This thesis evaluates domestic water heating systems in conjunction with energy saving technologies such as solar water heating, drain water heat recovery, and heat pump water heating. Five dynamic models are developed using Matlab Simulink® with a time-step of one minute. Using minute resolution hot water flow, hourly solar radiation data and ambient temperature, the performance of various configurations are assessed when operating in Victoria, Kamloops, and Williams Lake, B.C. Twelve different demand profiles on a summer day and winter day are simulated. Some specific metrics, such as conventional energy consumption, system energy factor, and equivalent CO2 emissions are used as the basis of evaluating the system efficiency. Results indicate the potential improvements in system performance over a conventional domestic water heating system in lower conventional energy consumption and lower CO2 emissions when applying any one of the three energy saving technologies mentioned above. For example, on a representative summer day (Day 228) in Victoria with a load profile of a low-use two-person family on a weekday, the system‟s energy factor can be improved from 0.50 to up to 2.84, and the corresponding conventional energy consumption and the CO2 emissions decrease from 9.86 kwh to 1.67 kwh, and 1.77 kg/day to 0.06 kg/day, respectively depending on which energy saving technology is applied. The modeling tool developed in this research can be used to guide the design of domestic water heating systems with various system configurations. / Graduate

Yes / Fresh water is crucial for life, supporting human civilizations and ecosystems, and its production is one of the global issues. To cope with this issue, we evaluated the performance and cost of a solar-powered direct contact membrane distillation (DCMD) unit for fresh water production in Karachi, Pakistan. The solar water heating system (SWHS) was evaluated with the help of a system advisor model (SAM) tool. The evaluation of the DCMD unit was performed by solving the DCMD mathematical model through a numerical iterative method in MATLAB software®. For the SWHS, the simulation results showed that the highest average temperature of 55.05 ◦C and lowest average temperature of 44.26 ◦C were achieved in May and December, respectively. The capacity factor and solar fraction of the SWHS were found to be 27.9% and 87%, respectively. An exponential increase from 11.4 kg/m2 ·h to 23.23 kg/m2 ·h in permeate flux was observed when increasing the hot water temperatures from 44 ◦C to 56 ◦C. In the proposed system, a maximum of 279.82 L/day fresh water was produced in May and a minimum of 146.83 L/day in January. On average, the solar-powered DCMD system produced 217.66 L/day with a levelized water cost of 23.01 USD/m3 / This research was funded by the Researcher’s Supporting Project Number (RSP-2021/269), King Saud University, Riyadh, Saudi Arabia.

O objetivo deste trabalho é investigar o desempenho energético de dois diferentes tipos de sistemas de aquecimento de piscinas: á gás natural e por bomba de calor elétrica. Foi realizada instrumentação em duas piscinas localizadas em uma mesma academia, cada uma delas dotada de um dos tipos de sistema de aquecimento. Além destas duas piscinas, que são objeto de investigação desta pesquisa, outras quatro piscinas, localizadas cada uma em um local distinto na cidade de São Paulo, também receberam instrumentação e a coleta de dados está sendo executada através de sistemas de aquisição de dados, para posterior análise e novos trabalhos de pesquisa. Como resultados da análise das duas piscinas, obteve-se um coeficiente de desempenho - COP, médio para o sistema de aquecimento por bomba de calor igual a 4. Para o sistema a gás natural, os resultados para a eficiência global do sistema indicaram 76%, ao passo que o rendimento apenas dos aquecedores foi de 82%. As análises dos dados permitiram comprovar a influência da temperatura ambiente sobre o COP da bomba de calor. Quanto menor a temperatura do ar, menor o COP. A Temperatura do ar também mostrou forte influência sobre o consumo de energia. / The aim of this research is to investigate the energetic performance of two distinct kinds of swimming pool heating systems: gas-fired and electric heat pump. A practical instrumentation research was prepared in these two indoor swimming pools, placed in the same location. Besides these, other four swimming pool, placed each in a different ambient in the city of São Paulo also received the instrumentation so that it will be possible to run future researches, once the data is already being collected by the data loggers installed. As a result of the data analysis, it was found that the average coefficient of performance of the heat pumps studied is 4. For the natural gas fired system, the global efficiency factor was found to be 76%. The efficiency of the heaters isolated was found to be 82%. This research showed that the COP of heat pump systems has strong correlation with the air temperature. The lower the air temperature, the lower the COP. Temperature also has strong influence on the consumption of energy.

