilation systems, the influence of window types, and the influence of building structures. The pressure conditions to be expected for larger building complexes in the case of natural ventilation should be assessed with the help of models put to wind tunnel tests.

Development of a solar powered residential air conditioner (General optimization)

Science.gov (United States)

Lowen, D. J.

1976-01-01

A commercially available 3-ton residential Lithium Bromide (LiBr) absorption air conditioner was modified for use with lower temperature solar heated water. The modification included removal of components such as the generator, concentration control chamber, liquid trap, and separator; and the addition of a Chrysler designed generator, an off-the-shelf LiBr-solution pump. The design goal of the modified unit was to operate with water as the heat-transfer fluid at a target temperature of 85 C (185 F), 29.4 C (85 F) cooling water inlet, producing 10.5 kW (3 tons) of cooling. Tests were performed on the system before and after modification to provide comparative data. At elevated temperatures (96 C, 205 F), the test results show that Lithium Bromide was carried into the condenser due to the extremely violent boiling and degraded the evaporator performance.

Swozzle based burner tube premixer including inlet air conditioner for low emissions combustion

Science.gov (United States)

Tuthill, Richard Sterling; Bechtel, II, William Theodore; Benoit, Jeffrey Arthur; Black, Stephen Hugh; Bland, Robert James; DeLeonardo, Guy Wayne; Meyer, Stefan Martin; Taura, Joseph Charles; Battaglioli, John Luigi

2002-01-01

A burner for use in a combustion system of a heavy-duty industrial gas turbine includes a fuel/air premixer having an air inlet, a fuel inlet, and an annular mixing passage. The fuel/air premixer mixes fuel and air into a uniform mixture for injection into a combustor reaction zone. The burner also includes an inlet flow conditioner disposed at the air inlet of the fuel/air premixer for controlling a radial and circumferential distribution of incoming air. The pattern of perforations in the inlet flow conditioner is designed such that a uniform air flow distribution is produced at the swirler inlet annulus in both the radial and circumference directions. The premixer includes a swozzle assembly having a series of preferably air foil shaped turning vanes that impart swirl to the airflow entering via the inlet flow conditioner. Each air foil contains internal fuel flow passages that introduce natural gas fuel into the air stream via fuel metering holes that pass through the walls of the air foil shaped turning vanes. By injecting fuel in this manner, an aerodynamically clean flow field is maintained throughout the premixer. By injecting fuel via two separate passages, the fuel/air mixture strength distribution can be controlled in the radial direction to obtain optimum radial concentration profiles for control of emissions, lean blow outs, and combustion driven dynamic pressure activity as machine and combustor load are varied.

The role of technology, product lifetime, and energy efficiency in climate mitigation: A case study of air conditioners in Japan

International Nuclear Information System (INIS)

Nishijima, Daisuke

2017-01-01

This study analyzed the impact on the life-cycle CO_2 emissions derived from a specific durable good (i.e., household air conditioners in this study) of industrial technology changes, product lifetime changes, and energy efficiency improvements. I proposed a comprehensive structural decomposition analysis including two factors of average lifetime and energy efficiency trend of household air conditioners and applied the decomposition method to the Japanese environmental input-output tables of 1990, 1995, 2000, and 2005. The empirical results show that “Household air-conditioner sector” itself contributed to reducing life-cycle CO_2 emissions derived from household air conditioners, while other sectors such as “On-site power generation sector” and “Retail trade sector” contributed to increasing life-cycle CO_2 emissions derived from household air conditioners. I also conducted combined scenario analysis about reduction potential of product lifetime and energy efficiency of air conditioners and the results showed the reduction rate of energy efficiency necessary for maintain CO_2 emissions in 2005 at 1990 level on each average lifetime scenario. (e.g. if average lifetime of air conditioners is shortened by 1 year, energy efficiency of air conditioners have to be further improved by 20.6% from current level. - Highlights: • This study provides a decomposition framework for air conditioner’s CO_2 emissions. • Technology, product lifetime and energy efficiency are considered in the framework. • “Household air conditioner” sector contributed to reducing CO_2 emissions largely. • “On-site power generation” indirectly contributed to increasing CO_2 emissions. • I showed the improvement rates of energy efficiency to achieve a reduction target.

Statistical analysis of the count and profitability of air conditioners.

Science.gov (United States)

Rady, El Houssainy A; Mohamed, Salah M; Abd Elmegaly, Alaa A

2018-08-01

This article presents the statistical analysis of the number and profitability of air conditioners in an Egyptian company. Checking the same distribution for each categorical variable has been made using Kruskal-Wallis test.

Feasibility study of a green energy powered thermoelectric chip based air conditioner for electric vehicles

International Nuclear Information System (INIS)

Miranda, Á.G.; Chen, T.S.; Hong, C.W.

2013-01-01

Traditional compressed-refrigerant air conditioning systems consume substantial energy that may reduce the driving performance and cruising mileage of electric vehicles considerably. It is crucial to design a new climate control system, using a direct energy conversion principle, to further aid in the commercialization of modern electric vehicles. A solid state air conditioner model consisting on TECs (thermoelectric chips) as the load, DSSCs (dye sensitized solar cells) as the renewable energy source and high power LiBs (lithium-ion batteries) as an energy storage device are considered for a personal mobility vehicle. The power management between the main power net and the solid state air conditioner interface is designed with an outer proportional-integral controller and an inner passivity based current controller with a loss included model for perfect tracking. This model is intended to comprise thermal and electrical elements which can be tunable for performance benchmarking and optimization of a solid state air conditioning system. Dynamic performance simulations of the solid-state air conditioner are performed, alongside guidelines for feasibility. - Highlights: • Alternative model extraction for dye sensitized solar cells. • Improved and computationally fast model for the cabin air temperature dynamics. • Euler–Lagrange loss included modeling of a buck converter. • Loss-included passivity based inner loop current control. • The thermoelectric chip air conditioner is tested in simulated cooling/heating scenarios

Study of noise in offices with window-type room air-conditioners

International Nuclear Information System (INIS)

Shaikh, G.H.; Hashmi, R.; Shareef, A.

2005-01-01

A Study of Noise has been carried out in 17 private offices, with window-type room air-conditioners, to assess noise levels in these offices. A-Weighted equivalent sound-pressure levels (dB(A) LAeq) and equivalent octave-band sound-pressure levels (dB Leq) were measured in each office, and Preferred Speech Interference Levels (PSIL) evaluated. The results show that the interior noise-levels in these offices vary from 59.6 to 72.2 dB(A) LAeq. which are very high and much above the interior noise limits, recommended for offices by some individual workers. Some ways and means to limit its emission of high level of noise from the air conditioners are also discussed. (author)

Design of direct solar PV driven air conditioner

KAUST Repository

Huang, Bin-Juine; Hou, Tung-Fu; Hsu, Po-Chien; Lin, Tse-Han; Chen, Yan-Tze; Chen, Chi-Wen; Li, Kang; Lee, K.Y.

2015-01-01

). The measured OPB is found to be greater than 0.98 at instantaneous solar irradiation IT > 600 W m-2 if rpL > 1.71 RF approaches 1.0 (the air conditioner is run in 100% with solar power) at daily-total solar radiation higher than 13 MJ m-2 day-1, if rpL > 3.

Air conditioner operation behaviour based on students' skin temperature in a classroom.

Science.gov (United States)

Song, Gook-Sup; Lim, Jae-Han; Ahn, Tae-Kyung

2012-01-01

A total of 25 college students participated in a study to determine when they would use an air conditioner during a lecture in a university classroom. The ambient temperature and relative humidity were measured 75 cm above the floor every minute. Skin temperatures were measured every minute at seven points, according to the recommendation of Hardy and Dubois. The average clothing insulation value (CLO) of subjects was 0.53 ± 0.07 CLO. The mean air velocity in the classroom was 0.13 ± 0.028 m/s. When the subjects turned the air conditioner both on and off, the average ambient temperatures, relative humidity and mean skin temperatures were 27.4 and 23.7 °C (p = 0.000), 40.9 and 40.0% (p = 0.528) and 32.7 and 32.2 °C (p = 0.024), respectively. When the status of the air conditioner was changed, the differences of skin temperatures in core body parts (head, abdomen and thigh) were not statistically significant. However, in the extremities (mid-lower arm, hand, shin and instep), the differences were statistically significant. Subjects preferred a fluctuating environment to a constant temperature condition. We found that a changing environment does not affect classroom study. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Ventilation air conditioner for a reactor container

International Nuclear Information System (INIS)

Ikegame, Noboru; Nakagawa, Takeshi.

1980-01-01

Purpose: To suppress the variations in the internal pressure of a reactor container and smoothly ventilate the reactor container. Constitution: The air conditioner provides an air-flow-rate-control damper, a purge-air supply fan, and a filter device in the air-supply pipe of a reactor container. Furthermore, it provides a pressure difference detector at a part of the container. The air-flow-rate-control damper is connected electrically through a position-modulator-comparison amplifier to the pressure difference detector. When the filtration becomes insufficient by clogging of the filter device and the internal pressure increased abruptly in the container, the pressure-difference detector can detect it, and the damper is operated by a pressure regulator and the comparator so as to control the air flow to the container. Thus, the internal pressure variation is controlled so as to easily ventilate the container. (J.P.N.)

Electric efficiency in lighting system and air conditioners replacement and automation of air conditioners split type in public buildings; Eficiencia eletrica na substituicao do sistema de iluminacao e de condicionadores de ar e automacao do sistema de condicionadores de ar tipo split em predios publicos

Energy Technology Data Exchange (ETDEWEB)

Vasconcellos, Arnulfo Barroso de; Apolonio, Roberto; Silva, Luciana Oliveira da; Gomes, Fernanda Leles [Universidade Federal de Mato Grosso (UFMT), MT (Brazil); Malheiro, Teresa Irene Ribeiro de Carvalho [Instituto Federal de Educacao, Ciencia e Tecnologia de Mato Grosso (IFMT), MT (Brazil); Barros, Regiane Silva de [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

2010-07-01

The reduction in expenditure on electricity is a major benefit not only consumers but also to utilities. In this context, this article examines the process of replacing the system of internal lighting, window type air conditioners and automation of Split type air conditioners from buildings of public institutions of the state of Mato Grosso during 2009 year and verifies the reduction in annual consumption of electric power and demand active power. Thus, measurements and calculations performed are presented for the interior lighting systems and air conditioners of these buildings before and after implementation of the process of replacing the system of internal lighting and window type air conditioners and automation of Split type air conditioners. This work is the result of integration among the Dealer Network Energy Rede Cemat, the Federal University of Mato Grosso (UFMT) and the Administration of all public buildings, where the academy answered these real issues, solving the specific problem presented. (author)

The application of fuzzy control on energy saving for multi-unit room air-conditioners

International Nuclear Information System (INIS)

Chiou, C.B.; Chiou, C.H.; Chu, C.M.; Lin, S.L.

2009-01-01

Most research, on energy saving methods for air-conditioners have focused on large chillers as its subject. As most school offices, laboratories, and classrooms are equipped with unitary systems for air-conditioning, this paper discusses methods for energy savings with regard to unitary systems. This paper will put forward the fuzzy temperature control method for multi-unit air-conditioners to enhance energy efficiency. The results show that the use of fuzzy control is efficient for energy saving as well as causing temperature control be steadier, even if there is a change to the thermal loading, the fuzzy control system is able to control the air-conditioning in stable conditions

Air conditioner for radioactive material handling facility

International Nuclear Information System (INIS)

Tanaka, Takeaki.

1991-01-01

An air conditioner intakes open-air from an open-air intake port to remove sands and sea salt particles by air filters. Then, natural and artificial radioactive particles of less than 1 μm are removed by high performance particulate filters. After controlling the temperature by an air heater or an air cooler, air is sent to each of chambers in a facility under pressure elevation by a blower. In this case, glass fibers are used as the filter material for the high performance particulate filter, which has a performance of more than 99.97% for the particles of 0.3 μm grain size. Since this can sufficiently remove the natural radioactive materials intruded from the outside, a detection limit value in each of the chambers of the facility can be set 10 -13 to 10 -14 μci/cm 3 in respect of radiation control. Accordingly, radiation control can be conducted smoothly and appropriately. (I.N.)

Experimental Determination of Demand Response Control Models and Cost of Control for Ensembles of Window-Mount Air Conditioners

Energy Technology Data Exchange (ETDEWEB)

Geller, Drew Adam [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-09-29

Control of consumer electrical devices for providing electrical grid services is expanding in both the scope and the diversity of loads that are engaged in control, but there are few experimentally-based models of these devices suitable for control designs and for assessing the cost of control. A laboratory-scale test system is developed to experimentally evaluate the use of a simple window-mount air conditioner for electrical grid regulation services. The experimental test bed is a single, isolated air conditioner embedded in a test system that both emulates the thermodynamics of an air conditioned room and also isolates the air conditioner from the real-world external environmental and human variables that perturb the careful measurements required to capture a model that fully characterizes both the control response functions and the cost of control. The control response functions and cost of control are measured using harmonic perturbation of the temperature set point and a test protocol that further isolates the air conditioner from low frequency environmental variability.

Refrigerant lines in split-type air conditioners

Energy Technology Data Exchange (ETDEWEB)

Rettenberger, P

1979-01-01

Condensator and evaporating units of split-type air conditioners are evaluated and filled with the refrigerant by the producer. The line systems are hermetically closed and prevent the loss of refrigerant and the penetration of moisture or dirt. The best installation method is the 'bendable lines'. They combine flexibility and easy installation with the advantages of the copper pipe. Several ducting systems and their connecting elements like couplings and valves are described, their installation is explained. These flexible systems are especially suitable for small air-condition plants of the split-type the evaporating unit of which is portable and can put where it is desired.

Product lifetime, energy efficiency and climate change: A case study of air conditioners in Japan.

Science.gov (United States)

Nishijima, Daisuke

2016-10-01

This study proposed a modelling technique for estimating life-cycle CO2 emissions of durable goods by considering changes in product lifetime and energy efficiency. The stock and flow of durable goods was modelled by Weibull lifetime distributions and the trend in annual energy efficiency (i.e., annual electricity consumption) of an "average" durable good was formulated as a reverse logistic curve including a technologically critical value (i.e., limit energy efficiency) with respect to time. I found that when the average product lifetime is reduced, there is a trade-off between the reduction in emissions during product use (use phase), due to the additional purchases of new, more energy-efficient air conditioners, and the increase in emissions arising from the additional production of new air conditioners stimulated by the reduction of the average product lifetime. A scenario analysis focused on residential air conditioners in Japan during 1972-2013 showed that for a reduction of average lifetime of 1 year, if the air conditioner energy efficiency limit can be improved by 1.4% from the estimated current efficiency level, then CO2 emissions can be reduced by approximately the same amount as for an extension of average product lifetime of 1 year. Copyright © 2016 Elsevier Ltd. All rights reserved.

Consumer life-cycle cost impacts of energy-efficiency standards for residential-type central air conditioners and heat pumps

International Nuclear Information System (INIS)

Rosenquist, Gregory; Chan, Peter; Lekov, Alex; McMahon, James; Van Buskirk, Robert

2001-01-01

In support of the federal government's efforts to raise the minimum energy-efficiency standards for residential-type central air conditioners and heat pumps, a consumer life-cycle cost (LCC) analysis was conducted to demonstrate the economic impacts on individual consumers from revisions to the standards. LCC is the consumer's cost of purchasing and installing an air conditioner or heat pump and operating the unit over its lifetime. The LCC analysis is conducted on a nationally representative sample of air conditioner and heat pump consumers resulting in a distribution of LCC impacts showing the percentage of consumers that are either benefiting or being burdened by increased standards. Relative to the existing minimum efficiency standard of 10 SEER, the results show that a majority of split system air conditioner and heat pump consumers will either benefit or be insignificantly impacted by increased efficiency standards of up to 13 SEER

Consumer life-cycle cost impacts of energy-efficiency standards for residential-type central air conditioners and heat pumps

Energy Technology Data Exchange (ETDEWEB)

Rosenquist, Gregory; Chan, Peter; Lekov, Alex; McMahon, James; Van Buskirk, Robert

2001-10-10

In support of the federal government's efforts to raise the minimum energy-efficiency standards for residential-type central air conditioners and heat pumps, a consumer life-cycle cost (LCC) analysis was conducted to demonstrate the economic impacts on individual consumers from revisions to the standards. LCC is the consumer's cost of purchasing and installing an air conditioner or heat pump and operating the unit over its lifetime. The LCC analysis is conducted on a nationally representative sample of air conditioner and heat pump consumers resulting in a distribution of LCC impacts showing the percentage of consumers that are either benefiting or being burdened by increased standards. Relative to the existing minimum efficiency standard of 10 SEER, the results show that a majority of split system air conditioner and heat pump consumers will either benefit or be insignificantly impacted by increased efficiency standards of up to 13 SEER.

[A patient with acute hypersensitivity pneumonitis with a diagnosis of air-conditioner lung, who responded to therapy].

Science.gov (United States)

Ishikawa, Rie; Kamiya, Hiroyuki; Ikushima, Souichiro; Oristu, Masaru; Takemura, Tamiko

2010-02-01

The patient was a 48-year-old woman and current smoker. In May 2007, she moved to a new residence. In the middle of the following month, she developed acute respiratory distress and a fever (38 degrees C) after running her air conditioner continuously throughout the night. The chest X-ray film showed diffuse infiltrative shadows in the middle and lower lung fields. After hospital admission, her oxygenation improved without treatment and the infiltrates improved over the clinical course. As a consequence, we suspected hypersensitivity pneumonitis. The bronchoalveolar lavage showed predominant lymphocytes of 72.6%, with a low CD 4/8 ratio of 0.2. Transbronchial lung biopsy findings corresponded to acute hypersensitivity pneumonitis. The results of the environmental challenge test were positive only when her air conditioner was on, resulting, in a diagnosis of air-conditioner lung. Several microorganisms were detected in an environmental sample, but 20 kinds of serum precipitating antibodies were negative on a thorough screening, so no responsible antigen could be identified. The patient's symptoms did not recur after her air conditioner was replaced.

Energy performance and consumption for biogas heat pump air conditioner

Energy Technology Data Exchange (ETDEWEB)

Xu, Zhenjun [Architectural Engineering College, Qingdao Agricultural University, 266109 (China); Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Tianjin University, Tianjin, 300072 (China); Wu, Huaizhi; Wu, Meiling [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Tianjin University, Tianjin, 300072 (China)

2010-12-15

Biogas engine-driven heat pump air conditioner is a new-style system which includes biogas engine-driven heat pump, primary heat exchanger, second heat exchanger, sprayed room and fans, pumps, etc. In summertime, the air can be reheated by the waste heat water from the biogas engine in the system, while the air can be reheated and humidified by the waste heat water in winter. Reducing or displacing electrical heating requirements can achieve the great opportunity for significant energy savings. This paper, therefore, aims to improve the energy performance of the AC system by using the waste heat from the biogas engine. The mathematic model was used to research the BHPAC. Explicitly, we investigated the influence of various factors including the outdoor air temperature and humidity in summer and winter. Results show that the biogas engine-driven heat pump air conditioner can save more energy than the electrical power heat pump. In summer, the minimum for percentage of primary energy saving for BHPAC is over 25%. With the outdoor air dry-bulb temperature and the relative humidity rises, the saving energy percentage rises. In winter, the minimum for percentage of primary energy saving for BHPAC is 37%. The more the outdoor air relative humidity of the outdoor air decreases, the more the BHPAC saves energy. It is proved that the system which is a highly actively fully utilizing energy technology has good partial load characteristic and good effects of energy saving. (author)

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

International Nuclear Information System (INIS)

Yitai, M.; Shengchun, L.; Lirong, M.

2005-01-01

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)

Domestic Refrigeration, Freezer, and Window Air Conditioner Service. Teacher Edition.

Science.gov (United States)

Clemons, Mark

This curriculum guide contains six units of instruction for a course in domestic refrigerator, freezer, and window air conditioner service. The units cover the following topics: (1) service fundamentals; (2) mechanical components and functions; (3) electrical components and control devices; (4) refrigerator and freezer service; (5) domestic ice…

The Research on Programmable Control System of Lithium-Bromide Absorption Refrigerating Air Conditioner Based on the Network

Directory of Open Access Journals (Sweden)

Sun Lunan

2016-01-01

Full Text Available This article regard the solar lithium-bromide absorption refrigerating air conditioning system as the research object, and it was conducting adequate research of the working principle of lithium bromide absorption refrigerating machine, also it was analyzing the requirements of control system about solar energy air conditioning. Then the solar energy air conditioning control system was designed based on PLC, this system was given priority to field bus control system, and the remote monitoring is complementary, which was combining the network remote monitoring technology. So that it realized the automatic control and intelligent control of new lithium bromide absorption refrigerating air conditioning system with solar energy, also, it ensured the control system can automatically detect and adjust when the external conditions was random changing, to make air conditioning work effectively and steadily, ultimately ,it has great research significance to research the air conditioning control system with solar energy.

Huffing air conditioner fluid: a cool way to die?

Science.gov (United States)

Phatak, Darshan R; Walterscheid, Jeffrey

2012-03-01

"Huffing," the form of substance abuse involving inhalants, is growing in popularity because of the ease and availability of chemical inhalants in many household products. The purpose in huffing is to achieve euphoria when the chemicals in question interact with the central nervous system in combination with oxygen displacement. The abuser is lulled into a false sense of safety despite the well-documented potential for lethal cardiac arrhythmia and the effects of chronic inhalant abuse, including multisystem organ failure, and brain damage. Huffing air conditioner fluid is a growing problem given the accessibility to outdoor units and their fluid components, such as difluorochloromethane(chlorodifluoromethane, Freon), and we have classified multiple cases of accidental death due to the toxicity of difluorochloromethane. Given the ubiquity of these devices and the vast lack of gating or security devices, they make an inviting target for inhalant abusers. Acute huffing fatalities have distinct findings that are present at the scene, given the position of the decedent and proximity to the air conditioner unit. The purpose of the autopsy in these cases is to exclude other potential causes of death and to procure specimens for toxicological analysis.

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

Science.gov (United States)

Lv, Jinze; Zhu, Lizhong

2013-03-01

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

Numerical Study of an Ejector as an Expansion Device in Split-type Air Conditioners for Energy Savings

Directory of Open Access Journals (Sweden)

Kasni Sumeru

2013-07-01

Full Text Available The present study describes a numerical approach for determining both the motive nozzle and constant-area diameters of an ejector as an expansion device, based on the cooling capacity of a split-type air-conditioner using R290 as refrigerant. Previous studies have shown that replacement of HCFC R22 with HC290 (propane in the air conditioner can improve the coefficient of performance (COP. The purpose of replacing the capillary tube with an ejector as an expansion device in a split-type air conditioner using HC290 is to further improve the COP. In developing the model, conservation laws of mass, momentum and energy equations were applied to each part of the ejector. The numerical results show that the motive nozzle diameter remains constant (1.03 mm under varying condenser temperatures, whereas the diameter of the constant-area decreases as the condenser temperature increases. It was also found that improvement of the COP can reach 32.90% at a condenser temperature of 55 °C. From the results mentioned above, it can be concluded that the use of an ejector can further improve the COP of a split-type air conditioner using HC290 as working fluid.

Influence of local air velocity from air conditioner evaluated by salivary and skin biomarkers

OpenAIRE

Yamaguchi, Masaki; Takahashi, Takayuki; Yoshino, Yuichiro; Sasaki, Makoto; Nishiyama, Hajime

2010-01-01

The purpose of this paper is to reveal both the psychosomatic and the physical effects of local air velocity from an air conditioner using biomarkers which can be collected noninvasively. Salivary α-amylase activity (SAA) and salivary cortisol were used as the indexes of psychosomatic effects. The total protein (TP) collected from stratum corneum was used as an index of the physical condition of dry skin. A continuous experiment over a 5 days period in summer was conducted using 8 healthy you...

Room air conditioner load control under summer comfort constraint

OpenAIRE

Da Silva , David; Brancaccio , M; Duplessis , Bruno; Adnot , J

2010-01-01

International audience; Load control options interest is growing because it can represent a response to future network investments and to congestion problems. In this frame, the present paper gives a methodology to quantify the value of load control for heat pumps (room air conditioners), in small tertiary and residential buildings, considering the occupant's comfort and the electrical grid needs for load shift. This methodology was applied to a small office building where simulations were ma...

Compressor motor for air conditioners realizing high efficiency and low cost; Kokoritsu tei cost wo jitsugenshita eakonyo asshukuki motor

Energy Technology Data Exchange (ETDEWEB)

Inaba, Y.; Kawamura, K.; Imazawa, K. [Toshiba Corp., Tokyo (Japan)

2000-01-01

The compressor motor accounts for most of the consumption of electric power in an air conditioner. To promote energy-saving, Toshiba has been progressively changing the compressor motors in its air conditioners to high-efficiency brushless DC motors. We have now developed a new compressor motor in order to achieve even greater energy-saving. A concentrated winding system was adopted featuring direct winding on the teeth of the stator core, for the first time in the industry. As a result, it was possible to realize a high-efficiency, compact, lightweight, and low-cost motor. Moreover, by constructing a new system for production, we were able to improve productivity and quality. The newly developed motor is expected to contribute to the further diffusion of energy-saving air conditioners. (author)

Small fan assisted air conditioner for thermal comfort and energy saving in Thailand

International Nuclear Information System (INIS)

Atthajariyakul, Surat; Lertsatittanakorn, Charoenporn

2008-01-01

From the fact that Thai people have a tolerance to high air temperature and are accustomed to high air movement from electric fans in non-air conditioned space, this paper proposes the use of small fan assisted air conditioners for human thermal comfort and energy saving in Thailand. In the study, a total 15 students were tested in a 2.5 x 3.5 x 2.5 m 3 test room equipped with a 12,000 Btu/h split type air conditioner. During the tests, the room air temperature was varied from 25, 26, 27 and 28 deg. C every 1 h. A small fan with 15 cm diameter was placed in front of each subject. In each hour, the small fan was varied to supply a small area with velocity from 0.2, 0.5, 1, 1.5 and 2 m/s. In each condition, the subjects were asked to vote for their thermal sensation. The results showed that the temperature set point could be increased up to 28 deg. C when a small fan was used to supply local air velocity from 0.5 to 2 m/s according to individual preference. This would reduce the electricity consumption of the air conditioning unit. According to the proposed method, this can save energy for office buildings in the commercial sector as high as 1959.51 GWh/year

Applying water cooled air conditioners in residential buildings in Hong Kong

International Nuclear Information System (INIS)

Chen Hua; Lee, W.L.; Yik, F.W.H.

2008-01-01

The objective of this study is to conduct a realistic prediction of the potential energy saving for using water cooled air conditioners in residential buildings in Hong Kong. A split type air conditioner with air cooled (AAC) and water cooled (WAC) options was set up for experimental study at different indoor and outdoor conditions. The cooling output, power consumption and coefficient of performance (COP) of the two options were measured and calculated for comparison. The experimental results showed that the COP of the WAC is, on average, 17.4% higher than that of the AAC. The results were used to validate the mathematical models formulated for predicting the performance of WACs and AACs at different operating conditions and load characteristics. While the development of the mathematical models for WACs was reported in an earlier paper, this paper focuses on the experimental works for the AAC. The mathematical models were further used to predict the potential energy saving for application of WACs in residential buildings in Hong Kong. The predictions were based on actual building developments and realistic operating characteristics. The overall energy savings were estimated to be around 8.7% of the total electricity consumption for residential buildings in Hong Kong. Wider use of WACs in subtropical cities is, therefore, recommended

The Performance of a Desiccant-Based air Conditioner on a Florida School

Energy Technology Data Exchange (ETDEWEB)

Miller, J.

2001-08-22

Indoor air quality has become a major public health issue in recent years. ASHRAE standard 62-1989-which is an attempt to improve indoor air quality by increasing building ventilation rates-greatly increases the latent loads on many buildings. In more humid climates, the Sensible Heat Ratio (SHR) of a building's air conditioner (which is the fraction of total delivered cooling that is sensible) is too high to meet the existing latent loads. The implementation of ASHRAE 62-1989 will only exacerbate this problem.

Size optimization of stand-alone photovoltaic (PV) room air conditioners

International Nuclear Information System (INIS)

Chen, Chien-Wei; Zahedi, A.

2006-01-01

Sizing of a stand-alone PV system determines the main cost of the system. PV electricity cost is determined by the amount of solar energy received, hence the actual climate and weather conditions such as solar irradiance and ambient temperature affect the size required and cost of the system. Air conditioning demand also depends on the weather conditions. Therefore, sizing a PV powered air conditioner must consider the characteristics of local climate and temperature. In this paper, sizing procedures and special considerations for air conditioning under Melbourne's climatic conditions is presented. The reliability of various PV-battery size combinations is simulated by MATLAB. As a result, excellent system performance can be predicated.(Author)

Development and Analysis of Desiccant Enhanced Evaporative Air Conditioner Prototype

Energy Technology Data Exchange (ETDEWEB)

Kozubal, E.; Woods, J.; Judkoff, R.

2012-04-01

This report documents the design of a desiccant enhanced evaporative air conditioner (DEVAP AC) prototype and the testing to prove its performance. Previous numerical modeling and building energy simulations indicate a DEVAP AC can save significant energy compared to a conventional vapor compression AC (Kozubal et al. 2011). The purposes of this research were to build DEVAP prototypes, test them to validate the numerical model, and identify potential commercialization barriers.

Transient modeling of an air conditioner with a rapid cycling compressor and multi-indoor units

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wei-Jiang [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Zhang, Chun-Lu [College of Mechanical Engineering, Tongji University, 4800 Cao An Highway, Shanghai 201804 (China)

2011-01-15

Rapid cycling the compressor is an alternative of the variable speed compressor to modulate the capacity of refrigeration systems for the purpose of energy saving at part-load conditions. The multi-evaporator air conditioner combined with the rapid cycling compressor brings difficulties in control design because of the sophisticated system physics and dynamics. In this paper the transient model of a multi-split air conditioner with a digital scroll compressor is developed for predicting the system transients under performance modulations. The predicted cycling dynamics are in good agreement with the experimental data. Based on the validated model, the impact of compressor idle power and cycle period to the part load performance is discussed. (author)

Transient modeling of an air conditioner with a rapid cycling compressor and multi-indoor units

Energy Technology Data Exchange (ETDEWEB)

Zhang Weijiang [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Zhang Chunlu, E-mail: chunlu.zhang@carrier.utc.co [College of Mechanical Engineering, Tongji University, 4800 Cao An Highway, Shanghai 201804 (China)

2011-01-15

Rapid cycling the compressor is an alternative of the variable speed compressor to modulate the capacity of refrigeration systems for the purpose of energy saving at part-load conditions. The multi-evaporator air conditioner combined with the rapid cycling compressor brings difficulties in control design because of the sophisticated system physics and dynamics. In this paper the transient model of a multi-split air conditioner with a digital scroll compressor is developed for predicting the system transients under performance modulations. The predicted cycling dynamics are in good agreement with the experimental data. Based on the validated model, the impact of compressor idle power and cycle period to the part load performance is discussed.

Transient modeling of an air conditioner with a rapid cycling compressor and multi-indoor units

International Nuclear Information System (INIS)

Zhang Weijiang; Zhang Chunlu

2011-01-01

Rapid cycling the compressor is an alternative of the variable speed compressor to modulate the capacity of refrigeration systems for the purpose of energy saving at part-load conditions. The multi-evaporator air conditioner combined with the rapid cycling compressor brings difficulties in control design because of the sophisticated system physics and dynamics. In this paper the transient model of a multi-split air conditioner with a digital scroll compressor is developed for predicting the system transients under performance modulations. The predicted cycling dynamics are in good agreement with the experimental data. Based on the validated model, the impact of compressor idle power and cycle period to the part load performance is discussed.

Hardware-in-the-Loop Simulation of a Distribution System with Air Conditioners under Model Predictive Control: Preprint

Energy Technology Data Exchange (ETDEWEB)

Sparn, Bethany F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ruth, Mark F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Krishnamurthy, Dheepak [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Pratt, Annabelle [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lunacek, Monte S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jones, Wesley B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wu, Hongyu [Kansas State University; Mittal, Saurabh [Mitre Corporation; Marks, Jesse [University of Missouri

2017-08-01

Many have proposed that responsive load provided by distributed energy resources (DERs) and demand response (DR) are an option to provide flexibility to the grid and especially to distribution feeders. However, because responsive load involves a complex interplay between tariffs and DER and DR technologies, it is challenging to test and evaluate options without negatively impacting customers. This paper describes a hardware-in-the-loop (HIL) simulation system that has been developed to reduce the cost of evaluating the impact of advanced controllers (e.g., model predictive controllers) and technologies (e.g., responsive appliances). The HIL simulation system combines large-scale software simulation with a small set of representative building equipment hardware. It is used to perform HIL simulation of a distribution feeder and the loads on it under various tariff structures. In the reported HIL simulation, loads include many simulated air conditioners and one physical air conditioner. Independent model predictive controllers manage operations of all air conditioners under a time-of-use tariff. Results from this HIL simulation and a discussion of future development work of the system are presented.

Performance analysis of a novel heat pump type air conditioner coupled with a liquid dehumidification/humidification cycle

International Nuclear Information System (INIS)

Cai, Dehua; Qiu, Chengbo; Zhang, Jiazheng; Liu, Yue; Liang, Xiao; He, Guogeng

2017-01-01

Graphical abstract: Cycle performance of a small scale heat pump type air conditioner coupled with a liquid desiccant/humidification cycle has been theoretically and experimentally evaluated by the present study. The liquid desiccant and humidification cycle is driven by the exhaust heat of the compressor. LDAC not only greatly improves the indoor air quality by controlling the humidity and temperature independently, but also decrease the electrical energy consumption of the traditional air conditioner. Parametric analysis on cycle performance of the present cycle based on both theoretical and experimental methods are carried out. - Highlights: • Hybrid cycle consists of refrigeration cycle and liquid desiccant cycle is proposed. • Liquid desiccant cycle is driven by the compressor exhaust heat. • Theoretical and experimental studies on cycle performance are provided. • Energy consumption decreases about 22.64% compared with the conventional one. - Abstract: In recent years, liquid desiccant air-conditioning system (LDAC) has shown a great potential alternative to the conventional vapor compression systems. LDAC not only greatly improves the indoor air quality by controlling the humidity and temperature independently, but also deceases the electrical energy consumption of the conventional air conditioner. In this work, the liquid desiccant and humidification cycle is driven by the exhaust heat of the compressor. Cycle performance of a small-scale heat pump type air conditioner coupled with a liquid desiccant/humidification cycle has been theoretically and experimentally evaluated by the present study. Parametric analysis on cycle performance of the present cycle is carried out through both theoretical and experimental methods, and lithium chloride aqueous solution is used as the working fluid of the solution cycle. The thermodynamic analysis results show that while the evaporating temperature of the present cycle increases to 15 °C, the energy consumption

Comparative analysis of objective techniques for criteria weighing in two MCDM methods on example of an air conditioner selection

Directory of Open Access Journals (Sweden)

Vujičić Momčilo D.

2017-01-01

Full Text Available This paper deals with comparative analysis of two different types of objective techniques for criteria weighing: Entropy and CRITIC and two MCDM methods: MOORA and SAW on example of an air conditioner selection. We used six variants for calculation of normalized performance ratings. Results showed that the decision of the best air conditioner was basically independent of the MCDM method used, despite the applied technique for determination of criteria weights. Complete ranking within all of the combinations of methods and techniques with diverse ratio calculation variants showed that the best ranked air conditioner was A7, while the worst ones were A5 and A9. Significant positive correlation was obtained for almost all the pairs of variants in all the combinations except for the MOORA - CRITIC combination with SAW - Entropy combination to have the highest correlations between variants (p < 0.01.

Simulated and experimental performance of split packaged air conditioner using refrigerant HC-290 as a substitute for HCFC-22

International Nuclear Information System (INIS)

Padalkar, Atul S.; Mali, Kundlik V.; Devotta, Sukumar

2014-01-01

This paper discusses the use of propane (HC-290) as a safe and energy efficient alternative to HCFC-22 in a typical split air conditioner with nominal cooling capacities up to 5.1 kW. Initially split air conditioner performance is simulated for cooling capacity, energy efficiency ratio (EER), and refrigerant charge. Tests were conducted for different test cases in a psychrometric test chamber with HCFC-22 and HC-290. The test conditions considered are as per Indian Standards, IS 1391 (1992) Part I. The various parameters considered were based on simulated performance with the objective to achieve maximum EER for the desired cooling capacity. As the flammability is an issue for HC-290, the reduction of HC-290 charge was another objective. Two different types of condensers, first with smaller size tubing and another parallel flow condenser (PFC) or minichannel condenser were used in order to reduce HC-290 charge. For HC-290, the highest EER achieved was 3.7 for cooling capacity 4.90 kW for a refrigerant charge of 360 g. The important safety aspects of using HC-290 in air conditioner are discussed. The refrigerant charge as per EN 378 for different cooling capacities and room sizes is also considered. -- Highlights: • Simulation for performance of split air conditioner has been done using HC-290 as a replacement to HCFC-22. • The safety aspects of HC-290 are discussed when used in split air conditioner. • HC-290 was tested in psychrometric test chamber as per IS 1391 part 1. • With PFC, HC-290 gave highest EER of 3.7 which was 37% higher than that of HCFC-22. • The lowest HC-290 charge used in test was 340 g which is well below LFL

Determination of heavy metals in air conditioner dust using FAAS and INAA

International Nuclear Information System (INIS)

Siddique, N.

2012-01-01

The elements Cd, Cr, Cu, Mn, Ni, Pb and Zn were determined in dust samples collected from air conditioner (AC) filters from 15 commercial sites of Lahore using flame atomic absorption spectroscopy (FAAS). The elements Cr, Mn and Zn were also determined using instrumental neutron activation analysis (INAA). The results obtained showed that higher amounts of these metals were measured in these dust samples than normally found in soil. This was especially true for Cd, Cu, Pb and Zn. Generally the amounts of Cd, Cr and Mn did not vary throughout the city of Lahore but the amounts of the traffic related Cu, Pb and Zn elements had the more variable ranges of 30-140, 30-230 and 74-2810 mg/kg respectively. The concentrations obtained for Cr, Mn and Zn by INAA were found to be higher than those obtained using FAAS. Analysis of the data obtained showed the digestion procedure employed to be the possible cause for this occurrence. It was also found that Mn was being over-estimated by INAA due to the interference from the Mg peak. (author)

Towards a Residential Air-Conditioner Usage Model for Australia

Directory of Open Access Journals (Sweden)

Mark Goldsworthy

2017-08-01

Full Text Available Realistic models of occupant behaviour in relation to air-conditioner (a/c use are fundamentally important for developing accurate building energy simulation tools. In Australia and elsewhere, such simulation tools are inextricably bound both in legislation and in the design of new technology, electricity infrastructure and regulatory schemes. An increasing number of studies in the literature confirm just how important occupants are in determining overall energy consumption, but obtaining the data on which to build behaviour models is a non-trivial task. Here data is presented on air-conditioner usage derived from three different types of case study analyses. These are: (i use of aggregate energy consumption data coupled with weather, demographic and building statistics across Australia to estimate key predictors of energy use at the aggregate level; (ii use of survey data to determine characteristic a/c switch on/off behaviours and usage frequencies; and (iii use of detailed household level sub-circuit monitoring from 140 households to determine a/c switch on/off probabilities and their dependence on different building and occupant parameters. These case studies are used to assess the difficulties associated with translation of different forms of individual, aggregate and survey based information into a/c behaviour simulation models. Finally a method of linking the data gathering methodologies with the model development is suggested. This method would combine whole-of-house “smart”-meter data measurements with linked targeted occupant surveying.

Numerical Analysis and Geometry Optimisation of Vertical Vane of Room Air-conditioner

Directory of Open Access Journals (Sweden)

Al-Obaidi Abdulkareem Sh. Mahdi

2018-01-01

Full Text Available Vertical vanes of room air-conditioners are used to control and direct cold air. This paper aims to study vertical vane as one of the parameters that affect the efficiency of dissipating cold air to a given space. The vertical vane geometry is analysed and optimised for lower production cost using CFD. The optimised geometry of the vertical vane should have the same or increased efficiency of dissipating cold air and have lesser mass compared to the existing original design. The existing original design of vertical vane is simplified and analysed by using ANSYS Fluent. Efficiency of wind direction is define as how accurate the direction of airflow coming out from vertical vane. In order to calculate the efficiency of wind direction, 15° and 30° rotation of vertical vane inside room air-conditioner are simulated. The efficiency of wind direction for 15° rotation of vertical vane is 57.81% while efficiency of wind direction for 30° rotation of vertical vane is 47.54%. The results of the efficiency of wind direction are used as base reference for parametric study. The parameters investigated for optimisation of vertical vane are focused at length of long span, tip chord and short span. The design of 15% decreased in vane surface area at tip chord is the best optimised design of vertical vane because the efficiency of wind direction is the highest as 60.32%.

Acoustic resonance of outer-rotor brushless dc motor for air-conditioner fan

Science.gov (United States)

Lee, Hong-Joo; Chung, Shi-Uk; Hwang, Sang-Moon

2008-04-01

Generation of acoustic noise in electric motor is an interacting combination of mechanical and electromagnetic sources. In this paper, a brushless dc motor for air-conditioner fan is analyzed by finite element method to identify noise source, and the analysis results are verified by experiments, and sensitivity analysis is performed by design of experiments.

Experimental study on the performance of a multi-functional domestic air conditioner with integrated water heater

International Nuclear Information System (INIS)

Dong, Jiankai; Li, Hui; Yao, Yang; Jiang, Yiqiang; Zhang, Xinran

2017-01-01

Highlights: • A novel MDACWH was presented and experimentally studied. • MDACWH has high performance on making domestic hot water and air conditioning. • The time for heating water reduced to 22.0 min after modification. • Average COP reached 4.32, which was 1.58 times higher than the unmodified unit. - Abstract: The recovery of condenser heat is concerned one of the most effective methods to curb energy consumption in residential dwellings. Aiming at recovering the condenser heat of domestic air conditioner, this paper experimentally studied a multi-functional domestic air conditioner with integrated water heater (MDACWH) which can effectively provide space – cooling and domestic hot water simultaneously. The dynamic operation characteristics, such as hot water supply and energy efficiency were tested to verify the availability of the MDACWH. The results showed that the MDACWH can effectively heat the domestic hot water without losing its cooling capacity. It was also found that with the use of MDACWH, the coefficient of comprehensive energy performance of the MDACWH was about 1.58 times higher than that of the unmodified experimental unit. Furthermore, the water-heating time was shorten remarkably from 128.5 min to 22.0 min. The novel domestic air conditioner, compared with the unmodified initial prototype, can be more practical and provide significant energy savings in space-cooling and hot water supply.

Cardio-Muscular Conditioner

Science.gov (United States)

1993-01-01

In the mid-sixties, Gary Graham, a Boeing designer, developed a cardiovascular conditioner for a planned Air Force orbiting laboratory. After the project was cancelled, Graham participated in space station conditioning studies for the Skylab program. Twenty years later, he used this expertise to develop the Shuttle 2000-1, a physical therapy and athletic development conditioner, available through Contemporary Designs. The machine is used by football teams, sports clinics and medical rehabilitation centers. Cardiovascular fitness and muscular strength development are promoted through both kinetic and plyometric exercises.

Optimum dry-cooling sub-systems for a solar air conditioner

Science.gov (United States)

Chen, J. L. S.; Namkoong, D.

1978-01-01

Dry-cooling sub-systems for residential solar powered Rankine compression air conditioners were economically optimized and compared with the cost of a wet cooling tower. Results in terms of yearly incremental busbar cost due to the use of dry-cooling were presented for Philadelphia and Miami. With input data corresponding to local weather, energy rate and capital costs, condenser surface designs and performance, the computerized optimization program yields design specifications of the sub-system which has the lowest annual incremental cost.

Energy efficiency and energy saving air conditioners window and split type; Eficiencia energetica e economia de energia de condicionadores de ar tipo janela e split

Energy Technology Data Exchange (ETDEWEB)

Souza, Edson Palhares de; Cardoso, Rafael Balbino; Nogueira, Luiz Augusto Horta [Universidade Federal de Itajuba (EXCEN/UNIFEI), MG (Brazil). Centro de Excelencia em Eficiencia Energetica

2010-07-01

The air-conditioners of window end Split type are responsible for a significant portion of energy consumption in residential sector of Brazil, from 20% of the sector. This study evaluates the impact energy of the Seal Program PROCEL in air-conditioners of window end Split type, showing the efficiency gains for the country in terms of energy saving. For this evaluation it was considered the effects of temperature and loss of performance due to age, PROCEL Stamp Program resulted in a power savings of 664 GWh in air-conditioners of window type residential sector in 2008. (author)

Consumption-efficient regulation and switching concepts for air conditioners in buses; Verbrauchseffiziente Regelungs- und Verschaltungskonzepte fuer Omnibusklimaanlagen

Energy Technology Data Exchange (ETDEWEB)

Kaiser, Christian; Tegethoff, Wilhelm [TLK-Thermo GmbH, Braunschweig (Germany); Koehler, Juergen [TU Braunschweig (Germany). Inst. fuer Thermodynamik; Sonnekalb, Michael [Konvekta AG, Schwalmstadt (Germany)

2012-07-01

The reduction of the fuel consumption and the related reduction of CO{sub 2} emissions is one of the most important requirements in the current development of vehicles. This includes the development of fuel-efficient drive systems and the optimization of the so-called auxiliary users such as the air conditioner. The majority of the buses used today have an air conditioner in order to meet the increased demand of passengers for comfort. Since the operation of the air conditioner results in a significant increase in fuel consumption and thus in enhanced emissions of CO{sub 2}, an essential task of the development engineer is to minimize this additional consumption. In order to identify possible optimization potentials, a bus simulation model was developed which investigates not only exclusively compression refrigeration systems, but also is in communication with their relevant systems: heating circuit with engine cooling circuit, vehicle interior, on-board electrical system and vehicle longitudinal dynamics with the drive train. In the contribution under consideration, potentials of energy conservation should be identified that can be achieved due to the use of improved control and switching concepts. For this purpose, both the conventional R-744 (CO{sub 2}) bus air conditioning systems as well as alternative systems such as an ejector cycle were studied by means of a total vehicle simulation of the bus and compared.

