Página 1 dos resultados de 116 itens digitais encontrados em 0.005 segundos

Comparação do desempenho energético de sistemas de climatização para uma edificação comercial em Florianópolis/SC

Duarte, Vanessa Cavalcanti Paes
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: Dissertação de Mestrado Formato: 184 p.| il., grafs., tabs.
POR
Relevância na Pesquisa
26.72%
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Civil, Florianópolis, 2014.; O estudo consiste em comparar o desempenho energético no resfriamento entre dois sistemas de climatização do tipo VAV e dois do tipo VRF para aplicação em uma edificação comercial na cidade de Florianópolis-SC, utilizando o programa de simulação computacional EnergyPlus. Esta comparação de desempenho é proposta adotando-se o mesmo modelo de edificação, com mesma envoltória, mesmas cargas internas, taxas de infiltração e renovação de ar. As características técnicas dos sistemas de condicionamento de ar são baseadas nos requisitos mínimos de eficiência energética apresentados nas normas de referência, o Apêndice G da ASHRAE Standard 90.1 (2007a) e o Regulamento Técnico de Qualidade de Eficiência de Edifícios Comerciais, de Serviço e Públicos (RTQ-C, 2010). A avaliação de desempenho energético é realizada para dois padrões de uso de edificação. São avaliados os resultados de consumo de energia elétrica anuais e mensais para cada uso final. São analisados dados horários de potência consumida por uso final, de capacidade de resfriamento...

Monitoring of Bacterial Sugars and Hydroxy Fatty Acids in Dust from Air Conditioners by Gas Chromatography-Mass Spectrometry

Fox, Alvin; Rosario, Rose Marie T.; Larsson, Lennart
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1993 EN
Relevância na Pesquisa
36.31%
Bacterial levels in dust collected from hospital air-conditioning filters were examined by chemical analysis (without prior culture). The dust was analyzed by gas chromatography-mass spectrometry after hydrolysis and derivatization. l-Glycero-d-mannoheptose and hydroxy fatty acids (3-OH 12:0 and 3-OH 14:0) (primarily found in lipopolysaccharide) and muramic acid (a chemical marker for bacterial peptidoglycan) were present at higher levels in dust collected from filters primarily contacting outdoor (as opposed to indoor) air. The ratio of l-glycero-d-mannoheptose to muramic acid in dust (compared with those of a group of gram-positive and gram-negative bacteria) suggested that both dust types contained appreciable numbers of gram-negative bacteria. There is potential for the chemical assessment of the microbial content of airborne dust.

Keeping Cool: Use of Air Conditioning by Australians with Multiple Sclerosis

Summers, Michael P.; Simmons, Rex D.; Verikios, George
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.42%
Despite the known difficulties many people with MS have with high ambient temperatures, there are no reported studies of air conditioning use and MS. This study systematically examined air conditioner use by Australians with MS. A short survey was sent to all participants in the Australian MS Longitudinal Study cohort with a response rate of 76% (n = 2,385). Questions included hours of air-conditioner use, areas cooled, type and age of equipment, and the personal effects of overheating. Air conditioners were used by 81.9% of respondents, with an additional 9.6% who could not afford an air conditioner. Regional and seasonal variation in air conditioning use was reported, with a national annual mean of 1,557 hours running time. 90.7% reported negative effects from overheating including increased fatigue, an increase in other MS symptoms, reduced household and social activities, and reduced work capacity. Households that include people with MS spend between 4 and 12 times more on keeping cool than average Australian households.

Air Change Rates and Interzonal Flows in Residences, and the Need for Multi-Zone Models for Exposure and Health Analyses

Du, Liuliu; Batterman, Stuart; Godwin, Christopher; Chin, Jo-Yu; Parker, Edith; Breen, Michael; Brakefield, Wilma; Robins, Thomas; Lewis, Toby
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.4%
Air change rates (ACRs) and interzonal flows are key determinants of indoor air quality (IAQ) and building energy use. This paper characterizes ACRs and interzonal flows in 126 houses, and evaluates effects of these parameters on IAQ. ACRs measured using weeklong tracer measurements in several seasons averaged 0.73 ± 0.76 h−1 (median = 0.57 h−1, n = 263) in the general living area, and much higher, 1.66 ± 1.50 h−1 (median = 1.23 h−1, n = 253) in bedrooms. Living area ACRs were highest in winter and lowest in spring; bedroom ACRs were highest in summer and lowest in spring. Bedrooms received an average of 55 ± 18% of air from elsewhere in the house; the living area received only 26 ± 20% from the bedroom. Interzonal flows did not depend on season, indoor smoking or the presence of air conditioners. A two-zone IAQ model calibrated for the field study showed large differences in pollutant levels between the living area and bedroom, and the key parameters affecting IAQ were emission rates, emission source locations, air filter use, ACRs, interzonal flows, outdoor concentrations, and PM penetration factors. The single-zone models that are commonly used for residences have substantial limitations and may inadequately represent pollutant concentrations and exposures in bedrooms and potentially other environments other where people spend a substantial fraction of time.