Thesis (MTech (Faculty of Engineering))--Cape Peninsula University of Technology, 2009.Included bibliographical references (p. 98-99).

O objetivo deste trabalho é investigar o desempenho energético de dois diferentes tipos de sistemas de aquecimento de piscinas: á gás natural e por bomba de calor elétrica. Foi realizada instrumentação em duas piscinas localizadas em uma mesma academia, cada uma delas dotada de um dos tipos de sistema de aquecimento. Além destas duas piscinas, que são objeto de investigação desta pesquisa, outras quatro piscinas, localizadas cada uma em um local distinto na cidade de São Paulo, também receberam instrumentação e a coleta de dados está sendo executada através de sistemas de aquisição de dados, para posterior análise e novos trabalhos de pesquisa. Como resultados da análise das duas piscinas, obteve-se um coeficiente de desempenho - COP, médio para o sistema de aquecimento por bomba de calor igual a 4. Para o sistema a gás natural, os resultados para a eficiência global do sistema indicaram 76%, ao passo que o rendimento apenas dos aquecedores foi de 82%. As análises dos dados permitiram comprovar a influência da temperatura ambiente sobre o COP da bomba de calor. Quanto menor a temperatura do ar, menor o COP. A Temperatura do ar também mostrou forte influência sobre o consumo de energia. / The aim of this research is to investigate the energetic performance of two distinct kinds of swimming pool heating systems: gas-fired and electric heat pump. A practical instrumentation research was prepared in these two indoor swimming pools, placed in the same location. Besides these, other four swimming pool, placed each in a different ambient in the city of São Paulo also received the instrumentation so that it will be possible to run future researches, once the data is already being collected by the data loggers installed. As a result of the data analysis, it was found that the average coefficient of performance of the heat pumps studied is 4. For the natural gas fired system, the global efficiency factor was found to be 76%. The efficiency of the heaters isolated was found to be 82%. This research showed that the COP of heat pump systems has strong correlation with the air temperature. The lower the air temperature, the lower the COP. Temperature also has strong influence on the consumption of energy.

Current federal and provincial efficiency standards for residential water heating are based solely on the tested efficiency of individual water heating devices. Additional energy expended or saved as the water cycles through the home is not taken into account. This research, co-funded by British Columbia’s Ministry of Energy, Mines and Petroleum Resources (MEMPR), is a first step toward the Province’s goal of developing a new energy efficiency standard for water heating systems in new construction. This groundbreaking new standard would employ a “systems” approach, establishing guidelines for new construction based on the total energy used for water heating within the building envelope The research team has developed a Simulink computer model which, using a one-minute time-step, simulates 24-hour cycles of water heating in a single-family home. The objectives of this thesis are to use that model to simulate a variety of water heating technology combinations, and to devise methods of utilizing the resulting data to evaluate water heating systems as a whole and to quantify each system’s relative energy impact. A metric has been developed to evaluate the efficiency of the system: the system energy factor (SEF) is the ratio of energy used directly to heat water over the amount of energy drawn from conventional fuel sources. The CO2 impact of that energy draw is also considered. Data is generated for cities in three different climates around BC: Kamloops, Victoria and Williams Lake. Electric and gas-fired tank water heaters of various sizes and efficiencies are simulated, along with less traditional energy-saving technologies such as solar-assisted pre-heat and waste water heat recovery components. A total of 7,488 six-day simulations are run, each representing a unique combination of technology, load size, location and season. The resulting data is presented from a variety of angles, including the relative impacts of water heater rating, additional technology type, location and season on the SEF of the system. The interplay between SEF and carbon dioxide production is also examined. These two factors are proposed as the basis for devising performance tiers by which to rank water heating systems. Two proposals are made regarding how these tiers might be organized based on the data presented here, though any tiers will have to be re-evaluated pending data on a wider range of technology combinations. A brief financial analysis is also offered, exploring the potential payback period for various technology combinations in each location. Given current equipment and energy costs, the financial savings garnered by the increase in energy efficiency are not, in most cases, found to be sufficient to justify the expense to the homeowner from a purely fiscal perspective. Additional changes would need to take place to ensure the financial viability of these technologies before large-scale adoption of systems-based standards could be employed. / Graduate