Long-term indoor air conditioner filtration and cardiovascular health: A randomized crossover intervention study.

Science.gov (United States)

Chuang, Hsiao-Chi; Ho, Kin-Fai; Lin, Lian-Yu; Chang, Ta-Yuan; Hong, Gui-Bing; Ma, Chi-Ming; Liu, I-Jung; Chuang, Kai-Jen

2017-09-01

The association of short-term air pollution filtration with cardiovascular health has been documented. However, the effect of long-term indoor air conditioner filtration on the association between air pollution and cardiovascular health is still unclear. We recruited 200 homemakers from Taipei and randomly assigned 100 of them to air filtration or control intervention; six home visits were conducted per year from 2013 to 2014. The participants under air filtration intervention during 2013 were reassigned to control intervention in 2014. The air pollution measurements consisted of particulate matter less than or equal to 2.5μm in diameter (PM 2.5 ) and total volatile organic compounds (VOCs); blood pressure was monitored for each participant during each visit. The following morning, blood samples were collected after air pollution monitoring. The blood samples were used to analyze biological markers, including high sensitivity-C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and fibrinogen. Household information, including cleaning, cooking, and air conditioning, was collected by a questionnaire. Mixed-effects models were used to investigate the associations among air pollution measurements, blood pressure and biological markers. The results showed that increased levels of PM 2.5 and total VOCs were associated with increased hs-CRP, 8-OHdG and blood pressure. The health variables were higher among participants in the control intervention phase than among those in the air filtration intervention phase. We concluded that air pollution exposure was associated with systemic inflammation, oxidative stress and elevated blood pressure. The long-term filtration of air pollution with an air conditioner filter was associated with cardiovascular health of adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

Deaths Due to Accidental Air Conditioner Compressor Explosion: A Case Series.

Science.gov (United States)

Behera, Chittaranjan; Bodwal, Jatin; Sikary, Asit K; Chauhan, Mohit Singh; Bijarnia, Manjul

2017-01-01

In an air-conditioning system, the compressor is a large electric pump that pressurizes the refrigerant gas as part of the process of turning it back into a liquid. The explosion of an air conditioner (AC) compressor is an uncommon event, and immediate death resulted from the blast effect is not reported in forensic literature. We report three such cases in which young AC mechanics were killed on the spot due to compressor blast, while repairing the domestic split AC unit. The autopsy findings, the circumstances leading to the explosion of the compressor, are discussed in this study. © 2016 American Academy of Forensic Sciences.

Development of a solar-powered residential air conditioner: Economic analysis

Science.gov (United States)

1975-01-01

The results of investigations aimed at the development of cost models to be used in the economic assessment of Rankine-powered air conditioning systems for residential application are summarized. The rationale used in the development of the cost model was to: (1) collect cost data on complete systems and on the major equipment used in these systems; (2) reduce these data and establish relationships between cost and other engineering parameters such as weight, size, power level, etc; and (3) derive simple correlations from which cost-to-the-user can be calculated from performance requirements. The equipment considered in the survey included heat exchangers, fans, motors, and turbocompressors. This kind of hardware represents more than 2/3 of the total cost of conventional air conditioners.

ENERGY STAR Certified Non-AHRI Central Air Conditioner Equipment and Air Source Heat Pump

Science.gov (United States)

Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Air Source Heat Pump and Central Air Conditioner Equipment that are effective as of September 15, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=airsrc_heat.pr_crit_as_heat_pumps Listed products have been submitted to EPA by ENERGY STAR partners that do not participate in the AHRI certification program. EPA will continue to update this list with products that are certified by EPA-recognized certification bodies other than AHRI. The majority of ENERGY STAR products, certified by AHRI, can be found on the CEE/AHRI Verified Directory at http://www.ceedirectory.org/

Experimental study on split air conditioner with new hybrid equipment of energy storage and water heater all year round

International Nuclear Information System (INIS)

Wang Shaowei; Liu Zhenyan; Li Yuan; Zhao Keke; Wang Zhigang

2005-01-01

This paper presents a split air conditioner with a new hybrid equipment of energy storage and water heater all year round (ACWES). The authors made a special design on the storage tank to adjust the refrigerant capacity in the storage coils under different functions, instead of adding an accumulator to the system. An ACWES prototype, rebuilt from an original split air conditioner, has been finished, and experimental study of the operation processes of the prototype was done from which some important conclusions and suggestions have been made, which were helpful in the primary design and improvement of an ACWES system for potential users

Performance evaluation of a stack cooling system using CO{sub 2} air conditioner in fuel cell vehicles

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung Chul; Won, Jong Phil [Thermal Management Research Center, Korea Automotive Technology Institute, Chungnam 330-912 (Korea); Park, Yong Sun; Lim, Tae Won [Corporate Research and Development Division, Hyundai-Kia Motors, Gyeonggi 449-912 (Korea); Kim, Min Soo [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744 (Korea)

2009-01-15

A relation between the heat release from a fuel cell stack and an air conditioning system's performance was investigated. The air conditioning system installed in a fuel cell vehicle can be used for stack cooling when additional stack heat release is required over a fixed radiator capacity during high vehicle power generation. This study investigated the performance of a stack cooling system using CO{sub 2} air conditioner at various operating conditions. Also, the heat releasing effectiveness and mutual interference were analyzed and compared with those for the conventional radiator cooling system with/without cabin cooling. When the radiator coolant inlet temperature and flow rate were 65 C and 80 L/min, respectively, for the outdoor air inlet speed of 5 m/s, the heat release of the stack cooling system with the aid of CO{sub 2} air conditioner increased up to 36% more than that of the conventional radiator cooling system with cabin cooling. Furthermore, this increased by 7% versus the case without cabin cooling. (author)

Pulmonary functions in air conditioner users.

Science.gov (United States)

Khaliq, Farah; Sharma, Sameer; Tandon, O P

2006-01-01

Air conditioning may affect human health since it has profound effect on our environment, than just lowering temperature. The present study was planned to assess the effect of air conditioners (AC) on pulmonary functions in young healthy non-smoker males. The study group comprised of ten subjects who were using AC's in their cars for at least 1 hr daily since last 6 months. While ten subjects who did not use AC at all served as controls. The pulmonary functions were assessed using PK Morgan 232 spirometer in a closed room. The peak expiratory flow rate (PEFR) and Forced expiratory flow between 25-75% of vital capacity (FEF25-75) were significantly reduced in subjects using car AC's. Inspiratory flow rates also showed a trend towards decline in AC users but could not reach the level of significance. The lung volumes and capacities were not significantly different in the two groups except for forced expiratory volume in 0.5 sec (FEV 0.5 sec), which also decreased in AC users. The airway resistance and lung compliance did not show significant change. In the presence of normal FEV1, reduced FEF25-75% which is the flow rate over the middle half of vital capacity, is an evidence of mild airflow limitation. The result is suggestive of predisposition of AC users towards respiratory disorders in form of mild airflow restriction.

Life cycle analysis of retrofitting with high energy efficiency air-conditioner and fluorescent lamp in existing buildings

International Nuclear Information System (INIS)

Techato, Kua-anan; Watts, Daniel J.; Chaiprapat, Sumate

2009-01-01

Life cycle analysis of mercury in discarded low energy efficiency fluorescent lamps (36 W) and of HCFC in air-conditioners (12,000 Btu) removed from service has been conducted in this study. The objective was to find out the environmental impact (EDIP 1997 category, waste evaluation) of the products that appear in the waste stream as a result of facility upgrades. The scope of the study starts from retrofitting of the lamps and air-conditioners through recycling and disposal. For a 36 W fluorescent lamp, the bulk waste 1.64E-5 kg, hazardous waste 1.11E-4 kg, radioactive waste 1.09E-9 kg, and slag-ash 6.02E-7 kg occurred at the end of life of the retrofitting cycle. For a 12,000 Btu air-conditioner, the bulk waste 0.58 kg, hazardous waste 0.11 kg, radioactive waste 0.0002 kg, and slag-ash 0.01 kg also occurred at the end of life of the retrofitting cycle. These small amounts become important when viewed at the country level. These quantities imply that the policy makers who deal with hazardous waste should be aware of this waste-generating characteristic before issuing any pertinent policy. Consideration of this characteristic and planning for appropriate waste management methods at the beginning stage will reduce any future problem of contamination by the hazardous waste

Life cycle analysis of retrofitting with high energy efficiency air-conditioner and fluorescent lamp in existing buildings

Energy Technology Data Exchange (ETDEWEB)

Techato, Kua-anan [International Postgraduate Programs in Environmental Management (Hazardous Waste Management) and ERI (Energy Research Institute), Chulalongkorn University, Bangkok 10330 (Thailand); Watts, Daniel J. [Otto H. York Center for Environmental Engineering and Science, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Chaiprapat, Sumate [Department of Civil Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai Campus, Hat Yai, Songkhla 90112 (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management-Satellite Center at Prince of Songkla University (Thailand)

2009-01-15

Life cycle analysis of mercury in discarded low energy efficiency fluorescent lamps (36 W) and of HCFC in air-conditioners (12,000 Btu) removed from service has been conducted in this study. The objective was to find out the environmental impact (EDIP 1997 category, waste evaluation) of the products that appear in the waste stream as a result of facility upgrades. The scope of the study starts from retrofitting of the lamps and air-conditioners through recycling and disposal. For a 36 W fluorescent lamp, the bulk waste 1.64E-5 kg, hazardous waste 1.11E-4 kg, radioactive waste 1.09E-9 kg, and slag-ash 6.02E-7 kg occurred at the end of life of the retrofitting cycle. For a 12,000 Btu air-conditioner, the bulk waste 0.58 kg, hazardous waste 0.11 kg, radioactive waste 0.0002 kg, and slag-ash 0.01 kg also occurred at the end of life of the retrofitting cycle. These small amounts become important when viewed at the country level. These quantities imply that the policy makers who deal with hazardous waste should be aware of this waste-generating characteristic before issuing any pertinent policy. Consideration of this characteristic and planning for appropriate waste management methods at the beginning stage will reduce any future problem of contamination by the hazardous waste. (author)

Utilization of air conditioner condenser as water heater in an effort to energy conservation

Science.gov (United States)

Sonawan, Hery; Saputro, Panji; Kurniawan, Iden Muhtar

2018-04-01

This paper presents an experimental study of utilization of air conditioner condenser as water heater. Modification of existing air conditioner system is an effort to harvest waste heat energy from condenser. Modification is conducted in order to test the system into two mode tests, first mode with one condenser and second mode with two condensers. Harvesting the waste heat from condenser needs a theoretical and practice study to see how much the AC performance changes if modifications are made. It should also be considered how the technique of harvesting waste heat for water heating purposes. From the problem, this paper presents a comparison between AC performance before and after modification. From the experiment, an increase in compressor power consumption is 4.3% after adding a new condenser. The hot water temperature is attained to 69 °C and ready for warm bath. The increase in power consumption is not too significant compared to the attainable hot water temperature. Also seen that the value of condenser Performance Factor increase from 5.8 to 6.25 or by 7.8%.

Orbiting compressor for residential air-conditioners

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Jin; Kim, Woo Young; Ahn, Jong Min [Department of Mechanical Engineering, University of Incheon, 12-1 Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea)

2010-01-15

A new type of compressor, called an orbiting compressor, is introduced in this paper. The orbiting compressor is characterized by an orbiting piston, and the piston or orbiter consists of a circular base plate and a ring type vane protruding vertically from the base plate. The orbiter is made to orbit in an annular space formed between two concentric circular walls via an Oldham-ring mechanism, producing two sealed gas pockets on both sides of the vane wrap with a 180 phase difference. This operating mechanism leads to alternating compression and discharge processes, which results in low torque variation. The orbiting compressor has been designed for an R410A residential air conditioner with a cooling capacity of 10.0 kW. The performance of the orbiting compressor model has been analytically investigated, where the volumetric, adiabatic and mechanical efficiencies were calculated to be 94.8%, 90.4% and 93.4%, respectively for the ARI condition. The EER was estimated to be about 10.86 with a motor efficiency of 89%. (author)

Modeling of a split type air conditioner with integrated water heater

International Nuclear Information System (INIS)

Techarungpaisan, P.; Theerakulpisut, S.; Priprem, S.

2007-01-01

This paper presents a steady state simulation model to predict the performance of a small split type air conditioner with integrated water heater. The mathematical model consists of submodels of system components such as evaporator, condenser, compressor, capillary tube, receiver and water heater. These submodels were built based on fundamental principles of heat transfer, thermodynamics, fluid mechanics, empirical relationships and manufacturer's data as necessary. The model was coded into a simulation program and used to predict system parameters of interest such as hot water temperature, condenser exit air temperature, evaporator exit air temperature, mass flow rate of refrigerant, heat rejection in the condenser and cooling capacity of the system. The simulation results were compared with experimental data obtained from an experimental rig built for validating the mathematical model. It was found that the experimental and simulation results are in good agreement

Thermoeconomic optimization of small size central air conditioner

International Nuclear Information System (INIS)

Zhang, G.Q.; Wang, L.; Liu, L.; Wang, Z.

2004-01-01

The application of thermoeconomic optimization design in an air-conditioning system is important in achieving economical life cycle cost. Previous work on thermoeconomic optimization mainly focused on directly calculating exergy input into the system. However, it is usually difficult to do so because of the uncertainty of input power of fan on the air side of the heat-exchanger and that of pump in the system. This paper introduces a new concept that exergy input into the system can be substituted for the sum of exergy destruction and exergy output from the system according to conservation of exergy. Although it is also difficult for a large-scale system to calculate exergy destruction, it is feasible to do so for a small-scale system, for instance, villa air conditioner (VAC). In order to perform thermoeconomic optimization, a program is firstly developed to evaluate the thermodynamic property of HFC134a on the basis of Martin-Hou state equation. Authors develop thermodynamic and thermoeconomic objective functions based on second law and thermoeconomic analysis of VAC system. Two optimization results are obtained. The design of VAC only aimed at decreasing the energy consumption is not comprehensive. Life cycle cost at thermoeconomic optimization is lower than that at thermodynamic optimization

Analysis of a variable speed air conditioner considering the R-290/POE ISO 22 mixture effect

International Nuclear Information System (INIS)

Ribeiro, Guilherme B.; Barbosa, Jader R.

2016-01-01

Highlights: • A numerical model that considers the oil-refrigerant mixture effect is proposed. • In order to compare the model, an air conditioner calorimeter was constructed. • The system was evaluated under oil circulation ratios between 1 and 7%. • The presence of oil resulted in a significant SEER deterioration (around 69%). - Abstract: Air-conditioning applications using propane (R-290) have several environmental and thermodynamic advantages over more commonly used refrigerants, such as R-410A and R-22. This paper presents the development of a mathematical model for variable capacity air conditioning systems that use R-290/POE ISO 22 as refrigerant/lubricant. The thermodynamic performance of the refrigeration system is evaluated in terms of the SEER (Seasonal Energy Efficiency Ratio). The thermodynamic properties of the refrigerant/lubricant mixture were obtained from a departure-function approach using the Peng-Robinson equation of state. The effect of the oil on the condenser and evaporator heat transfer coefficients and pressure drops was also taken into account. Sub-models were developed for each component of the air conditioning system, including the connecting lines and the scroll compressor. Furthermore, an air conditioner experimental calorimeter was constructed and tested in order to validate the proposed model.

Natural refrigerants for air conditioners in passenger cars. A contribution to climate protection. Background; Natuerliche Kaeltemittel fuer PKW-Klimaanlagen. Ein Beitrag zum Klimaschutz. Hintergrund

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, Gabriele; Plehn, Wolfgang

2010-09-15

Air conditioners in passenger cars contain a refrigerant which significantly increases the greenhouse effect. Currently about 30 % of global emissions of partially fluorinated hydrocarbons originate from these air conditioners. According to the directive 2006/40/EC, this refrigerant must be replaced by a less harmful substance. Under this aspect, the contribution under consideration initially reports on the stock and level of air conditioning of passenger cars as well as on the refrigerant tetrafluoroethane. Subsequently, refrigerants for air conditioning of passenger cars such as carbon dioxide, 1.1-difluoroethane and 2,3,3,3-tetrafluoro propylene are described. Overall, the refrigerant carbon dioxide is the best alternative for mobile air conditioning.

Study on residential appliances energy efficiency standards Refrigerators, air-conditioners, incandescent lamps, fluorescent lamps, color TVs

Energy Technology Data Exchange (ETDEWEB)

Lee, S.G.; Cho, S.K.; Choi, S.H.; Jung, B.M.; Han, S.B.; Kim, K.D. [Korea Inst. of Energy Research, Taejon (Korea, Republic of)

1995-12-01

The energy efficiency standards and rating act, as amended by the rational energy utilization act, provides energy efficiency standards and ratings for 6 types of consumer products(refrigerators, air-conditioners, fluorescent lamps, incandescent lamps, ballasts and cars) authorizes the Ministry of Trade, Industry and Energy(MOTIE) to prescribe amended or new energy efficiency standards and rating standards. This study was initiated by the KIER in 1992. KIER`s assessment of the standards is designed to evaluate their statistical and engineering analysis according to Korean(Industrial) Standards(KS). And to make distinction between the poor efficiency and good efficiency models, 5 grades are classified depending on their tested energy efficiency. This year, based on our analysis, MOTIE mandated updated standards for refrigerators, air-conditioners, incandescent lamps, and fluorescent lamps. Also the objective of this study is to set the energy efficiency standards and to grade for color TV sets. (author). 37 refs., 89 figs., 85 tabs.

Development of a solar-powered residential air conditioner: Screening analysis

Science.gov (United States)

1975-01-01

Screening analysis aimed at the definition of an optimum configuration of a Rankine cycle solar-powered air conditioner designed for residential application were conducted. Initial studies revealed that system performance and cost were extremely sensitive to condensing temperature and to the type of condenser used in the system. Consequently, the screening analyses were concerned with the generation of parametric design data for different condenser approaches; i. e., (1) an ambient air condenser, (2) a humidified ambient air condenser (3) an evaporative condenser, and (4) a water condenser (with a cooling tower). All systems feature a high performance turbocompressor and a single refrigerant (R-11) for the power and refrigeration loops. Data were obtained by computerized methods developed to permit system characterization over a broad range of operating and design conditions. The criteria used for comparison of the candidate system approaches were (1) overall system COP (refrigeration effect/solar heat input), (2) auxiliary electric power for fans and pumps, and (3) system installed cost or cost to the user.

Accelerating Energy Efficiency Improvements in Room Air Conditioners in India: Potential, Costs-Benefits, and Policies

OpenAIRE

Abhyankar, N; Shah, N; Park, WY; Phadke, AA

2017-01-01

Rising incomes, increasing urbanization, and large cooling demand prompted by India’s hot, humid climate are driving increasing uptake of room air conditioners (ACs). Air conditioning already accounts for 40-60% of summer peak load in large Indian cities such as Delhi and is on track to contribute 140 gigawatts (GW) ( 30%) to peak demand in 2030. India’s standards and labeling policies improved the market average efficiency of room ACs by about 35% between 2006 and 2016 (3% per year) even as ...

Increased prevalence of IgG-induced sensitization and hypersensitivity pneumonitis (humidifier lung) in nonsmokers exposed to aerosols of a contaminated air conditioner.

Science.gov (United States)

Baur, X; Richter, G; Pethran, A; Czuppon, A B; Schwaiblmair, M

1992-01-01

Specific IgG antibodies against antigens of a contaminated air conditioner were estimated in serum of 134 workers of a printing company. Altogether 64% of the workers investigated revealed significantly elevated levels (> 3 U/ml) of IgG antibodies specific to these antigens as compared to a nonexposed control group. The occurrence of IgG antibodies for microbial extracts were 25% for Fusarium, 23% for Penicillium notatum, 13% for Alternaria tenuis, 12% for Aureobasidium pullulans, 9% for Sphaeropsidales species, 3% for Micropolyspora faeni, 2% for Aspergillus fumigatus and 2% for Thermoactionomyces vulgaris. Out of the 86 workers with elevated IgG antibodies for air conditioner antigens, 59 were nonsmokers. Considering a cut-off level of 10 U/ml IgG for high values, the proportion of smokers to nonsmokers becomes even more pronounced (6 to 36 respectively, binominal test p air conditioners are the best choice as antigen source for the diagnosis of humidifier lung in exposed workers. Nonsmokers are shown to have a high risk for immunological sensitization.

Performance of a prototype micro wind turbine in the manmade wind field from air conditioner of buildings

Directory of Open Access Journals (Sweden)

K. H. Goh

2012-03-01

Full Text Available Harnessing waste energy from the manmade air fields of buildings presents a new area of renewable energy to explore. Due to the unpredictability of the natural wind, this study is to evaluate the practicality for harnessing waste energy from the air conditioner exhaust units which are a more constant and predictable source available in the buildings. A prototype of the micro wind turbine has been designed to minimize the negative effect of the exhaust sources. After the micro wind turbine was manufactured, the performance of the turbine was tested in the selected air conditioner exhaust unit. Increasing the rotor solidity and decreasing the resistance of the generator contribute to improved starting torque and decreased generator break in torque respectively in the design. The power generation of the micro wind turbine increases with an increase of the rotor speed. The 24-hour operation of the prototype presents an observation for both exhaust performance and power generation prediction when the prototype is mounted on the exhaust unit.

Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building

Energy Technology Data Exchange (ETDEWEB)

Ni Honggang; Cao Shanping; Chang Wenjing [Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055 (China); Zeng Hui, E-mail: huizeng0608@gmail.com [Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055 (China); Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China)

2011-07-15

This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM{sub 2.5} (Particulate Matter up to 2.5 {mu}m in size) bounded {Sigma}{sub 15}PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM{sub 10} (Particulate Matter up to 10 {mu}m in size) bounded {Sigma}{sub 15}PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of {Sigma}{sub 15}PBDEs via dust inhalation and ingestion for adults reached {approx}141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. - Highlights: > Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than that in the old ones. > PBDE emissions from indoor sources can be expected to continue for a long time as the PBDE-containing products in offices were to be kept many years. > The household consumer products, especially computers, are the main sources of PBDEs in central air conditioner filter dust. > Further studies are needed to fully understand the emission mechanism of PBDE from indoor consumer products. - PBDEs in central air conditioner filter dust from a new building were investigated

Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building

International Nuclear Information System (INIS)

Ni Honggang; Cao Shanping; Chang Wenjing; Zeng Hui

2011-01-01

This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM 2.5 (Particulate Matter up to 2.5 μm in size) bounded Σ 15 PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM 10 (Particulate Matter up to 10 μm in size) bounded Σ 15 PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ 15 PBDEs via dust inhalation and ingestion for adults reached ∼141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. - Highlights: → Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than that in the old ones. → PBDE emissions from indoor sources can be expected to continue for a long time as the PBDE-containing products in offices were to be kept many years. → The household consumer products, especially computers, are the main sources of PBDEs in central air conditioner filter dust. → Further studies are needed to fully understand the emission mechanism of PBDE from indoor consumer products. - PBDEs in central air conditioner filter dust from a new building were investigated

Temperature control of the four-zone split inverter air conditioners using LMI expression based on LQR for mixed H2/H∞

International Nuclear Information System (INIS)

Yang, YauBin; Wu, Min-Der; Chang, Yu-Choung

2014-01-01

Highlights: • The optimal control gains were obtained from the linear matrix inequalities with mixed H 2 and H ∞ control algorithm. • The proposed method guaranteed convergence, stability, and provided a way for disturbance rejection and energy savings. • The coupling effects occurred among the compressor speed, opening degrees, evaporator temperatures and superheats. • The system identification and thermal dynamics equations could obtain the inner and outer loop transfer functions. • All simulations in this paper were in discrete time domain. - Abstract: Air conditioners in either commercial or residential buildings consume substantial electricity. Enhancing the air conditioner efficiency by using a new control scheme is critical. In four-zone multi-evaporator air conditioner systems, coupling effects occur among the compressor speed, the degree of opening of the four electronic expansion valves, the temperatures of the four evaporators, and the four superheats. The system identification and thermodynamic equations could be used to obtain the inner and outer loop transfer functions between the air conditioner and its environment. A variable structure (switching) for the proportional integral anti-windup method could circumvent the saturation phenomenon generated from the integral controller. The optimal control gains were obtained from the linear matrix inequalities (LMI) based on a linear quadratic regulator (LQR) with a mixed H 2 and H ∞ control algorithm. In a simulated example, this efficient method, through those feedback gains, guaranteed convergence and stability. In addition, the results indicated that the proposed LMI using a mixed H 2 and H ∞ control method is also an alternative way for disturbance rejection and energy savings in buildings

Comparison of air conditioners for horticulture; Vergelijking van luchtbehandelingssystemen voor de tuinbouw

Energy Technology Data Exchange (ETDEWEB)

Knoll, B.; Hendriksen, L. [TNO, Delft (Netherlands)

2011-12-15

The desire to reduce energy consumption in the greenhouse sector results into new techniques and applications. As such air conditioners are applied in greenhouses. They serve to control temperature, relative humidity and air flow in the greenhouse. However, because of the totally different climatic conditions in the greenhouses such systems must be adapted. TNO investigates how the systems can be evaluated properly [Dutch] De wens om het energieverbruik in de glastuinbouw omlaag te brengen, leidt tot nieuwe technieken en toepassingen. Zo vinden in de utiliteit gangbare luchtbehandelingssystemen nu ook hun weg naar de kas. Ze dienen om temperatuur, relatieve luchtvochtigheid en luchtbeweging in de kas te beheersen. Maar vanwege de totaal andere klimaatomstandigheden moeten de systemen worden aangepast. TNO onderzoekt hoe de systemen goed kunnen worden geevalueerd.

Study on the complexity pricing game and coordination of the duopoly air conditioner market with disturbance demand

Science.gov (United States)

Ma, Junhai; Xie, Lei

2016-03-01

The paper focuses on the dynamic pricing game of the duopoly air conditioner market with disturbance in demand and analyzes the influence of disturbance on the dynamic game system. Considering the demand for products, such as air conditioner, varies with different seasons, we assume three cases based on the condition of disturbance, including growth market (Case 1), declining market (Case 2) and completely random market (Case 3). By analyzing these three cases and making comparison among them, the paper shows that the growth market is more sensitive to the changing parameters such as the adjustment variable and the competitive factor than the declining market. It is more difficult to keep the system stable in a growth market. Although the demand is completely random, the dynamic system can reach a stable state, on condition that the adjustment variable is small enough. The results also indicate that the bullwhip effect between the order quantity and the actual demand is weakened gradually along with the price adjustment.

Investigation of the compressor part-load behaviour and its effects on the per annum energy consumption of the air conditioner; Untersuchung des Kompressor-Teillastverhaltens im Hinblick auf den Jahresverbrauch der Klimaanlage

Energy Technology Data Exchange (ETDEWEB)

Martin, Klaus; Lechner, Bernhard [Virtual Vehicle. Kompetenzzentrum - Das virtuelle Fahrzeug Forschungsgesellschaft mbH (ViF), Graz (Austria); Rieberer, Rene [Technische Univ. Graz (Austria); Moenkediek, Thomas [Audi AG, Ingolstadt (Germany)

2010-07-01

The air conditioning system is one of the most important ancillary units of a motor vehicle. Energetic optimization of air conditioners has been a key issue of research at AUDI AG during the past few years. As a rule, the cooling capacity of the air conditioner is controlled by adapting the compressor lift if the compressor is driven by the car engine and control via the rotational speed is not possible. As air conditioners ted to be designed for extreme conditions, the compressor will work at part load in most operating conditions. Optimization of the energetic efficiency of the air conditioner also means to look at the part-load behaviour of the compressor. Simulations have been used successfully by AUDI AG for many years now; the have helped to shorten development times and improve the product quality. The contribution describes an advanced model of a swivel plate compressor of a R134a cooling cycle with particular consideration of part-lift operation. The simulation model is based on measurements with continous recording of the piston lift. The focus is on the influence of reduced lift on the compressor efficiency. Another point of interest is the successful integration of the compressor model in the overall refrigerating cycle model which will be used for simulations of system performance and efficiency and for further optimization of the air conditioner. (orig.)

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%.

Optimum placement of condensing units of split-type air-conditioners by numerical simulation

Energy Technology Data Exchange (ETDEWEB)

Avara, Abdollah; Daneshgar, Ehsan [Mechanical Engineering Department, Persian Gulf University, Bushehr (Iran, Islamic Republic of)

2008-07-01

Split-type air-conditioners used in residential or office buildings often have the outdoor condensing units installed at the sidewalls or on the roofs. Installation distance from the supporting wall for the first group and the height of installation for the second group are two factors that affect the condenser efficiency. In this study, a CFD code is used to calculate the effect of distance from the supporting wall on the entrance air temperature and on the on-coil temperature of condenser installed between two walls. In the case of condenser installed on the roof, the effect of installation height of the condenser from the finished roof on on-coil temperature is investigated and the minimum recommended height of installation is determined. (author)

Select Components and Finish System Design of a Window Air Conditioner with Propane

Energy Technology Data Exchange (ETDEWEB)

Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-05-01

This report describes the technical targets for developing a high efficiency window air conditioner (WAC) using propane (R-290). The baseline unit selected for this activity is a GE R-410A WAC. We established collaboration with a Chinese rotary compressor manufacturer, to select an R-290 compressor. We first modelled and calibrated the WAC system model using R-410A. Next, we applied the calibrated system model to design the R-290 WAC, and decided the strategies to reduce the system charge below 260 grams and achieve the capacity and efficiency targets.

An experimental and theoretical study on an injection-assisted air-conditioner using R32 in the refrigeration cycle

International Nuclear Information System (INIS)

Qv, Dehu; Dong, Bingbing; Cao, Lin; Ni, Long; Wang, Jijin; Shang, Runxin; Yao, Yang

2017-01-01

Highlights: • An advanced injection-assisted air-conditioner (IAC) using R32 was proposed. • In the whole day-night cycle, cooling capacity and energy efficiency ratio of the IAC were enhanced dramatically. • The injection duration of 8 s maximized the IAC cooling potential. • Two-phase injection attained the highest exergetic efficiency approximating 50% or more. • The economic and environmental benefits of the IAC were demonstrated. - Abstract: An air-conditioner (AC) that uses refrigerant R32 assisted with one-phase vapor injection shows high energy efficiency and low discharge temperature in the heat-pump cycle, but the performance is not satisfactory in the refrigeration cycle. In this study, an improved injection cycle consisting of one-phase vapor injection mode and two-phase injection mode is proposed and integrated into an AC using R32, which is now referred to as an advanced injection-assisted air-conditioner (IAC). Through an experimental and theoretical study, an optimal injection duration of 8 s is attained for maximizing the refrigeration potential of the IAC. Furthermore, in an entire day–night cycle, both the cooling capacity and energy efficiency ratio (EER) of the IAC within the two-phase injection cycle are enhanced by 25% and 32%, respectively, compared with those of a noninjection-assisted AC. Moreover, two-phase injection offers the highest exergetic efficiency, approximately 50% or more in the refrigeration cycle, exhibiting remarkable thermodynamic performance of the IAC. In addition, compared to the conventional AC using R410A, the IAC using R32 within a two-phase injection cycle demonstrates reasonable payback performance and substantial reduction in carbon dioxide and sulfur dioxide emissions in the refrigeration cycle.

Effectiveness of finish materials and room air-conditioner on the reduction of indoor radon concentration in Hong Kong

International Nuclear Information System (INIS)

Ma, A.K.; Man, C.K.; Ho, E.; Pang, S.W.

1995-01-01

Four different kinds of finish material were investigated: wallpaper, paint, plaster and tile. When applied to the bare concrete walls of uninhabited rooms in flats of a building under construction, all of them were found to reduce indoor radon concentration. The magnitude of reduction by these finish materials ranged from 20% to 80%. Wallpaper was found to provide the best protection against radon emission from bare concrete walls in a bedroom with a size of 19.3 m 3 . Wallpaper can reduce the indoor radon concentration about twice as much as paint (water-based) or plaster in this investigation. Tile was also found to be a good material against radon emission from concrete walls in a bathroom with a size of 6.3 m 3 . Indoor radon concentration was found to decrease with elevation from the ground level, and was affected strongly by mechanical ventilation. Another 30% to 50% reduction in indoor radon concentration in addition to finish material can be achieved by a room air-conditioner. It was also found that indoor radon concentrations were not affected by turning the fresh air shutter to the 'on' or 'off' position in the room air-conditioner. (author)

A Proposal for the Time Domain Modeling of Split Air Conditioners for Consumer Reimbursement Studies

Science.gov (United States)

Rezende, Paulo Henrique Oliveira; Almeida Junior, Afonso Bernardino; Gondim, Isaque Nogueira; Oliveira, José Carlos

2015-04-01

This paper deals with computer application procedures for the evaluation of the causal consistency between anomalous phenomena manifested in electrical networks, along with the physical damage associated with electrical equipment and possible reimbursement requests. The focus is on the development of an air conditioner appliance model of the type known as split founded upon a representation, in the time domain, in accordance with the Alternative Transients Program (ATP) simulator requirements. This approach permits investigations concerning the performance of the product when submitted to ideal and non-ideal supply conditions. Once the equipment model is implemented in the program, a set of investigative studies are carried out to show the device performance under specific energy quality disturbance conditions. In addition, there are still the results for the validation of the process established through the correlation between computational performance of the air conditioner with corresponding studies carried out experimentally, which are presented herein. Moreover, once the effectiveness of the developed model is verified, it is implemented into the Requests for Reimbursement Software. Investigations related to the correlation between disturbances and the levels of thermal and dielectric tolerance are then performed aiming at illustrating the use of the research results for the reimbursement analyzes purposes.

Designing and testing the optimum design of automotive air-to-air thermoelectric air conditioner (TEAC) system

International Nuclear Information System (INIS)

Attar, Alaa; Lee, HoSung

2016-01-01

Highlights: • The optimum design of automotive thermoelectric AC system is proposed. • It is optimized by combining the thermal isolation and the dimensionless methods. • An experiment is conducted to validate the analytical design. - Abstract: The current project is discussing the optimization of counter flow air-to-air thermoelectric air conditioners (TEAC) system. Previous work showed an analytical model with experimental validation of a unit cell of TEAC system. However, the focus of this work is to simulate the optimum design of a whole TEAC system from given inlet parameters (i.e., hot and cold air mass flow rates and ambient temperatures). The analytical model was built by combining an optimal design method with dimensional analysis, which was recently developed, and the thermal isolation method in order to optimize the thermoelectric parameters (i.e., electrical current supplied and the number of thermocouples or the geometric factor, simultaneously). Moreover, based on the designed model, an experiment was conducted in order to study the accuracy of the analytical model. Even though the analytical model was built based on the thermoelectric ideal equations, it shows a good agreement with the experiment. This agreement was mainly a result of the use of the thermoelectric effective material properties which are obtained from the measured maximum thermoelectric module parameters. Since the experiment validate the analytical model, this model provides uncomplicated method to study the optimum design at given inputs.

A desiccant-enhanced evaporative air conditioner: Numerical model and experiments

International Nuclear Information System (INIS)

Woods, Jason; Kozubal, Eric

2013-01-01

Highlights: ► We studied a new process combining liquid desiccants and evaporative cooling. ► We modeled the process using a finite-difference numerical model. ► We measured the performance of the process with experimental prototypes. ► Results show agreement between model and experiment of ±10%. ► Results add confidence to previous modeled energy savings estimates of 40–85%. - Abstract: This article presents modeling and experimental results on a recently proposed liquid desiccant air conditioner, which consists of two stages: a liquid desiccant dehumidifier and an indirect evaporative cooler. Each stage is a stack of channel pairs, where a channel pair is a process air channel separated from an exhaust air channel with a thin plastic plate. In the first stage, a liquid desiccant film, which lines the process air channels, removes moisture from the air through a porous hydrophobic membrane. An evaporating water film wets the surface of the exhaust channels and transfers the enthalpy of vaporization from the liquid desiccant into an exhaust airstream, cooling the desiccant and enabling lower outlet humidity. The second stage is a counterflow indirect evaporative cooler that siphons off and uses a portion of the cool-dry air exiting the second stage as the evaporative sink. The objectives of this article are to (1) present fluid-thermal numerical models for each stage, (2) present experimental results of prototypes for each stage, and (3) compare the modeled and experimental results. Several experiments were performed on the prototypes over a range of inlet temperatures and humidities, process and exhaust air flow rates, and desiccant concentrations and flow rates. The model predicts the experiments within ±10%.

Performance analysis of the electric vehicle air conditioner by replacing hydrocarbon refrigerant

Science.gov (United States)

Santoso, Budi; Tjahjana, D. D. D. P.

2017-01-01

The thermal comfort in passenger cabins needs an automotive air-conditioning system. The electric vehicle air conditioner system is driven by an electric compressor which includes a compressor and an electric motor. Almost air-conditioning system uses CFC-12, CFC-22 and HFC-134a as refrigerant. However, CFC-12 and CFC-22 will damage the ozone layer. The extreme huge global warming potentials (GWP) values of CFC-12, CFC-22, and HFC-134a represent the serious greenhouse effect of Earth. This article shows new experimental measurements and analysis by using a mixture of HC-134 to replace HFC-134a. The result is a refrigerating effect, the coefficient of performance and energy factor increase along with cooling capacity, both for HFC-134a and HC-134. The refrigerating effect of HC-134 is almost twice higher than HFC-134a. The coefficient of performance value of HC-134 is also 36.42% greater than HFC-134a. Then, the energy factor value of HC-134 is 3.78% greater than HFC-134a.

Substantial energy conservation in air conditioners; Substantiele energiebesparing bij luchtbehandelingsinstallaties

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-03-01

An air conditioner has been retrofitted by application of an optimized fan in combination with an EC motor (brushless dc-motor). Attention is paid to the difference between an AC- and and EC motor, between free-running and spiral housing fans, between direct or indirect-driven, and between forward-bended and backward-bended blades. By means of equations and diagrams the realized energy conservation is visualized. [Dutch] De renovatie van een luchtbehandelingskast wordt besproken. Door de toepassing van ventilatoren met een geoptimaliseerde waaier in combinatie met een EC-motor (borstelloze gelijkstroommotor) wordt een substantiele energiebesparing gerealiseerd. Er wordt op verschillende aspecten ingegaan. Onder meer het verschil tussen een AC- en EC-motor, tussen vrijlopende en slakkenhuisventilatoren, tussen direct- of indirect-gedreven schoepen en tussen voorwaarts- of achterwaartsgebogen schoepen. Aan de hand van vergelijkingen en diagrammen wordt de energiewinst zichtbaar gemaakt.

High efficiency novel window air conditioner

International Nuclear Information System (INIS)

Bansal, Pradeep

2015-01-01

Highlights: • Use of novel refrigerant mixture of R32/R125 (85/15% molar conc.) to reduce global warming and improve energy efficiency. • Use of novel features such as electronically commuted motor (ECM) fan motor, slinger and sub-merged sub-cooler. • Energy savings of up to 0.1 Quads per year in USA and much more in Asia/Middle East where WACs are used in large numbers. • Payback period of only 1.4 years of the novel efficient WAC. - Abstract: This paper presents the results of an experimental and analytical evaluation of measures to raise the efficiency of window air conditioners (WAC). In order to achieve a higher energy efficiency ratio (EER), the original capacity of a baseline R410A unit was reduced by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. Subsequent major modifications included – replacing the alternating current fan motor with a brushless high efficiency electronically commutated motor (ECM) motor, replacing the capillary tube with a needle valve to better control the refrigerant flow and refrigerant set points, and replacing R410A with a ‘drop-in’ lower global warming potential (GWP) binary mixture of R32/R125 (85/15% molar concentration). All these modifications resulted in significant enhancement in the EER of the baseline WAC. Further, an economic analysis of the new WAC revealed an encouraging payback period

The design of the motor bracket for reduction of structure-borne noise in package air-conditioner

Energy Technology Data Exchange (ETDEWEB)

Sim, Hyoun Jin; Lee, Sung Jin; Oh, Jae Eung [Hanyang University, Seoul (Korea, Republic of); Kang, Tae Ho [WiniaMando, Asan (Korea, Republic of); Lee, Jung Yoon [Kyonggi University, Suwon (Korea, Republic of)

2006-02-15

As the economic power is improved and the customer's demand is hard to please, the noise and vibration is the most important yardstick that can determine the quality of the product. Especially, as the air-conditioner's demand increase suddenly, the product of quality and the noise is becoming a decisive factor of determining whether purchase the product or not. Therefore, every manufactory is investing a lot of money and research to cut down the unpleasantness induced from noise and vibration. And they are emphasizing their product's difference by advertising a silence very actively. With these reason, the demand of a silent indoor air-conditioner is the essential research filed when the product is developed. In this study, the noise and vibration is visualized in the space and frequency domain by using experimental methods such as Operational Deflection Shape (ODS), modal testing and sound intensity. Also the location of noise source and its characteristic is analyzed in an acoustical point of view to reduce the structure borne noise that come from the fan motor, and the pertinent control method is suggested. Furthermore, the most suitable shape of the motor bracket is suggested by applying FEM and DOE (Design of Experiments) in the noise and vibration point a view.

The design of the motor bracket for reduction of structure-borne noise in package air-conditioner

International Nuclear Information System (INIS)

Sim, Hyoun Jin; Lee, Sung Jin; Oh, Jae Eung; Kang, Tae Ho; Lee, Jung Yoon

2006-01-01

As the economic power is improved and the customer's demand is hard to please, the noise and vibration is the most important yardstick that can determine the quality of the product. Especially, as the air-conditioner's demand increase suddenly, the product of quality and the noise is becoming a decisive factor of determining whether purchase the product or not. Therefore, every manufactory is investing a lot of money and research to cut down the unpleasantness induced from noise and vibration. And they are emphasizing their product's difference by advertising a silence very actively. With these reason, the demand of a silent indoor air-conditioner is the essential research filed when the product is developed. In this study, the noise and vibration is visualized in the space and frequency domain by using experimental methods such as Operational Deflection Shape (ODS), modal testing and sound intensity. Also the location of noise source and its characteristic is analyzed in an acoustical point of view to reduce the structure borne noise that come from the fan motor, and the pertinent control method is suggested. Furthermore, the most suitable shape of the motor bracket is suggested by applying FEM and DOE (Design of Experiments) in the noise and vibration point a view

A review on the recent development of solar absorption and vapour compression based hybrid air conditioning with low temperature storage

Directory of Open Access Journals (Sweden)

Noor D. N.

2016-01-01

Full Text Available Conventional air conditioners or vapour compression systems are main contributors to energy consumption in modern buildings. There are common environmental issues emanating from vapour compression system such as greenhouse gas emission and heat wastage. These problems can be reduced by adaptation of solar energy components to vapour compression system. However, intermittence input of daily solar radiation was the main issue of solar energy system. This paper presents the recent studies on hybrid air conditioning system. In addition, the basic vapour compression system and components involved in the solar air conditioning system are discussed. Introduction of low temperature storage can be an interactive solution and improved economically which portray different modes of operating strategies. Yet, very few studies have examined on optimal operating strategies of the hybrid system. Finally, the findings of this review will help suggest optimization of solar absorption and vapour compression based hybrid air conditioning system for future work while considering both economic and environmental factors.

Particulate matter concentrations in residences: an intervention study evaluating stand-alone filters and air conditioners.

Science.gov (United States)

Batterman, S; Du, L; Mentz, G; Mukherjee, B; Parker, E; Godwin, C; Chin, J-Y; O'Toole, A; Robins, T; Rowe, Z; Lewis, T

2012-06-01

This study, a randomized controlled trial, evaluated the effectiveness of free-standing air filters and window air conditioners (ACs) in 126 low-income households of children with asthma. Households were randomized into a control group, a group receiving a free-standing HEPA filter placed in the child's sleeping area, and a group receiving the filter and a window-mounted AC. Indoor air quality (IAQ) was monitored for week-long periods over three to four seasons. High concentrations of particulate matter (PM) and carbon dioxide were frequently seen. When IAQ was monitored, filters reduced PM levels in the child's bedroom by an average of 50%. Filter use varied greatly among households and declined over time, for example, during weeks when pollutants were monitored, filter use was initially high, averaging 84±27%, but dropped to 63±33% in subsequent seasons. In months when households were not visited, use averaged only 34±30%. Filter effectiveness did not vary in homes with central or room ACs. The study shows that measurements over multiple seasons are needed to characterize air quality and filter performance. The effectiveness of interventions using free-standing air filters depends on occupant behavior, and strategies to ensure filter use should be an integral part of interventions. Environmental tobacco smoke (ETS) increased particulate matter (PM) levels by about 14 μg/m3 and was often detected using ETS-specific tracers despite restrictions on smoking in the house as reported on questionnaires administered to caregivers. PM concentrations depended on season, filter usage, relative humidity, air exchange ratios, number of children, outdoor PM levels, sweeping/dusting, and presence of a central air conditioner (AC). Free-standing air filters can be an effective intervention that provides substantial reductions in PM concentrations if the filters are used. However, filter use was variable across the study population and declined over the study duration, and

Automotive absorption air conditioner utilizing solar and motor waste heat

Science.gov (United States)

Popinski, Z. (Inventor)

1981-01-01

In combination with the ground vehicles powered by a waste heat generating electric motor, a cooling system including a generator for driving off refrigerant vapor from a strong refrigerant absorbant solution is described. A solar collector, an air-cooled condenser connected with the generator for converting the refrigerant vapor to its liquid state, an air cooled evaporator connected with the condenser for returning the liquid refrigerant to its vapor state, and an absorber is connected to the generator and to the evaporator for dissolving the refrigerant vapor in the weak refrigerant absorbant solution, for providing a strong refrigerant solution. A pump is used to establish a pressurized flow of strong refrigerant absorbant solution from the absorber through the electric motor, and to the collector.