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

Li, Chao-Pin; Guo, Wei; Zhan, Xiao-Dong; Zhao, Bei-Bei; Diao, Ji-Dong; Li, Na; He, Lian-Ping
Fonte: e-Century Publishing Corporation Publicador: e-Century Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 15/06/2014 EN
Relevância na Pesquisa
36.68%
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 < 0.01)...

Air-conditioner filters enriching dust mites allergen

Zhan, Xiaodong; Li, Chaopin; Xu, Haifeng; Xu, Pengfei; Zhu, Haibin; Diao, Jidong; Li, Na; Zhao, Beibei
Fonte: e-Century Publishing Corporation Publicador: e-Century Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 15/03/2015 EN
Relevância na Pesquisa
36.72%
We detected the concentration of dust mites allergen (Der f1 & Der p1) in the air of different places before and after the starting of air-conditioners in Wuhu City, Anhui, China, and to discuss the relation between the dust mites allergen in air-conditioner filters and the asthma attack. The dust samples were collected from the air-conditioner filters in dining rooms, shopping malls, hotels and households respectively. Concentrations of dust mites major group allergen 1 (Der f 1, Der p1) were detected with enzyme linked immunosorbent assay (ELISA), and the dust mite immune activities were determined by dot-ELISA. The concentration of Der f1 in dining rooms, shopping malls, hotels and households was 1.52 μg/g, 1.24 μg/g, 1.31 μg/g and 1.46 μg/g respectively, and the concentration of Der p1 in above-mentioned places was 1.23 μg/g, 1.12 μg/g, 1.16 μg/g and 1.18 μg/g respectively. The concentration of Der f1 & Der p1 in air was higher after the air-conditioners starting one hours later, and the difference was significant (P<0.05, respectively). Additionally, dot-ELISA findings revealed that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. The study concludes that air-conditioner filters can enrich dust mites major group allergen...

Microbiota fúngica do ambiente da UTI neonatal e de amostras clínicas dos recém-nascidos internados no Hospital Universitário de Maceió, AL; Mycoflora the environment and neonatal ICU clinical samples from newborns admitted to the University Hospital in Maceió, AL.

Souza, Aryanna Kelly Pinheiro
Fonte: Universidade Federal de Alagoas; BR; Biologia; Programa de Pós-Graduação em Ciências da Saúde; UFAL Publicador: Universidade Federal de Alagoas; BR; Biologia; Programa de Pós-Graduação em Ciências da Saúde; UFAL
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
26.8%
The fungi are being opportunistic, with wide distribution in nature, including the hospital environment, where it is frequent the presence of microorganisms that cause hospital infection, especially in immunocompromised patients. To identify and quantify the fungal microbiota in air, the filters of air-conditioners and samples of newborns from the neonatal ICU at University Hospital / HUPA, Maceió, Alagoas. Were held 20 exhibitions of collections totaling 400 disposable Petri dishes containing Sabouraud agar medium plus antibiotic. The plates were placed randomly inside and open the two neonatal ICUs (A and B) for 20 minutes. Also, there were 20 samples of the filters of air-conditioners of neonatal ICUs and conducted the direct examination and culture of clinical samples from newborns. CFU were isolated in 1209, these 675 (55.8%) were isolated CFU before cleaning to be done in the neonatal ICU and 534 (44.2%) CFU obtained after cleaning. Of 697 CFU of the environment of the NICU, 372 were isolated before and 325 after cleaning. Environment B, were obtained of 512 CFU and 303 CFU were obtained before cleaning and 209 after UFC. During the study species of Cladosporium was the most representative in the air and in the filters of air-conditioners. The clinical sample was more representative urine with 79.5%. Among the identified yeast Candida parapsilosis was present in 38.9% of environmental isolates of yeast and Candida albicans was isolated in 20% of clinical samples of newborns. The presence of pathogenic fungi in the two environments of the neonatal ICU and clinical samples of infants...