Este trabalho é motivado pela constatação de que a instalação de sistemas de aquecimento de água a gases combustíveis nos apartamentos novos pode ter custos inferiores à instalação de sistemas elétricos e pelas perspectivas de aumento da oferta de gás natural no país. Considerando isso e a perspectiva de aumento no consumo de eletricidade, a pesquisa procura identificar barreiras para expansão do uso dos sistemas a gás, sugerindo formas para que sejam superadas. Considerando que as decisões tomadas durante a construção definem em grande medida os usos da energia nos imóveis, o trabalho se baseia numa pesquisa de campo desenvolvida por meio de entrevistas com agentes da construção civil. Inclui ainda uma contextualização sobre o uso da energia no setor residencial. Essa contextualização mostra a evolução do mercado brasileiro de gases combustíveis, a baixa participação histórica desses energéticos no aquecimento de água e as perspectivas de crescimento da oferta de gás natural no país. Também descreve o uso de água quente para banho, abordando os principais sistemas de aquecimento disponíveis no mercado paulistano. Perspectivas relativas ao aumento do consumo de eletricidade e de desenvolvimento do mercado imobiliário completam essa contextualização. A pesquisa mostra que já há ampla disseminação do uso de sistemas de aquecimento de água a gás na cidade de São Paulo. Esse desenvolvimento deveu-se a fatores como a obrigatoriedade da introdução de tais sistemas em alguns tipos de construção a partir de meados dos anos 1980, as exigências de conforto dos consumidores de classe média e classe alta e ao racionamento de eletricidade de 2001. Por outro lado, verifica-se que o chuveiro elétrico continua sendo usado nas construções voltadas para a classe baixa. Como esse é o segmento com maior demanda por novas residências, identifica-se um espaço importante para substituição de eletrotermia e aumento do uso dos gases combustíveis para aquecimento de água. / This research is motivated by the verification that the installation of gas based water-heating systems in new apartments may be cheaper than the use of electric systems. It is also motivated by the perspectives of a growing supply of natural gas in the country. Considering these points and the perspective of general growing use of electricity, this research identifies barriers to expand the use of gas based systems, suggesting ways to overcome those barriers. Considering that the energy uses in an apartment are largely affected by decisions taken during the construction of the building, the study is based on a field research developed through interviews with construction agents. It also includes a definition on the residential energy use, which details the gas (natural gas and LPG) market evolution, the historically reduced use of these fuels in water-heating systems, and the perspectives of rising supply of natural gas in Brazil. It also describes the use of hot water to hygiene, considering the main systems available in São Paulo. This context is completed by the perspectives related to the increase of electricity demand and the current real estate market development. The research concludes that gas based water-heating systems are already extensively used in São Paulo. This development is related to the mandatory use of those systems in some apartment configurations, the users demand for comfort, and the 2001 electric power shortage. On the other hand, it shows that electric showers are still largely used in building of poorer families. Since this segment has the largest demand for new houses in the country, there is space to substitute energy consumed for thermal purposes with the direct use of gas.

O setor residencial reflete a cultura do uso excessivo da eletricidade para aquecimento de água. Para este uso final, a inclusão de gás e complementação com energia termo-solar pode apresentar vantagem por se tratar de energia final mais compatível com os processos de transformação em energia útil na forma de calor. A inclusão destas fontes pode propiciar uma diminuição de sobrecarga no sistema elétrico e da eletrotermia no setor residencial. Este trabalho faz uma avaliação econômica dos sistemas de aquecimento de água elétrico, a gás e solar. Os sistemas são analisados considerando custos de infra-estrutura, com diferentes disponibilidades de uso, custos de equipamentos e de operação para vários níveis de consumo. A avaliação é aplicada a 3 tipologias de edificações verticais representativas no mercado da construção civil da Região Metropolitana de São Paulo. Os custos de serviço de aquecimento de água quente estão apresentados em função do volume de água consumido. / The residential sector reflects the culture of the indiscriminate use of electricity water heating. Inclusion of gas and thermosolar energy to the electrical supply system may present advantages as they are more compatible to consumer\"s heat transformation processes. In addition these new sources of energy may decrease the electrical and electrothermal system overload in the residential sector. This study is an economic evaluation of the electric, gas and solar water heating systems. The heating systems are analyzed taking in consideration infrastructure costs, and equipment and operation costs for different levels of consumption. The evaluation is applied to three typologies of vertical residential edifications that represent the civil construction market of the São Paulo metropolitan area. The costs of water heating service are presented in function of the consumed volume of water.