Evaluation of malodor for automobile air conditioner evaporator by using laboratory-scale test cooling bench.

Science.gov (United States)

Kim, Kyung Hwan; Kim, Sun Hwa; Jung, Young Rim; Kim, Man Goo

2008-09-12

As one of the measures to improve the environment in an automobile, malodor caused by the automobile air-conditioning system evaporator was evaluated and analyzed using laboratory-scale test cooling bench. The odor was simulated with an evaporator test cooling bench equipped with an airflow controller, air temperature and relative humidity controller. To simulate the same odor characteristics that occur from automobiles, one previously used automobile air conditioner evaporator associated with unpleasant odors was selected. The odor was evaluated by trained panels and collected with aluminum polyester bags. Collected samples were analyzed by thermal desorption into a cryotrap and subsequent gas chromatographic separation, followed by simultaneous olfactometry, flame ionization detector and identified by atomic emission detection and mass spectrometry. Compounds such as alcohols, aldehydes, and organic acids were identified as responsible odor-active compounds. Gas chromatography/flame ionization detection/olfactometry combined sensory method with instrumental analysis was very effective as an odor evaluation method in an automobile air-conditioning system evaporator.

Experimental investigations on performance of liquid desiccant-vapor compression hybrid air conditioner

International Nuclear Information System (INIS)

Mohan, B. Shaji; Tiwari, Shaligram; Maiya, M.P.

2015-01-01

A coupled desiccant column is integrated with a conventional room air conditioner (AC) to enhance dehumidification of the room air. One desiccant column (absorber) is placed after the evaporator the other (regenerator) after the condenser of the AC unit. Such a novel liquid desiccant vapour compression hybrid air conditioning system has been fabricated and tested in a balanced ambient room type calorimeter for very low flow rates of liquid desiccant (lithium bromide solution). The moisture from the cold supply air is transferred to the hot condenser air by the desiccant flowing in the loop, thereby complimenting the dehumidification of the room air at the evaporator. The supply air is also sensibly heated during the dehumidification process by liquid desiccant in the absorber, which together enables the hybrid system to maintain low humidity in the room. Whereas the liquid desiccant is regenerated by the condenser waste heat, the entire cooling is derived only by the AC unit. The experimental results show that an increase of room temperature reduces both dehumidification of process air and regeneration of liquid desiccant, whereas an increase of room specific humidity enhances both these for the flow rate of the liquid desiccant in the range of 0.2–1.6% of the air flow rate through the absorber. - Highlights: • A liquid desiccant vapor compression hybrid system is fabricated and tested. • The liquid desiccant reduces latent load but equally increases sensible load. • Hybrid system performance is studied for varying room temperature and humidity. • Higher room temperature lowers air dehumidification and desiccant regeneration. • Increase of room specific humidity enhances dehumidification and also regeneration

Energy savings and economics of advanced control strategies for packaged air conditioners with gas heat

Energy Technology Data Exchange (ETDEWEB)

Wang, Weimin; Katipamula, Srinivas; Huang, Yunzhi; Brambley, Michael R.

2013-10-01

This paper presents an evaluation of the potential energy savings from adding advanced control to existing packaged air conditioners. Advanced control options include air-side economizer, multi-speed fan control, demand control ventilation and staged cooling. The energy and cost savings from the different control strategies individually and in combination are estimated using the EnergyPlus detailed energy simulation program for four building types, namely, a small office building, a stand-alone retail building, a strip mall building and a supermarket building. For each of the four building types, the simulation was run for 16 locations covering all 15 climate zones in the U.S. The maximum installed cost of a replacement controller that provides acceptable payback periods to owners is estimated.

The experimental investigation of refrigerant distribution and leaking characteristics of R290 in split type household air conditioner

International Nuclear Information System (INIS)

Tang, Weier; He, Guogeng; Cai, Dehua; Zhu, Yihao; Zhang, Aoni; Tian, Qiqi

2017-01-01

Highlights: • A new quasi-liquid nitrogen method (QLNM) was proposed and firstly applied in experiments. • The R290 distribution was investigated by QLNM and the results proved the validation. • A solenoid valve was proposed to install near the capillary in STHAC in order to reduce risk factor. • R290 leaking rate was firstly measured by QLNM before and after the installation a solenoid valve. - Abstract: As a high-profile replacement for R22 split type household air conditioner (STHAC), R290 has several advantages in terms of thermodynamic properties, environmental characteristics, and cost. However, the obvious shortcoming of R290 is its flammability, which has a potential fire risk to the building. At present, the most important measure to ensure the safety of a R290 STHAC is to limit the refrigerant charge by domestic and international standards. But in fact, when the leakage of R290 occur from a STHAC, the distribution of R290 in STHAC, and the leaking rate also will seriously affect the safety of an R290 STHAC. In this study, a new quasi-liquid nitrogen method (QLNM) has been proposed in order to investigate the refrigerant distribution in R290 STHACs and the leaking rate under various conditions, and the experiments have been conducted. The experimental results of distribution proved the validation of the QLNM and showed that a large portion of the refrigerant distributed in the condenser when the air conditioner is on running stage and the refrigerant will migrate from the condenser to the evaporator when the air conditioner is on closed stage. Based on this, the installation of a solenoid valve near the capillary has been proposed. The comparison of experimental results of R290 leaking rate before and after the installation of a solenoid valve showed it will obviously reduce the leaking rate and thereby improve the safety of the R290 STHACs.

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)

Study on load levelling by means of the control of air conditioner operation; Kuchoki kado seigyo ni yoru fuka heijunka ni kansuru ichikosatsu

Energy Technology Data Exchange (ETDEWEB)

Sasaki, H. [Hiroshima University, Hiroshima (Japan); Sadakuni, S. [Japan Broadcasting Corp., Tokyo (Japan)

1995-04-20

The recent drastic increase in the number of air conditioners has caused sharp and narrow peaks in summer seasons due to the inherent temperature sensitive characteristics. The authors proposed to reduce the peak power demand by controlling air conditioner operations, verifying its effectiveness on peak demand clipping. However, the former study has shortcomings in that any qualitative treatment of room temperatures or pleasant feeling was not attempted and it did not provide a way of assessing peak demand clipping in a power system as a whole. In this paper, we shall first propose a new control method that can compromise pleasant feeling and reduction in power demand. Although air conditioners are used to pursue `pleasant feeling`, this contradicts to reduce power consumption and further more the concept of `pleasant feeling` is very vague. Hence, `Weber-Fechner`s law` is utilized to quantify the pleasant feeling which is treated as fuzzy quantity. Fuzzy co-ordination method is used to compromise power demand curtailment and pleasantness. In the second part of this paper, we shall propose an approach of assessing the amount of peak load clipping when the newly proposed control strategy is adopted in a real size power system: A decrease in the required generation capacity is estimated provided that the Loss of Load Probability (LOLP) is maintained at the same level before and after the application of the new control strategy. The reduction can be regarded as a dividend of load management. 5 refs., 9 figs., 5 tabs.

Efficiency and limitations of the upper airway mucosa as an air conditioner evaluated from the mechanisms of bronchoconstriction in asthmatic subjects.

Science.gov (United States)

Konno, A; Terada, N; Okamoto, Y; Togawa, K

1985-01-01

To elucidate a limit to the efficiency of the upper airway mucosa as an air conditioner, the temperatures of the inspiratory air and mucosa were measured in the cervical trachea. Both of them were affected only minimally by change of atmospheric air temperature during resting nose breathing, but were affected greatly by change of mode of breathing. During hyperventilation through the mouth, when the atmospheric air temperature was 1 degree C, a temperature difference of 9 degrees C was noted between inspiratory air in the cervical trachea and body temperature, together with a mucosal temperature fall by 1.86 +/- 0.61 degree C. Wearing of a mask caused a rise of 3 degrees C in the inspiratory air temperature in the cervical trachea.

Effects of ejector geometries on performance of ejector-expansion R410A air conditioner considering cooling seasonal performance factor

International Nuclear Information System (INIS)

Jeon, Yongseok; Jung, Jongho; Kim, Dongwoo; Kim, Sunjae; Kim, Yongchan

2017-01-01

Highlights: •The performance of an ejector-expansion R410A air conditioner is measured. •The effect of ejector geometries on the COP and CSPF is analyzed. •The mixing-section diameter of the ejector is optimized based on the CSPF. •The mixing-section diameter is optimized based on the climatic conditions. -- Abstract: The objective of this study was to investigate the effects of ejector geometries on the performance of an ejector-expansion air conditioner (EEAC) considering the cooling seasonal performance factor (CSPF). The performance of the EEAC using R410A was measured and analyzed by varying the compressor speed, outdoor-bin temperature, operating pressures, nozzle-throat diameter, and mixing-section diameter. The EEAC in the medium-capacity mode exhibited maximum coefficient of performance (COP) improvement, i.e., 7.5%, over the baseline (conventional) cycle. The optimum mixing-section diameter was determined to be 9 mm based on the CSPF. In addition, the optimum mixing-section diameter increased with an increase in the annual average outdoor temperature. The CSPF of the EEAC with the optimized mixing-section diameter improved in the range of 16.0–20.3% over the baseline cycle depending on the climatic conditions.

Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Rooftop Air Conditioners

Energy Technology Data Exchange (ETDEWEB)

Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Bargach, Youssef [Navigant Consulting Inc., Burlington, MA (United States)

2016-09-01

The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for Low-Global Warming Potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants relative to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in packaged or Rooftop Unit (RTU) air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerants selection process, the test procedures, and the final results.

Locating room air-conditioners at floor level for energy saving in residential buildings

International Nuclear Information System (INIS)

Gao, C.F.; Lee, W.L.; Chen Hua

2009-01-01

Residential air-conditioning becomes a common feature in our daily life. They are typically installed at high level known as ceiling-based system (CAC). With the increasing use of floor-based air-conditioning system in commercial buildings for energy saving, it is proposed in this study to locate a top discharge/front return air-conditioner at floor level to resemble a floor-based air-conditioning system (FAC) to curb energy use in residential buildings. Given the concerns about draught discomfort and thermal stratification associated with floor-based air-conditioning systems, the objective of this study is to evaluate the air distribution performance and to quantify the possible energy benefits. Bedroom was chosen as a sensitive case for detailed air distribution performance evaluation. Experimental study, CFD simulations and energy simulations were conducted in achieving the specific objectives. CAC and FAC were installed in a bedroom-like environmental chamber for experimental study at different indoor and outdoor conditions. The air velocities and temperatures at various positions and levels inside the chamber were measured to determine the air distribution performance indices (ADPI) and airflow draft risk (DR). The cooling output, power consumption and coefficient of performance (COP) of the two units were measured and calculated for comparison. The experimental results show that ADPI of CAC and FAC are 92.3% and 84.6%, respectively. COP of FAC is 8.11% higher than CAC, and the corresponding DR are comparable. The experimental results were used to validate the CFD simulations as well as providing actual performance data for predicting the energy use of applying CAC and FAC in a case-study building. CFD simulations and draught assessment confirmed that there is no potential draught discomfort and thermal stratification associated with the use of FAC. Energy simulations predicted that the associated energy saving is 6.9%. Wider use of FAC in residential

Elemental analysis of dust trapped in air conditioner filters for the assessment of Lahore city's air quality

International Nuclear Information System (INIS)

Siddique, N.

2011-01-01

A study was undertaken to assess the air quality of Lahore by the elemental analysis of air conditioner (AC) filter dust samples collected from 15 different commercial sites. Samples were prepared using the Leeds Public Analyst Method and were analyzed using instrumental neutron activation analysis (INAA) for up to 31 elements. The elements Al, As, Ba, Ce, Co, Cr, Cs, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sc, Sm, Sn, Ta, Th, Yb and Zn were detected in all 15 samples whereas the remaining elements have been detected in fewer samples; i.e. Mg, Sb and Tb were detected in 14 samples, Br and V in ten samples, U in nine samples and Ca and Ti in eight samples only. Al, Ca, Fe, K, Mg and Na were determined in all samples at percentage levels. The concentrations of most elements were found to lie around the mean values for the 15 samples studied and were not orders of magnitude different. However the concentrations of Ca, Mg, Sn and Zn were found to be more variable and were found to be dependant on activities such as construction, fruit and vegetable handling, tin plating and transport, respectively. (author)

Life-cycle cost and payback period analysis for commercial unitary air conditioners

Energy Technology Data Exchange (ETDEWEB)

Rosenquist, Greg; Coughlin, Katie; Dale, Larry; McMahon, James; Meyers, Steve

2004-03-31

This report describes an analysis of the economic impacts of possible energy efficiency standards for commercial unitary air conditioners and heat pumps on individual customers in terms of two metrics: life-cycle cost (LCC) and payback period (PBP). For each of the two equipment classes considered, the 11.5 EER provides the largest mean LCC savings. The results show how the savings vary among customers facing different electricity prices and other conditions. At 11.5 EER, at least 80% of the users achieve a positive LCC savings. At 12.0 EER, the maximum efficiency analyzed, mean LCC savings are lower but still positive. For the {ge} $65,000 Btu/h to <135,000 Btu/h equipment class, 59% of users achieve a positive LCC savings. For the $135,000 Btu/h to <240,000 Btu/h equipment class, 91% of users achieve a positive LCC savings.

Experimental investigations on automobile air conditioners working with R134a and R290/R600a as an alternative

Directory of Open Access Journals (Sweden)

Kandhaswamy Karthikeyan

2017-01-01

Full Text Available In this work, the performance of R134a based automobile air conditioning system has been evaluated by retrofitted with R290/R600a mixture (in the ratio of 50:50, by mass, as an alternative. The performance was evaluated at five different operating speeds (1000, 1500, 2000, 2500, and 3000, which covers the entire range of working conditions with four different cabin load (100, 200, 300, and 400 W. The condenser inlet air temperature was varied in the range between 30 and 50°C, which covers the entire climatic variations in Coimbatore city of India. The performance characteristics such as, refrigerating effect, coefficient of performance, compressor power consumption, and compressor discharge temperatures were considered for comparison. The results showed that, hydrocarbon mixture has faster cooling rate due to its high latent heat of vaporization, 5% higher coefficient of performance due to higher refrigeration effect, 8-10 K lower compressor discharge temperature due to its lower specific heat ratio with 5% lower compressor power consumption due to its lower viscosity and lower liquid density. The charge requirement of R290/R600a mixture is about 50% less compared to R134a. However, the mixture composition is considered as an interment replacement in automobile air conditioners due to composition shift under leak-age conditions. Hence, R290/R600a mixture is considered as an interim energy efficient and environment friendly option in R134a automobile air conditioners to extend its life.

The use of heteroduplex analysis of polymerase chain reaction products to support the possible transmission of Legionella pneumophila from a malfunctioning automobile air conditioner.

Science.gov (United States)

Pinar, Ahmet; Ramirez, Julio A; Schindler, Laura L; Miller, Richard D; Summersgill, James T

2002-03-01

Air conditioner condensates have not been previously associated with cases of Legionnaires' disease. We report the possible transmission of Legionella pneumophila serogroup 1 from a malfunctioning automobile air conditioning system's leaking water onto the floorboard of a car driven for a long distance by the patient. Heteroduplex analysis of polymerase chain reaction products was used to help establish an epidemiologic link between the water specimen and the patient.

Alternative Refrigerant Evaluation for High-Ambient Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

Energy Technology Data Exchange (ETDEWEB)

Abdelaziz, Omar [ORNL; Munk, Jeffrey D [ORNL; Shrestha, Som S [ORNL; Linkous, Randall Lee [ORNL; Goetzler, William [Navigant Consulting Inc.; Guernsey, Matt [Navigant Consulting Inc.; Kassuga, Theo [Navigant Consulting Inc.

2015-08-01

The Oak Ridge National Laboratory (ORNL) High-Ambient Temperature Testing Program for Low-GWP Refrigerants aims to develop an understanding of the performance of low-Global Warming Potential (low-GWP) alternatives to Hydrochlorofluorocarbon (HCFC) and Hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high ambient temperature conditions. This interim working paper describes the parties involved, the alternative refrigerants selection process, the test procedures, and the preliminary results.

Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

Energy Technology Data Exchange (ETDEWEB)

Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Kassuga, Theo [Navigant Consulting Inc., Burlington, MA (United States)

2015-10-01

The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for low– global warming potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerant selection process, the test procedures, and the final results.

Micromorphology of pelletized soil conditioners

Science.gov (United States)

Hirsch, Florian; Dietrich, Nils; Knoop, Christine; Raab, Thomas

2017-04-01

Soil conditioners produced by anaerobic digestion and subsequent composting of organic household waste, bear the potential to improve unproductive farmland together with a reduced input risk of unwanted pollutants into the soils. Within the VeNGA project (http://www.biogas-network.de/venga), soil conditioners from anaerobically digested organic household waste are tested for their potential to increase plant growth in glasshouse and field experiments. Because the production techniques of these soil conditioners may influence their physical and chemical behaviour in the soil, two different techniques for pelletizing the soil conditioners where applied. We present findings from a pot experiment with cereal that has been sampled after two months for micromorphological analyses. We visualize the decomposition and the physical behaviour of the soil conditioners. Pellets produced in an agglomeration mixer result in dense balls, that are only slightly decomposed after the trial. But the soil conditioners created under pressure in a screw extruder are rich in voids and have the potential of retaining more soil water.

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

International Nuclear Information System (INIS)

Noh, Kwang-Chul; Jang, Jae-Soo; Oh, Myung-Do

2007-01-01

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 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 3 /h, the average CO 2 concentration can be satisfied with the standard limits of Japanese in our case studies. (author)

10 CFR Appendix M to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps

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... Consumption of Central Air Conditioners and Heat Pumps 1. DEFINITIONS 2. TESTING CONDITIONS 2.1Test room... more common ducts within each test room that contains multiple indoor coils. At the plane where each...

Experimental investigation of HFC407C/HC290/HC600a mixture in a window air conditioner

International Nuclear Information System (INIS)

Jabaraj, D.B.; Avinash, P.; Lal, D. Mohan; Renganarayan, S.

2006-01-01

HCFC22, one of the widely used refrigerants in window air conditioners must be phased out soon as per the Montreal protocol. Presently, HFC407C is considered as a potential drop in substitute for HCFC22, but retrofitting HCFC22 systems with HFC407C with polyol ester oil (POE) is a major issue as HFC407C is immiscible with mineral oil. The miscibility issue of HFC407C with mineral oil was overcome with the addition of a HC blend to it. The above technoeconomic feasibility issues to retrofit the existing HCFC22 systems with an ozone friendly refrigerant and retain the energy efficiency of the system are challenges in the air conditioning sector. In this present work, an experimental analysis has been conducted in a window air conditioner retrofitted with eco-friendly refrigerant mixtures of HFC407C/HC290/HC600a without changing the mineral oil. Its performance, as well as energy consumption, was compared with the conventional one. It is observed that the mixtures demand lengthening of the condenser in order to maintain the discharge pressure within acceptable limits. This also resulted in better heat transfer at the condenser. Therefore, in this study, the condenser tube length was increased by 19% to suit the mixtures as compared to HCFC22. Compared to HCFC22, the refrigeration capacity of the new mixture was 9.54-12.76% higher than that of HCFC22, while the actual COP was found to be 11.91-13.24% higher than that of HCFC22. The overall performance has proved that the HFC407C/HC blend refrigerant mixture could be an eco-friendly substitute to phase out HCFC22

Draft Genome Sequence of a Novel Chitinophaga sp. Strain, MD30, Isolated from a Biofilm in an Air Conditioner Condensate Pipe.

Science.gov (United States)

Wan, Xuehua; Darris, Maxwell; Hou, Shaobin; Donachie, Stuart P

2017-10-19

Most of the 24 known Chitinophaga species were originally isolated from soils. We report the draft genome sequence of a putatively novel Chitinophaga sp. from a biofilm in an air conditioner condensate pipe. The genome comprises 7,661,303 bp in one scaffold, 5,694 predicted protein-coding sequences, and a G+C content of 47.6%. Copyright © 2017 Wan et al.

Effect of heat recovery water heater system on the performance of residential split air conditioner using hydrocarbon refrigerant (HCR22)

Science.gov (United States)

Aziz, A.; Thalal; Amri, I.; Herisiswanto; Mainil, A. K.

2017-09-01

This This paper presents the performance of residential split air conditioner (RSAC) using hydrocarbon refrigerant (HCR22) as the effect on the use of heat recovery water heater system (HRWHS). In this study, RSAC was modified with addition of dummy condenser (trombone coil type) as heat recovery water heater system (HRWHS). This HRWHS is installed between a compressor and a condenser by absorbing a part of condenser waste heat. The results show that RSAC with HRWHS is adequate to generate hot water with the temperature range about 46.58˚C - 48.81˚C when compared to without HRWHS and the use of dummy condenser does not give significant effect to the split air conditioner performance. When the use of HRWHS, the refrigerant charge has increase about 19.05%, the compressor power consumption has slightly increase about 1.42% where cooling capacity almost the same with slightly different about 0.39%. The condenser heat rejection is lower about 2.68% and the COP has slightly increased about 1.05% when compared to without HRWHS. The use of HRWHS provide free hot water, it means there is energy saving for heating water without negative impact to the system performance of RSAC.

Solar-Powered, Liquid-Desiccant Air Conditioner for Low-Electricity Humidity Control

Science.gov (United States)

2012-11-01

reading Current transformer Regen and conditioner Continental Controls CTS-0750-30 1 % of reading Pyranometer Horizontal Campbell...indoor comfort conditions. A pyranometer was used to quantify the efficiency of the solar collector array. Two measurements of electric energy were

Locating room air-conditioners at floor level for energy saving in residential buildings

Energy Technology Data Exchange (ETDEWEB)

Gao, C.F.; Lee, Hua; Chen, W.L. [Department of Building Services Engineering, Hong Kong Polytechnic University, Hung Hom (China)

2009-08-15

Residential air-conditioning becomes a common feature in our daily life. They are typically installed at high level known as ceiling-based system (CAC). With the increasing use of floor-based air-conditioning system in commercial buildings for energy saving, it is proposed in this study to locate a top discharge/front return air-conditioner at floor level to resemble a floor-based air-conditioning system (FAC) to curb energy use in residential buildings. Given the concerns about draught discomfort and thermal stratification associated with floor-based air-conditioning systems, the objective of this study is to evaluate the air distribution performance and to quantify the possible energy benefits. Bedroom was chosen as a sensitive case for detailed air distribution performance evaluation. Experimental study, CFD simulations and energy simulations were conducted in achieving the specific objectives. CAC and FAC were installed in a bedroom-like environmental chamber for experimental study at different indoor and outdoor conditions. The air velocities and temperatures at various positions and levels inside the chamber were measured to determine the air distribution performance indices (ADPI) and airflow draft risk (DR). The cooling output, power consumption and coefficient of performance (COP) of the two units were measured and calculated for comparison. The experimental results show that ADPI of CAC and FAC are 92.3% and 84.6%, respectively. COP of FAC is 8.11% higher than CAC, and the corresponding DR are comparable. The experimental results were used to validate the CFD simulations as well as providing actual performance data for predicting the energy use of applying CAC and FAC in a case-study building. CFD simulations and draught assessment confirmed that there is no potential draught discomfort and thermal stratification associated with the use of FAC. Energy simulations predicted that the associated energy saving is 6.9%. Wider use of FAC in residential

Ventilation influence upon indoor air radon level

International Nuclear Information System (INIS)

Tian Deyuan

1995-01-01

Levels of indoor radon in air are studied by a continuous electrostatic radon monitor under normal living conditions to evaluate the influence of air conditioned ventilation on indoor air radon level. Results show that the indoor air radon concentrations are not much more than those without household conditioner living condition, although using household conditioner requires a sealed room which should lead to a higher radon level. Turning on air conditioner helps lower indoor radon level. Therefore, the total indoor air Rn levels are normal > ventilation > exhaust or in-draft > exhaust plus in-draft

Greenhouse gas emissions for refrigerant choices in room air conditioner units.

Science.gov (United States)

Galka, Michael D; Lownsbury, James M; Blowers, Paul

2012-12-04

In this work, potential replacement refrigerants for window-mounted room air conditioners (RACs) in the U.S. have been evaluated using a greenhouse gas (GHG) emissions analysis. CO(2)-equivalent emissions for several hydrofluoroethers (HFEs) and other potential replacements were compared to the most widely used refrigerants today. Included in this comparison are pure refrigerants that make up a number of hydrofluorocarbon (HFC) mixtures, pure hydrocarbons, and historically used refrigerants such as propane and ammonia. GHG emissions from direct and indirect sources were considered in this thermodynamic analysis. Propylene, dimethyl ether, ammonia, R-152a, propane, and HFE-152a all performed effectively in a 1 ton window unit and produced slightly lower emissions than the currently used R-22 and R-134a. The results suggest that regulation of HFCs in this application would have some effect on reducing emissions since end-of-life emissions remain at 55% of total refrigerant charge despite EPA regulations that mandate 80% recovery. Even so, offsite emissions due to energy generation dominate over direct GHG emissions and all the refrigerants perform similarly in totals of indirect GHG emissions.

Bifurcated SEN with Fluid Flow Conditioners

Directory of Open Access Journals (Sweden)

F. Rivera-Perez

2014-01-01

Full Text Available This work evaluates the performance of a novel design for a bifurcated submerged entry nozzle (SEN used for the continuous casting of steel slabs. The proposed design incorporates fluid flow conditioners attached on SEN external wall. The fluid flow conditioners impose a pseudosymmetric pattern in the upper zone of the mold by inhibiting the fluid exchange between the zones created by conditioners. The performance of the SEN with fluid flow conditioners is analyzed through numerical simulations using the CFD technique. Numerical results were validated by means of physical simulations conducted on a scaled cold water model. Numerical and physical simulations confirmed that the performance of the proposed SEN is superior to a traditional one. Fluid flow conditioners reduce the liquid free surface fluctuations and minimize the occurrence of vortexes at the free surface.

Using Field-Metered Data to Quantify Annual Energy Use of Portable Air Conditioners

Energy Technology Data Exchange (ETDEWEB)

Burke, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Willem, Henry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Ni, Chun Chun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Stratton, Hannah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Chen, Yuting [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Ganeshalingam, Mohan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Iyer, Maithili [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Price, Sarah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Dunham, Camilla [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division

2014-12-12

As many regions of the United States experience rising temperatures, consumers have come to rely increasingly on cooling appliances (including portable air conditioners) to provide a comfortable indoor temperature. Home occupants sometimes use a portable air conditioner (PAC) to maintain a desired indoor temperature in a single room or enclosed space. Although PACs in residential use are few compared to centrally installed and room air conditioning (AC) units, the past few years have witnessed an increase of PACs use throughout the United States. There is, however, little information and few research projects focused on the energy consumption and performance of PACs, particularly studies that collect information from field applications of PACs. The operation and energy consumption of PACs may differ among geographic locations and households, because of variations in cooling load, frequency, duration of use, and other user-selected settings. In addition, the performance of building envelope (thermal mass and air leakage) as well as inter-zonal mixing within the building would substantially influence the ability to control and maintain desirable indoor thermal conditions. Lawrence Berkeley National Laboratory (LBNL) conducted an initial field-metering study aimed at increasing the knowledge and data related to PAC operation and energy consumption in the United States. LBNL performed its field-metering study from mid-April to late October 2014. The study, which monitored 19 sites in the Northeastern United States (4 in upstate New York and 15 near Philadelphia), collected real-time data on PAC energy consumption along with information regarding housing characteristics, consumer behavior, and environmental conditions that were expected to affect PAC performance. Given the limited number of test sites, this study was not intended to be statistically representative of PAC users in the United States but rather to understand the system response to the cooling demand and to

Space shuttle aps propellant thermal conditioner study

Science.gov (United States)

Fulton, D. L.

1973-01-01

An analytical and experimental effort was completed to evaluate a baffle type thermal conditioner for superheating O2 and H2 at supercritical pressures. The thermal conditioner consisted of a heat exchanger and an integral reactor (gas generator) operating on O2/H2 propellants. Primary emphasis was placed on the hydrogen conditioner with some effort on the oxygen conditioner and a study completed of alternate concepts for use in conditioning oxygen. A hydrogen conditioner was hot fire tested under a range of conditions to establish ignition, heat exchange and response parameters. A parallel technology task was completed to further evaluate the integral reactor and heat exchanger with the side mounted electrical spark igniter.

Proposal of digital interface for the system of the air conditioner's remote control: analysis of the system of feedback.

Science.gov (United States)

da Silva de Queiroz Pierre, Raisa; Kawada, Tarô Arthur Tavares; Fontes, André Guimarães

2012-01-01

Develop a proposal of digital interface for the system of the remote control, that functions as support system during the manipulation of air conditioner adjusted for the users in general, from ergonomic parameters, objectifying the reduction of the problems faced for the user and improving the process. 20 people with questionnaire with both qualitative and quantitative level. Linear Method consists of a sequence of steps in which the input of one of them depends on the output from the previous one, although they are independent. The process of feedback, when necessary, must occur within each step separately.

Double utilization of the roof. 'Solar green roofs' - the advantages are in the combination; Das Dach zweifach nutzen. 'SolarGruenDaecher - die Vorteile liegen in der Kombination

Energy Technology Data Exchange (ETDEWEB)

Mann, Gunter

2013-06-01

Air conditioners cooling with solar energy have already existed for a long time. The core principles are adsorption chillers, absorption chillers and DEC chillers. However, these chillers are relatively expensive compared to air conditioners in compression technology and therefore not often used in the mass market. Since January 2013, Sedna Aire Europe GmbH (Dortmund, Federal Republic of Germany) offers solar-assisted air-conditioners that cost the same as commercial non-solar comparable equipment and enable significant cost savings from the first year. In addition, these air-conditioners are designed as heat pumps, which can be heated.

Shuttle APS propellant thermal conditioner study

Science.gov (United States)

Pearson, W. E.

1971-01-01

A study program was performed to allow selection of thermal conditioner assemblies for superheating O2 and H2 at supercritical pressures. The application was the auxiliary propulsion system (APS) for the space shuttle vehicle. The O2/H2 APS propellant feed system included propellant conditioners, of which the thermal conditioner assemblies were a part. Cryogens, pumped to pressures above critical, were directed to the thermal conditioner assembly included: (1) a gas generator assembly with ignition system and bipropellant valves, which burned superheated O2 and H2 at rich conditions; (2) a heat exchanger assembly for thermal conditioning of the cryogenic propellant; and (3) a dump nozzle for heat exchanger exhaust.

Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner

Energy Technology Data Exchange (ETDEWEB)

Kim, Chul Jin; Choi, Hyo Hyun [Department of Mechanical Engineering, Sejong University, Seoul 143-747 (Korea, Republic of); Sohn, Chae Hoon, E-mail: chsohn@sejong.ac.kr [Department of Mechanical Engineering, Sejong University, Seoul 143-747 (Korea, Republic of)

2011-01-15

Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 deg. C. First, its auto-ignition temperature is measured 365 deg. C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 deg. C to 255 deg. C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor.

Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner

International Nuclear Information System (INIS)

Kim, Chul Jin; Choi, Hyo Hyun; Sohn, Chae Hoon

2011-01-01

Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 deg. C. First, its auto-ignition temperature is measured 365 deg. C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 deg. C to 255 deg. C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor.

A hybrid air conditioner driven by a hybrid solar collector

Science.gov (United States)

Al-Alili, Ali

The objective of this thesis is to search for an efficient way of utilizing solar energy in air conditioning applications. The current solar Air Conditioners (A/C)s suffer from low Coefficient of Performance (COP) and performance degradation in hot and humid climates. By investigating the possible ways of utilizing solar energy in air conditioning applications, the bottlenecks in these approaches were identified. That resulted in proposing a novel system whose subsystem synergy led to a COP higher than unity. The proposed system was found to maintain indoor comfort at a higher COP compared to the most common solar A/Cs, especially under very hot and humid climate conditions. The novelty of the proposed A/C is to use a concentrating photovoltaic/thermal collector, which outputs thermal and electrical energy simultaneously, to drive a hybrid A/C. The performance of the hybrid A/C, which consists of a desiccant wheel, an enthalpy wheel, and a vapor compression cycle (VCC), was investigated experimentally. This work also explored the use of a new type of desiccant material, which can be regenerated with a low temperature heat source. The experimental results showed that the hybrid A/C is more effective than the standalone VCC in maintaining the indoor conditions within the comfort zone. Using the experimental data, the COP of the hybrid A/C driven by a hybrid solar collector was found to be at least double that of the current solar A/Cs. The innovative integration of its subsystems allows each subsystem to do what it can do best. That leads to lower energy consumption which helps reduce the peak electrical loads on electric utilities and reduces the consumer operating cost since less energy is purchased during the on peak periods and less solar collector area is needed. In order for the proposed A/C to become a real alternative to conventional systems, its performance and total cost were optimized using the experimentally validated model. The results showed that for an

Smart Sensors Enable Smart Air Conditioning Control

Directory of Open Access Journals (Sweden)

Chin-Chi Cheng

2014-06-01

Full Text Available 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.

Conditioner for a helically transported electron beam

International Nuclear Information System (INIS)

Wang, Changbiao.

1992-05-01

The kinetic theory is developed to investigate a conditioner for a helically transported electron beam. Linear expressions for axial velocity spread are derived. Numerical simulation is used to check the theoretical results and examine nonlinear aspects of the conditioning process. The results show that in the linear regime the action of the beam conditioner on a pulsed beam mainly depends on the phase at which the beam enters the conditioner and depends only slightly on the operating wavelength. In the nonlinear regime, however, the action of the conditioner strongly depends on the operating wavelength and only slightly upon the entrance phase. For a properly chosen operating wavelength, a little less than the electron's relativistic cyclotron wavelength, the conditioner can decrease the axial velocity spread of a pulsed beam down to less than one-third of its initial value

Conditioner for a helically transported electron beam

International Nuclear Information System (INIS)

Wang, C.

1992-05-01

The kinetic theory is developed to investigate a conditioner for a helically imported electron beam. Linear expressions for axial velocity spread are derived. Numerical simulation is used to check the theoretical results and examine nonlinear aspects of the conditioning process. The results show that in the linear regime the action of the beam conditioner on a pulsed beam mainly depends on the phase at which the beam enters the conditioner and depends only slightly on the operating wavelength. In the nonlinear regime, however, the action of the conditioner strongly depends on the operating wavelength and only slightly upon the entrance phase. For a properly chosen operating wavelength, a little less than the electron's relativistic cyclotron wavelength, the conditioner can decrease the axial velocity spread of a pulsed beam down to less than one-third of its initial value

Semi-empiric model of an air cooled cabinet air conditioner for the dynamic analysis of the building and acclimation systems integrated behaviour; Modelo semi-empirico de condicionador de gabinete resfriado a ar para analise dinamica do comportamento integrado de edificacoes e sistemas de climatizacao

Energy Technology Data Exchange (ETDEWEB)

Correa, Jorge E. [Para Univ., Belem (Brazil). Dept. de Engenharia Mecanica]. E-mail: jecorrea@amazon.com.br; Melo, Claudio. E-mail: melo@nrva.ufsc.br; Negrao, Cezar O. R. E-mail: negrao@energia.damec.cefetpr.br

2000-07-01

This work presents a semi-empirical model for a air cooled case air conditioner. This model is to be inserted in the EPS-r program (Environmental System Performance - research version) allowing the dynamic analysis of the integrated behaviour of buildings and acclimation systems using this equipment. Results obtained from simulations under the operation conditions existing in Brazil are analysed.

78 FR 37220 - Proposed Information Collection Request; Comment Request; EPA-ICR No. 1774.05-Mobile Air...

Science.gov (United States)

2013-06-20

.... Regulations promulgated under SNAP require that Motor Vehicle Air Conditioners (MVACs) retrofitted to use a... respondents: 294 (total). Frequency of response: Once per retrofit of a motor vehicle air conditioner. Total... Request; Comment Request; EPA-ICR No. 1774.05--Mobile Air Conditioner Retrofitting Program AGENCY...

Experimental performance of R432A to replace R22 in residential air-conditioners and heat pumps

International Nuclear Information System (INIS)

Park, Ki-Jung; Shim, Yun-Bo; Jung, Dongsoo

2009-01-01

In this study, thermodynamic performance of R432A and HCFC22 is measured in a heat pump bench tester under both air-conditioning and heat pumping conditions. R432A has no ozone depletion potential and very low greenhouse warming potential of less than 5. R432A also offers a similar vapor pressure to HCFC22 for 'drop-in' replacement. Test results showed that the coefficient of performance and capacity of R432A are 8.5-8.7% and 1.9-6.4% higher than those of HCFC22 for both conditions. The compressor discharge temperature of R432A is 14.1-17.3 deg. C lower than that of HCFC22 while the amount of charge for R432A is 50% lower than that of HCFC22 due to its low density. Overall, R432A is a good long term 'drop-in' environmentally friendly alternative to replace HCFC22 in residential air-conditioners and heat pumps due to its excellent thermodynamic and environmental properties

Effects of a non-rinse conditioner on the enamel of primary teeth

Directory of Open Access Journals (Sweden)

Fava Marcelo

2003-01-01

Full Text Available The aim of this in vitro study was to evaluate by scanning electron microscopy the morphological aspects of the enamel of primary teeth after etching with 36% phosphoric acid or a non-rinse conditioner. Ten naturally exfoliated anterior primary teeth were selected. The samples were subjected to prophylaxis with pumice paste and water using a low-speed hand piece. Etching was done on the buccal surface. Specimens were divided into 2 groups: G1 (n=10: etching with 36% phosphoric acid gel - Conditioner 36 (Dentsply for 20 s, followed by water rinse for 15 s; G2 (n=10: etching with NRC - Non Rinse Conditioner (Dentsply for 20 s, followed by air drying for 15 s. The samples were dehydrated, mounted on metal stubs, coated with gold and observed with Jeol JSM-6100 scanning electron microscope. Electron-micrographic analysis showed that both etching agents were effective for etching the enamel of primary teeth causing the formation of microporosities on the enamel surface, although the etching pattern was more effective with the use of 36% phosphoric acid gel.

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.

Performance computation of window air conditioner with very low GWP near azeotropic refrigerant mixtures as a drop in Substitutes to R22

Directory of Open Access Journals (Sweden)

Vali Shaik Sharmas

2018-01-01

Full Text Available The principal objective of the present study is to compute the thermodynamic performance of window air conditioner based on standard vapour compression refrigeration cycle using R22, R407C and nineteen refrigerant mixtures. In this work nineteen R290/R1270 blends at different compositions are developed. A MATLAB code is developed to compute the thermodynamic performance parameters of all the studied refrigerants at condensing and evaporating temperatures of 54.4°C and 7.2°C respectively. The performance parameters are cooling effect, compressor work, COP, compressor discharge temperature, power per ton of refrigeration and volumetric cooling capacity respectively. Analytical results revealed that COP of new binary mixture R290/R1270 (90/10 by mass % is 2.82% higher among R22, R407C and nineteen studied refrigerants. Energy required by the compressor per ton of refrigeration for R290/R1270 (90/10 by mass % is 2.73% lower among R22, R407C and nineteen studied fluids. The discharge temperature of the compressor for all the nineteen investigated blends are reduced by 6.0-8.9oC compared to R22. Overall thermodynamic performance of window air conditioner with R290/R1270 (90/10 by mass % is better than R22 with significant savings in energy consumption and hence it is an energy efficient ecofriendly refrigerant mixture as a drop in substitute to R22.

Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner.

Science.gov (United States)

Kim, Chul Jin; Choi, Hyo Hyun; Sohn, Chae Hoon

2011-01-15

Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 °C. First, its auto-ignition temperature is measured 365 °C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 °C to 255 °C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor. Copyright © 2010 Elsevier B.V. All rights reserved.

Power conditioner without isolation transformer; Toransuresu power conditioner no shohin kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Okado, C; Itami, T; Kimoto, K [Toshiba Corp., Tokyo (Japan)

1996-10-27

A light-weight downsized and high efficiency transformer-less type 4 kW power conditioner (inverter) has been developed. This power conditioner insures the system interconnection protection by monitoring the voltage of two single-phase three-line circuits. The power conditioner has weight of 17.5 kg and efficiency of 94%. Potential fluctuation of photovoltaic cells due to the switching of power devices at the inverter was reduced. Output capacity was reduced in the low input voltage range. Outflow of DC component was prevented in high accuracy by usually correcting the zero point drift of detector, and by using the current detector with excellent linearity. To detect the DC ground fault, and to trip the output side breaker locating at the ground fault current pass, a zero phase converter detection circuit has been developed, by which the DC component can be detected at the DC input side. As a result of performance verification, the efficiency, power factor, EMI level, protection of outflow of DC component, protection of ground fault, protection of single operation detection, and noise level were satisfied. This system is prospective for the diffusion of photovoltaic power generation in the future. 3 refs., 8 figs., 1 tab.

Technical and Economic Aspects of Designing an Efficient Room Air-Conditioner Program in India

Energy Technology Data Exchange (ETDEWEB)

Abhyankar, Nikit [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Div.; Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Div.; Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Div.; Park, Won Young [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Div.

2017-09-05

Several studies have projected a massive increase in the demand for air conditioners (ACs) over the next two decades in India. By 2030, room ACs could add 140 GW to the peak load, equivalent to over 30% of the total projected peak load. Therefore, there is significant interest among policymakers, regulators, and utilities in managing room AC demand by enhancing energy efficiency. Building on the historical success of the Indian Bureau of Energy Efficiency’s star-labeling program, Energy Efficiency Services Limited recently announced a program to accelerate the sale of efficient room ACs using bulk procurement, similar to their successful UJALA light-emitting diode (LED) bulk procurement program. This report discusses some of the key considerations in designing a bulk procurement or financial incentive program for enhancing room AC efficiency in India. We draw upon our previous research to demonstrate the overall technical potential and price impact of room AC efficiency improvement and its technical feasibility in India. We also discuss the importance of using low global warming potential (GWP) refrigerants and smart AC equipment that is demand response (DR) ready.

Lemongrass-Incorporated Tissue Conditioner Against Candida albicans Culture

Science.gov (United States)

Amornvit, Pokpong; Srithavaj, Theerathavaj

2014-01-01

Background: Tissue conditioner is applied popularly with dental prosthesis during wound healing process but it becomes a reservoir of oral microbiota, especially Candida species after long-term usage. Several antifungal drugs have been mixed with this material to control fungal level. In this study, lemongrass essential oil was added into COE-COMFORT tissue conditioner before being determined for anti-Candida efficacy. Materials and Methods: Lemongrass (Cymbopogon citratus) essential oil was primarily determined for antifungal activity against C. albicans American type culture collection (ATCC) 10231 and MIC (minimum inhibitory concentration) value by agar disk diffusion and broth microdilution methods, respectively. COE-COMFORT tissue conditioner was prepared as recommended by the manufacturer after a fixed volume of the oil at its MIC or higher concentrations were mixed thoroughly in its liquid part. Antifungal efficacy of the tissue conditioner with/without herb was finally analyzed. Results: Lemongrass essential oil displayed potent antifungal activity against C. albicans ATCC 10231and its MIC value was 0.06% (v/v). Dissimilarly, the tissue conditioner containing the oil at MIC level did not cease the growth of the tested fungus. Both reference and clinical isolates of C. albicans were completely inhibited after exposed to the tissue conditioner containing at least 0.25% (v/v) of the oil (approximately 4-time MIC). The tissue conditioner without herb or with nystatin was employed as negative or positive control, respectively. Conclusion: COE-COMFORT tissue conditioner supplemented with lemongrass essential oil obviously demonstrated another desirable property as in vitro anti-Candida efficacy to minimize the risk of getting Candidal infection. PMID:25177638

Roseomonas aerofrigidensis sp. nov., isolated from an air conditioner.

Science.gov (United States)

Hyeon, Jong Woo; Jeon, Che Ok

2017-10-01

A Gram-stain-negative, strictly aerobic bacterium, designated HC1 T , was isolated from an air conditioner in South Korea. Cells were orange, non-motile cocci with oxidase- and catalase-positive activities and did not contain bacteriochlorophyll a. Growth of strain HC1 T was observed at 10-45 °C (optimum, 30 °C), pH 4.5-9.5 (optimum, pH 7.0) and 0-3 % (w/v) NaCl (optimum, 0 %). Strain HC1 T contained summed feature 8 (comprising C18 : 1ω7c/C18 : 1ω6c), C16 : 0 and cyclo-C19 : 0ω8c as the major fatty acids and ubiquinone-10 as the sole isoprenoid quinone. Phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unknown aminolipid were detected as the major polar lipids. The major carotenoid was hydroxyspirilloxanthin. The G+C content of the genomic DNA was 70.1 mol%. Phylogenetic analysis, based on 16S rRNA gene sequences, showed that strain HC1 T formed a phylogenetic lineage within the genus Roseomonas. Strain HC1 T was most closely related to the type strains of Roseomonas oryzae, Roseomonas rubra, Roseomonas aestuarii and Roseomonas rhizosphaerae with 98.1, 97.9, 97.6 and 96.8 % 16S rRNA gene sequence similarities, respectively, but the DNA-DNA relatedness values between strain HC1 T and closely related type strains were less than 70 %. Based on phenotypic, chemotaxonomic and molecular properties, strain HC1 T represents a novel species of the genus Roseomonas, for which the name Roseomonas aerofrigidensis sp. nov. is proposed. The type strain is HC1 T (=KACC 19097 T =JCM 31878 T ).