Modelagem e análise de condicionadores de ar dos tipos convencional e inteligente e influência no comportamento dinâmico das redes elétricas; Modelling and analysis of conventional and intelligent air conditioner types and influence on dynamical behaviour of electrical utility grids

Sanhueza, Sergio Manuel Rivera
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Tese de Doutorado
POR
Relevância na Pesquisa
46.84%
Devido à crescente demanda e diversidade de aparelhos de consumo, os sistemas de energia elétrica têm experimentado, atualmente, problemas com a sua operação, tanto em regime permanente para manter o nível de tensão dentro de uma faixa adequada, quanto também em regime transitório diante de perturbações do tipo curto circuito, perda de geração, etc. Para estudar os efeitos destas perturbações no planejamento de sistemas elétricos, modelos de cargas precisos são muito importantes para obtenção de resultados confiáveis. Nas concessionárias de energia elétrica é muito comum a adoção do conhecido modelo ZIP (impedância, corrente ou potência constante), no entanto, quando as cargas da rede são compostas por motores, o modelo estático pode ser inadequado. Isto tem motivado a busca de uma representação mais detalhada de diversas cargas, principalmente daquelas consideradas mais importantes ou que constituem uma grande parcela do carregamento de uma rede elétrica. Neste contexto, os condicionadores de ar merecem destaque, não somente pela sua intensa demanda, mas também por suas peculiaridades dinâmicas, as quais influenciam o comportamento dos sistemas elétricos. presently Assim, este trabalho tem o objetivo de preencher algumas lacunas quanto à utilização e aprimoramento de modelos no domínio do tempo de aparelhos de ar condicionados...

Achieving urban climate adaptation in Europe and Central Asia

Carmin, JoAnn; Zhang, Yan
Fonte: Banco Mundial Publicador: Banco Mundial
Relevância na Pesquisa
26.66%
Many cities across Europe and Central Asia are experiencing the impacts of climate change, but most have not integrated climate adaptation into their agendas. This paper examines the threats faced and measures that can be taken by cities in the region to protect buildings, heritage sites, municipal functions, and vulnerable urban populations. In general, local governments must be proactive in ensuring that existing buildings are climate ready, paying particular attention to emerging technologies for retrofitting the prefabricated, panel style buildings that dominate the landscape while assessing the viability of homes situated in flood plains, coastal areas, and steep slopes. They also must ensure that new developments and buildings are designed in ways that account for climatic fluctuations. Although the resilience of all populations needs to be considered, historical patterns of discrimination require that special provisions are made for the poor and for ethnic minorities such as the Roma because these groups will be most at risk...

Beyond the Sum of its Parts : Combining Financial Instruments for Impact and Efficiency

Hosier, Richard; Kulichenko, Nataliya; Maheshwari, Aditi; Toba, Natsuko; Wang, Xiaodong
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
Relevância na Pesquisa
26.68%
The Global Environment Facility (GEF), carbon finance, and the Clean Technology Fund (CTF) constitute the bulk of dedicated funding for low-carbon development. To achieve the largest possible impact, practitioners must learn to combine these resources in the same project or program in order to both reduce transaction costs and maximize synergies. This issues brief considers six projects that are using resources from one or all of these sources in combination with development finance to advance low-carbon development. It lays out a conceptual basis for how GEF, carbon finance, and CTF resources can be fit together to make a wider range of mitigation projects financially and economically attractive.

Transport impacts on atmosphere and climate: Land transport

Uherek, Elmar; Halenka, Tomas; Borken-Kleefeld, Jens; Balkanski, Yves; Berntsen, Terje; Borrego, Carlos; Gauss, Michael; Hoor, Peter; Juda-Rezler, Katarzyna; Lelieveld, Jos; Melas, Dimitrios; Rypdal, Kristin; Schmid, Stephan
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.68%
Emissions from land transport, and from road transport in particular, have significant impacts on the atmosphere and on climate change. This assessment gives an overview of past, present and future emissions from land transport, of their impacts on the atmospheric composition and air quality, on human health and climate change and on options for mitigation. In the past vehicle exhaust emission control has successfully reduced emissions of nitrogen oxides, carbon monoxide, volatile organic compounds and particulate matter. This contributed to improved air quality and reduced health impacts in industrialised countries. In developing countries however, pollutant emissions have been growing strongly, adversely affecting many populations. In addition, ozone and particulate matter change the radiative balance and hence contribute to global warming on shorter time scales. Latest knowledge on the magnitude of land transport's impact on global warming is reviewed here. In the future, road transport's emissions of these pollutants are expected to stagnate and then decrease globally. This will then help to improve the air quality notably in developing countries. On the contrary, emissions of carbon dioxide and of halocarbons from mobile air conditioners have been globally increasing and are further expected to grow. Consequently...