Este trabalho é motivado pela constatação de que a instalação de sistemas de aquecimento de água a gases combustíveis nos apartamentos novos pode ter custos inferiores à instalação de sistemas elétricos e pelas perspectivas de aumento da oferta de gás natural no país. Considerando isso e a perspectiva de aumento no consumo de eletricidade, a pesquisa procura identificar barreiras para expansão do uso dos sistemas a gás, sugerindo formas para que sejam superadas. Considerando que as decisões tomadas durante a construção definem em grande medida os usos da energia nos imóveis, o trabalho se baseia numa pesquisa de campo desenvolvida por meio de entrevistas com agentes da construção civil. Inclui ainda uma contextualização sobre o uso da energia no setor residencial. Essa contextualização mostra a evolução do mercado brasileiro de gases combustíveis, a baixa participação histórica desses energéticos no aquecimento de água e as perspectivas de crescimento da oferta de gás natural no país. Também descreve o uso de água quente para banho, abordando os principais sistemas de aquecimento disponíveis no mercado paulistano. Perspectivas relativas ao aumento do consumo de eletricidade e de desenvolvimento do mercado imobiliário completam essa contextualização. A pesquisa mostra que já há ampla disseminação do uso de sistemas de aquecimento de água a gás na cidade de São Paulo. Esse desenvolvimento deveu-se a fatores como a obrigatoriedade da introdução de tais sistemas em alguns tipos de construção a partir de meados dos anos 1980, as exigências de conforto dos consumidores de classe média e classe alta e ao racionamento de eletricidade de 2001. Por outro lado, verifica-se que o chuveiro elétrico continua sendo usado nas construções voltadas para a classe baixa. Como esse é o segmento com maior demanda por novas residências, identifica-se um espaço importante para substituição de eletrotermia e aumento do uso dos gases combustíveis para aquecimento de água. / This research is motivated by the verification that the installation of gas based water-heating systems in new apartments may be cheaper than the use of electric systems. It is also motivated by the perspectives of a growing supply of natural gas in the country. Considering these points and the perspective of general growing use of electricity, this research identifies barriers to expand the use of gas based systems, suggesting ways to overcome those barriers. Considering that the energy uses in an apartment are largely affected by decisions taken during the construction of the building, the study is based on a field research developed through interviews with construction agents. It also includes a definition on the residential energy use, which details the gas (natural gas and LPG) market evolution, the historically reduced use of these fuels in water-heating systems, and the perspectives of rising supply of natural gas in Brazil. It also describes the use of hot water to hygiene, considering the main systems available in São Paulo. This context is completed by the perspectives related to the increase of electricity demand and the current real estate market development. The research concludes that gas based water-heating systems are already extensively used in São Paulo. This development is related to the mandatory use of those systems in some apartment configurations, the users demand for comfort, and the 2001 electric power shortage. On the other hand, it shows that electric showers are still largely used in building of poorer families. Since this segment has the largest demand for new houses in the country, there is space to substitute energy consumed for thermal purposes with the direct use of gas.

[pt] Esta dissertação analisa aspectos da utilização da energia solar para aquecimento de água. Dois são os aspectos abordados: O primeiro é quanto à utilização de valores médios mensais ou diários de temperatura e insolação utilizados por diversos métodos de dimensionamento ou simulação de sistemas de aquecimento solar, e o segundo é a utilização de múltiplos tanques de armazenamento de água quente ao invés de um único reservatório de maior volume. Assim, este estudo tem como objetivo formular, simular e analisar diferentes cenários de configurações de sistemas de aquecimento solar de água, variando-se o número de reservatórios térmicos para um mesmo volume total do sistema. Tem-se por finalidade atender um mesmo padrão de consumo de água quente, condicionado a um mesmo perfil climático, visando otimizar a contribuição da energia solar ao sistema e consequentemente minimizar o consumo de energia auxiliar elétrica. / [en] This dissertation examines aspects of the use of solar energy for water heating. Two aspects are handled: The first is regarding the use of average monthly or daily values of temperature and insolation used by different scaling methods or simulation of solar water heating systems, and the second is the use of multiple hot water storage tanks instead of a single larger volume reservoir of water. Thus, this study aims to formulate, simulate and analyze different configurations of solar water heating systems scenarios, varying the number of thermal reservoirs for the same total volume of the system. It intends to satisfy the same standard of hot water consumption, under same climatic conditions to optimize the contribution of solar energy to the system and consequently minimize the consumption of electric auxiliary energy.