Performance evaluation of a solar energy assisted hybrid desiccant air conditioner integrated with HDH desalination system

International Nuclear Information System (INIS)

Kabeel, A.E.; Abdelgaied, Mohamed; Zakaria, Yehya

2017-01-01

Highlights: • The performance of a solar hybrid air conditioner integrated with HDH desalination system is numerically investigated. • For increase the regeneration air from 70 to 130 m 3 /h, the distillate water productivity increases from 2.988 to 4.78 L/h. • For increase the regeneration air from 70 to 130 m 3 /h, COP overall daily decreases from 4.66 to 3.386. • For increases the regeneration air temperature from 75 to 95 °C, the distillate water increases from 3.1752 to 5.011 L/h. • For increases the regeneration air temperature from 75 to 95 °C, COP overall daily decreases from 4.392 to 3.636. - Abstract: In this study, the performances of a solar energy assisted hybrid desiccant air conditioning system integrated with humidification–dehumidification (HDH) desalination system are numerically investigated. The aim of this study is to benefit from the temperature rise of the regeneration air outside of the desiccant conditioning system as well as the water vapor content in this regeneration air by feeding it to the humidification-dehumidification water desalination unit to produce distillate water. The distillate water productivity, human thermal comfort issues, and energy saving represent the main objective of the present numerical study. The simulated results developed for subsystems are validated with the published experimental results. The effects of regeneration air temperature and flow rate on supply cooled air temperature, distillate water productivity, the cooling coefficient of performance and overall daily coefficient of performance of the proposed system are investigated. The results show that (i) the distillate water productivity increases from 3.175 to 5.011 L/h and overall daily coefficient of performance decreases from 4.392 to 3.636 with increasing the regeneration air temperature from 75 to 95 as (ii) the increase in the regeneration air flow rate from 70 to 130 m 3 /h, increases the distillate water productivity from 2.988 to 4

Simulation of Evacuated Tube Collector and Storage of Hybrid Air-conditioning System

Directory of Open Access Journals (Sweden)

Mustafa Ahmed Abdulhussain

2018-02-01

Full Text Available The CFD transient simulation of superheating the refrigerant R410 through the heat exchange with the evacuated tube water heating system of the hybrid split air conditioner that is subjected to solar radiation of constant intensity with the contribution of fan accelerated air is performed by the ANSYS-CFX code. The comparison with experimental work showed a minimum percentage error 8% of the predicted refrigerant evaporative heat transfer with storage tank horizontal tubing. In addition, the results denoted high absorption rate for the evacuated tubes, reducing highly reversed heat transmission for the circulated water. 

Performance of R433A for replacing HCFC22 used in residential air-conditioners and heat pumps

International Nuclear Information System (INIS)

Park, Ki-Jung; Shim, Yun-Bo; Jung, Dongsoo

2008-01-01

In this study, thermodynamic performance of R433A and HCFC22 is measured in a heat pump bench tester under air-conditioning and heat pumping conditions. R433A has no ozone depletion potential and very low greenhouse warming potential of less than 5. R433A also offers a similar vapor pressure to HCFC22 for possible 'drop-in' replacement. Test results showed that the coefficient of performance of R433A is 4.9-7.6% higher than that of HCFC22 while the capacity of R433A is 1.0-5.5% lower than that of HCFC22 for both conditions. The compressor discharge temperature of R433A is 22.6-27.9 deg. C lower than that of HCFC22 while the amount of charge for R433A is 57.0-57.7% lower than that of HCFC22 due to its low density. Overall, R433A is a good long term environmentally friendly alternative to replace HCFC22 in residential air-conditioners and heat pumps due to its excellent thermodynamic and environmental properties with minor adjustments

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

Modelagem de um condicionador de ar de alta precisão para uso em processamento agrícola Modeling of a high precision air conditioner for use in agricultural processing

Directory of Open Access Journals (Sweden)

Mauri Fortes

2006-08-01

Full Text Available Apresenta-se neste trabalho, estudo detalhado sobre a modelagem de um condicionador de ar com controle acurado de temperatura e umidade relativa. Desenvolveu-se um programa de computador que permite predizer o comportamento do sistema sob diferentes condições psicrométricas e de vazão do ar de entrada. O modelo global físico-matemático inclui equações de balanço de massa e de energia para três diferentes volumes de controle que compõem o condicionador. Modelaram-se os processos de mistura, evaporação (ou condensação simultânea de uma superfície d'água e de uma gota e o aquecimento de corrente de ar, separadamente. Propõem-se expressões semi-empíricas simples para os coeficientes de transferência de calor e massa inerentes ao processo de evaporação sobre uma superfície d'água e um modelo simplificado para o sistema de spray. Construiu-se um condicionador de ar no qual foram feitos testes experimentais para o ajuste das constantes que aparecem nas expressões para os coeficientes de transferência. Os dados obtidos validaram o modelo global, com precisão aceitável para projetos de engenharia.In this work, a detailed procedure for the analysis of an accurately controlled air conditioner is presented. A computer program, that allows predicting the behavior of the system under different psychrometric conditions and different input air mass flow rates, was developed. The global physical-mathematical model includes mass and energy conservation equations for three different control volumes that compose the conditioner. Thus, the processes of mixture of air, simultaneous evaporation (or condensation from a water surface and from a drop, and the air-stream heating are modeled separately. Simple semi-empiric expressions for heat and mass coefficients inherent to the evaporation process on a water surface are proposed as well a simplified model for the spray system. Experimental tests made on an air-conditioner allowed to obtain

Absorption generator for solar-powered air-conditioner

Science.gov (United States)

Lowen, D. J.; Murray, J. G.

1977-01-01

Device passes solar-heated water through coils. Hot lithium Bromide/Water solution leaves through central stand-pipe, and water vapor leaves through refrigerant outlet at top. Matching generation temperature to collector efficiency helps cut costs.

Residential Pre-Cooling: Mechanical Cooling and Air-Side Economizers:

OpenAIRE

Turner, William J.N; Walker, Iain S.; Roux, Jordan

2012-01-01

This study used an advanced airflow, energy and humidity modeling tool to evaluate residential air-side economizers and mechanical pre-cooling strategies using the air conditioner, in all US DOE Climate Zones for a typical new home with ASHRAE Standard 62.2 compliant ventilation. A residential air-side economizer is a large supply fan used for night ventilation. Mechanical pre-cooling used the building air conditioner operating at lower than usual set before the peak demand period. The simula...

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bracket adhesive resin and tooth conditioner. 872... SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a device...

Performance improvement of air-cooled refrigeration system by using evaporatively cooled air condenser

Energy Technology Data Exchange (ETDEWEB)

Hajidavalloo, E.; Eghtedari, H. [Mechanical Engineering Department, Shahid Chamran University, Golestan St., Ahvaz (Iran)

2010-08-15

Increasing the coefficient of performance of air conditioner with air-cooled condenser is a challenging problem especially in area with very hot weather conditions. Application of evaporatively cooled air condenser instead of air-cooled condenser is proposed in this paper as an efficient way to solve the problem. An evaporative cooler was built and coupled to the existing air-cooled condenser of a split-air-conditioner in order to measure its effect on the cycle performance under various ambient air temperatures up to 49 C. Experimental results show that application of evaporatively cooled air condenser has significant effect on the performance improvement of the cycle and the rate of improvement is increased as ambient air temperature increases. It is also found that by using evaporatively cooled air condenser in hot weather conditions, the power consumption can be reduced up to 20% and the coefficient of performance can be improved around 50%. More improvements can be expected if a more efficient evaporative cooler is used. (author)

Air-cooled LiBr-water absorption chillers for solar air conditioning in extremely hot weathers

International Nuclear Information System (INIS)

Kim, D.S.; Infante Ferreira, C.A.

2009-01-01

A low temperature-driven absorption cycle is theoretically investigated for the development of an air-cooled LiBr-water absorption chiller to be combined with low-cost flat solar collectors for solar air conditioning in hot and dry regions. The cycle works with dilute LiBr-water solutions so that risk of LiBr crystallization is less than for commercially available water-cooled LiBr-water absorption chillers even in extremely hot ambient conditions. Two-phase heat exchangers in the system were modelled taking account of the heat and mass transfer resistances in falling film flows by applying the film theory in thermal and concentration boundary layers. Both directly and indirectly air-cooled chillers were modelled by properly combining component models and boundary conditions in a matrix system and solved with an algebraic equation solver. Simulation results predict that the chillers would deliver chilled water around 7.0 deg. C with a COP of 0.37 from 90 deg. C hot water under 35 deg. C ambient condition. At 50 deg. C ambient temperature, the chillers retained about 36% of their cooling power at 35 deg. C ambient. Compared with the directly air-cooled chiller, the indirectly air-cooled chiller presented a cooling power performance reduction of about 30%

Monitoring and analysis of an absorption air-conditioning system

Energy Technology Data Exchange (ETDEWEB)

Perez de Vinaspre, M.; Bourouis, M.; Coronas, A. [Centro de Innovacion Tecnologica en Revalorizacion Energetica y Refrigeracion, Tarragona (Spain); Garcia, A.; Soto, V.; Pinazo, J.M. [E.T.S. Ingenieros Industriales, Valencia (Spain)

2004-09-01

In the last few years, high-energy consumption due to air-conditioning has led to a growing interest in the efficient use of energy in buildings. Although simulation programs have always been the main tools for analyzing energy in buildings, the reliability of their results is often compromised by a lack of certainty to reflect real conditions. The aim of this work is to monitorize and analyze the thermal behavior of an absorption-based air-conditioning installation of a university building in Tarragona, Spain. The existing monitoring system of the installation has been improved by implementing additional sensors and flow meters. The data has been stored during summer 2002 and used to assess the energy balance of the air-conditioning installation and the operational regime of the absorption chiller. [Author].

Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building.

Science.gov (United States)

Ni, Hong-Gang; Cao, Shan-Ping; Chang, Wen-Jing; Zeng, Hui

2011-07-01

This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM(2.5) (Particulate Matter up to 2.5 μm in size) bounded Σ(15)PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM(10) (Particulate Matter up to 10 μm in size) bounded Σ(15)PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ(15)PBDEs via dust inhalation and ingestion for adults reached ∼ 141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. Copyright © 2010 Elsevier Ltd. All rights reserved.

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.

Antifungal Effect of a Dental Tissue Conditioner Containing Nystatin-Loaded Alginate Microparticles.

Science.gov (United States)

Kim, Hyun-Jin; Son, Jun Sik; Kwon, Tae-Yub

2018-02-01

In this in vitro study, nystatin-alginate microparticles were successfully fabricated to control the release of nystatin from a commercial dental tissue conditioner. These nystatin-alginate microparticles were spherical and had a slightly rough surface. The microparticles incorporated into the tissue conditioner were distributed homogeneously throughout the tissue conditioner matrix. The incorporation of the microparticles did not deteriorate the mechanical properties of the original material. The agar diffusion test results showed that the tissue conditioner containing the microparticles had a good antifungal effect against Candida albicans. The nystatin-alginate microparticles efficiently controlled the release of nystatin from the tissue conditioner matrix over the experimental period of 14 days. Moreover, the nystatin-alginate microparticles incorporated in the tissue conditioner showed effective antifungal function even at lower concentrations of nystatin. The current study suggests that the tissue conditioner containing the nystatin-alginate microparticle carrier system has potential as an effective antifungal material.

Formulation of humic-based soil conditioners

Science.gov (United States)

Amanova, M. A.; Mamytova, G. A.; Mamytova, B. A.; Kydralieva, K. A.; Jorobekova, Sh. J.

2009-04-01

The goal of the study is to prepare soil conditioners (SC) able to carry out the following functions: (i) the chemical conditioning of soil mainly comprising the adjustment of pH, (ii) the balancing of inorganic nutrients, (iii) the physical conditioning of soil mainly comprising the improvement of water permeability, air permeability and water retention properties, and (iv) improvement of the ecological system concerning of useful microorganisms activity in the soil. The SC was made of a mixture of inorganic ingredients, a chemical composition and physical and chemical properties of which promoted improvement of physical characteristic of soil and enrichment by its mineral nutritious elements. In addition to aforesaid ingredients, this soil conditioner contains agronomical-valued groups of microorganisms having the function promoting the growth of the crop. As organic component of SC humic acids (HA) was used. HA serve many major functions that result in better soil and plant health. In soil, HA can increase microbial and mycorrhizal activity while enhancing nutrient uptake by plant roots. HA work as a catalyst by stimulating root and plant growth, it may enhance enzymatic activity that in turn accelerates cell division which can lead to increased yields. HA can help to increase crop yields, seed germination, and much more. In short, humic acids helps keep healthy plants health. The first stage goal was to evaluate mineral and organic ingredients for formulation of SC. Soil conditioners assessed included ash and slag. The use of slags has been largelly used in agriculture as a source of lime and phosphoric acid. The silicic acid of slags reduces Al-acitivity thus, promoting a better assimilation of P-fertilizer by plants. Additionally, silicic acid is also known to improve soil moisture capacity, thus enhancing soil water availability to plants. Physico-chemical characteristics of ash and slag were determined, as a total - about 20 samples. Results include

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.

Swimming pools as heat sinks for air conditioners: Model design and experimental validation for natural thermal behavior of the pool

Energy Technology Data Exchange (ETDEWEB)

Woolley, Jonathan; Harrington, Curtis; Modera, Mark [University of California Davis, Western Cooling Efficiency Center, 1450 Drew Avenue, Suite 100, Davis, CA 95618 (United States)

2011-01-15

Swimming pools as thermal sinks for air conditioners could save approximately 40% on peak cooling power and 30% of overall cooling energy, compared to standard residential air conditioning. Heat dissipation from pools in semi-arid climates with large diurnal temperature shifts is such that pool heating and space cooling may occur concurrently; in which case heat rejected from cooling equipment could directly displace pool heating energy, while also improving space cooling efficiency. The performance of such a system relies on the natural temperature regulation of swimming pools governed by evaporative and convective heat exchange with the air, radiative heat exchange with the sky, and conductive heat exchange with the ground. This paper describes and validates a model that uses meteorological data to accurately predict the hourly temperature of a swimming pool to within 1.1 C maximum error over the period of observation. A thorough review of literature guided our choice of the most appropriate set of equations to describe the natural mass and energy exchange between a swimming pool and the environment. Monitoring of a pool in Davis, CA, was used to confirm the resulting simulations. Comparison of predicted and observed pool temperature for all hours over a 56 day experimental period shows an R-squared relatedness of 0.967. (author)

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

Photovoltaic array: Power conditioner interface characteristics

Science.gov (United States)

Gonzalez, C. C.; Hill, G. M.; Ross, R. G., Jr.

1982-01-01

The electrical output (power, current, and voltage) of flat plate solar arrays changes constantly, due primarily to changes in cell temperature and irradiance level. As a result, array loads such as dc-to-ac power conditioners must be capable of accommodating widely varying input levels while maintaining operation at or near the maximum power point of the array. The array operating characteristics and extreme output limits necessary for the systematic design of array load interfaces under a wide variety of climatic conditions are studied. A number of interface parameters are examined, including optimum operating voltage, voltage energy, maximum power and current limits, and maximum open circuit voltage. The effect of array degradation and I-V curve fill factor or the array power conditioner interface is also discussed. Results are presented as normalized ratios of power conditioner parameters to array parameters, making the results universally applicable to a wide variety of system sizes, sites, and operating modes.

A comparative study on the performance and environmental characteristics of R410A and R22 residential air conditioners

International Nuclear Information System (INIS)

Chen, W.

2008-01-01

R410A is a long-term alternative refrigerant with zero ODP (ozone-depleting-potential) for replacing R22. In this paper, four sets of comparable R410A and R22 split-type residential A/C (air conditioners) were developed and then their performance was comparatively studied using one simulation software. The A/C performance compared in this paper included the cooling capacity, EER (energy efficiency ratio), annual power consumption of A/C and the global warming impact of refrigerants adopted by the A/C. It was concluded that the adoption of R410A could be helpful for A/C to decrease their heat exchanger size or improve their operation efficiency for power saving. Moreover, compared to R22, R410A could in fact help alleviate its overall impact on global warming through significantly reducing the indirect global warming impact caused by operating R410A A/C

Thermodynamic performance analysis of gas-fired air-cooled adiabatic absorption refrigeration systems

International Nuclear Information System (INIS)

Wang, L.; Chen, G.M.; Wang, Q.; Zhong, M.

2007-01-01

In China, the application of small size gas-fired air-cooled absorption refrigeration systems as an alternative for electric compression air conditioning systems has shown broad prospects due to occurrence of electricity peak demand in Chinese big cities and lack of water resources. However, for conventional air-cooled absorption refrigeration systems, it is difficult to enhance the heat and mass transfer process in the falling film absorber, and may cause problems, for example, remarkable increase of pressure, temperature and concentration in the generators, risk of crystallization, acceleration of corrosion, degradation of performance, and so on. This paper presents a gas-fired air-cooled adiabatic absorption refrigeration system using lithium bromide-water solutions as its working fluid, which is designed with a cooling capacity of 16 kW under standard conditions. The system has two new features of waste heat recovery of condensed water from generator and an adiabatic absorber with an air cooler. Performance simulation and characteristic analysis are crucial for the optimal control and reliability of operation in extremely hot climates. A methodology is presented to simulate thermodynamic performance of the system. The influences of outdoor air temperature on operation performances of the system are investigated

Computer Model to Estimate Reliability Engineering for Air Conditioning Systems

International Nuclear Information System (INIS)

Afrah Al-Bossly, A.; El-Berry, A.; El-Berry, A.

2012-01-01

Reliability engineering is used to predict the performance and optimize design and maintenance of air conditioning systems. Air conditioning systems are expose to a number of failures. 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 can be due to a variety of problems with one or more components of an air conditioner or air conditioning system. Forecasting for system failure rates are very important for maintenance. This paper focused on the reliability of the air conditioning systems. Statistical distributions that were commonly applied in reliability settings: the standard (2 parameter) Weibull and Gamma distributions. After distributions parameters had been estimated, reliability estimations and predictions were used for evaluations. To evaluate good operating condition in a building, the reliability of the air conditioning system that supplies conditioned air to the several The company's departments. This air conditioning system is divided into two, 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 40-45 degree F (4-7 degree C). 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, this is due to the Weibull and Gamma distributions 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 was studied. It was found that Weibull method performed for decision making.

The use of helical heat exchanger for heat recovery domestic water-cooled air-conditioners

International Nuclear Information System (INIS)

Yi Xiaowen; Lee, W.L.

2009-01-01

An experimental study on the performance of a domestic water-cooled air-conditioner (WAC) using tube-in-tube helical heat exchanger for preheating of domestic hot water was carried out. The main aims are to identify the comprehensive energy performance (space cooling and hot water preheating) of the WAC and the optimum design of the helical heat exchanger taking into account the variation in tap water flow rate. A split-type WAC was set up for experimental study at different indoor and outdoor conditions. The cooling output, the amount of recovered heat, and the power consumption for different hot water flow rates were measured. The experimental results showed that the cooling coefficient of performance (COP) of the WAC improves with the inclusion of the heat recovery option by a minimum of 12.3%. This can be further improved to 20.6% by an increase in tap water flow rate. Same result was observed for the comprehensive COP of the WAC. The maximum achievable comprehensive COP was 4.92 when the tap water flow rate was set at 7.7 L/min. The overall heat transfer coefficient of the helical heat exchanger under various operating conditions were determined by Wilson plot. A mathematical model relating the over all heat transfer coefficient to the outer pipe diameter was established which provides a convenient way of optimising the design of the helical heat exchanger

76 FR 18105 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Central Air...

Science.gov (United States)

2011-04-01

... the lab-added transformer. Id. Under this proposal, the instrument used to measure the electrical... the low-voltage transformer used when testing coil-only residential central air conditioners and heat... the Low-Voltage Transformer Used When Testing Coil- Only Central Air Conditioners and Heat Pumps and...

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.

Spectra of conditionalization and typicality in the multiverse

Science.gov (United States)

Azhar, Feraz

2016-02-01

An approach to testing theories describing a multiverse, that has gained interest of late, involves comparing theory-generated probability distributions over observables with their experimentally measured values. It is likely that such distributions, were we indeed able to calculate them unambiguously, will assign low probabilities to any such experimental measurements. An alternative to thereby rejecting these theories, is to conditionalize the distributions involved by restricting attention to domains of the multiverse in which we might arise. In order to elicit a crisp prediction, however, one needs to make a further assumption about how typical we are of the chosen domains. In this paper, we investigate interactions between the spectra of available assumptions regarding both conditionalization and typicality, and draw out the effects of these interactions in a concrete setting; namely, on predictions of the total number of species that contribute significantly to dark matter. In particular, for each conditionalization scheme studied, we analyze how correlations between densities of different dark matter species affect the prediction, and explicate the effects of assumptions regarding typicality. We find that the effects of correlations can depend on the conditionalization scheme, and that in each case atypicality can significantly change the prediction. In doing so, we demonstrate the existence of overlaps in the predictions of different "frameworks" consisting of conjunctions of theory, conditionalization scheme and typicality assumption. This conclusion highlights the acute challenges involved in using such tests to identify a preferred framework that aims to describe our observational situation in a multiverse.

Residential solar air conditioning: Energy and exergy analyses of an ammonia–water absorption cooling system

International Nuclear Information System (INIS)

Aman, J.; Ting, D.S.-K.; Henshaw, P.

2014-01-01

Large scale heat-driven absorption cooling systems are available in the marketplace for industrial applications but the concept of a solar driven absorption chiller for air-conditioning applications is relatively new. Absorption chillers have a lower efficiency than compression refrigeration systems, when used for small scale applications and this restrains the absorption cooling system from air conditioning applications in residential buildings. The potential of a solar driven ammonia–water absorption chiller for residential air conditioning application is discussed and analyzed in this paper. A thermodynamic model has been developed based on a 10 kW air cooled ammonia–water absorption chiller driven by solar thermal energy. Both energy and exergy analyses have been conducted to evaluate the performance of this residential scale cooling system. The analyses uncovered that the absorber is where the most exergy loss occurs (63%) followed by the generator (13%) and the condenser (11%). Furthermore, the exergy loss of the condenser and absorber greatly increase with temperature, the generator less so, and the exergy loss in the evaporator is the least sensitive to increasing temperature. -- Highlights: • 10 kW solar thermal driven ammonia–water air cooled absorption chiller is investigated. • Energy and exergy analyses have been done to enhance the thermal performance. • Low driving temperature heat sources have been optimized. • The efficiencies of the major components have been evaluated

Adhesive bonding of super-elastic titanium-nickel alloy castings with a phosphate metal conditioner and an acrylic adhesive.

Science.gov (United States)

Matsumura, H; Tanoue, N; Yanagida, H; Atsuta, M; Koike, M; Yoneyama, T

2003-06-01

The purpose of the current study was to evaluate the bonding characteristics of super-elastic titanium-nickel (Ti-Ni) alloy castings. Disk specimens were cast from a Ti-Ni alloy (Ti-50.85Ni mol%) using an arc centrifugal casting machine. High-purity titanium and nickel specimens were also prepared as experimental references. The specimens were air-abraded with alumina, and bonded with an adhesive resin (Super-Bond C & B). A metal conditioner containing a phosphate monomer (Cesead II Opaque Primer) was also used for priming the specimens. Post-thermocycling average bond strengths (MPa) of the primed groups were 41.5 for Ti-Ni, 30.4 for Ti and 19.5 for Ni, whereas those of the unprimed groups were 21.6 for Ti, 19.3 for Ti-Ni and 9.3 for Ni. Application of the phosphate conditioner elevated the bond strengths of all alloy/metals (P elastic Ti-Ni alloy castings can be achieved with a combination of a phosphate metal conditioner and a tri-n-butylborane-initiated adhesive resin.

Chemical Risk Evaluation: A Case Study in an Automotive Air Conditioner Production Facility

Directory of Open Access Journals (Sweden)

Tengku Hanidza T.I.

2010-01-01

Full Text Available There has been limited knowledge on worker’s exposure to chemicals used in the automotive industries. The purpose of this study is to assess chemical risk and to determine the adequacy of the existing control measures to reduce chemical exposure. A cross sectional survey was conducted in a factory involving installation and servicing of automotive air conditioner units. Qualitative exposure assessment was carried out following the Malaysian Chemical Health Risk Assessment Manual (CHRA. There were 180 employees, 156 workers worked in the production line, which constitutes six work units Tube fin pressed, Brazing, Welding, Final assembly, Piping and Kit II. From the chemical risk evaluation for each work unit, 26 chemical compounds were used. Most of the chemicals were irritants (eye and skin and some were asphyxiants and sensitizers. Based on the work assignment, 93 out of 180 (51.67% of the workers were exposed to chemicals. The highest numbers of workers exposed to chemicals were from the Brazing section (22.22% while the Final Assembly section was the lowest (1.67%. Health survey among the workers showed occurrence of eye irritation, skin irritation, and respiratory irritation, symptoms usually associated with chemical exposure. Using a risk rating matrix, several work process were identified as having ‘significant risk’. For these areas, the workers are at risk of adverse health effects since chemical exposure is not adequately controlled. This study recommends corrective actions be taken in order to control the level of exposure and to provide a safe work environment for workers.

UPQC (Unified power Quality Conditioner)

Indian Academy of Sciences (India)

First page Back Continue Last page Graphics. UPQC (Unified power Quality Conditioner). Hybrid of Shunt and Series compensator. Compensate both Current Quality and Voltage Quality. Costlier Solution as it involves two set of Inverters.

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

Directory of Open Access Journals (Sweden)

Daniela Pinheiro da Silva

2013-10-01

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.

Open absorption system for cooling and air conditioning using membrane contactors - Final report

Energy Technology Data Exchange (ETDEWEB)

Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R.; Dorer, V. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland)

2008-07-01

Air conditioning systems based upon the open absorption principle, essentially an absorption device operating at atmospheric pressure, have been proposed and investigated at many instances in the past eighty years. Their potential for improving energy efficiency is clearly recognized in the earliest research reports. By the mid 1950ies, solar thermal energy was being applied to drive open absorption-based air conditioning systems. For several reasons, however, the open absorption technology was not mature enough to take place in the mainstream. In the past two decades, vigorous efforts have been undertaken to reverse this situation, but success continued to elude, despite the fact that the main problems, such as corrosion, aerosols in the supply air, etc., have been identified. This report details the work and the main results from the MemProDEC Project. In this project innovative solutions were proposed, and successfully investigated, for the corrosion problem and the improvement of efficiency of the absorption process, in particular a new method to cool a very compact absorber. The practically uniform flow distribution for all three streams in the absorber (air, water and desiccant) warrants the contact of the air to be dehumidified with the desiccant over the whole surface of exchange (across a porous membrane). This, together with the cooling with water in counter flow to the air, are the key factors for the excellent effectiveness of the absorber. As the results show, the dehydration effectiveness of the prototype absorber is up to 150 % higher than that previously obtained by others. The solutions developed for compactness and modularity represent an important step in the way to flexible manufacturing, i.e. using a single element size to assemble autonomous air handling units of various nominal capacities. And although the manufacturing methods of the individual elements require improvement, namely by avoiding adhesive bonding, the choice of materials and the

The Use of an Air-Natural Gas Flame in Atomic Absorption.

Science.gov (United States)

Melucci, Robert C.

1983-01-01

Points out that excellent results are obtained using an air-natural gas flame in atomic absorption experiments rather than using an air-acetylene flame. Good results are obtained for alkali metals, copper, cadmium, and zinc but not for the alkaline earths since they form refractory oxides. (Author/JN)

Experimental evaluation of a direct air-cooled lithium bromide-water absorption prototype for solar air conditioning

International Nuclear Information System (INIS)

Gonzalez-Gil, A.; Izquierdo, M.; Marcos, J.D.; Palacios, E.

2011-01-01

A new direct air-cooled single-effect LiBr-H 2 O absorption prototype is described and proposed for use in solar cooling. As distinguishing aspects, it presents: an adiabatic absorber using flat-fan sheets; an air-cooling system that directly refrigerates both the condenser and the absorber and; the possibility of being operated also as a double-effect unit. A solar facility comprising a 48 m 2 field of flat-plate collectors was used to test the single-effect operation mode of the prototype. Results from an experimental campaign carried out in Madrid during summer 2010 are shown and operation parameters corresponding to two typical summer days are detailed. The prototype worked efficiently, with COP values around 0.6. Cooling power varied from 2 kW to 3.8 kW, which represented about 85% of the prototype's nominal capacity. Chilled water temperatures mostly ranged between 14 o C and 16 o C, although the lowest measured value was of 12.8 o C. Condensation and absorption temperatures were under 50 o C and 46 o C, respectively, even with outdoor temperatures of 40 o C. Driving water temperature ranged between 85 o C and 110 o C. As a mean, the system was able to meet 65% of the cooling demand corresponding to a room of 40 m 2 . No signs of crystallization were observed during about a hundred hours of operation. - Highlights: → A novel direct air-cooled single-effect absorption prototype is described. → Feasibility of air-cooled technology for LiBr-H 2 O absorption cooling is proved. → An adiabatic absorber using flat-fan sheets avoids crystallization of the solution. → A field of flat-plate collectors powers the chiller at temperatures from 85 to 110 o C. → The prototype works with thermal COP about 0.6.

Effect of conditioner load on the polishing pad surface during chemical mechanical planarization process

Energy Technology Data Exchange (ETDEWEB)

Shin, Cheol Min; Qin, Hong Yi; Hong, Seok Jun; Jeon, Sang Hyuk; Kulkarni, Atul; Kim, Tae Sun [Sungkyunkwan University, Suwon (Korea, Republic of)

2016-12-15

During the Chemical mechanical planarization (CMP), the pad conditioning process can affect the pad surface characteristics. Among many CMP process parameters, the improper applied load on the conditioner arm may have adverse effects on the polyurethane pad. In this work, we evaluated the pad surface properties under the various conditioner arm applied during pad conditioning process. The conditioning pads were evaluated for surface topography, surface roughness parameters such as Rt and Rvk and Material removal rate (MRR) and within-wafer non-uniformity after wafer polishing. We observed that, the pad asperities were collapsed in the direction of conditioner rotation and blocks the pad pores applied conditioner load. The Rvk value and MRR were founded to be in relation with 4 > 1 > 7 kgF conditioner load. Hence, this study shows that, 4 kgF applied load by conditioner is most suitable for the pad conditioning during CMP.

Experimental results of a direct air-cooled ammonia–lithium nitrate absorption refrigeration system

International Nuclear Information System (INIS)

Llamas-Guillén, S.U.; Cuevas, R.; Best, R.; Gómez, V.H.

2014-01-01

Absorption thermal cooling systems driven by renewable energy are a viable option in order to reduce fossil fuel consumption and the associated emissions. This work shows the results of an air cooled absorption cooling prototype working with an ammonia–lithium nitrate mixture at high ambient temperatures. An absorption refrigeration system was designed and built. The prototype is a one stage ammonia–lithium nitrate air cooled chiller. The experimental system was instrumented to evaluate each component. This paper shows the operation conditions in the experimental unit as well as some of the heat loads encountered at different operating conditions. The system was operated successfully at ambient temperatures in the range of 25–35 °C. A series of test showed that even at ambient temperatures it can be operated at evaporator temperatures below 10 °C producing chilled water for air conditioning applications such as radiative cooling panels. The system proved to stabilize very quickly and no risk of crystallization was encountered so the first results are promising in order to continue with the development of a more advanced prototype. - Highlights: •Experimental results of a direct air-cooled ammonia–lithium nitrate system. •The prototype is a one stage ammonia–lithium nitrate air cooled chiller. •The absorption system was operated successfully at ambient temperatures. •Cooling loads of 4.5 kW were reached in the chilled water side

Modeling and experimental study on performance of inverter air conditioner with variation of capillary tube using R-22 and R-407C

International Nuclear Information System (INIS)

Sarntichartsak, Pongsakorn; Monyakul, Veerapol; Thepa, Sirichai

2007-01-01

This paper focuses on an investigation of the proper capillary tube length for an inverter air conditioner. Air to air variable capacity systems with R-22 and R-407C were tested and modeled. First, the optimum refrigerant charge was determined for four capillary tubes at full load condition by varying the mass charge from 1.1 kg to 1.9 kg. The capillary tube lengths were 1.016 m, 0.914 m, 0.813 m and 0.711 m. The two zone model, the distributed model and the combined model were compared to estimate the optimal charge inventory. The combined model analysed a simple path evaporator, a complex path condenser with a two zone model and a distributed model, respectively. It obtained good agreement with experimental results for the system performances and the optimum mass charge. Furthermore, four capillary tubes with specific optimum mass charges were investigated at compressor frequencies in a range of 30-50 Hz. The R-22 capillary tube obtains the best performance with the addition length of 1.016 m at the lowest frequency. Especially, the length of 0.813 m with R-407C is the appropriate size at the operation frequency of 30-35 Hz. The base capillary tube of 0.914 m is optimum at other frequencies. The model prediction agrees with the experimental data in a range of 40-50 Hz

Effects of natural and synthetic soil conditioners on soil moisture ...

African Journals Online (AJOL)

The efficacy of a natural soil conditioner, Coco-Peat (C-P), and synthetic soil conditioners, Terawet (T-200) and Teraflow (T-F), in improving soil moisture content were examined on five Ghanaian soil series (Akroso, Akuse, Amo, Hake and Oyarifa). In general, the water retention of T-200 and C-P treated soils were similar ...

Techno-Economic Analysis of Solar Absorption Cooling for Commercial buildings in India

Directory of Open Access Journals (Sweden)

Muthalagappan Narayanan

2017-11-01

Full Text Available Space cooling and heating always tends to be a major part of the primary energy usage. By using fossil fuel electricity for these purposes, the situation becomes even worse. One of the major electricity consumptions in India is air conditioning. There are a lot of different technologies and few researchers have come up with a debate between solar absorption cooling and PV electric cooling. In a previous paper, PV electric cooling was studied and now as a continuation, this paper focuses on solar thermal absorption cooling systems and their application in commercial/office buildings in India. A typical Indian commercial building is taken for the simulation in TRNSYS. Through this simulation, the feasibility and operational strategy of the system is analysed, after which parametric study and economic analysis of the system is done. When compared with the expenses for a traditional air conditioner unit, this solar absorption cooling will take 13.6 years to pay back and will take 15.5 years to payback the price of itself and there after all the extra money are savings or profit.  Although the place chosen for this study is one of the typical tropical place in India, this payback might vary with different places, climate and the cooling demand. Article History: Received May 12th 2017; Received in revised form August 15th 2017; Accepted 1st Sept 2017; Available online How to Cite This Article: Narayanan, M. (2017. Techno-Economic Analysis of Solar Absorption Cooling for Commercial Buildings in India.  International Journal of Renewable Energy Development, 6(3, 253-262. https://doi.org/10.14710/ijred.6.3.253-262

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.

Numerically efficient simulation of multi-vaporator air conditioners in highly dynamic boundary conditions; Numerisch effiziente Simulation von Mehrverdampfer-Klimaanlagen unter hochdynamischen Randbedingungen

Energy Technology Data Exchange (ETDEWEB)

Schulze, Christian; Kaiser, Christian [TLK-Thermo GmbH, Braunschweig (Germany); Tegethoff, Wilhelm; Koehler, Juergen [TU Braunschweig (Germany). Inst. fuer Thermodynamik

2011-07-01

In the development of physically based models for dynamic simulations of cycle processes, a good equilibrium must be chosen between the degree of detailing and the speed of calculation. Dynamic modelling of mult-evaporator air conditioners is a special challenge as the interaction of several heat transfer fluides at one pressure level may result in numerically challenging effects like reflux. The contribution goes into the simulation of the heat transfer fluids in such systems in highly dynamic boundary conditions, e.g. after shutoff of the compressor. There are different modelling methods, e.g. finite volume, moving boundary, or finite element analysis. The methods are presented and evaluated. For the 1-D finite volume method, various established simplification strategies are presented that may enhance numerical efficiency. It is also shown that the equation system will not always be solvable with these strategies, and an approach to ensure solvability is presented. The new approach is illustrated by the example of a multi-evaporator bus air conditioner. [German] Bei der Erstellung von physikalisch basierten Modellen fuer die dynamische Simulation von Kreisprozessen muss ein gutes Gleichgewicht zwischen Detaillierungsgrad und Rechengeschwindigkeit gewaehlt werden: Das Modell muss die Realitaet hinreichend genau abbilden, im Gegenzug jedoch auch innerhalb eines angemessenen Zeitraums Ergebnisse liefern sowie in allen Betriebszustaenden loesbar sein. Die dynamische Modellierung von Mehrverdampfer-Klimaanlagen stellt im Vergleich zu einfachen Kreisprozessen eine besondere Herausforderung dar, da in diesen Systemen die Interaktion mehrerer Waermeuebertrager auf einem Druckniveau zu numerisch herausfordernden Effekten wie z. B. Rueckstroemung fuehren kann. Dieser Beitrag beschaeftigt sich mit der Simulation der Waermeuebertrager in diesen Systemen unter hochdynamischen Randbedingungen wie z. B. einer Abschaltung des Verdichters. Zur Modellierung der Waermeuebertrager

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.

Study of Flexible Load Dispatch to Improve the Capacity of Wind Power Absorption

Science.gov (United States)

Yunlei, Yang; Shifeng, Zhang; Xiao, Chang; Da, Lei; Min, Zhang; Jinhao, Wang; Shengwen, Li; Huipeng, Li

2017-05-01

The dispatch method which track the trend of load demand by arranging the generation scheme of controllable hydro or thermal units faces great difficulties and challenges. With the increase of renewable energy sources such as wind power and photovoltaic power introduced to grid, system has to arrange much more spinning reserve units to compensate the unbalanced power. How to exploit the peak-shaving potential of flexible load which can be shifted with time or storage energy has become many scholars’ research direction. However, the modelling of different kinds of load and control strategy is considerably difficult, this paper choose the Air Conditioner with compressor which can storage energy in fact to study. The equivalent thermal parameters of Air Conditioner has been established. And with the use of “loop control” strategies, we can predict the regulated power of Air Conditioner. Then we established the Gen-Load optimal scheduling model including flexible load based on traditional optimal scheduling model. At last, an improved IEEE-30 case is used to verify. The result of simulation shows that flexible load can fast-track renewable power changes. More than that, with flexible load and reasonable incentive method to consumers, the operating cost of the system can be greatly cut down.

Power system stabilization by SMES using current-fed pwm power conditioner

International Nuclear Information System (INIS)

Ishikawa, T.; Akita, S.; Taniguchi, H.; Kosho, S.; Tanaka, T.

1988-01-01

A superconducting magnetic energy storage (SMES) unit, consisted of superconducting coil and AC/DC power conditioner, can be used to suppress various kinds of instability that may cause service interruption in electric power system as it has high controllability of input/output electric power. Power system stabilizing ability of SMES has been examined experimentally by using model power system and small SMES unit. Current-fed PWM power conditioner was used to obtain maximum stabilizing effect by controlling active and reactive power simultaneously and independently. Power conditioner configuration, operating characteristics and control scheme for power system stabilization are also described. Results from experiments show the effectiveness of SMES on power system stabilization

Inverted Unified Power Quality Conditioner to compensate overvoltage

Directory of Open Access Journals (Sweden)

Yeison Alberto Garcés Gómez

2017-07-01

Full Text Available Introduction: The use of unified power quality conditioners UPQC in the electric systems can correct waveform distortions in a steady state, like harmonics, flicker, and the power factor. Objective: This paper presents a novel approach for active compensation of overvoltage with a UPQC in dual topology or iUPQC. Methodology: The study it is presented in five stages, the section I shows an introduction and the state of the art, section II presents the unified power quality conditioner UPQC, section III describes the generalized reactive power theory applied to the iUPQC (dual topology, section IV shows the numerical simulations and the results and section V presents the conclusions of the study. Results: The results for the application of the iUPQC to the compensation of overvoltage are proved and compared with the more representative theory related to compensation of harmonics and low power factor. Conclusions: The control algorithm presented for the unified power quality conditioner in dual topology allows to compensate the overvoltage in three-phase systems as well as voltage and current harmonics and the low power factor.

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.

Improved Sound Absorption Performance of Nonwoven Fabric using Fabric Facing and Air Back Cavity

Directory of Open Access Journals (Sweden)

Ismail Ahmad Yusuf

2017-01-01

Full Text Available This paper presents the improvement methods to increase sound absorption performance of polyethylene based nonwoven fabric (PNF. The methods are placing a woven fabric in front of the sample as well as providing air cavity behind the sample. The samples were experimentally tested in an impedance tube based on ISO 10354-2:2001 whereby two microphones are used and the transfer matrix methods are employed. From the results, it can be seen that placing front woven fabric effectively increases sound absorption performance. Moreover, introducing air cavity gap behind the sample is also found to be more significant to increase sound absorption.

High-throughput liquid-absorption air-sampling apparatus and methods

Science.gov (United States)

Zaromb, Solomon

2000-01-01

A portable high-throughput liquid-absorption air sampler [PHTLAAS] has an asymmetric air inlet through which air is drawn upward by a small and light-weight centrifugal fan driven by a direct current motor that can be powered by a battery. The air inlet is so configured as to impart both rotational and downward components of motion to the sampled air near said inlet. The PHTLAAS comprises a glass tube of relatively small size through which air passes at a high rate in a swirling, highly turbulent motion, which facilitates rapid transfer of vapors and particulates to a liquid film covering the inner walls of the tube. The pressure drop through the glass tube is 20% for vapors or airborne particulates in the 2-3.mu. range and >50% for particles larger than 4.mu.. In conjunction with various analyzers, the PHTLAAS can serve to monitor a variety of hazardous or illicit airborne substances, such as lead-containing particulates, tritiated water vapor, biological aerosols, or traces of concealed drugs or explosives.

High-throughput liquid-absorption air-sampling apparatus and methods

International Nuclear Information System (INIS)

2000-01-01

A portable high-throughput liquid-absorption air sampler [PHTLAAS] has an asymmetric air inlet through which air is drawn upward by a small and light-weight centrifugal fan driven by a direct current motor that can be powered by a battery. The air inlet is so configured as to impart both rotational and downward components of motion to the sampled air near said inlet. The PHTLAAS comprises a glass tube of relatively small size through which air passes at a high rate in a swirling, highly turbulent motion, which facilitates rapid transfer of vapors and particulates to a liquid film covering the inner walls of the tube. The pressure drop through the glass tube is 20% for vapors or airborne particulates in the 2--3 microns range and > 50% for particles larger than 4 microns. In conjunction with various analyzers, the PHTLAAS can serve to monitor a variety of hazardous or illicit airborne substances, such as lead-containing particulates, tritiated water vapor, biological aerosols, or traces of concealed drugs or explosives

Flow, stock, and impact assessment of refrigerants in the Japanese household air conditioner sector.

Science.gov (United States)

Xue, Mianqiang; Kojima, Naoya; Machimura, Takashi; Tokai, Akihiro

2017-05-15

Refrigerants provide society with great benefits while have the potential to cause adverse effects on the environment and human health. The present study estimated time-dependent flows and stocks and assessed the effects of refrigerants (R-22, R-410a, and R-32) in household air conditioners in Japan. It was found that stock of R-22 and R-410a peaked at 49,147t in 2000 and 55,994t in 2017, respectively. The largest flow of R-22 and R-410a to waste phase occurred at 3417t/yr. in 2005 and 4011t/yr. in 2023, respectively. The total global warming potential (GWP) due to refrigerant emissions increased from 3.6kt CO 2 eq. in 1952 to 6999kt CO 2 eq. in 2019, and then decreased to 5314kt CO 2 eq. in 2030. The ozone depletion potential (ODP) peaked at 141t CFC-11 eq. in 2002. When substituting R-410a for R-22, the ODP decreased 50% while the GDP increased 8%. When substituting R-32 for R-410a, there was no effect on the ODP while the GDP decreased 6%. The human health damage due to the global warming effect of refrigerant emission was much higher than that due to the ozone depleting effect. The refrigerant emission in use and waste management phases dominated the human health damage. The dynamic estimation not only allows us to evaluate the performance of past policies but also supports the future sustainable management associated with the health effects of refrigerants. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

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.)

Energy and parametric analysis of solar absorption cooling systems in various Moroccan climates

Directory of Open Access Journals (Sweden)

Y. Agrouaz

2017-03-01

Full Text Available The aim of this work is to investigate the energetic performance of a solar cooling system using absorption technology under Moroccan climate. The solar fraction and the coefficient of performance of the solar cooling system were evaluated for various climatic conditions. It is found that the system operating in Errachidia shows the best average annual solar fraction (of 30% and COP (of 0.33 owing to the high solar capabilities of this region. Solar fraction values in other regions varied between 19% and 23%. Moreover, the coefficient of performance values shows in the same regions a significant variation from 0.12 to 0.33 all over the year. A detailed parametric study was as well carried out to evidence the effect of the operating and design parameters on the solar air conditioner performance.