Consumption Management of Air Conditioning Devices for the Participation in Demand Response Programs

Barrias, Fernando; Faria, Pedro; Vale, Zita
Fonte: ELECON Project Publicador: ELECON Project
Tipo: Conferência ou Objeto de Conferência
Publicado em 28/10/2014 ENG
Relevância na Pesquisa
56.77%
Demand Response has been taking over the years an extreme importance. There’s a lot of demand response programs, one of them proposed in this paper, using air conditioners that could increase the power quality and decrease the spent money in many ways like: infrastructures and customers energy bill reduction. This paper proposes a method and a study on how air conditioners could integrate demand response programs. The proposed method has been modelled as an energy resources management optimization problem. This paper presents two case studies, the first one with all costumers participating and second one with some of costumers. The results obtained for both case studies have been analyzed.

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

Batterman, S.; Du, L.; Mentz, G.; Mukherjee, B.; Parker, E.; Godwin, C.; Chin, J.-Y.; O'Toole, A.; Robins, T.; Rowe, Z.; Lewis, T.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.68%
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.

Smart Sensors Enable Smart Air Conditioning Control

Cheng, Chin-Chi; Lee, Dasheng
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 24/06/2014 EN
Relevância na Pesquisa
36.42%
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.

Multiple model approach and experimental validation of a residential air-to-air heat pump

Garde, François; Boyer, Harry; Pignolet, Florence; Lucas, Franck; Brau, Jean
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 22/12/2012
Relevância na Pesquisa
36.35%
The beginning of this work is the achievement of a design tool, which is a multiple model software called " CODYRUN ", suitable for professionnals and usable by researchers. The original aspect of this software is that the designer has at his disposal a wide panel of choices between different heat transfer models More precisely, it consists in a multizone software integrating both natural ventilation and moisture tranfers . This software is developed on PC micro computer and gets advantage of the Microsoft WINDOWS front-end. Most of time, HVAC systems and specially domestic air conditioners, are taken into account in a very simplified way, or in a elaborated one. On one side,they are just supposed to supply the demand of cooling loads with an ideal control loop (no delay between the sollicitations and the time response of the system), The available outputs are initially the hourly cooling and heating consumptions without integrating the real caracteristics of the HVAC system This paper is also following the same multiple model approach than for the building modelling by defining different modelling levels for the air conditionning systems, from a very simplified one to a detailled one. An experimental validation is achieved in order to compare the sensitivity of each defined model and to point out the interaction between the thermal behaviour of the envelop and the electrical system consumption. For validation purposes...

Consumer valuation of energy-saving features of residential air conditioners with hedonic and choice models

Matsumoto, Shigeru
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Trabalho em Andamento Formato: application/pdf
Publicado em //2015 ENG
Relevância na Pesquisa
46.51%
The promotion of energy-efficient appliances is necessary to reduce the energetic and environmental burden of the household sector. However, many studies have reported that a typical consumer underestimates the benefits of energy-saving investment on the purchase of household electric appliances. To analyze this energy-efficiency gap problem, many scholars have estimated implicit discount rates that consumers use for energy-consuming durables. Although both hedonic and choice models have been used in previous studies, a comparison between two models has not yet been done. This study uses point of sale data about Japanese residential air conditioners and estimates implicit discounts rates with both hedonic and choice models. Both models demonstrate that a typical consumer underinvests in energy efficiency. Although choice models estimate a lower implicit discount rate than hedonic models, the latter models estimate the values of other product characteristics more consistently than choice models.