Estimation of heat rejection based on the air conditioner use time and its mitigation from buildings in Taipei City

Energy Technology Data Exchange (ETDEWEB)

Hsieh, Chun-Ming; Aramaki, Toshiya; Hanaki, Keisuke [The University of Tokyo, Bunkyo-ku, Tokyo (Japan). Department of Urban Engineering

2007-09-15

The main work in the research focuses on the analysis and mitigation of the anthropogenic heat discharged from buildings, which is one of the main reasons leading to the heat island effect. The residential and commercial buildings, divided into 10 categories, with HVAC systems were analyzed by the building energy program, EnergyPlus. With the help of GIS, the heat rejection of all the residential and commercial buildings in DaAn Ward of Taipei City were evaluated, in which the spatial data and diurnal variation of the heat rejection were described by 3-h time periods. Furthermore, the effect of mitigation strategies was discussed. The first strategy was to change the wall/roof material of building envelope. The second and third strategies, from the viewpoint of energy saving, were to change the temperature setting of air conditioners and to turn off the lighting and equipment when not in use. The fourth strategy was to use a better efficiency of the cooling systems. Finally, the evaluation of installing the water-cooled cooling system, which discharges heat in the form of sensible and latent heat, was also included. (author)

LiCl Dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery

Science.gov (United States)

Ko, Suk M.

1980-01-01

This invention relates to a hybrid air conditioning system that combines a solar powered LiCl dehumidifier with a LiBr absorption chiller. The desiccant dehumidifier removes the latent load by absorbing moisture from the air, and the sensible load is removed by the absorption chiller. The desiccant dehumidifier is coupled to a regenerator and the desiccant in the regenerator is heated by solar heated hot water to drive the moisture therefrom before being fed back to the dehumidifier. The heat of vaporization expended in the desiccant regenerator is recovered and used to partially preheat the driving fluid of the absorption chiller, thus substantially improving the overall COP of the hybrid system.

Development of new products for Europe and individual customer support: Sanden Technical Centre (Europe) GmbH. High-efficiency wind tunnel for passenger car air conditioners at Bad Nauheim; Entwicklung neuer Produkte fuer Europa und individuelle Kundenunterstuetzung: Sanden Technical Centre (Europe) GmbH. Hocheffizienter Klimawindkanal fuer Pkw-Klimaanlagen in Bad Nauheim

Energy Technology Data Exchange (ETDEWEB)

Anon.

2007-05-15

As the importance of passenger cars as part of everyday life increased in Japan, Sanden decided that air conditioners for passenger cars would soon be indispensable. Since 1971, Sanden has worked on new technologies in this field, including compact refrigerating compressors. (orig.)

Future air conditioning energy consumption in developing countries and what can be done about it: the potential of efficiency in the residential sector

Energy Technology Data Exchange (ETDEWEB)

McNeil, Michael A.; Letschert, Virginie E. [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory (United States)

2007-07-01

The dynamics of air conditioning are of particular interest to energy analysts, both because of the high energy consumption of this product, but also its disproportionate impact on peak load. This paper addresses the special role of this end use as a driver of residential electricity consumption in rapidly developing economies. Recent history has shown that air conditioner ownership grows more rapidly than economic growth in warm-climate countries. In 1990, less than a percent of urban Chinese households owned an air conditioner; by 2003 this number rose to 62 %. The evidence suggests a similar explosion of air conditioner use in many other countries is not far behind. Room air conditioner purchases in India are currently growing at 20 % per year, with about half of these purchases attributed to the residential sector. This paper draws on two distinct methodological elements to assess future residential air conditioner 'business as usual' electricity consumption by country/region and to consider specific alternative 'high efficiency' scenarios. The first component is an econometric ownership and use model based on household income, climate and demographic parameters. The second combines ownership forecasts and stock accounting with geographically specific efficiency scenarios within a unique analysis framework (BUENAS) developed by LBNL. The efficiency scenario module considers current efficiency baselines, available technologies, and achievable timelines for development of market transformation programs, such as minimum efficiency performance standards (MEPS) and labeling programs. The result is a detailed set of consumption and emissions scenarios for residential air conditioning.

Application of the CPE-air conditioner

Energy Technology Data Exchange (ETDEWEB)

Van Hest, J.; Van der Neut, R.P.; Wijnstra, K.P.

1986-09-01

Described is an air conditioning system with a special cooling unit, CPE (combined dew point and heat exchanger). The system has been installed for the first time in the Netherlands in a shop in Utrecht. Results of measurements during September 1985 are presented. 7 figs.

High-throughput liquid-absorption air-sampling apparatus and methods

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-11

A portable high-throughput liquid-absorption air sampler [PHTLAAS] has an asymmetric air inlet through which air is drawn upward by a small and light-weight centrifugal fan driven by a direct current motor that can be powered by a battery. The air inlet is so configured as to impart both rotational and downward components of motion to the sampled air near said inlet. The PHTLAAS comprises a glass tube of relatively small size through which air passes at a high rate in a swirling, highly turbulent motion, which facilitates rapid transfer of vapors and particulates to a liquid film covering the inner walls of the tube. The pressure drop through the glass tube is < 10 cm of water, usually < 5 cm of water. The sampler's collection efficiency is usually > 20% for vapors or airborne particulates in the 2--3 microns range and > 50% for particles larger than 4 microns. In conjunction with various analyzers, the PHTLAAS can serve to monitor a variety of hazardous or illicit airborne substances, such as lead-containing particulates, tritiated water vapor, biological aerosols, or traces of concealed drugs or explosives.

Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air

NARCIS (Netherlands)

Scholten, E.; Bromberg, L.; Rutledge, G.C.; Hatton, T.A.

2011-01-01

Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and

A Two-Level Optimal Scheduling Strategy for Central Air-Conditioners Based on Metal Model with Comprehensive State-Queueing Control Models

Directory of Open Access Journals (Sweden)

Yebai Qi

2017-12-01

Full Text Available Unlike some thermostatically controlled appliances (TCAs with small capacities, Central Air-conditioner (CAC has huge potential for demand response because of its large capacity. This paper presents a new CAC control strategy under multiple constraints. The CAC is modeled by three main modules: CAC central unit, water pumps, and temperature simulation of terminal users. The CAC’s power consumption is mainly determined by users’ load ratio. As the information and communication system have become the central nervous system of the smart grid, big data analysis is of great significance. Assuming that reliable two-way communication systems are preset, an integrated parameter priority list (IPPL control strategy is used to control and monitor CAC. A new intelligent algorithm, Space Exploration and Unimodal Region Elimination (SEUMRE algorithm, is introduced for solving the optimization problem of demand response targets generation under multiple constraints with the help of big data analysis. In this paper, influences and constrain factors, such as price and users’ comfortable levels are taken into account to satisfy the need of actual situation. Simulation results show that the proposed approach, when comparing with other typical optimization algorithms, yields better performances and efficiency.

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,…

Future emissions and atmospheric fate of HFC-1234yf from mobile air conditioners in Europe.

Science.gov (United States)

Henne, Stephan; Shallcross, Dudley E; Reimann, Stefan; Xiao, Ping; Brunner, Dominik; O'Doherty, Simon; Buchmann, Brigitte

2012-02-07

HFC-1234yf (2,3,3,3-tetrafluoropropene) is under discussion for replacing HFC-134a (1,1,1,2-tetrafluoroethane) as a cooling agent in mobile air conditioners (MACs) in the European vehicle fleet. Some HFC-1234yf will be released into the atmosphere, where it is almost completely transformed to the persistent trifluoroacetic acid (TFA). Future emissions of HFC-1234yf after a complete conversion of the European vehicle fleet were assessed. Taking current day leakage rates and predicted vehicle numbers for the year 2020 into account, European total HFC-1234yf emissions from MACs were predicted to range between 11.0 and 19.2 Gg yr(-1). Resulting TFA deposition rates and rainwater concentrations over Europe were assessed with two Lagrangian chemistry transport models. Mean European summer-time TFA mixing ratios of about 0.15 ppt (high emission scenario) will surpass previously measured levels in background air in Germany and Switzerland by more than a factor of 10. Mean deposition rates (wet + dry) of TFA were estimated to be 0.65-0.76 kg km(-2) yr(-1), with a maxium of ∼2.0 kg km(-2) yr(-1) occurring in Northern Italy. About 30-40% of the European HFC-1234yf emissions were deposited as TFA within Europe, while the remaining fraction was exported toward the Atlantic Ocean, Central Asia, Northern, and Tropical Africa. Largest annual mean TFA concentrations in rainwater were simulated over the Mediterranean and Northern Africa, reaching up to 2500 ng L(-1), while maxima over the continent of about 2000 ng L(-1) occurred in the Czech Republic and Southern Germany. These highest annual mean concentrations are at least 60 times lower than previously determined to be a safe level for the most sensitive aquatic life-forms. Rainwater concentrations during individual rain events would still be 1 order of magnitude lower than the no effect level. To verify these results future occasional sampling of TFA in the atmospheric environment should be considered. If future HFC-1234yf

LDDX: A High Efficiency Air Conditioner for DOD Buildings

Science.gov (United States)

2017-02-01

Additional Benefits ........................................................................................................ 3 1.2.6 Deliverables...inadequate latent cooling can lead building managers to restrict ventilation to minimal levels that further compromise both the comfort and health of...bulb temperatures for outdoor air and return air respectively per ANSI/AHRI Standard 210/240 “Performance Rating of Unitary Air-Conditioning and Air

Conformational aspects of proteins at the air/water interface studied by infrared reflection-absorption spectroscopy

NARCIS (Netherlands)

Martin, A.H.; Meinders, M.B.J.; Bos, M.A.; Cohen Stuart, M.A.; Vliet, T. van

2003-01-01

From absorption spectra obtained with infrared reflection - absorption spectroscopy (IRRAS), it is possible to obtain information on conformational changes at a secondary folding level of proteins adsorbed at the air/water interface. In addition, information on protein concentration at the interface

Performance of a split-type air conditioner matched with coiled adiabatic capillary tubes using HCFC22 and HC290

International Nuclear Information System (INIS)

Zhou, Guobing; Zhang, Yufeng

2010-01-01

This paper experimentally investigated the system performance of a split-type air conditioner matching with different coiled adiabatic capillary tubes for HCFC22 and HC290. Experiments were carried out in a room-type calorimeter. The results have shown that (1) similar cooling effects can be achieved by matching various capillary tubes of different inner diameters; (2) parallel capillary tubes presented better system performance and flow stability with weaker inlet pressure fluctuations than the single capillary tube; (3) with the coil diameter of the capillary tube increasing from 40 mm to 120 mm, the mass flow rate tended to increase slightly. But the cooling capacity, input power and energy efficiency ratio (EER) did not show evident tendency of change; (4) the refrigerant charge and mass flow rate for HC290 were only 44% and 47% of that for HCFC22, respectively, due to the much lower density. And HC290 had 4.7-6.7% lower cooling capacity and 12.1-12.3% lower input power with respect to HCFC22. However, the EER of HC290 can be 8.5% higher than that of HCFC22, which exhibits the advantage of using HC290. In addition, the experimental uncertainties were analyzed and some application concerns of HC290 were discussed.

Factors influencing on the bioaccessibility of polybrominated diphenyl ethers in size-specific dust from air conditioner filters.

Science.gov (United States)

Yu, Yingxin; Yang, Dan; Wang, Xinxin; Huang, Ningbao; Zhang, Xinyu; Zhang, Dongping; Fu, Jiamo

2013-11-01

Size-specific concentrations and bioaccessibility of polybrominated diphenyl ethers (PBDEs) in dust from air conditioner filters were measured, and the factors influencing the PBDE bioaccessibility were determined. Generally, the PBDE concentrations increased with decreasing dust particle size, and BDE209 (deca-BDE) was generally the predominant congener. The bioaccessibility ranged from 20.3% to 50.8% for tri- to hepta-BDEs, and from 5.1% to 13.9% for BDE209 in dust fractions of varied particle size. The bioaccessibility of most PBDE congeners decreased with increasing dust particle size. The way of being of PBDE (adsorbed to dust surface or incorporated into polymers) in dust significantly influenced the bioaccessibility. There was a significant negative correlation between the tri- to hepta-BDE bioaccessibility and organic matter (OM) contents in dust. Furthermore, tri- to hepta-BDE bioaccessibility increased with increasing polarity of OMs, while with decreasing aromaticity of OMs. The tri- to hepta-BDE bioaccessibility significantly positively correlated with the surface areas and pore volumes of dust. Using multiple linear regression analysis, it was found that the OM contents and pore volumes of dust were the most important factors to influence the tri- to hepta-BDE bioaccessibility and they could be used to estimate the bioaccessibility of tri- to hepta-BDEs according to the following equation: bioaccessibility (%)=45.05-0.49 × OM%+1.79 × pore volume. However, BDE209 bioaccessibility did not correlate to any of these factors. Copyright © 2013 Elsevier Ltd. All rights reserved.

Numerical study of the flow conditioner for the IFMIF liquid lithium target

Energy Technology Data Exchange (ETDEWEB)

Gordeev, S., E-mail: sergej.gordeev@kit.edu [Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute for Thechnology, Campus North, Hermann v. Helmholtz Platz 1, D76344, Eggenstein-Leopoldshafen (Germany); Gröschel, F. [KIT Fusion Program, Karlsruhe Institute for Thechnology, Campus North, Hermann v. Helmholtz Platz 1, D76344, Eggenstein-Leopoldshafen (Germany); Heinzel, V.; Hering, W.; Stieglitz, R. [Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute for Thechnology, Campus North, Hermann v. Helmholtz Platz 1, D76344, Eggenstein-Leopoldshafen (Germany)

2014-10-15

Highlights: • A detailed numerical analysis of the flow conditioner efficiency has been performed. • The calculations show that the present design of the flow conditioner cannot suppress swirl motions emerging from the bend. • The transient simulation reveals flow instabilities between the separation zone and the accelerated outer region. • Calculation shows that pitched guide vanes upstream the elbow reduces a generation of backflow areas downstream. - Abstract: IFMIF (International Fusion Materials Irradiation Facility) is an accelerator-based deuteron–lithium (D–Li) neutron source to simulate the neutron irradiation field in a fusion reactor. The target assembly of the IFMIF consists of the flow conditioners and the nozzle, which has to form a stable lithium jet. This work focuses on a numerical study of the flow conditioner efficiency, in which two different types of flow conditioners are compared by means of a detailed numerical analysis with respect to specific hydraulic effects in the pipe elbow and the inflow conditioners. The adequateness of three different turbulence models to simulate a flow through a 90° bend of circular cross section has been examined. The calculations show that a honeycomb-screen combination is not capable to suppress effectively large scale swirl motions emerging from the bend. An increasing number of screens improves the flow uniformity downstream, but increases the pressure drop. In order to detect any transient effects in the separation area a flow straightener configuration consisting of a honeycomb with a subsequent screen has been analyzed by means of a detached eddy simulation (DES). A frequency analysis of the normalized static pressure amplitude conducted by means of a detached eddy simulation (DES) reveals instabilities in the shear layer between the separation zone and the accelerated outer region, which additionally increase the inhomogeneity of the axial velocity distribution. A set of six circumferentially

Improve the material absorption of light and enhance the laser tube bending process utilizing laser softening heat treatment

Science.gov (United States)

Imhan, Khalil Ibraheem; Baharudin, B. T. H. T.; Zakaria, Azmi; Ismail, Mohd Idris Shah B.; Alsabti, Naseer Mahdi Hadi; Ahmad, Ahmad Kamal

2018-02-01

Laser forming is a flexible control process that has a wide spectrum of applications; particularly, laser tube bending. It offers the perfect solution for many industrial fields, such as aerospace, engines, heat exchangers, and air conditioners. A high power pulsed Nd-YAG laser with a maximum average power of 300 W emitting at 1064 nm and fiber-coupled is used to irradiate stainless steel 304 (SS304) tubes of 12.7 mm diameter, 0.6 mm thickness and 70 mm length. Moreover, a motorized rotation stage with a computer controller is employed to hold and rotate the tube. In this paper, an experimental investigation is carried out to improve the laser tube bending process by enhancing the absorption coefficient of the material and the mechanical formability using laser softening heat treatment. The material surface is coated with an oxidization layer; hence, the material absorption of laser light is increased and the temperature rapidly rises. The processing speed is enhanced and the output bending angle is increased to 1.9° with an increment of 70% after the laser softening heat treatment.

Requirements of air conditioners for office buildings. Pt. 2

Energy Technology Data Exchange (ETDEWEB)

Radtke, W

1988-02-01

Presenting numerous explanatory diagrams part two of the report deals with auxiliary ventilation systems (mechanical systems); the influence of different ventilation circuits on the air quality (particle concentration, floor and ceiling air outlets); the requirements of heating systems (dimensioning of heating systems, effects of ventilation systems on the heat demand, reduced heat demand owing to auxiliary ventilation systems); the requirements of cooling (cooling loads in office buildings, room temperatures in the case of natural cooling, auxiliary ventilation systems, and cooling by means of refrigerators, floor/ceiling cooling systems); permissible ambient air velocities (complaints about draughts). Bottom-to-top ventilation circuits were found to provide for better air qualities and lower ambient air velocities without increasing the systems' energy demand. (HWJ).

Preliminary report of a gas conditioner to improve operational reliability of cryotherapy in developing countries

Directory of Open Access Journals (Sweden)

Broekhuizen Fredrik

2006-02-01

Full Text Available Abstract Background Cryotherapy is a safe, affordable, and effective method of treatment for cervical intraepithelial neoplasia. In some low-resource settings, environmental conditions or qualities of the refrigerant gas can lead to blockage of cryotherapy equipment, terminating treatment. A prototype of a gas conditioner to prevent operational failure was designed, built, and field tested. Methods The prototype conditioner device consists of an expansion chamber that filters and dries the refrigerant gas. Users in Peru and Kenya reported on their experience with the prototype conditioner. In Ghana, simulated cryotherapy procedures were used to test the effects of the prototype conditioner, as well as the commonly used "cough technique." Results Anecdotal reports from field use of the device were favorable. During simulated cryotherapy, the prevalence of blockage during freezing were 0% (0/25 with the device alone, 23.3% (7/30 with the cough technique alone, 5.9% (1/17 with both, and 55.2% (16/29 with neither (Pearson's Chi square = 26.6, df = 3, p Conclusion This prototype design of a cryotherapy gas conditioner is a potential solution for low-resource settings that are experiencing cryotherapy device malfunction.

Characteristics of indoor radon and its progeny in a Japanese dwelling while using air appliances

International Nuclear Information System (INIS)

Pornnumpa, C.; Tokonami, S.; Sorimachi, A.; Kranrod, C.

2015-01-01

Characteristics of radon and its progeny were investigated in different air conditions by turning four types of indoor air appliances on and off in a two-story concrete Japanese dwelling. The four appliances were air conditioner, air cleaner, gas heater and cooker hood. The measurements were done using two devices: (1) a Si-based semiconductor detector for continuous measurement of indoor radon concentration and (2) a ZnS(Ag) scintillation counting system for equilibrium-equivalent radon concentration. Throughout the entire experiment, the cooker hood was the most effective in decreasing indoor radon concentration over a long period of time and the less effective was the air conditioner, while the air cleaner and gas heater did not affect the concentration of radon. However, the results measured in each air condition will differ according to the lifestyles and activities of the inhabitants. In this study, indoor radon and its progeny in a Japanese dwelling will be characterised by the different air conditions. (authors)

Results of Self-Absorption Study on the Versapor 3000 Filters for Radioactive Particulate Air Sampling

International Nuclear Information System (INIS)

Barnett, J.M.

2008-01-01

Since the mid-1980s the Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as a correction factor for the self absorption of activity of particulate radioactive air samples. More recently, an effort was made to evaluate the current particulate radioactive air sample filters (Versapor(reg s ign) 3000) used at PNNL for self absorption effects. There were two methods used in the study, (1) to compare the radioactivity concentration by direct gas-flow proportional counting of the filter to the results obtained after acid digestion of the filter and counting again by gas-flow proportional detection and (2) to evaluate sample filters by high resolution visual/infrared microscopy to determine the depth of material loading on or in the filter fiber material. Sixty samples were selected from the archive for acid digestion in the first method and about 30 samples were selected for high resolution visual/infrared microscopy. Mass loading effects were also considered. From the sample filter analysis, large error is associated with the average self absorption factor, however, when the data is compared directly one-to-one, statistically, there appears to be good correlation between the two analytical methods. The mass loading of filters evaluated was <0.2 mg cm-2 and was also compared against other published results. The microscopy analysis shows the sample material remains on the top of the filter paper and does not imbed into the filter media. Results of the microscopy evaluation lead to the conclusion that there is not a mechanism for significant self absorption. The overall conclusion is that self-absorption is not a significant factor in the analysis of filters used at PNNL for radioactive air stack sampling of radionuclide particulates and that an applied correction factor is conservative in determining overall sample activity. A new self absorption factor of 1.0 is recommended

Active Sensing Air Pressure Using Differential Absorption Barometric Radar

Science.gov (United States)

Lin, B.

2016-12-01

Tropical storms and other severe weathers cause huge life losses and property damages and have major impacts on public safety and national security. Their observations and predictions need to be significantly improved. This effort tries to develop a feasible active microwave approach that measures surface air pressure, especially over open seas, from space using a Differential-absorption BArometric Radar (DiBAR) operating at 50-55 GHz O2 absorption band in order to constrain assimilated dynamic fields of numerical weather Prediction (NWP) models close to actual conditions. Air pressure is the most important variable that drives atmospheric dynamics, and currently can only be measured by limited in-situ observations over oceans. Even over land there is no uniform coverage of surface air pressure measurements. Analyses show that with the proposed space radar the errors in instantaneous (averaged) pressure estimates can be as low as 4mb ( 1mb) under all weather conditions. NASA Langley research team has made substantial progresses in advancing the DiBAR concept. The feasibility assessment clearly shows the potential of surface barometry using existing radar technologies. The team has also developed a DiBAR system design, fabricated a Prototype-DiBAR (P-DiBAR) for proof-of-concept, conducted laboratory, ground and airborne P-DiBAR tests. The flight test results are consistent with the instrumentation goals. The precision and accuracy of radar surface pressure measurements are within the range of the theoretical analysis of the DiBAR concept. Observational system simulation experiments for space DiBAR performance based on the existing DiBAR technology and capability show substantial improvements in tropical storm predictions, not only for the hurricane track and position but also for the hurricane intensity. DiBAR measurements will provide us an unprecedented level of the prediction and knowledge on global extreme weather and climate conditions.

77 FR 23278 - Notice of Lodging of Consent Decree Under the Clean Air Act

Science.gov (United States)

2012-04-18

... accept small appliances, motor vehicle air conditioners (``MVACs''), or MVAC- like appliances with cut... DEPARTMENT OF JUSTICE Notice of Lodging of Consent Decree Under the Clean Air Act Notice is hereby... Agency (``U.S. EPA''), sought penalties and injunctive relief under the Clean Air Act (``CAA'') against...

Conceptual Design of Automotive Compressor for Integrated Portable Air Conditioning System

Directory of Open Access Journals (Sweden)

Ishak Muhammad Ikman

2017-01-01

Full Text Available This study introduces a new concept of portable air conditioner which integrated with some available components in automotive air conditioning system. This new idea intends to solve the storage problems as well as to reduce the price of current portable air conditioner since some devices could directly be used from the automotive air conditioning system. The primary emphasis of this study was on the modification of automotive compressor design so as the system may alternately be operated. The length of conventional compressor shaft is extended to place an additional clutch pulley, a drive plate and a clutch coil. The new concept particularly the shaft and pulley were analysed through slope deflection and computational finite element analyses. The result of engineering analyses exhibited that the new design of compressor shaft and clutch pulleys promote a low risk of failure as the data values recorded are lower than the critical value for each criterion investigated.

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.

Chromatographic determination of the rate and extent of absorption of air pollutants by sea water

International Nuclear Information System (INIS)

Nikolakaki, S.; Vassilakos, C.; Katsanos, N.A.

1994-01-01

A simple chromatographic method is developed to determine the rate constant for expulsion of an air pollutant from water or its diffusion parameter in the liquid, the rate constant for chemical reaction of the pollutant with water, its mass transfer coefficient in the liquid, and the partition coefficient between liquid water and air. From these physicochemical parameters, the absorption rate by sea water and, therefore, the depletion rate of a polluting substance from the air can be calculated, together with the equilibrium state of this absorption. The method has been applied to nitrogen dioxide being absorbed by triple-distilled water and by sea water, at various temperatures. From the temperature variation of the reaction rate constant and of the partition coefficient, the activation energy for the reaction and the differential heat of solution were determined. (orig.)

Designing the lithium bromide air conditioning absorption system for a bus

International Nuclear Information System (INIS)

Yusoff Ali; Kamaruzzaman Sopian; Hariadi

2006-01-01

A system of air-conditioning using Lithium Bromide absorption system is used as an alternative refrigerant that will not pollute the atmosphere. Lithium Bromide is a chemical salt soluble in water. There is a big difference between vapour compression system and LiBr 2 absorption system. The absorption air conditioning system is made of a generator, a condenser, an evaporator and an absorber with necessary pumps and piping. When LiBr 2 solution is heated under low pressure, water will evaporate first, while LiBr 2 will remain in the solution and will become more concentrated. The water is the refrigerant in this system. The generator, where the water is vapourised, is heated using an electric heater or solar energy. The LiBr 2 weak solution under low pressure in the generator is heated and the water evaporate into vapour. The vapour produced is then cooled in the condenser and then expanded into the evaporator. The refrigerant (water) in evaporator change phase from liquid to vapour by absorbing heat from cooling water, which flow in the coil in the evaporator. The chilled water obtained is then pumped into the fan coil, which will be used in conditioning the passenger area of the bus. The water vapour from the evaporator is absorbed into LiBr 2 solution in the absorber, forming a weak solution of LiBr 2 . the weak solution from the absorber is then pumped back to the generator to regenerate. The absorption system does not use compressor, but requires pumps that need lower input power compared to that of a compressor. The system is considered as a new application for the bus. This will have great potential and will be environmentally friendly. The model in this study will be used for calculation of the cooling load for the bus

The Signal Validation method of Digital Process Instrumentation System on signal conditioner for SMART

International Nuclear Information System (INIS)

Moon, Hee Gun; Park, Sang Min; Kim, Jung Seon; Shon, Chang Ho; Park, Heui Youn; Koo, In Soo

2005-01-01

The function of PIS(Process Instrumentation System) for SMART is to acquire the process data from sensor or transmitter. The PIS consists of signal conditioner, A/D converter, DSP(Digital Signal Process) and NIC(Network Interface Card). So, It is fully digital system after A/D converter. The PI cabinet and PDAS(Plant Data Acquisition System) in commercial plant is responsible for data acquisition of the sensor or transmitter include RTD, TC, level, flow, pressure and so on. The PDAS has the software that processes each sensor data and PI cabinet has the signal conditioner, which is need for maintenance and test. The signal conditioner has the potentiometer to adjust the span and zero for test and maintenance. The PIS of SMART also has the signal conditioner which has the span and zero adjust same as the commercial plant because the signal conditioner perform the signal condition for AD converter such as 0∼10Vdc. But, To adjust span and zero is manual test and calibration. So, This paper presents the method of signal validation and calibration, which is used by digital feature in SMART. There are I/E(current to voltage), R/E(resistor to voltage), F/E(frequency to voltage), V/V(voltage to voltage). Etc. In this paper show only the signal validation and calibration about I/E converter that convert level, pressure, flow such as 4∼20mA into signal for AD conversion such as 0∼10Vdc

DISAIN SIMULATOR AUTOMOTIVE AIR CONDITIONING UNTUK MENINGKATKAN KOMPETENSI MAHASISWA

Directory of Open Access Journals (Sweden)

Kamin Sumardi

2015-08-01

Full Text Available Perkembangan teknologi automotive air conditioning dan aplikasinya sangat cepat, salah satunya dengan menerapkan green technology. Penerapan green technology pada teknologi air conditioning, karena masih menggunakan refrigeran yang mengandung unsur kimia yang merusak lapisan ozon dan pemanasan global. Alih teknologi bidang air conditioning yang ramah lingkungan, belum dibarengi dengan ketersediaan tenaga kerja pada tingkat SMK dan perguruan tinggi yang memadai, baik kuantitas maupun kompetensinya. Pada level SMK dan perguruan tinggi, kompetensi akademik dan vokasional bidang automotive air conditioning harus terus ditingkatkan dan diperbaharui sesuai dengan perkembangan teknologinya. Penelitian ini bertujuan untuk menghasilkan simulator automotive air conditioner dan model pembelajaran tata udara pada otomotif berwawasan teknologi ramah lingkungan. Penelitian menggunakan metode research and development dengan langkah-langkah: studi pendahuluan, perencanaan, pengembangan melalui uji coba simulator, validasi, dan produk akhir. Simulator dibuat sesuai dengan kondisi di dunia kerja agar tidak terjadi miskonsepsi dan mala-praktek automotive air conditioning. Simulator ini dibuat secara kompak dan mobile atau dapat dipindah dan dibawa. Model pembelajaran disesuaikan dengan kebutuhan kompetensi yang dipersyaratkan. Hasil penelitian menunjukkan bahwa dengan bantuan simulator automotive air conditioner dan model pembelajaran yang tepat mahasiswa mampu menyerap konsep dan praktek lebih cepat 85%. Hasil belajar pada ranah afektif, kognitif, psikomotor dan kompetensi meningkat secara signifikan.

76 FR 76762 - Notice of Lodging of Consent Decree Under the Clean Air Act

Science.gov (United States)

2011-12-08

... recovery at no additional cost; (2) no longer accept small appliances, motor vehicle air conditioners... DEPARTMENT OF JUSTICE Notice of Lodging of Consent Decree Under the Clean Air Act Notice is hereby.... Environmental Protection Agency (``U.S. EPA''), sought penalties and injunctive relief under the Clean Air Act...

76 FR 57764 - Notice of Lodging of Consent Decree Under the Clean Air Act

Science.gov (United States)

2011-09-16

... recovery at no additional cost; (2) no longer accept small appliances, motor vehicle air conditioners... DEPARTMENT OF JUSTICE Notice of Lodging of Consent Decree Under the Clean Air Act Notice is hereby... Agency (``U.S. EPA''), sought penalties and injunctive relief under the Clean Air Act (``CAA'') against...

Pulmonary function tests in air conditioner users

African Journals Online (AJOL)

McRoy

2014-07-26

Jul 26, 2014 ... Background: Modernization has been implicated in the pathogenesis of allergic airway diseases. House dust, mites, and indoor air pollutants have been reported to cause elevation of serum IgE levels and/or enhancement of eosinophil activity. A component of modern lifestyle is the intense use of ...

Concentrations of polybrominated diphenyl ethers (PBDEs) in central air-conditioner filter dust and relevance of non-dietary exposure in occupational indoor environments in Greece.

Science.gov (United States)

Besis, Athanasios; Katsoyiannis, Athanasios; Botsaropoulou, Elisavet; Samara, Constantini

2014-05-01

Polybrominated Diphenyl Ethers (PBDEs) are ubiquitous in the indoor environment owing to their use in consumer products and various studies around the world have found higher concentrations indoors than outdoors. Central air conditioner (A/C) systems have been widely used in many workplaces, therefore, studying of PBDEs in central A/C filter dust is useful to better understand the occurrences and health implications of PBDEs in indoor environments. The present study examined the occurrence of PBDEs in central A/C filter dust collected from various workplaces (n = 20) in Thessaloniki, Greece. The sum concentrations of 21 target congeners (∑21PBDE) in A/C dust ranged between 84 and 4062 ng g(-1) with a median value of 1092 ng g(-1), while BDE-209 was found to be the most abundant BDE congener. The daily intake via dust ingestion of PBDEs estimated for the employees of the occupational settings ranged from 3 to 45 ng day(-1) (median 12 ng day(-1)). Copyright © 2014 Elsevier Ltd. All rights reserved.

Air conditioning for data processing system areas

Directory of Open Access Journals (Sweden)

Hernando Camacho García

1996-09-01

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.

Use of nanoparticles to make mineral oil lubricants feasible for use in a residential air conditioner employing hydro-fluorocarbons refrigerants

Energy Technology Data Exchange (ETDEWEB)

Wang, Ruixiang [School of Energy and Power Engineering, Xi' an Jiaotong University 710049 Xi' an (China); School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, No. 1, Zhanlan Guan Road, Beijing 100044 (China); Wu, Qingping; Wu, Yezheng [School of Energy and Power Engineering, Xi' an Jiaotong University 710049 Xi' an (China)

2010-11-15

The application of nano-fluids in refrigerating systems is considered to be a potential way to improve the energy efficiency and reliability of HVAC and R facilities and to make economic the use of environment-friendly refrigerants. In this paper, we report a method that uses nanoparticles to enhance the energy efficiency of retrofitted residential air conditioners (RAC) employing HFCs as alternative refrigerants. The reliability and performance of RAC with nanoparticles in the working fluid have been investigated experimentally. A new mineral-based nano-refrigeration oil (MNRO), formed by blending some nanoparticles (NiFe{sub 2}O{sub 4}) into naphthene based oil B32, was employed in the RAC using R410a as refrigerant. A method showing how to disperse the NiFe{sub 2}O{sub 4} nanoparticles in the mineral oil refrigeration lubricants is presented together with an investigation of their stability. The solubilities of the new MNRO in R134a, R407C, R410a and R425a were measured. The performances of the RAC, such as the cooling/heating capacity, the power input and the energy efficiency ratio, were determined. The results indicate that the mixture of R410a/MNRO works normally in the RAC. The cooling/heating EER of the RAC increased about 6% by replacing the Polyol-Easter oil VG 32 lubricant with MNRO. (author)

Characteristics of indoor radon and its progeny in a Japanese dwelling while using air appliances.

Science.gov (United States)

Pornnumpa, C; Tokonami, S; Sorimachi, A; Kranrod, C

2015-11-01

Characteristics of radon and its progeny were investigated in different air conditions by turning four types of indoor air appliances on and off in a two-story concrete Japanese dwelling. The four appliances were air conditioner, air cleaner, gas heater and cooker hood. The measurements were done using two devices: (1) a Si-based semiconductor detector for continuous measurement of indoor radon concentration and (2) a ZnS(Ag) scintillation counting system for equilibrium-equivalent radon concentration. Throughout the entire experiment, the cooker hood was the most effective in decreasing indoor radon concentration over a long period of time and the less effective was the air conditioner, while the air cleaner and gas heater did not affect the concentration of radon. However, the results measured in each air condition will differ according to the lifestyles and activities of the inhabitants. In this study, indoor radon and its progeny in a Japanese dwelling will be characterised by the different air conditions. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Active power line conditioners design, simulation and implementation for improving power quality

CERN Document Server

Revuelta, Patricio Salmeron; Litrán, Salvador Pérez

2015-01-01

Active Power Line Conditioners: Design, Simulation and Implementation for Improving Power Quality presents a rigorous theoretical and practical approach to active power line conditioners, one of the subjects of most interest in the field of power quality. Its broad approach offers a journey that will allow power engineering professionals, researchers, and graduate students to learn more about the latest landmarks on the different APLC configurations for load active compensation. By introducing the issues and equipment needs that arise when correcting the lack of power quality in power grids

Characterization of the coal derived humic acids from Mukah, Sarawak as soil conditioner

Directory of Open Access Journals (Sweden)

Fong Sim Siong

2006-01-01

Full Text Available In Malaysia, abundant coal resources were found in Sarawak and Sabah. The utilization of coal resources, to date, is emphasized on the energy productions. The non-energy utilization as soil conditioner is unexplored. Therefore, this study attempted to characterize the coal humic acids extracted from Mukah coal and to evaluate its properties as soil conditioner. The coal humic acids from the regenerated sample were also assessed. The results revealed that different extractants and concentrations influenced the properties of humic acids. The extraction with KOH at 0.5 mol L-1 produced humic acids with low ash content and high acidic functional groups, which are substantial as soil conditioner. However, the yield was low. Regeneration of coal sample with 10% nitric acids improved the yield to an average of 83.45%. The acidic functional groups of nitrohumic acids were improved with the ash content remained at a low level.

Absorption spectrum and absorption cross sections of the 2ν1 band of HO2 between 20 and 760 Torr air in the range 6636 and 6639 cm-1

Science.gov (United States)

Assaf, Emmanuel; Liu, Lu; Schoemaecker, Coralie; Fittschen, Christa

2018-05-01

The absorption spectrum of HO2 radicals has been measured in the range 6636-6639 cm-1 at several pressures between 20 and 760 Torr of air. Absolute absorption cross sections of the strongest line at around 6638.2 cm-1 have been determined from kinetic measurements, taking advantage of the well known rate constant of the self-reaction. Peak absorption cross sections of 22.6, 19.5, 14.4, 7.88, 5.12 and 3.23 × 10-20 cm2 were obtained at 20, 50, 100, 200, 400 and 760 Torr, respectively. By fitting these data, an empirical expression has been obtained for the absorption cross section of HO2 in the range 20-760 Torr air: σ6638.2cm-1 = 1.18 × 10-20 + (2.64 × 10-19 × (1-exp (-63.1/p (Torr))) cm2.

High efficiency and long life of a three-phase power conditioner via interleave control

Directory of Open Access Journals (Sweden)

Kenji Amei

2016-01-01

Full Text Available This study describes the high efficiency and long life of three-phase power conditioners of a photovoltaic (PV system. The current PV system, which is widely spread, has two problems. The first problem is the lifetime of a power conditioner, whereas the other problem is the drop in the efficiency of the conversion because of the characteristics of the solar cell. For those problems, the solar panel and boost chopper circuit were divided into a plurality to configure a power conditioner, and an electrolytic capacitor-less driver with interleave control was realized. The drop in the current generated by the solar cell was suppressed, and an improvement in power generation efficiency was expected. The configuration and principle of a proposed circuit were explained, and results of simulation and experiment were reported.

Energy efficiency method of purification of water and air from bacteria

International Nuclear Information System (INIS)

Khaydarov, R.A.; Khaydarov, R.R.

2005-01-01

Full text: Creation of harmless and cheap water disinfection methods is one of important tasks today. Besides most of building ventilation systems and air conditioners using in many countries have inside some capacity of water as the component allowing to cooling air. There is a chance that if anthrax or legionella or several other dangerous bacteria will be entered in this water then such conditioners will become the source of infection, and it can lead to catastrophic consequences. To prevent this possibility we offer to set in each source of drinking water or air conditioner (especially those in public places) mini-size cheap energy-effective device developed using our new technology. This me of water disinfection is based on using of electrochemical processes treatment by electrostatic field. Experimental results from tests conducted in Uzbekistan, the United States, Russia, etc. concerning the destruction of vegetative forms of bacteria follow: Energy consumption of the unit with a production capacity of 5 cubic meters of water per hour did not exceed 50 watts. This is significantly less than conventional methods. The destruction time for bacteria did not exceed 60 minutes at a bacterial concentration 1000 CFU/L. Spores are more resistant to destruction than vegetative cells (orders of magnitude more difficult). Preliminary test results for destroying the spore form of bacteria follow: Bacteria destruction time was 2 hours at an initial concentration of 1000 CFU/L. Energy consumption of the unit with a production capacity of 5 cubic meters of water per hour did not exceed 50 watts The purpose of this work is further elaboration of this technology, and its accommodation to conditions of different countries. Test models will be made and tested in laboratories of interested countries. Research would be conducted with acceptable bacteria and analog spores. As the result, new cheap and energy-effective devices for disinfection of drinking water and defense of

Cogen-absorption plants for refrigeration purposes and turbine air inlet cooling

Energy Technology Data Exchange (ETDEWEB)

Langreck, Juergen [Colibri bv (Netherlands)

2000-04-01

Most cogeneration systems produce power and heat but with absorption refrigeration plants (ARP) the products are power and 'cold'. An ARP driven by heat from a turbine exhaust can provide the cooling for the inlet air with very low consumption of electricity, consequently there is a significant increase in power output from the cogeneration unit. Two different ARP systems are currently available but the author describes only the ammonia-water system, which can achieve temperatures down to -60 degrees C. The article discusses the principle behind ARP, the capital cost and returns on investment, how the cogeneration plant is linked to the ARP, ARP for turbine inlet air cooling, and the potential applications of cogeneration-ARP.

Characterization of water absorption by CFRP using air-coupled ultrasonic testing

International Nuclear Information System (INIS)

Lee, Joo Min; Lee, Joo Sung; Park, Ik Keun; Kim, Yong Kwon

2014-01-01

Carbon-fiber-reinforced plastic (CFRP) composites are increasingly being used in a variety of industry applications, such as aircraft, automobiles, and ships because of their high specific stiffness and high specific strength. Aircraft are exposed to high temperatures and high humidity for a long duration during flights. CFRP materials of the aircraft can absorb water, which could decrease the adhesion strength of these materials and cause their volumes to change with variation in internal stress. Therefore, it is necessary to estimate the characteristics of CFRP composites under actual conditions from the viewpoint of aircraft safety. In this study air-coupled ultrasonic testing (ACUT) was applied to the evaluation of water absorption properties of CFRP composites. CFRP specimens were fabricated and immersed in distilled water at 75 degree C for 30, 60, and 120 days, after which their ultrasonic images were obtained by ACUT. The water absorption properties were determined by quantitatively analyzing the changes in ultrasonic signals. Further, shear strength was applied to the specimens to verify the changes in their mechanical properties for water absorption.

Characterization of water absorption by CFRP using air-coupled ultrasonic testing

Energy Technology Data Exchange (ETDEWEB)

Lee, Joo Min; Lee, Joo Sung; Park, Ik Keun [Seoul National University of Science and Technology, Seoul (Korea, Republic of); Kim, Yong Kwon [Technology Research and Development Institute, KEPCO Plant Service and Engineering Co., Ltd, Naju (Korea, Republic of)

2014-04-15

Carbon-fiber-reinforced plastic (CFRP) composites are increasingly being used in a variety of industry applications, such as aircraft, automobiles, and ships because of their high specific stiffness and high specific strength. Aircraft are exposed to high temperatures and high humidity for a long duration during flights. CFRP materials of the aircraft can absorb water, which could decrease the adhesion strength of these materials and cause their volumes to change with variation in internal stress. Therefore, it is necessary to estimate the characteristics of CFRP composites under actual conditions from the viewpoint of aircraft safety. In this study air-coupled ultrasonic testing (ACUT) was applied to the evaluation of water absorption properties of CFRP composites. CFRP specimens were fabricated and immersed in distilled water at 75 degree C for 30, 60, and 120 days, after which their ultrasonic images were obtained by ACUT. The water absorption properties were determined by quantitatively analyzing the changes in ultrasonic signals. Further, shear strength was applied to the specimens to verify the changes in their mechanical properties for water absorption.

Performance of alternative refrigerants for residential air-conditioning applications

International Nuclear Information System (INIS)

Park, Ki-Jung; Seo, Taebeom; Jung, Dongsoo

2007-01-01

In this study, performances of two pure hydrocarbons and seven mixtures composed of propylene, propane, HFC152a, and dimethylether were measured to substitute for HCFC22 in residential air-conditioners and heat pumps. Thermodynamic cycle analysis was carried out to determine the optimum compositions before testing and actual tests were performed in a breadboard-type laboratory heat pump/air-conditioner at the evaporation and condensation temperatures of 7 and 45 deg. C, respectively. Test results show that the coefficient of performance of these mixtures is up to 5.7% higher than that of HCFC22. While propane showed a 11.5% reduction in capacity, most of the fluids had a similar capacity to that of HCFC22. For these fluids, compressor-discharge temperatures were reduced by 11-17 deg. C. For all fluids tested, the amount of charge was reduced by up to 55% as compared to HCFC22. Overall, these fluids provide good performances with reasonable energy-savings without any environmental problem and thus can be used as long-term alternatives for residential air-conditioning and heat-pumping applications

24 CFR 3280.511 - Comfort cooling certificate and information.

Science.gov (United States)

2010-04-01

... following shall be supplied in the Comfort Cooling Certificate: Air Conditioner Manufacturer Air Conditioner... Conditioner Manufacturer Certified Capacity ___ BTU/Hr. in accordance with the appropriate Air Conditioning... such air conditioners are rated at 0.3 inch water column static pressure or greater for the cooling air...

Analisa Performansi Sistem Air Conditioning Mobil tipe ET 450 dengan Variasi Tekanan Kerja Kompresor

Directory of Open Access Journals (Sweden)

Adi Purnawan

2012-11-01

Full Text Available Comfort and coolness when traveling by vehicle especially car is highly needed. So many attempts have been made byhumans that comfortable traveling by car can be achieved. One of the effective ways in which comfortable traveling by car can beobtained is by installing air conditioning. The performance of air conditioning system is highly influenced by how the compressorworks. In other words, the pressure resulting from the suction highly determines the performance of air conditioning system,which then affects how the compressor works, the compressor power, the refrigeration effect, the efficiency of isentropic andcoefficient of performance (COP of the car air conditioning sytem especially that of the car air conditioner type ET 450. Fromwhat has been described above, the writer would like to conduct a research entiled “ Analysis of the Performance of the Car AirConditioning system Type ET 450 with Variation of the Compressor Pressure”.The test was conducted on the car air conditioner type ET 450 with variations of suction 2.8 bar, 3 bar, 3.2 bar, 3.4bar, 3.6 bar and 3.8 bar. The data were obtained from the pressure of compressor output (P2, the temperatures in each point areT1, T2, T3, T4, the compressor rotationn is n, the strength of electrical current is I, and the volumetric flow rate. The data werethen processed and analyzed so that so that the performance of each variation of the suction could be actually and theoreticallyobtained.The findings show that the bigger the suction, the bigger the performance of the car air conditioner type ET 450 wouldbe. The theoretical coefficient of performance (COP produced was bigger than the actual COP. The optimal COP took placewhen the suction was 441.325 kPa, the actual COP was 3.513177 and the theoretical COP was 3.632062

Comparative scanning electron microscopic study of the effect of different dental conditioners on dentin micromorphology

Directory of Open Access Journals (Sweden)

Alexandre Henrique Susin

2008-04-01

Full Text Available This study evaluated comparatively by scanning electron microscopy (SEM the effect of different dental conditioners on dentin micromorphology, when used according to the same protocol. Forty dentin sticks were obtained from 20 caries-free third human molars and were assigned to 4 groups corresponding to 3 conditioners (phosphoric acid 37%, Clearfil SE Bond and iBond and an untreated control group. After application of the conditioners, the specimens were immersed in 50% ethanol solution during 10 s, chemically fixed and dehydrated to prepare them to SEM analysis. In the control group, dentin surface was completely covered by smear layer and all dentinal tubules were occluded. In the phosphoric acid-etched group, dentin surface was completely clean and presented exposed dentinal tubule openings; this was the only group in which the tubules exhibited the funnel-shaped aspect. In the groups conditioned with Clearfil SE Bond primer and iBond, which are less acidic than phosphoric acid, tubule openings were occluded or partially occluded, though smear layer removal was observed. SE Bond was more efficient in removing the smear layer than iBond. In the Clearfil SE Bond group, the cuff-like aspect of peritubular dentin was more evident. It may be concluded all tested conditioners were able to change dentin morphology. However, it cannot be stated that the agent aggressiveness was the only cause of the micromorphological alterations because a single morphological pattern was not established for each group, but rather an association of different aspects, according to the aggressiveness of the tested conditioner.

Shampoo and Conditioners: What a Dermatologist Should Know?

Science.gov (United States)

D'Souza, Paschal; Rathi, Sanjay K

2015-01-01

Dermatologists many a times encounter questions from patients and even colleagues asking about how to keep their hair looking clean, healthy and beautiful. Therefore, familiarity and a basic knowledge of the available hair care products will help them to guide their patients properly. A shampoo not only provides the cleaning of the scalp skin and hair as its primary function, but in addition also serves to condition and beautify hair and acts as an adjunct in the management of various scalp disorders. To achieve this, various ingredients in the correct proportion are mixed to provide a shampoo which is suitable for individuals having different hair types and hair need. Among the ingredients that go into the making of a shampoo are detergents, conditioners, thickeners, sequestering agents, pH adjusters, preservatives and specialty additives. Hair conditioners are designed to improve hair manageability, decrease hair static electricity and add luster. They are used in several ways depending upon the state of hair and requirement of the individual. This article attempts to put forward the basic and practical aspects regarding use of these products.

Sound absorption and transmission through flexible micro-perforated panels backed by an air layer and a thin plate.

Science.gov (United States)

Bravo, Teresa; Maury, Cédric; Pinhède, Cédric

2012-05-01

This paper describes theoretical and experimental investigations into the sound absorption and transmission properties of micro-perforated panels (MPP) backed by an air cavity and a thin plate. A fully coupled modal approach is proposed to calculate the absorption coefficient and the transmission loss of finite-sized micro-perforated panels-cavity-panel (MPPCP) partitions with conservative boundary conditions. It is validated against infinite partition models and experimental data. A practical methodology is proposed using collocated pressure-velocity sensors to evaluate in an anechoic environment the transmission and absorption properties of conventional MPPCPs. Results show under which conditions edge scattering effects should be accounted for at low frequencies. Coupled mode analysis is also performed and analytical approximations are derived from the resonance frequencies and mode shapes of a flexible MPPCP. It is found that the Helmholtz-type resonance frequency is deduced from the one associated to the rigidly backed MPPCP absorber shifted up by the mass-air mass resonance of the flexible non-perforated double-panel. Moreover, it is shown analytically and experimentally that the absorption mechanisms at the resonances are governed by a large air-frame relative velocity over the MPP surface, with either in-phase or out-of-phase relationships, depending on the MPPCP parameters.

Current Evaluation Procedures for Fertilizers and Soil Conditioners Used in Organic Agriculture. Proceedings of a workshop held April 29–30, 2004 at Emerson College, Great Britain

OpenAIRE

Canali, Stefano; Stopes, Christopher; Schmid, Otto; Speiser, Bernhard

2005-01-01

Table of Contents Fertilizers and soil conditioners in organic farming in Austria Alexandra Hozzank and Wilfried Hartl Fertilizers and soil conditioners in organic farming in the Czech Republic Anamarija Slabe Fertilizers and soil conditioners in organic farming in Denmark Rasmus Ørnberg Eriksen and Erik Steen Kristensen Fertilizers and soil conditioners in organic farming in France Marie-Christine Monnier Fertilizers and soil conditioners in organic fa...

Small photovoltaic setup for the air conditioning system

Directory of Open Access Journals (Sweden)

Masiukiewicz Maciej

2017-01-01

Full Text Available The increasing interest in air conditioning systems for residential applications in Poland will certainly increase the demand for electricity during the summer period. Due to this fact a growing interest in solutions that help to lower the electricity consumption in this sector is observed. The problem of increased energy demand for air conditioning purposes can be solved by transfer the consumption of electricity from the grid system to renewable energy sources (RES. The greatest demand for cooling occurs during the biggest sunlight. This is the basis for the analysis of technical power system based on photovoltaic cells (PV to power the split type air conditioner. The object of the study was the commercial residential airconditioning inverter units with a capacity of 2.5kW. A network electricity production system for their own use with the possibility of buffering energy in batteries (OFF-GRID system. Currently, on the Polish market, there are no developed complete solutions dedicated to air conditioning systems based on PV. In Poland, solar energy is mainly used for heat production in solar collectors. The proposed solution will help to increase the popularity of PV systems in the Polish market as an alternative to other RES. The basic conclusion is that the amount of PV energy generated was sufficient to cover the daily energy requirement of the air conditioner.

Small photovoltaic setup for the air conditioning system

Science.gov (United States)

Masiukiewicz, Maciej

2017-10-01

The increasing interest in air conditioning systems for residential applications in Poland will certainly increase the demand for electricity during the summer period. Due to this fact a growing interest in solutions that help to lower the electricity consumption in this sector is observed. The problem of increased energy demand for air conditioning purposes can be solved by transfer the consumption of electricity from the grid system to renewable energy sources (RES). The greatest demand for cooling occurs during the biggest sunlight. This is the basis for the analysis of technical power system based on photovoltaic cells (PV) to power the split type air conditioner. The object of the study was the commercial residential airconditioning inverter units with a capacity of 2.5kW. A network electricity production system for their own use with the possibility of buffering energy in batteries (OFF-GRID system). Currently, on the Polish market, there are no developed complete solutions dedicated to air conditioning systems based on PV. In Poland, solar energy is mainly used for heat production in solar collectors. The proposed solution will help to increase the popularity of PV systems in the Polish market as an alternative to other RES. The basic conclusion is that the amount of PV energy generated was sufficient to cover the daily energy requirement of the air conditioner.

How motor vehicles contribute to global warming and air pollution

International Nuclear Information System (INIS)

Anon.

1990-01-01

In this chapter, the authors describe ways in which motor vehicles are contributing to global climate change and health problems caused by air pollution. Globally, motor vehicles account for about a third of world oil consumption and about 14% of the world's carbon dioxide emissions from fossil fuel burning. For the US the figures are 50% of oil demand and about 25% of carbon dioxide emissions. Motor vehicles are the major source of ozone precursors and monitoring data suggest that ozone concentrations are increasing by about one percent per year in the northern hemisphere and are causing adverse effects on human health and on crops. A major source of chlorofluorocarbons in the atmosphere is motor vehicle air conditioning. Annually about 120,000 metric tons of CFCs are used in new vehicles and in serving air conditioners in older vehicles. According to the EPA, vehicle air conditioners accounted for about 16% of the total CFC use in the US during 1989. According to the Montreal Protocol, CFCs are to be completely phased out of new vehicles by the turn of the century, thus reducing the depletion of the stratospheric ozone layer

Indirect determination of uranium by atomic-absorption spectrophotometry using an air-acetylene flame

International Nuclear Information System (INIS)

Alder, J.F.; Das, B.C.

1977-01-01

An indirect method has been developed for the determination of uranium by atomic-absorption spectrophotometry using an air-acetylene flame. Use is made of the reduction of copper(II) by uranium(IV) followed by complex formation of the copper(I) ions so produced with neocuproine (2,9-dimethyl-1,10-phenanthroline) and finally the determination of copper in this complex by atomic-absorption spectrophotometry. The results show that the method can be recommended, provided that care is taken to ensure the complete reduction of uranium(VI) to uranium(IV). The sensitivity of the method is 4.9 μg of uranium and the upper limit 500 μg without dilution. (author)

Simulation Models of Leaf Area Index and Yield for Cotton Grown with Different Soil Conditioners.

Directory of Open Access Journals (Sweden)

Lijun Su

Full Text Available Simulation models of leaf area index (LAI and yield for cotton can provide a theoretical foundation for predicting future variations in yield. This paper analyses the increase in LAI and the relationships between LAI, dry matter, and yield for cotton under three soil conditioners near Korla, Xinjiang, China. Dynamic changes in cotton LAI were evaluated using modified logistic, Gaussian, modified Gaussian, log normal, and cubic polynomial models. Universal models for simulating the relative leaf area index (RLAI were established in which the application rate of soil conditioner was used to estimate the maximum LAI (LAIm. In addition, the relationships between LAIm and dry matter mass, yield, and the harvest index were investigated, and a simulation model for yield is proposed. A feasibility analysis of the models indicated that the cubic polynomial and Gaussian models were less accurate than the other three models for simulating increases in RLAI. Despite significant differences in LAIs under the type and amount of soil conditioner applied, LAIm could be described by aboveground dry matter using Michaelis-Menten kinetics. Moreover, the simulation model for cotton yield based on LAIm and the harvest index presented in this work provided important theoretical insights for improving water use efficiency in cotton cultivation and for identifying optimal application rates of soil conditioners.

[Evaluation of uncertainty for determination of tin and its compounds in air of workplace by flame atomic absorption spectrometry].

Science.gov (United States)

Wei, Qiuning; Wei, Yuan; Liu, Fangfang; Ding, Yalei

2015-10-01

To investigate the method for uncertainty evaluation of determination of tin and its compounds in the air of workplace by flame atomic absorption spectrometry. The national occupational health standards, GBZ/T160.28-2004 and JJF1059-1999, were used to build a mathematical model of determination of tin and its compounds in the air of workplace and to calculate the components of uncertainty. In determination of tin and its compounds in the air of workplace using flame atomic absorption spectrometry, the uncertainty for the concentration of the standard solution, atomic absorption spectrophotometer, sample digestion, parallel determination, least square fitting of the calibration curve, and sample collection was 0.436%, 0.13%, 1.07%, 1.65%, 3.05%, and 2.89%, respectively. The combined uncertainty was 9.3%.The concentration of tin in the test sample was 0.132 mg/m³, and the expanded uncertainty for the measurement was 0.012 mg/m³ (K=2). The dominant uncertainty for determination of tin and its compounds in the air of workplace comes from least squares fitting of the calibration curve and sample collection. Quality control should be improved in the process of calibration curve fitting and sample collection.

Room Air Conditioners; Appliance Repair--Advanced: 9027.04.

Science.gov (United States)

Dade County Public Schools, Miami, FL.

This Quinmester course includes installations, electrical and mechanical servicing, reverse cycle air conditioning, malfunctions, troubleshooting and repair, discharge, pump down, and recharging the system. The course may be taught as a two or three Quinmester credit course. In each instance the course consists of six instructional blocks:…

Locally produced natural conditioners for dewatering of faecal sludge.

Science.gov (United States)

Gold, Moritz; Dayer, Pauline; Faye, Marie Christine Amie Sene; Clair, Guillaume; Seck, Alsane; Niang, Seydou; Morgenroth, Eberhard; Strande, Linda

2016-11-01

In urban areas of low-income countries, treatment of faecal sludge (FS) is insufficient or non-existent. This results in large amounts of FS being dumped into the environment. Existing treatment technologies for FS, such as settling-thickening tanks and drying beds, are land intensive which is limiting in urban areas. Enhanced settling and dewatering by conditioning was evaluated in order to reduce the treatment footprint (or increase treatment capacity). Conventional wastewater conditioners, such as commercially available lime and polymers, are expensive, and commonly rely on complex supply chains for use in low-income countries. Therefore, the treatment performance of five conditioners which could be produced locally was evaluated: Moringa oleifera seeds and press cake, Jatropha curcas seeds, Jatropha Calotropis leaves and chitosan. M. oleifera seeds and press cake, and chitosan improved settling and dewatering and had a similar performance compared to lime and polymers. Optimal dosages were 400-500 kg M. oleifera/t TS, 300-800 kg lime/t TS and 25-50 kg polymer solution/t TS. In comparison, chitosan required 1.5-3.75 kg/t TS. These dosages are comparable to those recommended for wastewater (sludge). The results indicate that conditioning of FS can reduce total suspended solids (TSS) in the effluent of settling-thickening tanks by 22-81% and reduce dewatering time with drying beds by 59-97%. This means that the area of drying beds could be reduced by 59-97% with end-use as soil conditioner, or 9-26% as solid fuel. Least expensive options and availability will depend on the local context. In Dakar, Senegal, chitosan produced from shrimp waste appears to be most promising.

Air conditioning system

Science.gov (United States)

Lowenstein, Andrew; Miller, Jeffrey; Gruendeman, Peter; DaSilva, Michael

2005-02-01

An air conditioner comprises a plurality of plates arranged in a successively stacked configuration with portions thereof having a spaced apart arrangement, and defining between successive adjacent pairs of plates at the spaced apart portions a first and second series of discrete alternating passages wherein a first air stream is passed through the first series of passages and a second air stream is passed through the second series of passages; and said stacked configuration of plates forming integrally therewith a liquid delivery means for delivering from a source a sufficient quantity of a liquid to the inside surfaces of the first series of fluid passages in a manner which provides a continuous flow of the liquid from a first end to a second end of the plurality of plates while in contact with the first air stream.

Measurement of the mass energy-absorption coefficient of air for x-rays in the range from 3 to 60 keV.

Science.gov (United States)

Buhr, H; Büermann, L; Gerlach, M; Krumrey, M; Rabus, H

2012-12-21

For the first time the absolute photon mass energy-absorption coefficient of air in the energy range of 10 to 60 keV has been measured with relative standard uncertainties below 1%, considerably smaller than those of up to 2% assumed for calculated data. For monochromatized synchrotron radiation from the electron storage ring BESSY II both the radiant power and the fraction of power deposited in dry air were measured using a cryogenic electrical substitution radiometer and a free air ionization chamber, respectively. The measured absorption coefficients were compared with state-of-the art calculations and showed an average deviation of 2% from calculations by Seltzer. However, they agree within 1% with data calculated earlier by Hubbell. In the course of this work, an improvement of the data analysis of a previous experimental determination of the mass energy-absorption coefficient of air in the range of 3 to 10 keV was found to be possible and corrected values of this preceding study are given.

Passive air conditioning methods for different climates, special ...

African Journals Online (AJOL)

One of the most important parameters to be considered in life's style and life's situations of human is the comfort. The usual tools for making thermal comfort are traditional mechanical air conditioners. The disadvantage of them is using much energy and also being dangerous for environment ecological system. Therefore ...

Cavity Enhanced Absorption Spectroscopy in Air Pollution Monitoring

Directory of Open Access Journals (Sweden)

Janusz MIKOŁAJCZYK

2015-10-01

Full Text Available The paper presents some practical aspects of cavity enhanced absorption spectroscopy application in detection of nitrogen dioxide (NO2, nitrous oxide (N2O, nitric oxide (NO and carbon monoxide (CO. These gases are very important for monitoring of environment. There are shown results of lab-setups for N2O, NO, CO detection and portable sensor of NO2. The portable instrument operates in the UV spectral range and reaches a level of single ppb. The lab–devices use high precision mid-infrared spectroscopy and they was demonstrated during testing the laboratory air. These sensors are able to measure concentration at the ppb level using quantum cascade lasers, high quality optical cavities and modern MCT detection modules. It makes it possible to apply such sensors in monitoring the atmosphere quality.

Shampoo and conditioners: What a dermatologist should know?

Directory of Open Access Journals (Sweden)

Paschal D′Souza

2015-01-01

Full Text Available Dermatologists many a times encounter questions from patients and even colleagues asking about how to keep their hair looking clean, healthy and beautiful. Therefore, familiarity and a basic knowledge of the available hair care products will help them to guide their patients properly. A shampoo not only provides the cleaning of the scalp skin and hair as its primary function, but in addition also serves to condition and beautify hair and acts as an adjunct in the management of various scalp disorders. To achieve this, various ingredients in the correct proportion are mixed to provide a shampoo which is suitable for individuals having different hair types and hair need. Among the ingredients that go into the making of a shampoo are detergents, conditioners, thickeners, sequestering agents, pH adjusters, preservatives and specialty additives. Hair conditioners are designed to improve hair manageability, decrease hair static electricity and add luster. They are used in several ways depending upon the state of hair and requirement of the individual. This article attempts to put forward the basic and practical aspects regarding use of these products.

Transforming PC Power Supplies into Smart Car Battery Conditioners

Science.gov (United States)

Rodriguez-Ascariz, J. M.; Boquete-Vazquez, L.

2011-01-01

This paper describes a laboratory project consisting of a PC power supply modification into an intelligent car-battery conditioner with both wireless and wired networking capabilities. Adding a microcontroller to an average PC power supply transforms it into a flexible, intelligent device that can be configured and that is suitable to keep car…

On the performance of air conditioner with heat pipe for cooling air in the condenser

Energy Technology Data Exchange (ETDEWEB)

Naphon, Paisarn, E-mail: paisarnn@swu.ac.t [Thermo-Fluids and Heat Transfer Enhancement Laboratory (TFHT), Department of Mechanical Engineering, Faculty of Engineering, Srinakharinwirot University, 63 Rangsit-Nakhornnayok Rd., Ongkharak, Nakhorn-Nayok 26120 (Thailand)

2010-11-15

Improvement of the air conditioning system performance by using the heat pipe for cooling air before entering the condenser is presented. In the experiment, the heat pipe is fabricated from the straight copper tube with the diameter and length of 10, 600 mm, respectively. The arrangements of the heat pipe sets are arranged in the staggered layout with the tube rows of 1, 2, 3. R134a refrigerant is used as working fluid in the heat pipe set for this present study. By comparing with a conventional air conditioning system, the air conditioning system with three rows of heat pipe gives the highest COP and EER with increasing of 6.4%, 17.5%, respectively. On the global warming and environment problems, the results of this study are expected to lead to guidelines that will allow the improved performance of the air conditioning systems which reduce its energy consumption.

On the performance of air conditioner with heat pipe for cooling air in the condenser

International Nuclear Information System (INIS)

Naphon, Paisarn

2010-01-01

Improvement of the air conditioning system performance by using the heat pipe for cooling air before entering the condenser is presented. In the experiment, the heat pipe is fabricated from the straight copper tube with the diameter and length of 10, 600 mm, respectively. The arrangements of the heat pipe sets are arranged in the staggered layout with the tube rows of 1, 2, 3. R134a refrigerant is used as working fluid in the heat pipe set for this present study. By comparing with a conventional air conditioning system, the air conditioning system with three rows of heat pipe gives the highest COP and EER with increasing of 6.4%, 17.5%, respectively. On the global warming and environment problems, the results of this study are expected to lead to guidelines that will allow the improved performance of the air conditioning systems which reduce its energy consumption.

A questionnaire survey on sleeping thermal environment and bedroom air conditioning in high-rise residences in Hong Kong

Energy Technology Data Exchange (ETDEWEB)

Lin, Z. [Institute of Heating, Ventilation, Air Conditioning and Gas Engineering, Tongji University, Shanghai (China); Deng, S. [Department of Building Services Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR (China)

2006-07-01

This paper reports on the results of a questionnaire survey on sleeping thermal environment and bedroom air conditioning in high-rise residential buildings in Hong Kong. The survey aimed at investigating the current situation of sleeping thermal environment and bedroom air conditioning, in order to gather relevant background information to develop strategies for bedroom air conditioning in the subtropics. It focused on the use patterns and types of bedroom air conditioning systems used, human factors such as the use of bedding and sleep wear during sleep, preference for indoor air temperature settings in bedrooms, ventilation control at nighttime with room air conditioner (RAC) turned on, etc. The results of the survey showed that most of the respondents would prefer a relatively low indoor air temperature at below 24 {sup o}C. Most of the respondents might however not be satisfied with the indoor air quality (IAQ) in bedrooms in Hong Kong. On the other hand, 68% of the respondents did not use any ventilation control intentionally during their sleep with their RACs turned on. A lack of knowledge of the ventilation control devices provided on window type room air conditioners (WRACs) indicated an urgent need for user education. (author)

Effects of component performance on overall performance of R410A air conditioner with oil flooding and regeneration

International Nuclear Information System (INIS)

Luo, Baojun

2016-01-01

Highlights: • COP benefits more than cooling capacity with regenerator. • High oil temperature leads to degradation of the system. • The improvement brought by oil flooding was greatly reduced by solubility. • A modified system is proposed for reducing the negative effects of solubility. • Comprehensive effects of regenerator, oil temperature and solubility are obtained. - Abstract: Oil flooded compression with regenerator (OFCR) is one of the possible technologies to improve the performance of air conditioner. The addition of OFCR system to basic vapor compression system adds several components: oil separator, oil cooler and regenerator. These components can lead to a significant increase in performance. In this study, parametric studies of these components performance have been carried out under various operating conditions. Compared with basic vapor compression system, COP of OFCR system with 100% effective regenerator is improved by 0.7–11.8% while COP of OFCR system without regenerator is reduced by 0.6–1.8%. When oil temperature exiting the oil cooler reaches 40 °C and 50 °C, the performance of OFCR system is worse than that of basic system at evaporation temperature T_e = 15 °C and T_e ⩾ 5 °C respectively. COP and cooling capacity of OFCR with solubility are decreased by 6.9% and 14.3% respectively at T_e = 5 °C and 0.4 oil mass fraction. A modification of OFCR system is suggested for reducing the negative effects of solubility. The results of COP and cooling capacity show that the modified OFCR system has a 3–4% performance improvement. Comprehensive effects of regenerator efficiency, oil temperature and solubility are also studied. Taking the solubility into account, the effects of regenerator efficiency and oil temperature are slightly different from that without solubility.

Optimal heat rejection pressure in transcritical carbon dioxide air conditioning and heat pump systems

DEFF Research Database (Denmark)

Liao, Shengming; Jakobsen, Arne

1998-01-01

Due to the urgent need for environmentally benign refrigerants, the use of the natural substance carbon dioxide in refrigeration systems has gained more and more attention. In systems such as automobile air-conditioners and heat pumps, owing to the relatively high heat rejection temperatures, the...... dioxide air conditioning or heat pump systems and for intelligent controlling such systems.......Due to the urgent need for environmentally benign refrigerants, the use of the natural substance carbon dioxide in refrigeration systems has gained more and more attention. In systems such as automobile air-conditioners and heat pumps, owing to the relatively high heat rejection temperatures......, the cycles using carbon dioxide as refrigerant will have to operate in the transcritical area. In a transcritical carbon dioxide system, there is an optimal heat rejection pressure that gives a maximum COP. In this paper, it is shown that the value of this optimal heat rejection pressure mainly depends...

Thermionic reactor power conditioner design for nuclear electric propulsion.

Science.gov (United States)

Jacobsen, A. S.; Tasca, D. M.

1971-01-01

Consideration of the effects of various thermionic reactor parameters and requirements upon spacecraft power conditioning design. A basic spacecraft is defined using nuclear electric propulsion, requiring approximately 120 kWe. The interrelationships of reactor operating characteristics and power conditioning requirements are discussed and evaluated, and the effects on power conditioner design and performance are presented.

Solar air-conditioning. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

European countries (Ignasi Gurruchaga); (21) Optimisation potential of a large solar adsorption cooling plant (Antoine Dalibard); (22) Planning, commissioning and practical experience with first summer of operation of a cost effective solar air conditioning system for a Canteen at Munich Airport (Carsten Hindenburg); (23) Energy and economic performance of solar cooling systems (Ursula Eicker); (24) Solar-driven adsorption chiller controlled by hot and cooling water temperature (Jan Albers); (25) Comparative results of monitored solar assisted heating and cooling installations (Wolfram Sparber); (26) Heating and cooling with a small scale solar driven adsorption chiller combined with a borehole system - recent results (Tomas Nunez); (27) Solar heating and cooling - Town hall Gleisdorf (Alexander Thuer); (28) Solar dessicant cooling system operating in Palermo (Italy): Results and Validation of simulation models (Marco Beccali); (29) The application of a liquid-dessicant air conditioner to solar cooling (Andrew Lowenstein); (30) A compact solid adsorption chiller for solar air conditioning (Robert Critoph); (31) Development of a two-stage absorption chiller for solar-assisted cooling and heating (Manuel Riepl); (32) Ionic liquids - a promising solution for solar absorption chillers? (Annett Kuehn);(33) Parabolic trough design optimization for high temperature lift solar cooling applications (Marcello Aprile); (34) Tentative R and D program forgetting adsorbents effective for solar air conditioning (Yury Aristov); (35) An energy efficient solar driven two-stage rotary desiccant cooling system: Experiment and case study (Yanjun Dai); (36) Performance of a flat plate collector-regenerator that uses earth-to-air heat exchangers for regeneration of water-lithium chloride solution in a solar coolant plant (Roberto Bruno); (37) 350 KW of dual solar cooling for optimal flexibility and economic performance (Roel de Coninck); (38) Global performance of a solar absorption cooling

Future Air Conditioning Energy Consumption in Developing Countriesand what can be done about it: The Potential of Efficiency in theResidential Sector

Energy Technology Data Exchange (ETDEWEB)

McNeil, Michael A.; Letschert, Virginie E.

2007-05-01

The dynamics of air conditioning are of particular interestto energy analysts, both because of the high energy consumption of thisproduct, but also its disproportionate impact on peak load. This paperaddresses the special role of this end use as a driver of residentialelectricity consumption in rapidly developing economies. Recent historyhas shown that air conditioner ownership can grow grows more rapidly thaneconomic growth in warm-climate countries. In 1990, less than a percentof urban Chinese households owned an air conditioner; by 2003 this numberrose to 62 percent. The evidence suggests a similar explosion of airconditioner use in many other countries is not far behind. Room airconditioner purchases in India are currently growing at 20 percent peryear, with about half of these purchases attributed to the residentialsector. This paper draws on two distinct methodological elements toassess future residential air conditioner 'business as usual' electricityconsumption by country/region and to consider specific alternative 'highefficiency' scenarios. The first component is an econometric ownershipand use model based on household income, climate and demographicparameters. The second combines ownership forecasts and stock accountingwith geographically specific efficiency scenarios within a uniqueanalysis framework (BUENAS) developed by LBNL. The efficiency scenariomodule considers current efficiency baselines, available technologies,and achievable timelines for development of market transformationprograms, such as minimum efficiency performance standards (MEPS) andlabeling programs. The result is a detailed set of consumption andemissions scenarios for residential air conditioning.

A fundamentally new approach to air-cooled heat exchangers.

Energy Technology Data Exchange (ETDEWEB)

Koplow, Jeffrey P.

2010-01-01

We describe breakthrough results obtained in a feasibility study of a fundamentally new architecture for air-cooled heat exchangers. A longstanding but largely unrealized opportunity in energy efficiency concerns the performance of air-cooled heat exchangers used in air conditioners, heat pumps, and refrigeration equipment. In the case of residential air conditioners, for example, the typical performance of the air cooled heat exchangers used for condensers and evaporators is at best marginal from the standpoint the of achieving maximum the possible coefficient of performance (COP). If by some means it were possible to reduce the thermal resistance of these heat exchangers to a negligible level, a typical energy savings of order 30% could be immediately realized. It has long been known that a several-fold increase in heat exchanger size, in conjunction with the use of much higher volumetric flow rates, provides a straight-forward path to this goal but is not practical from the standpoint of real world applications. The tension in the market place between the need for energy efficiency and logistical considerations such as equipment size, cost and operating noise has resulted in a compromise that is far from ideal. This is the reason that a typical residential air conditioner exhibits significant sensitivity to reductions in fan speed and/or fouling of the heat exchanger surface. The prevailing wisdom is that little can be done to improve this situation; the 'fan-plus-finned-heat-sink' heat exchanger architecture used throughout the energy sector represents an extremely mature technology for which there is little opportunity for further optimization. But the fact remains that conventional fan-plus-finned-heat-sink technology simply doesn't work that well. Their primary physical limitation to performance (i.e. low thermal resistance) is the boundary layer of motionless air that adheres to and envelops all surfaces of the heat exchanger. Within this

Dynamic modeling of brushless dc motor-power conditioner unit for electromechanical actuator application

Science.gov (United States)

Demerdash, N. A.; Nehl, T. W.

1979-01-01

A comprehensive digital model for the analysis of the dynamic-instantaneous performance of a power conditioner fed samarium-cobalt permanent magnet brushless DC motor is presented. The particular power conditioner-machine system at hand, for which this model was developed, is a component of an actual prototype electromechanical actuator built for NASA-JSC as a possible alternative to hydraulic actuators as part of feasibility studies for the shuttle orbiter applications. Excellent correlation between digital simulated and experimentally obtained performance data was achieved for this specific prototype. This is reported on in this paper. Details of one component of the model, its applications and the corresponding results are given in this paper.

The effect of sealer and water storage on permanent deformation of a tissue conditioner

Directory of Open Access Journals (Sweden)

Rafael Leonardo Xediek Consani

2008-01-01

Full Text Available When they are used to treat inflamed, irritated, or distorted tissues or in implant therapy, tissue conditioners are required to function over relatively long time periods. Purpose: This in vitro study evaluated the effect of sealer and water storage on permanent deformation one tissue conditioner. Material and methods: Sixty cylindrically-shaped specimens (12.7-mm diameter 3 19.0-mm height were used for the deformation tests. Specimens were divided into 6 test groups (n=10, according to surface treatment (sealer application and water storage (1 hour, 1 week and 2 weeks. Permanent deformation, expressed as a percent (%, was determined using ADA specification no. 18. Data were examined a analysis of variance and a Mann-Whitney test (a= 0.05. Results: Significant differences were observed only after 1 week of water storage, for both groups. The surface treated group presented the highest permanent deformation percentage. Conclusions: This in vitro study indicated that the tissue conditioner evaluated is only useful for 1 week. After this period, the material must be replaced.

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

International Nuclear Information System (INIS)

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

1998-01-01

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

76 FR 37407 - Energy Conservation Program: Energy Conservation Standards for Residential Furnaces and...

Science.gov (United States)

2011-06-27

.... Background 1. Current Standards a. Furnaces b. Central Air Conditioners and Heat Pumps 2. History of... Compliance Requirements a. Central Air Conditioning and Heat Pumps b. Residential Furnaces 3. Duplication... residential central air conditioners and central air conditioning heat pumps (air conditioners and heat pumps...

Aerosol Light Absorption and Scattering Assessments and the Impact of City Size on Air Pollution

Science.gov (United States)

Paredes-Miranda, Guadalupe

The general problem of urban pollution and its relation to the city population is examined in this dissertation. A simple model suggests that pollutant concentrations should scale approximately with the square root of city population. This model and its experimental evaluation presented here serve as important guidelines for urban planning and attainment of air quality standards including the limits that air pollution places on city population. The model was evaluated using measurements of air pollution. Optical properties of aerosol pollutants such as light absorption and scattering plus chemical species mass concentrations were measured with a photoacoustic spectrometer, a reciprocal nephelometer, and an aerosol mass spectrometer in Mexico City in the context of the multinational project "Megacity Initiative: Local And Global Research Observations (MILAGRO)" in March 2006. Aerosol light absorption and scattering measurements were also obtained for Reno and Las Vegas, NV USA in December 2008-March 2009 and January-February 2003, respectively. In all three cities, the morning scattering peak occurs a few hours later than the absorption peak due to the formation of secondary photochemically produced aerosols. In particular, for Mexico City we determined the fraction of photochemically generated secondary aerosols to be about 75% of total aerosol mass concentration at its peak near midday. The simple 2-d box model suggests that commonly emitted primary air pollutant (e.g., black carbon) mass concentrations scale approximately as the square root of the urban population. This argument extends to the absorption coefficient, as it is approximately proportional to the black carbon mass concentration. Since urban secondary pollutants form through photochemical reactions involving primary precursors, in linear approximation their mass concentration also should scale with the square root of population. Therefore, the scattering coefficient, a proxy for particulate matter

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.

Measure Guideline: Air Conditioner Diagnostics, Maintenance, and Replacement

Energy Technology Data Exchange (ETDEWEB)

Springer, D.; Dakin, B.

2013-03-01

This guideline responds to the need for an efficient means of identifying, diagnosing, and repairing faults in air conditioning systems in existing homes that are undergoing energy upgrades. Inadequate airflow due to constricted ducts or undersized filters, improper refrigerant charge, and other system defects can be corrected at a fraction of the cost of equipment replacement and can yield significant savings. The guideline presents a two-step approach to diagnostics and repair.

Measure Guideline. Air Conditioner Diagnostics, Maintenance, and Replacement

Energy Technology Data Exchange (ETDEWEB)

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

2013-03-01

This guideline responds to the need for an efficient means of identifying, diagnosing, and repairing faults in air conditioning systems in existing homes that are undergoing energy upgrades. Inadequate airflow due to constricted ducts or undersized filters, improper refrigerant charge, and other system defects can be corrected at a fraction of the cost of equipment replacement and can yield significant savings. The guideline presents a two-step approach to diagnostics and repair.

Improved hopcalite procedure for the determination of mercury vapor in air by flameless atomic absorption.

Science.gov (United States)

Rathje, A O; Marcero, D H

1976-05-01

Mercury vapor is efficiently trapped from air by passage through a small glass tube filled with hopcalite. The hopcalite and adsorbed mercury are dissolved in a mixture of nitric and hydrochloric acids. Solution is rapid and complete, with no loss of mercury. Analysis is completed by flameless atomic absorption.

Research Proposal for the Design and Engineering Phase of a Solar Heating and Cooling System Experiment at the Warner Robins Public Library, Warner Robins, Georgia. Submitted to the United States Energy Research and Development Administration.

Science.gov (United States)

Phillips, Warren H.; And Others

A number of reasons are advanced to include a solar heating and cooling experiment in a library building. The unique aspects of the experiment are to be a seasonally adjustable collector tilt and testing of a new generation of absorption air conditioners. After a brief description of the proposed experiment, the proposal contains forms filed by…

Evaluation of ERINA Plus as a coat conditioner in canines

Directory of Open Access Journals (Sweden)

Srivastava

Full Text Available Coat conditioning, deodorant and cleansing properties of ERINA Plus were evaluated in fifty-one dogs of different breeds. More than 80% of dogs showed good to excellent conditioning, deodorant and cleansing effects supported ERINA Plus as safe conditioner shampoo. [Vet. World 2008; 1(12.000: 361-362

Evaluation of a clay-based acidic bedding conditioner for dairy cattle bedding.

Science.gov (United States)

Proietto, R L; Hinckley, L S; Fox, L K; Andrew, S M

2013-02-01

This study investigated the effects of a clay-based acidic bedding conditioner on sawdust bedding pH, dry matter (DM), environmental pathogen counts, and environmental bacterial counts on teat ends of lactating dairy cows. Sixteen lactating Holstein cows were paired based on parity, days in milk, milk yield, and milk somatic cell count, and were negative for the presence of an intramammary pathogen. Within each pair, cows were randomly assigned to 1 of 2 treatments with 3-wk periods in a crossover design. Treatment groups consisted of 9 freestalls per group bedded with either untreated sawdust or sawdust with a clay-based acidic bedding conditioner, added at 3- to 4-d intervals over each 21-d period. Bedding and teat ends were aseptically sampled on d 0, 1, 2, 7, 14, and 21 for determination of environmental bacterial counts. At the same time points, bedding was sampled for DM and pH determination. The bacteria identified in the bedding material were total gram-negative bacteria, Streptococcus spp., and coliform bacteria. The bacteria identified on the teat ends were Streptococcus spp., coliform bacteria, and Klebsiella spp. Teat end score, milk somatic cell count, and intramammary pathogen presence were measured weekly. Bedding and teat cleanliness, environmental high and low temperatures, and dew point data were collected daily. The bedding conditioner reduced the pH, but not the DM, of the sawdust bedding compared with untreated sawdust. Overall environmental bacterial counts in bedding were lower for treated sawdust. Total bacterial counts in bedding and on teat ends increased with time over both periods. Compared with untreated sawdust, the treated bedding had lower counts of total gram-negative bacteria and streptococci, but not coliform counts. Teat end bacterial counts were lower for cows bedded on treated sawdust for streptococci, coliforms, and Klebsiella spp. compared with cows bedded on untreated sawdust. The clay-based acidic bedding conditioner

Experimental investigation of hydrocarbon mixtures to replace HFC-134a in an automotive air conditioning system

International Nuclear Information System (INIS)

Wongwises, Somchai; Kamboon, Amnouy; Orachon, Banchob

2006-01-01

This paper presents an experimental study on the application of hydrocarbon mixtures to replace HFC-134a in automotive air conditioners. The hydrocarbons investigated are propane (R290), butane (R600) and isobutane (R600a). The measured data are obtained from an automotive air conditioning test facility utilizing HFC-134a as the refrigerant. The air conditioner, with a capacity of 3.5 kW driven by a Diesel engine, is charged and tested with four different ratios of hydrocarbon mixtures. The experiments are conducted at the same surrounding conditions. The temperature and pressure of the refrigerant at every major position in the refrigerant loop, the temperature, flow rate and humidity of air, torque and engine speed are recorded and analyzed. The parameters investigated are the refrigeration capacity, the compressor power and the coefficient of performance (COP). The results show that propane/butane/isobutane: 50%/40%/10% is the most appropriate alternative refrigerant to replace HFC-134a, having the best performance of all the hydrocarbon mixtures investigated

A LVDT conditioner for the beam profile monitors of the AmPS

International Nuclear Information System (INIS)

Es, J.T. van; Trigt, J.H. van.

1991-01-01

A LVDT (Linear Variable Differential Transformer) is a transducer for localization. Because of its applied materials, its construction and the absence of bearings etc. the instrument is suitable to be applied in locations where radioactive radiation is present. In order to obtain information about the position of the iron core in the transducer, a conditioner is needed. In 1977 by Digel a conditioner has been developed for the beam profile monitors (moving wire) of MEA because the 'market' could not meet the requirements then. Nowadays the 'market' offers i.c.'s which can take over the work of the Eurocard developed then. Digel has investigated them in order to see if they are applicable for the beam profile monitors of AmPS. (author). 5 refs.; 7 figs.; 13 tabs

Compressors. These little things that improve the operation of air conditioners. Danfoss-Turbocor: magnetic bearings for a centrifugal compressor. Copeland: the group stresses on the Digital power variation; Dossier compresseurs. Ces petits plus qui ameliorent le fonctionnement des climatiseurs. Danfoss-Turbocor: des paliers magnetiques pour un compresseur centrifuge. Copeland: le groupe met l'accent sur la variation de puissance Digital

Energy Technology Data Exchange (ETDEWEB)

Nicolas, J.

2005-09-01

This dossier about compressors for air conditioners comprises three articles dealing with: the improvements made by manufacturers of air-conditioning systems to increase the coefficient of performance and the lifetime of compressors, to reduce the refrigerant leaks and to reduce the power consumption; the electromagnetic bearings, the speed variation and the double stage compression used in the Danfoss-Turbocor centrifugal compressor; and the 'Digital' mechanical power variation system used by Copeland which does not change the motor velocity nor the operation limits of the compressor. (J.S.)

Physical Properties of Sandy Soil Affected by Soil Conditioner Under Wetting and Drying cycles

Directory of Open Access Journals (Sweden)

M.I. Choudhary

1998-06-01

Full Text Available Information on the effectiveness of soil conditioners over a prolonged period is scarce. A laboratory experiment was undertaken to evaluate the effectiveness of a polyacrylamide (Broadleaf P4 soil conditioner on the physical properties of sandy soil subjected to wetting and drying cycles. Four concentrations of Broadleaf P4 0, 0.2, 0.4, and 0.6% on dry weight basis were uniformly mixed with a calcareous sandy soil. Addition of Broadleaf P4 to sandy soil increased the water holding capacity, decreased the bulk density, and increased the porosity and void ratio at 0 and 16 wetting and drying cycles. The coefficient of linear extensibility increased considerably with increasing concentrations of the polymer. The addition of polymer at 0 and 16 cycles increased considerably the retention and availability of water in sandy soil. Saturated hydraulic conductivity decreased with increasing concentrations of Broadleaf P4 whereas unsaturated hydraulic conductivity at 0 and 16 cycles showed an increase with increasing soil moisture contents. After I6 wetting and drying cycles, the capacity of the soil to hold water was lost on average by 15.8% when compared to the 0 wetting and drying cycle. The effectiveness of the soil conditioner on bulk density, coefficient of linear extensibility, available water and saturated hydraulic conductivity was reduced on average by 14.1, 24.5, 21.l and 53.7% respectively. The significant changes in soil properties between 0 and 16 cycles suggested that the effectiveness of the conditioner decreased with the application of wetting and drying cycles. However, its effect was still considerable when compared to untreated soil under laboratory conditions.

Air Force Research Laboratory Success Stories. A Review of 2003

Science.gov (United States)

2003-01-01

or non-NBC mode. The ECU can act as either a heater or an air conditioner and can be operated with a remote control. Compared to previous models...separation system, PSC is developing a motorized activation mechanism. Once completed, this will allow for virtually unlimited testing of the actual...stories in this book or on the CD-ROM, or for other technical activities in the Air Force Research Laboratory, contact TECH CONNECT at (800) 203-6451

Mode switching control of dual-evaporator air-conditioning systems

International Nuclear Information System (INIS)

Lin, J.-L.; Yeh, T.-J.

2009-01-01

Modern air-conditioners incorporate variable-speed compressors and variable-opening expansion valves as the actuators for improving cooling performance and energy efficiency. These actuators have to be properly feedback-controlled; otherwise the systems may exhibit even poorer performance than the conventional machines which use fixed-speed compressors and mechanical expansion valves. Particularly for an air-conditioner with multiple evaporators, there are occasions that the machine is operated in a mode that only selected evaporator(s) is(are) turned on, and switching(s) between modes occurs(occur) during the control process. In this case, one needs to have more carefully designed control and switching strategies to ensure the system performance. In this paper, a framework for mode switching control of the dual-evaporator air-conditioning (DEAC) system is proposed. The framework is basically an integration of a controller and a dynamic compensator. The controller, which possesses the flow-distribution capability and assumes both evaporators are on throughout the control process, is intended to provide nominal performance. While mode switching is achieved by varying the reference settings in the controller, the dynamic compensator is used to improve the transient responses immediately after the switching. Experiments indicate that the proposed framework can achieve satisfactory indoor temperature regulation and provide bumpless switching between different modes of operation.

77 FR 26544 - Agency Information Collection Activities: Proposed Collection; Comment Request; Servicing of...

Science.gov (United States)

2012-05-04

... Activities: Proposed Collection; Comment Request; Servicing of Motor Vehicle Air Conditioners, EPA ICR Number... consideration may perform any service on a motor vehicle air conditioner involving the refrigerant for such air... used in servicing motor vehicle air conditioners and that each individual authorized by the purchaser...

CONVERTER SOLAR RADIATION INTO ELECTRICITY TO SUPPLY THE AUTOMOTIVE SEMICONDUCTOR THERMOELECTRIC AIR CONDITIONING

Directory of Open Access Journals (Sweden)

T. A. Ismailov

2015-01-01

Full Text Available The article considers the possibility to increase the efficiency of converters of solar radiation into electricity by combining constructive photoelectric effect, See-beck thermoeffect and semiconductor solar cells, which will create integrated device to provide power semiconductor thermoelectric automobile air conditioner. 

24 CFR 3280.811 - Calculations.

Science.gov (United States)

2010-04-01

... motors and heater loads (exhaust fans, air conditioners, electric, gas, or oil heating). Omit smaller of air conditioning and heating except include blower motor if used as air conditioner evaporator motor. When an air conditioner is not installed and a 40-ampere power supply cord is provided, allow 15...

Incorporating fan control into air-conditioning systems to improve energy efficiency and transient response

International Nuclear Information System (INIS)

Yeh, T.-J.; Chen, Yun-Jih; Hwang, Wei-Yang; Lin, Jin-Long

2009-01-01

Modern air-conditioners frequently incorporate variable-speed compressors and variable-opening expansion valves with feedback control to improve performance and power efficiency. Because making the fan speeds adjustable adds flexibility to the control design and thus can lead to further improvements in performance and efficiency, this paper proposes two control algorithms, respectively, incorporating the outdoor fan and the indoor fan as the additional control inputs for air-conditioning systems. Both of the control algorithms are designed based on a low-order, linear model obtained from system identification. The first algorithm, which modulates the outdoor fan speed, can reduce the steady state power consumption if the temperature difference between the condenser and the outdoor environment is controlled properly. The second algorithm, which adds one more degree of freedom to control by modulating the indoor fan speed, can improve the transient response because actuator saturations become less likely to occur. The two control algorithms are implemented on a split-type residential air-conditioner and their respective performance is validated experimentally.