A material cost and weight comparison of shipping containers using ECT versus burst strength for room air conditioners

McSweeney, Anne Margaret
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
36.31%
This research compares the material cost and weight of using edge crush specifications for the selection of a Whirlpool Corporation room air conditioner shipping container verses Mullen burst strength specifications. For the purposes of this thesis, the air conditioner studied is referred to as Product "M". The following presumptions are made. The material cost of using an ECT performance specified container is lower than the material cost of a Mullen specified container. The material weight is less using an ECT specified shipping container rather than a Mullen specified shipping container. The data generated first are the strength of the product and its interior packaging. This is determined through the use of vertical compression methods. After the internal product and package strength is determined, the stack height and safety factors required are used to calculate the necessary shipping container strength. The findings of this study on Product "M" are as follows. First, ECT specified material is 4.3% more cost effective than Mullen specified material. Second, ECT specification results in 17.5% less material by weight than Mullen specification. Using a hypothetical product volume of 250,000 units per year, the savings of $0.06 and 0.73 pounds...

THERMAL PERFORMANCE EVALUATION OF ROOM AIR CONDITIONERS EVAPORATORS

Piske, A. C.; Moura, L. M.; Mendes, N.
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Peer-reviewed Article Formato: application/pdf
Publicado em 31/08/2005 ENG
Relevância na Pesquisa
46.38%
This work presents a thermal performance evaluation of a fin-and-tube evaporator - that is widely used in packaged air conditioning equipment - using a balanced calorimeter developed to simulate similar running conditions. The calorimeter determines the heat rate absorbed by the evaporator, providing qualitative analysis of performance for a given geometry. The calorimeter inside air is dried out due to the condensation process on the evaporator under test during the transient period. By this way it is possible to preview the humidity of the calorimeter domain and its influence with the instrumentation measurement. The heat transfer rate absorbed by the evaporator is obtained by a lumped approach using the energy conservation that is applied to the calorimeter domain, and is taken on the boundaries of the equipment. Physical parameters such as overall heat transfer coefficient for several types of fins can then be predicted in order to provide information for improving the energy-efficiency-oriented design. The uncertainties are estimated by the propagation of relative effects. Uncertainties are evaluated taking into account the systematic effects. Results are shown in terms of evaporator overall heat transfer coefficient and heat transfer rate as a function of inlet air temperature.

Indirect assessment of air conditioning energy savings in buildings

Gutiérrez,Joaquín; Villa-Medina,Juan Francisco; Fernández-Zayas,José L.; Porta-Gándara,Miguel Ángel
Fonte: Sociedad Mexicana de Ingeniería Mecánica Publicador: Sociedad Mexicana de Ingeniería Mecánica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
46.31%
Electric consumption of a public building in the Northwestern Mexico town of La Paz is markedly oriented to the use of air conditioners (AC). The impact of AC on electrical bills is found to account for about one third of the total yearly expense. New laws and international agreements mandate that drastic electrical bill reductions be adopted in all public buildings, while no detailed measurements are available, and no specific savings opportunities have been established. An overall review of practical improvements reveals that implanting energy efficiency measures could be economically viable. An exploration of the overall electrical bill indicates which electrical uses would entail higher savings addressing weather- and non-weather-related electrical loads. Basic savings scenarios are explored to improve energy efficiency in office and laboratory equipment, as well as in electrical lighting. These findings indicate the need of measuring and monitoring, as part of a more lasting and formal campaign for energy savings in public buildings in Mexico.

Performance of A R22 split-air-conditioner when retrofitted with ozone friendly refrigerants (R410A and R417A)

Bolaji,Bukola Olalekan
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 EN
Relevância na Pesquisa
56.68%
R22 that has been used predominantly in air conditioning and in medium and low-temperature applications contains ozone depleting chlorine atoms and hence will be phased out eventually. This paper presents the experimental performance study of a split-air-conditioner using ozone friendly alternative refrigerants. The existing split-air-conditioner originally designed for R22 as the working fluid was retrofitted with R410A and R417A respectively, and the performance of the system was evaluated and compared with its performance when R22 was used. Experimental results showed that with R417A, the system had 1.9% higher refrigeration capacity and 14.2% lower with R410A when compared to that of R22. The average discharge pressure of the compressor obtained with R417A and R410A were 3.8% lower and 10.3% higher, respectively, than with R22. The lowest compressor power consumption and pressure ratio were obtained with the R417A retrofitted system. The average coefficient of performance (COP) obtained using R417A is 2.9% higher, while that of R410A is 8.4% lower than that of R22. Generally, with R417A the system consistently had the best performance in comparison to both R22 and R410A, indicating that R417A would be a better choice for retrofitting existing split-air-conditioners originally designed to use R22 as working fluid.