Acaroid mite allergens from the filters of air-conditioning system in China.

Science.gov (United States)

Li, Chao-Pin; Guo, Wei; Zhan, Xiao-Dong; Zhao, Bei-Bei; Diao, Ji-Dong; Li, Na; He, Lian-Ping

2014-01-01

Accumulation of acaroid mites in the filters of air-conditioners is harmful to human health. It is important to clarify the allergen components of mites from the filters of local air-conditioning system. The present study was to detect the allergen types in the filters of air-conditioners and assesse their allergenicity by asthmatic models. Sixty aliquots of dust samples were collected from air conditioning filters in civil houses in Wuhu area. Total protein was extracted from the dust samples using PBS and quantified by Bradford method. Allergens I and II were also detected by Western blot using primary antibody (anti-Der f1/2, Der p1/Der f2/Der p2, respectively). Ten aliquots of the positive samples were randomly selected for homogenization and sensitized the mice for developing asthmatic animal models. Total serum IgE level and IFN-γ, IL-4 and IL-5 in the bronchoalveolar lavage fluid (BALF). The allergenicity of the extraction was assessed using pathological sections developed from the mouse pulmonary tissues. The concentration of extract from the 60 samples was ranged from 4.37 μg/ml to 30.76 μg/ml. After analyzing with Western blot, 31 of 60 samples were positive for 4 allergens of acaroid mites, and yet 16 were negative. The levels of total IgE from serum IL-4 and IL-5 from the BALF in the experimental group were apparently higher than that of negative control and PBS group (P 0.05). However,the IFN-γ level in BALF was lower compared with the negative control and PBS group (P 0.05). The pathological changes were evidently emerged in pulmonary tissues, which were similar to those of OVA group, compared with the PBS ground and negative controls. The air-conditioner filters in human dwellings of Wuhu area potentially contain the major group allergen 1 and 2 from D. farinae and D. pteronyssinus, which may be associated with seasonal prevalence of allergic disorders in this area.

Energy efficient and environment-friendly air-air heat pumps; Lucht-luchtwarmtepompen zeer zuinig en milieuvriendelijk

Energy Technology Data Exchange (ETDEWEB)

Trautwein, M. [Stulz, Amsterdam (Netherlands)

2013-02-15

In many buildings often two different systems are applied: a gas installation for heating and an airconditioning system for cooling. However, an air conditioner can also be used for heating. This can save on the gas installation and/or the central heating system [Dutch] In veel gebouwen worden vaak twee verschillende installaties gebruikt: een gasinstallatie voor verwarming en een airconditioninginstallatie voor koeling. Echter, met airconditioners kan men ook prima verwarmen. Daarmee kan worden bespaard op gasaansluiting en CV-installatie.

Acoustic absorption behaviour of an open-celled aluminium foam

International Nuclear Information System (INIS)

Han Fusheng; Seiffert, Gary; Zhao Yuyuan; Gibbs, Barry

2003-01-01

Metal foams, especially close-celled foams, are generally regarded as poor sound absorbers. This paper studies the sound absorption behaviour of the open-celled Al foams manufactured by the infiltration process, and the mechanisms involved. The foams show a significant improvement in sound absorption compared with close-celled Al foams, because of their high flow resistance. The absorption performance can be further enhanced, especially at low frequencies, if the foam panel is backed by an appropriate air gap. Increasing the air-gap depth usually increases both the height and the width of the absorption peak and shifts the peak towards lower frequencies. The foam samples with the smallest pore size exhibit the best absorption capacities when there is no air gap, whereas those with medium pore sizes have the best overall performance when there is an air gap. The typical maximum absorption coefficient, noise reduction coefficient and half-width of the absorption peak are 0.96-0.99, 0.44-0.62 and 1500-3500 Hz, respectively. The sound dissipation mechanisms in the open-celled foams are principally viscous and thermal losses when there is no air-gap backing and predominantly Helmholtz resonant absorption when there is an air-gap backing

Control of multi-evaporator air-conditioning systems for flow distribution

International Nuclear Information System (INIS)

Lin, J.-L.; Yeh, T.-J.

2009-01-01

Modern air-conditioners incorporate variable-speed compressors and variable-opening expansion valves as the actuators for improving cooling performance and energy efficiency. These actuators have to be properly feedback-controlled; otherwise the systems may exhibit even poorer performance than the conventional machines which use fixed-speed compressors and mechanical expansion valves. In this paper, a control strategy with flow distribution capability is proposed for multi-evaporator air-conditioners to accommodate different thermal demands in different rooms. The structure in the control strategy is based on a low-order, linear model obtained from system identification. To determine appropriate control parameters, theorems regarding stability of the closed-loop system are given. Moreover, by performing steady-state analysis on the control system and utilizing characteristics of the identified system parameters, one can analytically explain the mechanics of flow distribution. Experiments indicate that the proposed strategy can successfully regulate the indoor temperatures regardless that the reference settings for respective rooms are different and the settings are switched in the middle of the control process.

78 FR 63183 - Information Collection Request Submitted to OMB for Review and Approval; Comment Request; Mobile...

Science.gov (United States)

2013-10-23

... promulgated under SNAP require that Motor Vehicle Air Conditioners (MVACs) retrofitted to use a SNAP... Request Submitted to OMB for Review and Approval; Comment Request; Mobile Air Conditioner Retrofitting... Environmental Protection Agency has submitted an information collection request (ICR), Mobile Air Conditioner...

Evaporative Air Coolers Optimization for Energy Consumption Reduction and Energy Efficiency Ratio Increment

OpenAIRE

Leila Torkaman; Nasser Ghassembaglou

2015-01-01

Significant quota of Municipal Electrical Energy consumption is related to Decentralized Air Conditioning which is mostly provided by evaporative coolers. So the aim is to optimize design of air conditioners to increase their efficiencies. To achieve this goal, results of practical standardized tests for 40 evaporative coolers in different types collected and simultaneously results for same coolers based on one of EER (Energy Efficiency Ratio) modeling styles are figured ...

Thermodynamic analysis of an absorption refrigeration system used to cool down the intake air in an Internal Combustion Engine

International Nuclear Information System (INIS)

Novella, R.; Dolz, V.; Martín, J.; Royo-Pascual, L.

2017-01-01

Highlights: • Enough power in the exhaust gases is available to operate the absorption cycle. • Three engine operating points are presented in the article. • Improvement potential up to 4% is possible in the engine indicated efficiency. • Engine indicated efficiency benefit was experimentally confirmed by direct testing. - Abstract: This paper deals with the thermodynamic analysis of an absorption refrigeration cycle used to cool down the temperature of the intake air in an Internal Combustion Engine using as a heat source the exhaust gas of the engine. The solution of ammonia-water has been selected due to the stability for a wide range of operating temperatures and pressures and the low freezing point. The effects of operating temperatures, pressures, concentrations of strong and weak solutions in the absorption refrigeration cycle were examined to achieve proper heat rejection to the ambient. Potential of increasing Internal Combustion Engine efficiency and reduce pollutant emissions was estimated by means of theoretical models and experimental tests. In order to provide boundary conditions for the absorption refrigeration cycle and to simulate its effect on engine performance, a 0D thermodynamic model was used to reproduce the engine performance when the intake air is cooled. Furthermore, a detailed experimental work was carried out to validate the results in real engine operation. Theoretical results show how the absorption refrigeration system decreases the intake air flow temperature down to a temperature around 5 °C and even lower by using the bottoming waste heat energy available in the exhaust gases in a wide range of engine operating conditions. In addition, the theoretical analysis estimates the potential of the strategy for increasing the engine indicated efficiency in levels up to 4% also at the operating conditions under evaluation. Finally, this predicted benefit in engine indicated efficiency has been experimentally confirmed by direct

Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 1, Methodology

Energy Technology Data Exchange (ETDEWEB)

1993-11-01

The Energy Policy and Conservation Act (P.L. 94-163), as amended, establishes energy conservation standards for 12 of the 13 types of consumer products specifically covered by the Act. The legislation requires the Department of Energy (DOE) to consider new or amended standards for these and other types of products at specified times. DOE is currently considering amending standards for seven types of products: water heaters, direct heating equipment, mobile home furnaces, pool heaters, room air conditioners, kitchen ranges and ovens (including microwave ovens), and fluorescent light ballasts and is considering establishing standards for television sets. This Technical Support Document presents the methodology, data, and results from the analysis of the energy and economic impacts of the proposed standards. This volume presents a general description of the analytic approach, including the structure of the major models.

Assessment of the thermal environment effects on human comfort and health for the development of novel air conditioning system in tropical regions

Energy Technology Data Exchange (ETDEWEB)

Sookchaiya, Thammanoon; Monyakul, Veerapol; Thepa, Sirichai [Division of Energy Technology, School of Energy Environment and Materials, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand)

2010-10-15

This research shows the result of a brainstorming by medical experts in the first ranking university medical school and hospital of Thailand. It was based on Delphi technique. The objective of this research was to study both direct and indirect effects of humidity and temperature on human health in air-conditioned buildings in Thailand. Afterwards, the result was used to design and develop split type air conditioner (conventional air conditioner) which could control relative humidity and temperature with precision air conditioning system to comply with the climate and the suitability of the people living in Thailand building. The result of operation with precision inverter air conditioning system showed that the temperature inside the room changed from the default value around {+-}0.2 C (Case 1) and around {+-}0.35 C (Case 2) and it could control relative humidity as a desired condition between 50-60% (both cases) which was the appropriate range for Thai climate. Moreover, energy consumption of precision inverter air conditioning system was still less than conventional air conditioning system for about 7.5%. This research could provide people living in Thailand air conditioned building with human thermal comfort and health. (author)

Design of a signal conditioner for the Fermilab Magnet Test Facility

Energy Technology Data Exchange (ETDEWEB)

Giannelli, Pietro [Turin Polytechnic

2012-01-01

This thesis describes the design of a remotely-programmable signal conditioner for the harmonic measurement of accelerator magnets. A 10-channel signal conditioning circuit featuring bucking capabilities was designed from scratch and implemented to the level of the printed circuit board layout. Other system components were chosen from those available on the market. Software design was started with the definition of routine procedures. This thesis is part of an upgrade project for replacing obsolescent automated test equipment belonging to the Fermilab Magnet Test Facility. The design started with a given set of requirements. Using a top-down approach, all the circuits were designed and their expected performances were theoretically predicted and simulated. A limited prototyping phase followed. The printed circuit boards were laid out and routed using a CAD software and focusing the design on maximum electromagnetic interference immunity. An embedded board was selected for controlling and interfacing the signal conditioning circuitry with the instrumentation network. Basic low level routines for hardware access were defined. This work covered the entire design process of the signal conditioner, resulting in a project ready for manufacturing. The expected performances are in line with the requirements and, in the cases where this was not possible, approval of trade-offs was sought and received from the end users. Part I deals with the global structure of the signal conditioner and the subdivision in functional macro-blocks. Part II treats the hardware design phase in detail, covering the analog and digital circuits, the printed circuit layouts, the embedded controller and the power supply selection. Part III deals with the basic hardware-related routines to be implemented in the final software.

Development of automatic air intake door control system for exhaust gas. Prevention of contaminated air by controlling A/C air intake door; Haiki gas taio auto naigaiki system no kaihatsu. Eakon suikomiguchi seigyo ni yoru haiki gas no shashitsunai eno shinnyu boshi

Energy Technology Data Exchange (ETDEWEB)

Honda, Y; Samukawa, K [Denso Corp., Aichi (Japan)

1997-10-01

Thermal comfort in the cabin of vehicle is upgraded by developing the climate control system Passengers must control the intake door of air conditioner to reduce entering Exhaust Gas into the cabin. This paper is concerned with development the automatic intake door control system to acquire high comfort performance of passengers. 8 figs., 1 tab.

76 FR 22324 - Energy Conservation Program: Energy Conservation Standards for Residential Clothes Dryers and...

Science.gov (United States)

2011-04-21

... standards, the current standards for room air conditioners and clothes dryers, and the history of the... Residential Clothes Dryers and Room Air Conditioners AGENCY: Office of Energy Efficiency and Renewable Energy... equipment, including residential clothes dryers and room air conditioners. EPCA also requires the U.S...

75 FR 7584 - Agency Information Collection Activities; Proposed Collection; Comment Request; EPA-ICR No. 1774...

Science.gov (United States)

2010-02-22

.... Regulations promulgated under SNAP require that Motor Vehicle Air Conditioners (MVACs) retrofitted to use a.... Frequency of response: Once per a retrofit done on a motor vehicle air conditioner. Estimated total annual... Activities; Proposed Collection; Comment Request; EPA-ICR No. 1774.05--Mobile Air Conditioner Retrofitting...

77 FR 50499 - Agency Information Collection Activities: Submission to OMB for Review and Approval; Comment...

Science.gov (United States)

2012-08-21

... docket, go to www.regulations.gov . Title: Servicing of Motor Vehicle Air Conditioners (Renewal). ICR..., 1992, no person may service any motor vehicle air conditioner without being properly trained and... also indicate that the equipment will be properly used in servicing motor vehicle air conditioners and...

Acoustic absorption behaviour of an open-celled aluminium foam

CERN Document Server

Han Fu Sheng; Zhao Yu Yuan; Gibbs, B

2003-01-01

Metal foams, especially close-celled foams, are generally regarded as poor sound absorbers. This paper studies the sound absorption behaviour of the open-celled Al foams manufactured by the infiltration process, and the mechanisms involved. The foams show a significant improvement in sound absorption compared with close-celled Al foams, because of their high flow resistance. The absorption performance can be further enhanced, especially at low frequencies, if the foam panel is backed by an appropriate air gap. Increasing the air-gap depth usually increases both the height and the width of the absorption peak and shifts the peak towards lower frequencies. The foam samples with the smallest pore size exhibit the best absorption capacities when there is no air gap, whereas those with medium pore sizes have the best overall performance when there is an air gap. The typical maximum absorption coefficient, noise reduction coefficient and half-width of the absorption peak are 0.96-0.99, 0.44-0.62 and 1500-3500 Hz, r...

Application of best practice for setting minimum energy efficiency standards in technically disadvantaged countries: Case study of Air Conditioners in Brunei Darussalam

International Nuclear Information System (INIS)

Shi, Xunpeng

2015-01-01

Highlights: • Setting MEPS requires significant data, financial resources and technical capacity. • Application of best practice in technical disadvantaged countries (TDCs) was demonstrated. • Best practice was successfully applied to Brunei for its AC MEPS. • For Brunei, COP at 2.9 is recommended and 15% efficiency improvement is achievable. • The methodology is applicable to other appliances in any TDCs. - Abstract: Application of the best practice of setting minimum energy performance standards (MEPS) in technically disadvantaged countries (TDCs) faces many barriers. The best practice of determining MEPS has a comprehensive analytical framework including engineering-economic analysis, life-cycle cost-benefit analysis, as well stakeholders’ and market impact assessments. However, TDCs usually are lack of reference product classes, market data, and other necessary inputs data. This study demonstrated how to overcome those barriers to apply the best practice to TDCs using the actual experience in setting initial MEPS for Air Conditioners (ACs) in Brunei from scratch with limited secondary data as an example. The series of application works include definition of the product classes and the baseline group; collection of market data; formulation of cost-efficiency relationship from the market data; examination of the economic, environmental, and financial impacts of various MEPS options; revealing of the consumers’ willingness to pay; and analysis of the impacts and responses from the industry and consumers. The coordination with the compliance of the Montreal Protocol was also considered. The methodology should also be applicable to setting MEPF for other appliances in any TDCs.

40 CFR 82.42 - Certification, recordkeeping and public notification requirements.

Science.gov (United States)

2010-07-01

... motor vehicle air conditioner and that is in a container of less than 20 pounds of such refrigerant must... service motor vehicle air conditioners for consideration must keep these records on-site. (5) All entities which service motor vehicle air conditioners for consideration must allow an authorized representative...

Enhanced light absorptivity of black carbon with air pollution development in urban Beijing, China

Science.gov (United States)

Zhang, Y.; Zhang, Q.; Cheng, Y.; Su, H.; He, K.

2017-12-01

The impacts of black carbon (BC) aerosols on air quality and climate are dependent on BC light absorptivity. However, the light absorptivity of ambient BC-containing particles remains conflicting. In this work, we investigated the evolution of BC light absorptivity with pollution development in urban Beijing, China. We found that the mass absorption cross-section (MAC) of ambient BC-containing particles measured during the campaign increased with BC mass concentration, which can be attributed to more coating materials on BC surface with pollution development. A single-particle soot photometer (SP2) measurement showed that the coating thickness (CT) of BC-containing particles increased by 48% with PM1 and BC mass concentration increasing from 10 μg m-3 and 0.3 μg m-3 to 230 μg m-3 and 12 μg m-3. Based on Mie calculation, the CT increase could led to light absorption enhancement (Eab) of BC-containing particles increasing by 22%, consistent with the increase of measured MAC. The relationship between growth rate of BC light absorptivity (kEab) and that of PM1 or rBC concentration (kPM1 or krBC) showed that kEab ≈ 4.8% kPM1 or kEab ≈ 2.5% krBC. The analysis of effective emission intensity (EEI) for BC revealed that the enhancement of BC light absorptivity with increasing pollution levels was dominated by regional transport. During the pollution period, 63% of BC over Beijing originated from regional sources. The aging of these regional BC during atmospheric transport controlled the increase of coating materials for BC-containing particles observed in Beijing. As a result of enhanced light absorptivity with pollution development, BC forcing efficiency could increase by 20% during polluted period. Our work identified the importance of BC on radiative forcing under polluted environment, which is determined by not only the increase of BC mass concentration, but also the enhancement of BC forcing efficiency due to more coating materials.

40 CFR 82.30 - Purpose and scope.

Science.gov (United States)

2010-07-01

... STRATOSPHERIC OZONE Servicing of Motor Vehicle Air Conditioners § 82.30 Purpose and scope. (a) The purpose of...) regarding the servicing of motor vehicle air conditioners (MVACs), and to implement section 608 of the Act regarding certain servicing, maintenance, repair and disposal of air conditioners in MVACs and MVAC-like...

EER, COP, and the Second Law Efficiency for Air Conditioners

Science.gov (United States)

Leff, Harvey S.; Teeters, William D.

1978-01-01

Describes the relationship existing between coefficient of performance (COP) and energy efficiency ratio (EER) in air conditioning units and introduces new efficiency parameters measured relative to the energy extracted from the primary energy source. (SL)

LDDX: A High Efficiency Air Conditioner for DOD Buildings

Science.gov (United States)

2017-02-01

and the entire 2016 cooling season. The LDDX-WF prototype met its performance objectives to supply dry air and to modulate the Sensible Heat Ratio... heat transfer of the desiccant on the fin is an effective substitute for the conductive heat transfer of the aluminum fins used in a conventional...respectively. 22 The May 2014 laboratory operation of the LDDX-WF prototype was the first opportunity to measure heat and mass transfer

Results of Self-Absorption Study on the Versapor 3000 Filters for Radioactive Particulate Air Sampling

International Nuclear Information System (INIS)

Barnett, J.M.; Cullinan, Valerie I.; Barnett, Debra S.; Trang-Le, Truc LT; Bliss, Mary; Greenwood, Lawrence R.; Ballinger, Marcel Y.

2009-01-01

Since the mid-1980s, Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as the correction factor for self absorption of activity for particulate radioactive air samples collected from building exhaust for environmental monitoring. This value accounts for activity that cannot be detected by direct counting of alpha and beta particles. Emissions can be degraded or blocked by filter fibers for particles buried in the filter material or by inactive dust particles collected with the radioactive particles. These filters are used for monitoring air emissions from PNNL stacks for radioactive particles. This paper describes an effort to re-evaluate self-absorption effects in particulate radioactive air sample filters (Versapor(reg s ign) 3000, 47 mm diameter) used at PNNL. There were two methods used to characterize the samples. Sixty samples were selected from the archive for acid digestion to compare the radioactivity measured by direct gas-flow proportional counting of filters to the results obtained after acid digestion of the filter and counting again by gas-flow proportional detection. Thirty different sample filters were selected for visible light microscopy to evaluate filter loading and particulate characteristics. Mass-loading effects were also considered. Filter ratios were calculated by dividing the initial counts by the post-digestion counts with the expectation that post-digestion counts would be higher because digestion would expose radioactivity embedded in the filter in addition to that on top of the filter. Contrary to expectations, the post digestion readings were almost always lower than initial readings and averaged approximately half the initial readings for both alpha and beta activity. Before and after digestion readings appeared to be related to each other, but with a low coefficient of determination (R 2 ) value. The ratios had a wide range of values indicating that this method did not provide sufficient precision to quantify

24 CFR 3280.702 - Definitions.

Science.gov (United States)

2010-04-01

... the removal of an access panel, door or similar obstruction. Air conditioner blower coil system means... connection between the two parts of the system is accomplished by tubing. Air conditioner split system means...) means the ratio of the cooling capacity output of an air conditioner for each unit of power input. EER...

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

Regeneration characteristics of desiccant rotor with microwave and hot-air heating

International Nuclear Information System (INIS)

Kubota, Mitsuhiro; Hanada, Takuya; Yabe, Satoshi; Matsuda, Hitoki

2013-01-01

Microwave heating, because of its advantages of direct and rapid heating of materials, has the potential to be employed as a novel regeneration method of desiccant rotors in humidity conditioners. We proposed a combined regeneration process, which combines microwave heating and conventional hot-air heating. The system is expected to achieve high heating rate during an initial regeneration period by assisting water desorption using the additional energy of the microwave. In this study, the regeneration characteristics of a desiccant rotor were experimentally investigated under conditions of microwave heating, hot-air heating, and combined heating at various microwave powers and hot-air temperatures. The effectiveness of the combined regeneration was evaluated in terms of the regeneration ratio, the initial regeneration rate, the temperature distribution in the rotor, and finally in terms of the energy consumption. It was demonstrated that combined heating was effective at leveling non-uniform temperature distribution in the rotor. Combined heating achieved higher ratios and initial rates in regeneration compared to just microwave and hot-air heating. This result was obviously attributed to the additional input of microwave energy, resulting that average rotor temperature increased by microwave absorption of rotor. Moreover, it was also effective for enhancement of regeneration to level the temperature distribution in the rotor by combination of two heating methods with different heating mechanisms. Both the initial regeneration rate and the equilibrium regeneration ratio for combined heating were found to increase as the microwave power increased. A linear relationship was observed with respect to microwave power. From the viewpoint of energy consumption, it may be possible to apply combined and microwave heating to humidity control systems that switch between adsorption and regeneration in short cycle times, if the conversion and absorption efficiencies of the

A CSMP commutation model for design study of a brushless dc motor power conditioner for a cruise missile fin control actuator

Science.gov (United States)

MacMillan, P. N.

1985-06-01

Recent improvements in rare earth magnets have made it possible to construct strong, lightweight, high horsepower dc motors. This has occasioned a reassessment of electromechanical actuators as alternatives to comparable pneumatic and hydraulic systems for use as flight control actuators for tactical missiles. A dynamic equivalent circuit model for the analysis of a small four pole brushless dc motor fed by a transistorized power conditioner utilizing high speed switching power transistors as final elements is presented. The influence of electronic commutation on instantaneous dynamic motor performance is particularly demonstrated and good correlation between computer simulation and typical experimentally obtained performance data is achieved. The model is implemented in CSMP language and features more accurate air gap flux representation over previous work. Hall effect sensor rotor position feedback is simulated. Both constant and variable air gap flux is modeled and the variable flux model treats the flux as a fundamental and one harmonic.

Starting and stopping control on power conditioner in photovoltaic power system; Taiyoko hatsuden system ni okeru power conditioner no kido teishi seigyo ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Hirose, M.; Ishihara, Y.; Todaka, T.; Harada, K. [Doshisha University, Kyoto (Japan); Oshiro, H.; Nakamura, H. [Japan Quality Assurance Organization, Tokyo (Japan)

1997-11-25

Studies are made about the control of the power conditioner over the maximum power point tracking (MPPT) function in a photovoltaic power generation system. The analysis is conducted by means of computer simulation into the effect of a start/stop function added to the control of MPPT and the effect on the generation of power of the setting of parameters in the start/stop function. The reduction in output power due to difference between the actual operation point and the optimum operation point is evaluated by use of a load matching correction factor. In this simulation, it is assumed that the solar cell array consists of 13 rows in 5 parallel columns, is capable of a normal output of 3.149kW, has a panel tilted at 30 degrees, and faces due south. The power conditioner is assumed to be a system rated at 3kVA, equipped with system interconnection and back flow features. As a result, it is learned that the stop voltage should be set at 180V or lower and the steady voltage near 185.5V for a good result and that there is not much need after all for the start/stop technique. 2 refs., 8 figs., 2 tabs.

Air Conditioner Selection with TOPSIS and VIKOR Methods In Multi Criteria Decision Making

Directory of Open Access Journals (Sweden)

İrfan ERTUĞRUL

2014-06-01

Full Text Available Technological and global changes nowadays enable air conditioning sector to gain a higher importance. Short and long term risks for comsumers, the use of air conditioningtechnology with cost minimization, the increase of product charesteristics and firms, and the variability of product features have led to the need for multi-criteria decision. Therefore, caring the multiple criteria and the alternatives, the multi-criteria decision making techniques are taken to the scope of application. The purpose of the study is to determine the factors which affect the decision of air conditioning choice and to present the preference ranking suggestion. Having the nearly have got the approximately equivalent heating and cooling capacity, air conditionings in A+ class are included in the scope of related research. In application, when choosing air conditioning products, Topsis and Vikor that are multi-criteria decision-making methods are used and the results are compared and evaluated. When choosing air conditioning products, preference plansa re presented in the application.

Development of a solar-powered residential air conditioner. Program review

Science.gov (United States)

1975-01-01

Progress in the effort to develop a residential solar-powered air conditioning system is reported. The topics covered include the objectives, scope and status of the program. The results of state-of-art, design, and economic studies and component and system data are also presented.

Influence of soil composition in the determination of chromium by atomic absorption spectrometry with flame air / acetylene

International Nuclear Information System (INIS)

Duran Sosa, Ibis; Granda Valdes, Mayra; Pomares Alfonso, Mario Simeon

2014-01-01

The Air-acetylene Flame Atomic Absorption determination of chromium is a complex task, being strongly influenced by sample composition and instrumental conditions. The objective of this work was to study the influence of Al, Ca, Fe, K, Mg, and Na on the absorption of chromium in the air-acetylene flame, both separately and combined in solution, when acetylene flow and burner height vary. Dissolutions of the mixtures simulated the composition of four soils from the Quibu River Basin in Havana, Cuba. Chromium absorption first increased and then decreased with increment of acetylene flow for shorter burner heights (∼ 2-4 mm); while a continuous increase was observed for larger heights (> 4 mm). This behavior was the same in the presence and absence of interfering chemical element, mentioned above. On the other hand, the dependence of the magnitude of the interference with acetylene flow and burner height was complex and dependent on the interfering element, particularly at larger heights where the behavior of Al was remarkably different. The interference of the four mixtures of Al, Ca, K, Fe, Mg and Na decreased in comparison to individual interfering effects and was less dependent on acetylene flow and burner height. Finally, a significant reduction of interference on chromium determination in soil samples was achieved by an adequate selection of acetylene flow and burner height

Photoacoustic and filter measurements related to aerosol light absorption during the Northern Front Range Air Quality Study (Colorado 1996/1997)

Science.gov (United States)

Moosmüller, H.; Arnott, W. P.; Rogers, C. F.; Chow, J. C.; Frazier, C. A.; Sherman, L. E.; Dietrich, D. L.

1998-11-01

A new photoacoustic instrument for the measurement of aerosol light absorption was collocated with conventional aerosol instrumentation during the 1996-1997 winter intensive monitoring period of the Northern Front Range Air Quality Study. Measurements of the light absorption efficiency for black carbon were 5 m2/g at 685 nm and 10 m2/g at 532 nm, and for elemental carbon, they were 3.6 m2/g at 685 nm. We show that these values together with previous photoacoustic measurements of aerosol light absorption shed some light on the wavelength dependence of absorption efficiency for carbonaceous aerosol in the visible and near-visible region. Integrating plate type filter measurements of aerosol light absorption result in far larger values than those measured with the photoacoustic instrument. We demonstrate that a recently published correction technique [Horvath, 1997] can yield improved agreement.

Open absorption system for cooling and air conditioning using membrane contactors. 2006 annual report

Energy Technology Data Exchange (ETDEWEB)

Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R. [Materials Science and Technology (EMPA), Abteilung Bautechnologien, Duebendorf (Switzerland)

2006-11-15

This illustrated annual report for 2006 for the Swiss Federal Office of Energy (SFOE) reports on work being done on the development of an open absorption system for cooling and air-conditioning. The report reviews the construction of a first prototype and the manufacture of its components. The conceptual design of this new type of air handling unit (AHU), operating with a liquid desiccant, is discussed. The AHU is to be autonomous and the system will not require additional mechanical refrigeration. It is to be thermally driven at temperatures below 80 {sup o}C. Waste heat sources, solar collectors, district heating plants and co-generation systems are targeted as providers of thermal energy at this temperature level. Work carried out is reported on, including that on two-stream membrane contactors.

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

A comparison of four methods to evaluate the effect of a utility residential air-conditioner load control program on peak electricity use

Energy Technology Data Exchange (ETDEWEB)

Newsham, Guy R., E-mail: guy.newsham@nrc-cnrc.gc.ca [National Research Council Canada-Institute for Research in Construction, Building M24, 1200 Montreal Road, Ottawa, Ontario, K1A 0R6 (Canada); Birt, Benjamin J. [National Research Council Canada-Institute for Research in Construction, Building M24, 1200 Montreal Road, Ottawa, Ontario, K1A 0R6 (Canada); Rowlands, Ian H. [University of Waterloo, Ontario (Canada)

2011-10-15

We analyzed the peak load reductions due to a residential direct load control program for air-conditioners in southern Ontario in 2008. In this program, participant thermostats were increased by 2 deg. C for four hours on five event days. We used hourly, whole-house data for 195 participant households and 268 non-participant households, and four different methods of analysis ranging from simple spreadsheet-based comparisons of average loads on event days, to complex time-series regression. Average peak load reductions were 0.2-0.9 kWh/h per household, or 10-35%. However, there were large differences between event days and across event hours, and in results for the same event day/hour, with different analysis methods. There was also a wide range of load reductions between individual households, and only a minority of households contributed to any given event. Policy makers should be aware of how the choice of an analysis method may affect decisions regarding which demand-side management programs to support, and how they might be incentivized. We recommend greater use of time-series methods, although it might take time to become comfortable with their complexity. Further investigation of what type of households contribute most to aggregate load reductions would also help policy makers better target programs. - Highlights: > We analyzed peak load reductions due to residential a/c load control. > We used four methods, ranging from simple comparisons to time-series regression. > Average peak load reductions were 0.2-0.9 kW per household, varying by method. > We recommend a move towards time-series regression for future studies. > A minority of participant households contributed to a given load control event.

Absorption heat pumps

International Nuclear Information System (INIS)

Formigoni, C.

1998-01-01

A brief description of the difference between a compression and an absorption heat pump is made, and the reasons why absorption systems have spread lately are given. Studies and projects recently started in the field of absorption heat pumps, as well as criteria usually followed in project development are described. An outline (performance targets, basic components) of a project on a water/air absorption heat pump, running on natural gas or LPG, is given. The project was developed by the Robur Group as an evolution of a water absorption refrigerator operating with a water/ammonia solution, which has been on the market for a long time and recently innovated. Finally, a list of the main energy and cost advantages deriving from the use of absorption heat pumps is made [it

Variable structure TITO fuzzy-logic controller implementation for a solar air-conditioning system

Energy Technology Data Exchange (ETDEWEB)

Lygouras, J.N.; Pachidis, Th. [Laboratory of Electronics, School of Electrical and Computer Engineering, Democritus University of Thrace, GR-67100 Xanthi (Greece); Kodogiannis, V.S. [Centre for Systems Analysis, School of Computer Science, University of Westminster, London HA1 3TP (United Kingdom); Tarchanidis, K.N. [Department of Petroleum Technology, Technological Education Institute of Kavala, GR-65404, Kavala (Greece); Koukourlis, C.S. [Laboratory of Telecommunications, School of Electrical and Computer Engineering, Democritus University of Thrace, GR-67100 Xanthi (Greece)

2008-04-15

The design and implementation of a Two-Input/Two-Output (TITO) variable structure fuzzy-logic controller for a solar-powered air-conditioning system is described in this paper. Two DC motors are used to drive the generator pump and the feed pump of the solar air-conditioner. The first affects the temperature in the generator of the solar air-conditioner, while the second, the pressure in the power loop. The difficulty of Multi-Input/Multi-Output (MIMO) systems control is how to overcome the coupling effects among each degree of freedom. First, a traditional fuzzy-controller has been designed, its output being one of the components of the control signal for each DC motor driver. Secondly, according to the characteristics of the system's dynamics coupling, an appropriate coupling fuzzy-controller (CFC) is incorporated into a traditional fuzzy-controller (TFC) to compensate for the dynamic coupling among each degree of freedom. This control strategy simplifies the implementation problem of fuzzy control, but can also improve the control performance. This mixed fuzzy controller (MFC) can effectively improve the coupling effects of the systems, and this control strategy is easy to design and implement. Experimental results from the implemented system are presented. (author)

Impacts of the Degradation of 2,3,3,3-Tetrafluoropropene into Trifluoroacetic Acid from Its Application in Automobile Air Conditioners in China, the United States, and Europe.

Science.gov (United States)

Wang, Ziyuan; Wang, Yuhang; Li, Jianfeng; Henne, Stephan; Zhang, Boya; Hu, Jianxin; Zhang, Jianbo

2018-03-06

HFO-1234yf (2,3,3,3-tetrafluoropropene) was proposed as an automobile air conditioner (MAC) refrigerant worldwide. However, its atmospheric degradation product is the highly soluble and phytotoxic trifluoroacetic acid (TFA), which persists in aquatic environments. We used a global three-dimensional chemical transport model to assess the potential environmental effects resulting from complete future conversion of the refrigerant in all MAC to HFO-1234yf in China, the United States, and Europe. The annual mean atmospheric concentrations of HFO-1234yf were 2.62, 2.20, and 2.73 pptv, and the mean deposition rates of TFA were 0.96, 0.45, and 0.52 kg km -2 yr -1 , in three regions. The regional TFA deposition sources mainly came from emissions within the same region. The annual TFA deposition in the North Pole region was lower than the global average and mainly originated from European emissions. A potential doubling in the future HFO-1234yf emissions in China mainly affected the local TFA depositions. The TFA concentrations in rainwater were strongly affected by the regional precipitation rates. North Africa and the Middle East, regions with scant rainfall, had extremely high TFA concentrations. The rainwater concentrations of TFA during individual rain events can exceed the level considered to be safe, indicating substantial potential regional risks from future HFO-1234yf use.

Simulation of an air conditioning absorption refrigeration system in a co-generation process combining a proton exchange membrane fuel cell

Energy Technology Data Exchange (ETDEWEB)

Pilatowsky, I.; Gamboa, S.A.; Rivera, W. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Romero, R.J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas - UAEM, Cuernavaca, Morelos (Mexico); Isaza, C.A. [Universidad Pontificia Bolivariana, Medellin (Colombia). Instituto de Energia y Termodinamica; Sebastian, P.J. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico); Moreira, J. [Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico)

2007-10-15

In this work, a computer simulation program was developed to determine the optimum operating conditions of an air conditioning system during the co-generation process. A 1 kW PEMFC was considered in this study with a chemical/electrical theoretical efficiency of 40% and a thermal efficiency of 30% applying an electrical load of 100%. A refrigeration-absorption cycle (RAC) operating with monomethylamine-water solutions (MMA-WS), with low vapor generation temperatures (up to 80 C) is proposed in this work. The computer simulation was based on the refrigeration production capacity at the maximum power capacity of the PEMFC. Heat losses between the fuel cell and the absorption air conditioning system at standard operating conditions were considered to be negligible. The results showed the feasibility of using PEMFC for cooling, increasing the total efficiency of the fuel cell system. (author)

Modelling LiBr-H2O solution concentration/crystallization of low thermal-powered absorption air conditioning system

International Nuclear Information System (INIS)

Abdullah, M.O.

2000-01-01

A computer model is developed to predict the concentration of lithium bromide - water (LiBr-H 2 O) solution for used in low thermal energy-driven absorption air conditioning plants design. The computer program is capable to alert the users from undesirable solidification or crystallization zones. Good agreements between simulated concentration and experimental data from standard chart/table have been obtained. (Author)

Ammonia removal from landfill leachate by air stripping and absorption.

Science.gov (United States)

Ferraz, Fernanda M; Povinelli, Jurandyr; Vieira, Eny Maria

2013-01-01

An old landfill leachate was pre-treated in a pilot-scale aerated packed tower operated in batch mode for total ammoniacal nitrogen (TAN) removal. The stripped ammonia was recovered with a 0.4 mol L(-1) H2SO4 solution, deionized water and tap water. Ca(OH)2 (95% purity) or commercial hydrated lime was added to the raw leachate to adjust its pH to 11, causing removal of colour (82%) and heavy metals (70-90% for Zn, Fe and Mn). The 0.4 molL(-1) H2SO4 solution was able to neutralize 80% of the stripped ammonia removed from 12 L of leachate. The effectiveness of the neutralization of ammonia with deionized water was 75%. Treating 100 L of leachate, the air stripping tower removed 88% of TAN after 72 h of aeration, and 87% of the stripped ammonia was recovered in two 31 L pilot-scale absorption units filled with 20 L of tap water.

Preliminary design package for residential heating/cooling system: Rankine air conditioner redesign

Science.gov (United States)

1978-01-01

A summary of the preliminary redesign and development of a marketable single family heating and cooling system is presented. The interim design and schedule status of the residential (3-ton) redesign, problem areas and solutions, and the definition of plans for future design and development activities were discussed. The proposed system for a single-family residential heating and cooling system is a single-loop, solar-assisted, hydronic-to-warm-air heating subsystem with solar-assisted domestic water heating and a Rankine-driven expansion air-conditioning subsystem.

Determination of benzene, toluene, ethyl benzene and xylene in administration room′s air of hospitals using solid phase micro extraction/gas chromatography/flame ionization detector

Directory of Open Access Journals (Sweden)

Maryam Kheirmand

2014-01-01

Conclusion: The accounting unit showed highest concentrations of BTEX that its possible due to usage of the numerous numbers of electronic devices (computers, printer and copier, official supply (ink varnish, adhesive, etc. and the air-conditioner.

Chemical Stability Analysis of Hair Cleansing Conditioners under High-Heat Conditions Experienced during Hair Styling Processes

Directory of Open Access Journals (Sweden)

Derek A. Drechsel

2018-03-01

Full Text Available Chemical stability is a key component of ensuring that a cosmetic product is safe for consumer use. The objective of this study was to evaluate the chemical stability of commercially available hair cleansing conditioners subjected to high heat stresses from the styling processes of blow drying or straightening. Two hair cleansing conditioners were subjected to temperatures of 60 °C and 185 °C to simulate the use of a blow dryer or flatiron hair straightener, respectively and analyzed via Gas Chromatography-Mass Spectrometry (GC-MS, High-Performance Liquid Chromatography-UV (HPLC and Fourier-Transform Infrared Spectroscopy (FT-IR to capture a chemical profile of the samples. The resulting spectra from matched heated and unheated samples were compared to identify any changes in chemical composition. Overall, no differences in the spectra were observed between the heated and unheated samples at both temperatures evaluated. Specifically, no new peaks were observed during analysis, indicating that no degradation products were formed. In addition, all chemicals identified during GC-MS analysis were known listed ingredients of the products. In summary, no measurable changes in chemical composition were observed in the hair cleansing conditioner samples under high-heat stress conditions. The presented analytical methods can serve as an initial screening tool to evaluate the chemical stability of a cosmetic product under conditions of anticipated use.

Price freezes, durables and residential electricity demand - Evidence from the Greater Buenos Aires

Energy Technology Data Exchange (ETDEWEB)

Casarin, Ariel; Delfino, Maria Eugenia

2010-09-15

This paper examines the determinants of residential electricity demand in the Greater Buenos Aires between 1997 and 2006. During the second half of this period, residential tariffs remained nominally fixed, while an income boom boosted up the sales of durables. This study differs from previous works in that it explicitly considers the impact of the stock of air-conditioners on residential demand. The paper reports short- and long-run elasticities and examines the contribution of prices and durables to recent demand growth. Simulations illustrate the impact of prices and durables on future demand.

Preliminary design package for residential heating/cooling system--Rankine air conditioner redesign

Energy Technology Data Exchange (ETDEWEB)

1978-12-01

This report contains a summary of the preliminary redesign and development of a marketable single-family heating and cooling system. The objectives discussed are the interim design and schedule status of the Residential (3-ton) redesign, problem areas and solutions, and the definition of plans for future design and development activities. The proposed system for a single-family residential heating and cooling system is a single-loop, solar-assisted, hydronic-to-warm-air heating subsystem with solar-assisted domestic water heating and a Rankine-driven expansion air-conditioning subsystem.

Design of Interline Unified Power Quality Conditioner for Power Quality Disturbances using Simulink

Science.gov (United States)

Kumaraswamy, G.; Reddy, Y. Rajasekhar; Harikrishna, Ch.

2012-10-01

Proliferation of electronic equipment in commercial and industrial processes has resulted in increasingly sensitive electrical loads to be fed from power distribution system which introduce contamination to voltage and current waveforms at the point of common coupling of industrial loads. The unified power quality conditioner (UPQC) is connected between two different feeders (lines), hence this method of connection of the UPQC is called as Interline UPQC (IUPQC).This paper proposes a new connection for a UPQC to improve the power quality of two feeders in a distribution system. Interline Unified Power Quality Conditioner (IUPQC), specifically aims at the integration of series VSC and Shunt VSC to provide high quality power supply by means of voltage sag/swell compensation, harmonic elimination and power factor correction in a power distribution network, so that improved power quality can be made available at the point of common coupling. The structure, control and capability of the IUPQC are discussed in this paper. The efficiency of the proposed configuration has been verified through simulation using MATLAB/ SIMULINK.

Performance analysis of solar air cooled double effect LiBr/H2O absorption cooling system in subtropical city

International Nuclear Information System (INIS)

Li, Zeyu; Ye, Xiangyang; Liu, Jinping

2014-01-01

Highlights: • The meteorological data during the working period of air conditioning was measured. • The suitable working range of collector temperature of system was gotten. • The characteristic of hourly and monthly total efficiency of system were obtained. • The yearly performance of system was calculated. - Abstract: Due to the absence of cooling tower and independent on water, the air cooled solar double effect LiBr/H 2 O absorption cooling system is more convenient to be used in commercial building and household use. The performance with collector temperature is an important field for such system. The paper mainly deals with the performance with collector temperature for the solar air cooled double effect LiBr/H 2 O absorption cooling system in subtropical city. The parameters of system are: aperture area of collector array is 27 m 2 , tilted angle of collector with respect to the horizontal plane is 20 toward to south evaporator temperature is 5 °C and the cooling capacity is 20 kW. The simulation is based on the meteorological data of monthly typical day which was summarized from a year round measured data. A corresponding parametric model was developed. The hourly and average performance with the collector temperature for monthly typical day was obtained and discussed. It was found that the suitable working range of inlet temperature of collector is 110–130 °C to improve performance and lower the risk of crystallization. The difference of hourly total efficiency in 9:00–16:00 is less, and the monthly total efficiency from May to October is approximate. The yearly performance of system including total efficiency, cooling capacity per area of collector and solar fraction was given. Furthermore, the effect of effectiveness of heat exchanger and pressure drop on total efficiency and solar fraction was studied and compared. The paper can serve as a preliminary investigation of solar air cooled double effect LiBr/H 2 O absorption cooling system in

Studi Eksperimen Pengaruh Dimensi Pipa Kapiler Pada Sistem Air Conditioning Dengan Pre-Cooling

Directory of Open Access Journals (Sweden)

Awan Satya Darmawan

2017-01-01

Full Text Available Penggunaan air conditioner semakin banyak digunakan pada kehidupan sehari-hari diiringi dengan harga jual energi yang semakin mahal. Pada studi eksperimen kali ini mencoba mengoptimalisasi dan menigkatkan efisiensi energi pada sistem air conditioner dengan cara menambahkan satu buah evaporator dan satu buah pre-cooling, dimana pre-cooling dimanfaatkan untuk memanaskan air yang nantinya akan digunakan untuk keperluan rumah tangga. Pada sistem pengkondisian udara yang telah dimodifikasi tersebut maka dilakukan studi eksperimen dengan variasi panjang pipa kapiler, diameter pipa kapiler d=0,054 in, dengan panjang kapiler 1 = 35 cm, kapiler 2 = 65 cm, kapiler 3 = 95 cm. Hasil yang didapat dari studi eksperimen kali ini adalah semakin bertambahnya panjang pipa kapiler, kapasitas pendinginan evaporator, kerja kompresor dan COP dari sistem juga akan semakin kecil dan juga mengakibatkan temperatur masuk evaporator akan semakin kecil, yang akan mengakibatkan efek pendinginan akan semakin besar. Pada variasi pipa kapiler terpendek 35 cm menghasilkan data kapasitas pendinginan total sebesar 2,25 kW, kerja kompresor 0,433 kW, temperatur masuk evaporator 7,26°C, COP sebesar 5,21 dan HRR sebesar 1,16. Sedangkan pada variasi pipa kapiler terpanjang 95 cm kapasitas pendinginan total sebesar 0,72 kW, kerja kompresor 0,332 kW, temperatur masuk evaporator 1,64°C, COP sebesar 4,35 dan HRR sebesar 1,26.

Performance of a biogas upgrading process based on alkali absorption with regeneration using air pollution control residues.

Science.gov (United States)

Baciocchi, Renato; Carnevale, Ennio; Costa, Giulia; Gavasci, Renato; Lombardi, Lidia; Olivieri, Tommaso; Zanchi, Laura; Zingaretti, Daniela

2013-12-01

This work analyzes the performance of an innovative biogas upgrading method, Alkali absorption with Regeneration (AwR) that employs industrial residues and allows to permanently store the separated CO2. This process consists in a first stage in which CO2 is removed from the biogas by means of chemical absorption with KOH or NaOH solutions followed by a second stage in which the spent absorption solution is contacted with waste incineration Air Pollution Control (APC) residues. The latter reaction leads to the regeneration of the alkali reagent in the solution and to the precipitation of calcium carbonate and hence allows to reuse the regenerated solution in the absorption process and to permanently store the separated CO2 in solid form. In addition, the final solid product is characterized by an improved environmental behavior compared to the untreated residues. In this paper the results obtained by AwR tests carried out in purposely designed demonstrative units installed in a landfill site are presented and discussed with the aim of verifying the feasibility of this process at pilot-scale and of identifying the conditions that allow to achieve all of the goals targeted by the proposed treatment. Specifically, the CO2 removal efficiency achieved in the absorption stage, the yield of alkali regeneration and CO2 uptake resulting for the regeneration stage, as well as the leaching behavior of the solid product are analyzed as a function of the type and concentration of the alkali reagent employed for the absorption reaction. Copyright © 2013 Elsevier Ltd. All rights reserved.

DEVELOPMENT OF A LINEAR COMPRESSOR FOR AIR CONDITIONERS AND HEAT PUMPS

Science.gov (United States)

The report discusses the design, building, testing, and delivering to the Environmental Protection Agency of a linear compressor for operation in a 3.0- ton (10.5 kW) residential air-conditioning and heat pumping system. The compressor design evolved from a linear resonant piston...

Application of a solar refrigeration system by absorption for the air conditioning of buildings

Energy Technology Data Exchange (ETDEWEB)

Machielsen, Cees H. M [Delft University of Technology, Mekelweg (Netherlands); Hagendijk, Andre E [Consultancy and Research (Netherlands)

2000-07-01

This paper describes the Sofri project, a cooperation between Ceeran Ltd and The Delft University of Technology. The main objective of this project is to develop the necessary knowledge and experience to commercialize solar-assisted air conditioning and dehumidification systems in the Dutch Caribbean. The project is motivated by the present needs of the Dutch Caribbean for renewable energy sources and the fact that the Caribbean has a high and uniform insolation throughout the year. Furthermore, hotels and offices in this area use more than 40% of their energy for air-conditioning purposes. Therefore solar-assisted air conditioning systems are a logic approach in reducing the energy demand and to lower the peak electricity reducing the energy demands for the local power station. Ceeran Ltd has the objective to reach full commercialization of the proposed technologies in the Dutch Caribbean. The research is concentrated on liquid absorption machines and solar collection systems such as flat plates with selective surfaces, heat pipe evacuated tubes flat plate collectors, and Compound Parabolic Concentrators. The first demonstration unit is planned to be installed in an office building in Curacao. The installation consists of a 35 kW LiBr/H{sub 2}O absorption machine driven by 100 m{sup 2} flat pate collectors with a gas backup system. The system will provide comfort air-conditioning for this these type of office buildings during daytime. [Spanish] Este documento describe el proyecto SOFRI, una cooperacion entre Ceeran, Ltd, y la Universidad Tecnologica del Delft. El principal objetivo de este proyecto es el de desarrollar el conocimiento necesario y la experiencia para comercializar los sistemas de aire acondicionado y deshumidificacion ayudados por la energia solar en el Caribe Holandes. Este proyecto ha sido motivado por las actuales necesidades del Caribe Holandes de fuentes de energia renovable y por el hecho de que el Caribe tiene una alta y uniforme insolacion

48 CFR 23.804 - Contract clauses.

Science.gov (United States)

2010-10-01

... refrigerant, such as air conditioners, including motor vehicles, refrigerators, chillers, or freezers. [61 FR... Equipment and Air Conditioners, in solicitations and contracts for services when the contract includes the...

High fungal spore burden with predominance of Aspergillus in hospital air of a tertiary care hospital in Chandigarh

Directory of Open Access Journals (Sweden)

S M Rudramurthy

2016-01-01

Full Text Available The prevalence of fungal spores in the hospital air is essential to understand the hospital-acquired fungal infections. Air conditioners (ACs used in hospitals may either reduce spores in air or be colonised by fungi and aid in its dissemination. The present study was conducted to assess the fungal spore burden in AC and non-AC areas. We found a high fungal spore count in air irrespective of whether the area was AC or non-AC. The most predominant species isolated were Aspergillus flavus and Aspergillus fumigatus. Such high concentrations of pathogenic fungi in air may predispose individuals to develop disease.

Remote Sensing Global Surface Air Pressure Using Differential Absorption BArometric Radar (DiBAR)

Science.gov (United States)

Lin, Bing; Harrah, Steven; Lawrence, Wes; Hu, Yongxiang; Min, Qilong

2016-01-01

Tropical storms and severe weathers are listed as one of core events that need improved observations and predictions in World Meteorological Organization and NASA Decadal Survey (DS) documents and have major impacts on public safety and national security. This effort tries to observe surface air pressure, especially over open seas, from space using a Differential-absorption BArometric Radar (DiBAR) operating at the 50-55 gigahertz O2 absorption band. Air pressure is among the most important variables that affect atmospheric dynamics, and currently can only be measured by limited in-situ observations over oceans. Analyses show that with the proposed space radar the errors in instantaneous (averaged) pressure estimates can be as low as approximately 4 millibars (approximately 1 millibar under all weather conditions). With these sea level pressure measurements, the forecasts of severe weathers such as hurricanes will be significantly improved. Since the development of the DiBAR concept about a decade ago, NASA Langley DiBAR research team has made substantial progress in advancing the concept. The feasibility assessment clearly shows the potential of sea surface barometry using existing radar technologies. The team has developed a DiBAR system design, fabricated a Prototype-DiBAR (P-DiBAR) for proof-of-concept, conducted lab, ground and airborne P-DiBAR tests. The flight test results are consistent with the instrumentation goals. Observational system simulation experiments for space DiBAR performance based on the existing DiBAR technology and capability show substantial improvements in tropical storm predictions, not only for the hurricane track and position but also for the hurricane intensity. DiBAR measurements will lead us to an unprecedented level of the prediction and knowledge on global extreme weather and climate conditions.

Performance analysis of a ground-assisted direct evaporative cooling air conditioner

Energy Technology Data Exchange (ETDEWEB)

Heidarinejad, Ghassem; Khalajzadeh, Vahid [Department of Mechanical Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran (Iran); Delfani, Shahram [Building and Housing Research Center (BHRC), P O Box 13145-1696, Tehran (Iran)

2010-11-15

In this paper, the results of performance analysis of a ground-assisted hybrid evaporative cooling system in Tehran have been discussed. A Ground Coupled Circuit (GCC) provides the necessary pre-cooling effects, enabling a Direct Evaporative Cooler (DEC) that cools the air even below its wet-bulb temperature. The GCC includes four vertical ground heat exchangers (GHE) which were arrayed in series configuration. In order to have an accurate prediction of the optimum performance of a GCC, a computational fluid dynamic simulation was performed. Simulation results revealed that the combination of GCC and DEC system could provide comfort condition whereas DEC alone did not. Based on the simulation results the cooling effectiveness of a hybrid system is more than 100%. Thus, this novel hybrid system could decrease the air temperature below the ambient wet-bulb temperature. This environmentally clean and energy efficient system can be considered as an alternative to the mechanical vapor compression systems. (author)

Absorption of carbon dioxide in waste tanks

International Nuclear Information System (INIS)

Hobbs, D.T.

1987-01-01

Air flow rates and carbon dioxide concentrations of air entering and exiting eight H-Area waste tanks were monitored for a period of one year. The average instanteous concentration of carbon dioxide in air is within the range reported offsite, and therefore is not affect by operation of the coal-fired power plant adjacent to the tank farm. Waste solutions in each of the tanks were observed to be continuously absorbing carbon dioxide. The rate of absorption of carbon dioxide decreased linearly with the pH of the solution. Personnel exposure associated with the routine sampling and analysis of radioactive wastes stored at SRP to determine the levels of corrosion inhibitors in solution could be reduced by monitoring the absorption of carbon dioxide and using the relationship between pH and carbon dioxide absorption to determine the free hydroxide concentration in solution

Response of microbial community of organic-matter-impoverished arable soil to long-term application of soil conditioner derived from dynamic rapid fermentation of food waste.

Science.gov (United States)

Hou, Jiaqi; Li, Mingxiao; Mao, Xuhui; Hao, Yan; Ding, Jie; Liu, Dongming; Xi, Beidou; Liu, Hongliang

2017-01-01

Rapid fermentation of food waste can be used to prepare soil conditioner. This process consumes less time and is more cost-effective than traditional preparation technology. However, the succession of the soil microbial community structure after long-term application of rapid fermentation-derived soil conditioners remains unclear. Herein, dynamic rapid fermentation (DRF) of food waste was performed to develop a soil conditioner and the successions and diversity of bacterial communities in an organic-matter-impoverished arable soil after six years of application of DRF-derived soil conditioner were investigated. Results showed that the treatment increased soil organic matter (SOM) accumulation and strawberry yield by 5.3 g/kg and 555.91 kg/ha, respectively. Proteobacteria, Actinobacteria, Acidobacteria, and Firmicutes became the dominant phyla, occupying 65.95%-77.52% of the bacterial sequences. Principal component analysis (PCA) results showed that the soil bacterial communities were largely influenced by the treatment. Redundancy analysis (RDA) results showed that the relative abundances of Gemmatimonadetes, Chloroflexi, Verrucomicrobia, Nitrospirae, and Firmicutes were significantly correlated with soil TC, TN, TP, NH4+-N, NO3--N, OM, and moisture. These communities were all distributed in the soil samples collected in the sixth year of application. Long-term treatment did not enhance the diversity of bacterial species but significantly altered the distribution of major functional bacterial communities in the soils. Application of DRF-derived soil conditioner could improve the soil quality and optimize the microbial community, ultimately enhancing fruit yields.

Simulation of absorption refrigeration system for automobile application

Directory of Open Access Journals (Sweden)

Ramanathan Anand

2008-01-01

Full Text Available An automotive air-conditioning system based on absorption refrigeration cycle has been simulated. This waste heat driven vapor absorption refrigeration system is one alternate to the currently used vapour compression refrigeration system for automotive air-conditioning. Performance analysis of vapor absorption refrigeration system has been done by developing a steady-state simulation model to find the limitation of the proposed system. The water-lithium bromide pair is used as a working mixture for its favorable thermodynamic and transport properties compared to the conventional refrigerants utilized in vapor compression refrigeration applications. The pump power required for the proposed vapor absorption refrigeration system was found lesser than the power required to operate the compressor used in the conventional vapor compression refrigeration system. A possible arrangement of the absorption system for automobile application is proposed.

Evaluation of rotor-bearing system dynamic response to unbalance. [air conditioning equipment

Science.gov (United States)

Thaller, R. E.; Ozimek, D. W.

1979-01-01

The vibration environment within air conditioner rotating machinery referred to as an air cycle machine (ACM) was investigated to effectively increase ACM reliability. To assist in the selection of design changes which would result in improved ACM performance, various design modifications were incorporated into a baseline ACM configuration. For each design change, testing was conducted with the best balance achieveable (baseline) and with various degrees of unbalance. Relationships between unbalance (within the context of design changes) and the parameters associated with design goals were established. The results of rotor dynamics tests used to establish these relationships are presented.

Effect of conditioners upon the thermodynamics and kinetics of methane hydrate formation. A preliminary structure-properties relationship study

Energy Technology Data Exchange (ETDEWEB)

Di Profio, Pietro; Arca, Simone; Germani, Raimondo; Savelli, Gianfranco

2005-07-01

The synthesis and stability of gas hydrates was found to be heavily affected by the presence of small quantities of additives, or conditioners, particularly surfactants. In a recent work, we showed that the enhancement of hydrate formation, both from previously described and newly synthesized surfactants, is probably due to surfactant monomers, rather than micelles, and that the features of hydrate induction time should not be used as a measure of critical micelle concentration. In the present paper, we discuss the results of a structure-properties relationship study in which a preliminary attempt to relate the structural features of several amphiphilic additives to some kinetic and thermodynamic parameters of methane hydrate formation - e.g., induction times, rate of formation, occupancy, etc. - is conducted. According to the present study, it is found that, for a particular conditioner, a reduction of induction time does not correlate to an increase of the formation rate and occupancy, and vice versa. This may be related to the nature of chemical moieties forming a particular amphiphile (e.g., the hydrophobic tail, head group, counterion, etc.). The understanding of the mechanisms by which those moieties play their differential role may be the key tool to the design and synthesis of tailored conditioners. (Author)

A Closed-Loop Control Strategy for Air Conditioning Loads to Participate in Demand Response

Directory of Open Access Journals (Sweden)

Xiaoqing Hu

2015-08-01

Full Text Available Thermostatically controlled loads (TCLs, such as air conditioners (ACs, are important demand response resources—they have a certain heat storage capacity. A change in the operating status of an air conditioner in a small range will not noticeably affect the users’ comfort level. Load control of TCLs is considered to be equivalent to a power plant of the same capacity in effect, and it can significantly reduce the system pressure to peak load shift. The thermodynamic model of air conditioning can be used to study the aggregate power of a number of ACs that respond to the step signal of a temperature set point. This paper analyzes the influence of the parameters of each AC in the group to the indoor temperature and the total load, and derives a simplified control model based on the two order linear time invariant transfer function. Then, the stability of the model and designs its Proportional-Integral-Differential (PID controller based on the particle swarm optimization (PSO algorithm is also studied. The case study presented in this paper simulates both scenarios of constant ambient temperature and changing ambient temperature to verify the proposed transfer function model and control strategy can closely track the reference peak load shifting curves. The study also demonstrates minimal changes in the indoor temperature and the users’ comfort level.

Resources and Fact Sheets on Servicing Motor Vehicle Air Conditioners (Summary Page)

Science.gov (United States)

Page provides links to resources that can assist motor vehicle air-conditioning system technicians in understanding system servicing requirements and best practices, and learn about alternative refrigerants.

Cycle performance of alternative refrigerants for domestic air-conditioning system based on a small finned tube heat exchanger

International Nuclear Information System (INIS)

Cheng, Song; Wang, Shuangfeng; Liu, Zhongmin

2014-01-01

In order to find alternative refrigerants which exhibit both favorable cycle performance and environmental friendliness, R32 and R290 were utilized to contrast to R22 and R410A as substitutes in the present study. The experiments were conducted with a 5 mm finned tube heat exchanger based on the enthalpy method in a small split household air conditioner. The results showed that in nominal cooling conditions, the COP R of R32 and R290 were 26.8% and 20.4% higher than R22, 7.3% and 2.1% higher than R410A. And in nominal heating conditions, the COP HR of R32 and R290 were both 11.0% higher than R22, 5.3% higher than R410A. The systems with R290 and R32 have similar capacities to that with R22 and R410A in heating mode, but a relatively huge difference of capacities in cooling mode. In consideration of charge amount, R290 could be considered as the most superior alternative refrigerant in air conditioners with the small finned tube heat exchanger. - Highlights: •Comparisons are made in the air conditioner system based on 5 mm tube fin heat exchanger. •The R22 system has a similar performance to others in heating mode while a huge difference in cooling mode. •The optimal charge of R290 is reduced with nearly no decline in the capacity and COP. •SLHX is attached to the system of R290 and successfully promote safety and capacity. •Heat loads are taken into account to evaluate the advantages and disadvantages of R290 and R32

インバータエアコンの冷房時部分負荷特性と除湿能力について

OpenAIRE

細川, 隆行; 林, 徹夫; 野村, 幸司; Hosokawa, Takayuki; Hayashi, Tetsuo; Nomura, Kouji

2005-01-01

Now, 90% or more of the air conditioner used at home is an ability changeable type of the inverter method. However, only the performance in the state of ratings of JIS is described in the catalog of the air conditioner, and the relation to the frequency of the inverter is uncertain. In this paper, the partial load characteristic and the dehumidification ability of the ability changeable type air conditioner of the inverter method are investigated. Moreover, a numeric computing model of a hous...

Determination of the ejector dimensions of a bus air-conditioning system using analytical and numerical methods

International Nuclear Information System (INIS)

Ünal, Şaban

2015-01-01

Comfortable journey with commercial buses is an essential goal of transportation companies. An air-conditioning system can play an important role for this comfortable journey but it can put extra load on the engine and extra cost in the fuel consumption. The purpose of this work is to increase the performance of air-conditioning system of the buses by reducing the load on the engine and fuel consumption. Using a two-phase ejector as an expansion valve can increase the coefficient of performance (COP) of the air-conditioning system. An improvement in the COP can reduce the empty vehicle weight and fuel consumption of buses. Two-phase ejector dimensions can be determined using the empirical methods available in the literature. In this paper, the two-phase ejector dimensions of air conditioning system for a bus are calculated using the analytical and numerical methods. First of all, the thermodynamic analysis of the vapor-compression refrigeration cycle with a two-phase ejector is performed, and then the ejector dimensions are subsequently determined. The cooling loads of the midibus and bus with R134a as a refrigerant are assumed to be 14 kW and 32 kW, respectively. The total length of the two-phase ejector for the midibuses and buses due to these cooling loads, are computed to be 480.8 mm and 793.1 mm, respectively. Also, an experimental setup is installed on a midibus air conditioner to turn it into the ejector air conditioning system to validate theoretical results with the experimental study. - Highlights: • Determination of two-phase ejector dimensions of a bus air-conditioning system. • Thermodynamic analysis of the two-phase ejector cooling system. • Experimental study on a midibus air conditioner using two-phase ejector.

Aerosol Absorption by Black Carbon and Dust: Implications of Climate Change and Air Quality in Asia

Science.gov (United States)

Chin, Mian

2010-01-01

Atmospheric aerosol distributions from 2000 to 2007 are simulated with the global model GOCART to attribute light absorption by aerosol to its composition and sources. We show the seasonal and interannual variations of absorbing aerosols in the atmosphere over Asia, mainly black carbon and dust. and their linkage to the changes of anthropogenic and dust emissions in the region. We compare our results with observations from satellite and ground-based networks, and estimate the importance of black carbon and dust on regional climate forcing and air quality.

THE EFFECT OF SOIL CONDITIONERS ON CELLULOSE, HEMICELLULOSE, AND THE ADL FIBRE FRACTION CONCENTRATION IN DACTYLIS GLOMERATA AND LOLIUM PERENNE

Directory of Open Access Journals (Sweden)

Milena Truba

2017-01-01

Full Text Available Replicated three times, the research was conducted in the experimental field between 2011 and 2014. Three soil conditioners with the following trade names: UGmax, Eko-Użyźniacz, and Humus Active Papka were used in the experiment, separately or together with NPK fertilisers. They were all used on plots sown with two species of grass, Dactylis glomerata of the Bora variety and Lolium perenne of the Info variety. The plant material from both grass species was tested for the concentration of ADL fraction (% DM, cellulose (% DM, and hemicellulose (% DM. It was found that the concentration of cellulose, hemicelluloses, and the ADL fraction was significantly higher in the biomass of Dactylis glomerata than in the biomass of Lolium perenne. The grass from the plot with the UGmax soil conditioner applied had the highest amount of cellulose and hemicellulose. The lowest amount of those organic compounds was found in the grass treated with UGmax together with mineral fertilisers and in plants treated with Humus Active, together with mineral fertilisers. However, the fertilisers and conditioners did not increase the ADL content in both grass species.

Experimental Investigation of Air Conditioner using the Desiccant Cooling System in Equatorial Climates

Directory of Open Access Journals (Sweden)

Abdullah Kamaruddin

2018-01-01

Full Text Available Indonesia lies in the tropical climate which requires air conditioning to increase working productivity of the people. Up to now people are still using the compressive cooling system which uses Freon as the refrigerant, which have been known to have a negative environmental impact. Therefore, new cooling system which is environmentally friendly is now needed. Desiccant cooling system manipulates the humidity condition of outside air in such a way so that the final temperature should become at 25 °C and RH of 65 %. Since it does not require refrigerant, a desiccant cooling has the potential to be developed in a tropical country like Indonesia. In this study an experimental desiccant cooling system has been designed and constructed and tested under laboratory condition. Experimental results have shown that the resulting air temperature was 26.1 °C with RH of 55.6 %, and average cooling capacity was 0.425 kW. The COP was found to be 0.44.

78 FR 7296 - Energy Conservation Program: Energy Conservation Standards for Small, Large, and Very Large...

Science.gov (United States)

2013-02-01

... Unit Challenge (RTU Challenge). This program provides a market mechanism that reduces barriers for... commercial air-cooler air conditioners and heat pumps in the field. \\7\\ U.S. Department of Energy. Building... the IEER more than the EER for commercial air conditioners and heat pumps. D. Engineering Analysis The...

40 CFR Appendix A to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes

Science.gov (United States)

2010-07-01

... safely in this end-use. CFC-12, motor vehicle air conditioners (retrofit) HCFC-22/HFC-142b/CFC-12... to demonstrate it can be used safely in this end-use. CFC-12, motor vehicle air conditioners (new... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE...

Concentrations of polybrominated diphenyl ethers (PBDEs) in central air-conditioner filter dust and relevance of non-dietary exposure in occupational indoor environments in Greece

International Nuclear Information System (INIS)

Besis, Athanasios; Katsoyiannis, Athanasios; Botsaropoulou, Elisavet; Samara, Constantini

2014-01-01

Polybrominated Diphenyl Ethers (PBDEs) are ubiquitous in the indoor environment owing to their use in consumer products and various studies around the world have found higher concentrations indoors than outdoors. Central air conditioner (A/C) systems have been widely used in many workplaces, therefore, studying of PBDEs in central A/C filter dust is useful to better understand the occurrences and health implications of PBDEs in indoor environments. The present study examined the occurrence of PBDEs in central A/C filter dust collected from various workplaces (n = 20) in Thessaloniki, Greece. The sum concentrations of 21 target congeners (∑ 21 PBDE) in A/C dust ranged between 84 and 4062 ng g −1 with a median value of 1092 ng g −1 , while BDE-209 was found to be the most abundant BDE congener. The daily intake via dust ingestion of PBDEs estimated for the employees of the occupational settings ranged from 3 to 45 ng day −1 (median 12 ng day −1 ). - Highlights: • PBDEs were investigated in dust of A/C filters in occupational settings in Thessaloniki, Greece. • BDE-209 was found to be the most abundant BDE congener. • High levels of PBDEs were found in a newspaper building, internet cafes and electronic shops. • PBDEs were attributable to the extensive presence and/or usage of electronic devices. • Exposure of employees to PBDEs via indoor dust ingestion was estimated at 12 ng day −1 . - PBDEs were for the first time measured in dust from central A/C filters in workplaces of Greece and their concentrations were used to estimate the non-dietary human exposure

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.

Large scale air monitoring: Biological indicators versus air particulate matter

International Nuclear Information System (INIS)

Rossbach, M.; Jayasekera, R.; Kniewald, G.

2000-01-01

Biological indicator organisms are widely used for monitoring and banking purposes since many years. Although the complexity of the interactions between bioorganisms and their environment is generally not easily comprehensible, environmental quality assessment using the bioindicator approach offers some convincing advantages compared to direct analysis of soil, water, or air. Direct measurement of air particulates is restricted to experienced laboratories with access to expensive sampling equipment. Additionally, the amount of material collected generally is just enough for one determination per sampling and no multidimensional characterization might be possible. Further, fluctuations in air masses have a pronounced effect on the results from air filter sampling. Combining the integrating property of bioindicators with the world wide availability and uniform matrix characteristics of air particulates as a prerequisite for global monitoring of air pollution will be discussed. A new approach for sampling urban dust using large volume filtering devices installed in air conditioners of large hotel buildings is assessed. A first experiment was initiated to collect air particulates (300 to 500 g each) from a number of hotels during a period of three to four months by successive vacuum cleaning of used inlet filters from high volume air conditioning installations reflecting average concentrations per three months in different large cities. This approach is expected to be upgraded and applied for global monitoring. Highly positive correlated elements were found in lichen such as K/S, Zn/P, the rare earth elements (REE) and a significant negative correlation between Fig and Cu was observed in these samples. The ratio of concentrations of elements in dust and Usnea spp. is highest for Cr, Zn, and Fe (400-200) and lowest for elements such as Ca, Rb, and Sr (20-10). (author)

Adhesive bonding of resin composite to various titanium surfaces using different metal conditioners and a surface modification system

Directory of Open Access Journals (Sweden)

Hercules Jorge ALMILHATTI

2013-12-01

Full Text Available Objective: This study evaluated the effect of three metal conditioners on the shear bond strength (SBS of a prosthetic composite material to cpTi grade I having three surface treatments. Material and Methods: One hundred sixty eight rivet-shaped specimens (8.0x2.0 mm were cast and subjected to polishing (P or sandblasting with either 50 mm (50SB or 250 mm (250SB Al2O3. The metal conditioners Metal Photo Primer (MPP, Cesead II Opaque Primer (OP, Targis Link (TL, and one surface modification system Siloc (S, were applied to the specimen surfaces, which were covered with four 1-mm thick layers of resin composite. The resin layers were exposed to curing light for 90 s separately. Seven specimens from each experimental group were stored in water at 37ºC for 24 h while the other 7 specimens were subjected to 5,000 thermal cycles consisting of water baths at 4ºC and 60ºC (n=7. All specimens were subjected to SBS test (0.5 mm/min until failure occurred, and further 28 specimens were analyzed using scanning electron microscope (SEM and X-ray energy-dispersive spectroscopy (EDS. Data were analyzed by 3-way ANOVA followed by post-hoc Tukey's test (α=0.05. Results: On 50SB surfaces, OP groups showed higher SBS means than MPP (P<0.05, while no significant difference was found among OP, S, and TL groups. On 250SB surfaces, OP and TL groups exhibited higher SBS than MPP and S (P<0.05. No significant difference in SBS was found between OP and TL groups nor between MPP and S groups. The use of conditioners on 250SB surfaces resulted in higher SBS means than the use of the same products on 50SB surfaces (P<0.05. Conclusion: Sandblasting associated with the use of metal conditioners improves SBS of resin composites to cpTi.

Replacement or additional purchase: The impact of energy-efficient appliances on household electricity saving under public pressures

International Nuclear Information System (INIS)

Mizobuchi, Kenichi; Takeuchi, Kenji

2016-01-01

This study examined the influence of additional and replacement purchases of energy-efficient air-conditioners on power savings. We used a questionnaire survey and measured electricity use data from 339 Japanese households, collected from two city areas with different level of government-requested electricity-saving rates, namely, Osaka (10%) and Matsuyama (5%). The main findings of our study are as follows: (1) Households that purchased energy-efficient air-conditioners saved more electricity than those that did not. (2) “Additional-purchase households” showed significant energy savings, whereas “replacement households” did not. The rebound effect may negate the energy-saving effects of a new air-conditioner. (3) Altruistic attitude is associated with more active participation in power saving. (4) Households in Osaka saved more electricity than those in Matsuyama, probably because the government call to save electricity was more forceful. - Highlights: •Energy efficient air conditioner purchases affect household power savings. •Additional air conditioner purchase led to significant energy savings. •Replacement units did not produce more savings than non-purchase. • “Electricity conservation directives” amount had a significant power-saving effect. •Altruistic households were more likely to cooperate with power-saving requests.

Radio decontamination of hair conditioner for capillary ammniotherapy

International Nuclear Information System (INIS)

Romay, Z.; Otero, I.; Chavez, A.; Torriente, I.

1996-01-01

The Hair conditioner, which belongs to the group of cosmetic products Dr Miyares Cao, was artificially contaminated, kept at different values of temperature (-20 oC , 0 oC and +20 oC ) and irradiated to different doses (6, 10, 12, 15, 20, 25 and 30 kGy) and 25 oC for studying the effect of gamma radiation on it and the possibility of use of this technology for its decontamination. The radiobiological parameters of the contaminator and the quality of irradiated products were determined. Was conclude that the product maintain its organolepthics characteristics and others quality parameters after irradiated to 20 kGy and +20 oC of temperature before irradiation. Finally, the decontamination of studied product was obtained by means its irradiation to 16.2 kGy

77 FR 62623 - 2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions and Corporate Average Fuel...

Science.gov (United States)

2012-10-15

... changes to the regulations applicable to model years 2012-2016, with respect to air conditioner... standards for emissions of pollutants from new motor vehicles which emissions cause or contribute to air... same improvements in air conditioner efficiency. \\5\\ This is further broken down by 5.0 and 7.2 g/mi...

40 CFR 82.154 - Prohibitions.

Science.gov (United States)

2010-07-01

... substance for use in motor vehicle air conditioners in accordance with 40 CFR part 82, subpart G; (4) The... wholly or in part of a class I or class II substance for use in motor vehicle air conditioners pursuant... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF...

Final Project Report Load Modeling Transmission Research

Energy Technology Data Exchange (ETDEWEB)

Lesieutre, Bernard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bravo, Richard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yinger, Robert [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chassin, Dave [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Huang, Henry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Ning [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hiskens, Ian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Venkataramanan, Giri [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2012-03-31

The research presented in this report primarily focuses on improving power system load models to better represent their impact on system behavior. The previous standard load model fails to capture the delayed voltage recovery events that are observed in the Southwest and elsewhere. These events are attributed to stalled air conditioner units after a fault. To gain a better understanding of their role in these events and to guide modeling efforts, typical air conditioner units were testing in laboratories. Using data obtained from these extensive tests, new load models were developed to match air conditioner behavior. An air conditioner model is incorporated in the new WECC composite load model. These models are used in dynamic studies of the West and can impact power transfer limits for California. Unit-level and systemlevel solutions are proposed as potential solutions to the delayed voltage recovery problem.

Assessment of commercially available energy-efficient room air conditioners including models with low global warming potential (GWP) refrigerants

Energy Technology Data Exchange (ETDEWEB)

Shah, N. K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Park, W. Y. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gerke, B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2017-08-30

Improving the energy efficiency of room air conditioners (RACs) while transitioning to low global-warming-potential (GWP) refrigerants will be a critical step toward reducing the energy, peak load, and emissions impacts of RACs while keeping costs low. Previous research quantified the benefits of leapfrogging to high efficiency in tandem with the transition to low-GWP refrigerants for RACs (Shah et al., 2015) and identified opportunities for initial action to coordinate energy efficiency with refrigerant transition in economies constituting about 65% of the global RAC market (Shah et al., 2017). This report describes further research performed to identify the best-performing (i.e., most efficient and low-GWP-refrigerant using) RACs on the market, to support an understanding of the best available technology (BAT). Understanding BAT can help support market-transformation programs for high-efficiency and low-GWP equipment such as minimum energy performance standards (MEPS), labeling, procurement, and incentive programs. We studied RACs available in six economies—China, Europe, India, Japan, South Korea, and the United States—that together account for about 70% of global RAC demand, as well as other emerging economies. The following are our key findings: • Highly efficient RACs using low-GWP refrigerants, e.g., HFC-32 (R-32) and HC-290 (R-290), are commercially available today at prices comparable to similar RACs using high-GWP HCFC-22 (R-22) or HFC-410A (R-410A). • High efficiency is typically a feature of high-end products. However, highly efficient, cost-competitive (less than 1,000 or 1,500 U.S. dollars in retail price, depending on size) RACs are available. • Where R-22 is being phased out, high GWP R-410A still dominates RAC sales in most mature markets except Japan, where R-32 dominates. • In all of the economies studied except Japan, only a few models are energy efficient and use low-GWP refrigerants. For example, in Europe, India, and Indonesia

Effect of Agri-SC as a soil conditioner on runoff, soil loss and crust ...

African Journals Online (AJOL)

This study was carried out to determine the effect of Agri-SC as a soil conditioner at different doses (0, 18.50, 37.00, 55.50 and 74.00 l ha-1) on water erosion and crust strengths under laboratory conditions with three replicates. The Agri-SC solutions were sprayed and two consecutive simulated rainfalls (60 mm h-1) were ...

Air source absorption heat pump in district heating: Applicability analysis and improvement options

International Nuclear Information System (INIS)

Wu, Wei; Shi, Wenxing; Li, Xianting; Wang, Baolong

2015-01-01

Highlights: • Applicability of air source absorption heat pump (ASAHP) district heating is studied. • Return temperature and energy saving rate (ESR) in various conditions are optimized. • ASAHP is more suitable for shorter distance or lower temperature district heating. • Two options can reduce the primary return temperature and improve the applicability. • The maximum ESR is improved from 13.6% to 20.4–25.6% by compression-assisted ASAHP. - Abstract: The low-temperature district heating system based on the air source absorption heat pump (ASAHP) was assessed to have great energy saving potential. However, this system may require smaller temperature drop leading to higher pump consumption for long-distance distribution. Therefore, the applicability of ASAHP-based district heating system is analyzed for different primary return temperatures, pipeline distances, pipeline resistances, supplied water temperatures, application regions, and working fluids. The energy saving rate (ESR) under different conditions are calculated, considering both the ASAHP efficiency and the distribution consumption. Results show that ASAHP system is more suitable for short-distance district heating, while for longer-distance heating, lower supplied hot water temperature is preferred. In addition, the advantages of NH 3 /H 2 O are inferior to those of NH 3 /LiNO 3 , and the advantages for warmer regions and lower pipeline resistance are more obvious. The primary return temperatures are optimized to obtain maximum ESRs, after which the suitable distances under different acceptable ESRs are summarized. To improve the applicability of ASAHP, the integration of cascaded heat exchanger (CHX) and compression-assisted ASAHP (CASAHP) are proposed, which can reduce the primary return temperature. The integration of CHX can effectively improve the applicability of ASAHP under higher supplied water temperatures. As for the utilization of CASAHP, higher compression ratio (CR) is better in

Experimental Assessment of residential split type air-conditioning systems using alternative refrigerants to R-22 at high ambient temperatures

International Nuclear Information System (INIS)

Joudi, Khalid A.; Al-Amir, Qusay R.

2014-01-01

Highlights: • R290, R407C and R410A in residential split A/C units at high ambient. • 1 and 2 TR residential air conditioners with R22 alternatives at high ambient. • Residential split unit performance at ambients up to 55 °C with R22 alternatives. - Abstract: Steady state performance of residential air conditioning systems using R22 and alternatives R290, R407C, R410A, at high ambient temperatures, have been investigated experimentally. System performance parameters such as optimum refrigerant charge, coefficient of performance, cooling capacity, power consumption, pressure ratio, power per ton of refrigeration and TEWI environmental factor have been determined. All refrigerants were tested in the cooling mode operation under high ambient air temperatures, up to 55 °C, to determine their suitability. Two split type air conditioner of 1 and 2 TR capacities were used. A psychrometric test facility was constructed consisting of a conditioned cool compartment and an environmental duct serving the condenser. Air inside the conditioned compartment was maintained at 25 °C dry bulb and 19 °C wet bulb for all tests. In the environmental duct, the ambient air temperature was varied from 35 °C to 55 °C in 5 °C increments. The study showed that R290 is the better candidate to replace R22 under high ambient air temperatures. It has lower TEWI values and a better coefficient of performance than the other refrigerants tested. It is suitable as a drop-in refrigerant. R407C has the closest performance to R22, followed by R410A

26 CFR 52.4682-4 - Floor stocks tax.

Science.gov (United States)

2010-04-01

... conditioners. Example 4. D operates an air-conditioning repair service and holds an ODC for use in repairing... automobile dealer, holds an ODC for use in charging air conditioners installed in automobiles that it sells... sale. However, the tax is imposed on a can of ODC used to recharge an air conditioning unit because the...

Absorption of water vapour in the falling film of water-(LiBr + LiI + LiNO{sub 3} + LiCl) in a vertical tube at air-cooling thermal conditions

Energy Technology Data Exchange (ETDEWEB)

Bourouis, Mahmoud; Valles, Manel; Medrano, Marc; Coronas, Alberto [Centro de Innovacion Tecnologica en Revalorizacion Energetica y Refrigeracion, CREVER, Universitat Rovira i Virgili, Autovia de Salou, s/n, 43006, Tarragona (Spain)

2005-05-01

In air-cooled water-LiBr absorption chillers the working conditions in the absorber and condenser are shifted to higher temperatures and concentrations, thereby increasing the risk of crystallisation. To develop this technology, two main problems are to be addressed: the availability of new salt mixtures with wider range of solubility than water-LiBr, and advanced absorber configurations that enable to carry out simultaneously an appropriate absorption process and an effective air-cooling. One way of improving the solubility of LiBr aqueous solutions is to add other salts to create multicomponent salt solutions. The aqueous solution of the quaternary salt system (LiBr + LiI + LiNO{sub 3} + LiCl) presents favourable properties required for air-cooled absorption systems: less corrosive and crystallisation temperature about 35 K lower than that of water-LiBr.This paper presents an experimental study on the absorption of water vapour over a wavy laminar falling film of an aqueous solution of (LiBr + LiI + LiNO{sub 3} + LiCl) on the inner wall of a water-cooled smooth vertical tube. Cooling water temperatures in the range 30-45 C were selected to simulate air-cooling thermal conditions. The results are compared with those obtained in the same experimental set-up with water-LiBr solutions.The control variables for the experimental study were: absorber pressure, solution Reynolds number, solution concentration and cooling water temperature. The parameters considered to assess the absorber performance were: absorber thermal load, mass absorption flux, degree of subcooling of the solution leaving the absorber, and the falling film heat transfer coefficient.The higher solubility of the multicomponent salt solution makes possible the operation of the absorber at higher salt concentration than with the conventional working fluid water-LiBr. The absorption fluxes achieved with water-(LiBr + LiI + LiNO{sub 3} + LiCl) at a concentration of 64.2 wt% are around 60 % higher than

Modeling of in-vehicle magnetic refrigeration

DEFF Research Database (Denmark)

Olsen, Ulrik Lund; Bahl, Christian R.H.; Engelbrecht, Kurt

2014-01-01

A high-performance magnetic refrigeration device is considered as a potential technology for in-vehicle air conditioners in electric vehicles. The high power consumption of a conventional air conditioner in an electric vehicle has considerable impacts on cruising distance. For this purpose...

Modeling of In-vehicle Magnetic refrigeration

DEFF Research Database (Denmark)

Olsen, Ulrik Lund; Bahl, Christian; Engelbrecht, Kurt

2012-01-01

A high-performance magnetic refrigeration device is considered as a potential technology for in-vehicle air conditioners in electric vehicles. The high power consumption of a conventional air conditioner in an electric vehicle has considerable impacts on cruising distance. For this purpose...

Noble gas absorption process

International Nuclear Information System (INIS)

Thomas, J.W.

1975-01-01

A method of removing a noble gas from air comprising the use of activated carbon filters in stages in which absorption and desorption steps in succession are conducted in order to increase the capacity of the filters is described. (U.S.)

Future Air Conditioning Energy Consumption in Developing Countries and what can be done about it: The Potential of Efficiency in the Residential Sector

OpenAIRE

McNeil, Michael A.; Letschert, Virginie E.

2008-01-01

The dynamics of air conditioning are of particular interest to energy analysts, both because of the high energy consumption of this product, but also its disproportionate impact on peak load. This paper addresses the special role of this end use as a driver of residential electricity consumption in rapidly developing economies. Recent history has shown that air conditioner ownership can grow grows more rapidly than economic growth in warm-climate countries. In 1990, less than a percent o...

Air change rates of motor vehicles and in-vehicle pollutant concentrations from secondhand smoke.

Science.gov (United States)

Ott, Wayne; Klepeis, Neil; Switzer, Paul

2008-05-01

The air change rates of motor vehicles are relevant to the sheltering effect from air pollutants entering from outside a vehicle and also to the interior concentrations from any sources inside its passenger compartment. We made more than 100 air change rate measurements on four motor vehicles under moving and stationary conditions; we also measured the carbon monoxide (CO) and fine particle (PM(2.5)) decay rates from 14 cigarettes smoked inside the vehicle. With the vehicle stationary and the fan off, the ventilation rate in air changes per hour (ACH) was less than 1 h(-1) with the windows closed and increased to 6.5 h(-1) with one window fully opened. The vehicle speed, window position, ventilation system, and air conditioner setting was found to affect the ACH. For closed windows and passive ventilation (fan off and no recirculation), the ACH was linearly related to the vehicle speed over the range from 15 to 72 mph (25 to 116 km h(-1)). With a vehicle moving, windows closed, and the ventilation system off (or the air conditioner set to AC Max), the ACH was less than 6.6 h(-1) for speeds ranging from 20 to 72 mph (32 to 116 km h(-1)). Opening a single window by 3'' (7.6 cm) increased the ACH by 8-16 times. For the 14 cigarettes smoked in vehicles, the deposition rate k and the air change rate a were correlated, following the equation k=1.3a (R(2)=82%; n=14). With recirculation on (or AC Max) and closed windows, the interior PM(2.5) concentration exceeded 2000 microg m(-3) momentarily for all cigarettes tested, regardless of speed. The concentration time series measured inside the vehicle followed the mathematical solutions of the indoor mass balance model, and the 24-h average personal exposure to PM(2.5) could exceed 35 microg m(-3) for just two cigarettes smoked inside the vehicle.

A CO{sub 2} air conditioning system to fight against greenhouse effect; Une climatisation a CO{sub 2} pour lutter contre l'effet de serre

Energy Technology Data Exchange (ETDEWEB)

Anon.

2005-10-05

Automotive air-conditioning systems, with the induced additional fuel consumption and with the type of refrigerants used, contribute to the global warming. Several car fitters, like Delphi, have developed prototypes of CO{sub 2} air conditioners. CO{sub 2} is a greenhouse gas but is less harmful for the environment than other classical refrigerants. The use of CO{sub 2} needs a complete re-design of air-conditioning systems which have to stand pressures of 130 bars and temperatures of 165 deg. C. Short paper. (J.S.)

Use of appropriate absorption coefficients in gamma-ray dosimetry

International Nuclear Information System (INIS)

Gopinath, D.V.; Natarajan, A.; Subbaiah, K.V.

1985-01-01

The current use of the different types of absorption coefficients in the computation of γ-ray energy deposition rates and air dose is critically analyzed. Transport calculations are presented to bring out the errors associated with the use of different absorption coefficients. It is observed that except for source energies in the range of 0.3 to 3.0 MeV the consistent use of the absorption coefficient, μ/sub a/ results in an underestimate of the air dose everywhere and of energy deposition at regions away from source. The underestimate becomes more significant with increased atomic number (Z) of the medium. Based on the computations and analysis it is concluded that the absorption coefficients μ/sub a/ and μ/sub k/ are of very limited use in practical γ-ray dosimetry

Endow My Air Conditioner!

Science.gov (United States)

Simmons, Charles E. P.

1982-01-01

Administrators need to plan and set priorities in various energy/maintenance areas, and trustees and legislators, faculty and students have to be educated regarding maintenance and conservation. Cost of energy consumption by area and department must be worked out. (MLW)

Control strategy for Single-phase Transformerless Three-leg Unified Power Quality Conditioner Based on Space Vector Modulation

DEFF Research Database (Denmark)

Lu, Yong; Xiao, Guochun; Wang, Xiongfei

2016-01-01

The unified power quality conditioner (UPQC) is known as an effective compensation device to improve PQ for sensitive end-users. This paper investigates the operation and control of a single-phase three-leg UPQC (TL-UPQC), where a novel space vector modulation method is proposed for naturally...

THE USE OF AIR LAYERS IN BUILDING ENVELOPES FOR ENERGY SAVING DURING AIR CONDITIONING

Directory of Open Access Journals (Sweden)

S. N. Osipov

2017-01-01

Full Text Available Since there are no large natural energy resources in Belarus, energy savings ought to be a point of the special attention. With this regard it is important to develop modern ways of savings during the process of air conditioning inside new buildings with an air layer in the enclosure, especially in translucent ones. The system of ventilation of air layers in the enclosure of a building has been introduced in which air movement is caused by the gravitational and aerodynamic forces. It makes it possible to arrange further ventilation – a natural, forced or a hybrid one. With the purpose of increasing and streamlining natural draught the partitions are used separating the different parts of air layers. For natural ventilation with the use of gravitational forces the holes in the upper and lower parts of the partitions between adjacent air layers are applied. Natural ventilation in the holes of the partitions is regulated by movable shutters, blinds or other adjusting devices. For combined or forced air exchange between adjacent zones of air layers fans are used pumping air from the air layer zones with a higher temperature to zones of air layers with lower temperature and vice versa. When air exchange is forced, in order to intensify the infiltration of air into zones of air layers jets are laid on a hard surface. In order to cool a multi-layered enclosure of a building, where the movement of air between the air layers (that have been formed by internal partitions is being fulfilled by a natural, forced or combined mode, a part of the air or the total air processed inside the building (i.e. conditioned or non-conditioned air cooler as compared with the outside one is being sent to these strata. Combined or forced flow of the air processed inside the building into the air layers is done through the ducts associated with the output channels of the air conditioners. The internal partitions are equipped with the air valve hole.