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- An Eco-Energetic Performance Comparison of Dehumidification Systems in High-Moisture Indoor EnvironmentsPublication . Santos, Alexandre Fernandes; Gaspar, Pedro Dinis; Souza, Heraldo; Caldeira, João M. L. P.; Soares, Vasco N. G. J.This study discusses the choice of dehumidification systems for high-moisture indoor environments, such as indoor swimming pools, supported by an eco-energetic performance comparison. Initially, the causes of the high relative humidity and condensation in these spaces are reported, as well as the available dehumidification technologies. Two different solutions are described: desiccant wheel dehumidification and re-cooling. The energy demand required by a refrigeration system is lower than the desiccant wheel; however, the former system requires less maintenance and does not require refrigerant fluid. An eco-energetic comparison is performed between the two systems in two countries with different energy matrices (Brazil and USA). In Brazil, the desiccant wheel is the best choice for the past 10 years, with a predicted 351,520 kgCO2 of CO2 emissions, which is 38% lower than the refrigeration system. In the USA, the best option is the refrigeration system (1,463,350 kgCO2), a 12% more efficient option than desiccant wheels. This model can be considered for energy and CO2 emissions assessment, predicting which system has better energy efficiency and lower environmental impact, depending on the refrigerant type, location and environmental conditions.
- Ecoenergetic Comparison of HVAC Systems in Data CentersPublication . Santos, Alexandre F.; Gaspar, Pedro Dinis; Souza, Heraldo J. L. deThe topic of sustainability is of high importance today. Global efforts such as the Montreal Protocol (1987) and the Kigali Amendment (2016) are examples of joint work by countries to reduce environmental impacts and improve the level of the ozone layer, the choice of refrigerants and air conditioning systems, which is essential for this purpose. But what indicators are to be used to measure something so necessary? In this article, the types of air conditioning and GWP (Global Warming Potential) levels of equipment in the project phase were discussed, the issue of TEWI (Total Equivalent Warming Impact) that measures the direct and indirect environmental impacts of refrigeration equipment and air conditioning and a new methodology for the indicator was developed, the TEWI DC (DC is the direct application for Data Center), and using the formulas of this new adapted indicator it was demonstrated that the TEWI DC for Chicago (USA) was 2,784,102,640 kg CO2/10 years and Curitiba (Brazil) is 1,252,409,640 kg CO2/10 years. This difference in value corresponds to 222.30% higher annual emissions in Chicago than in Curitiba, showing that it is much more advantageous to install a Data Center in Curitiba than in Chicago in terms of environmental impact. The TEWI indicator provides a more holistic view, helping to combine energy and emissions into the same indicator.
- New HVAC Sustainability Index - TWI (Total Water Impact)Publication . Santos, Alexandre Fernandes; Gaspar, Pedro Dinis; Souza, HeraldoSales of air conditioning are growing rapidly in buildings, more than tripling between 1990 and 2016. This energy use for air conditioning comes from a combination of rising temperatures, rising population and economic growth. Energy demand for climate control will triple by 2050, consuming more energy than that currently consumed altogether by the United States, the European Union and Japan. This increase in energy will directly impact water consumption, either to directly cool a condenser of an equipment or to serve indirectly as a basis for energy sources such as hydroelectric power that feed these heating, ventilation and air conditioning (HVAC) systems. Knowing the unique and growing importance of water, a new index, Total Water Impact (TWI) is presented, which allows a holistic comparison of the impact of water use on water, air and evaporative condensation climate systems. 200 and 500 TON (tons of refrigeration) air-cooled and water-cooled systems are theoretically compared to evaluate the general water consumption level. The TWI index is higher in the smallest water condensing system. That is, holistically, water consumption is higher in the water condensing system than in the air condensing system. Thus, this index provides a new insight about energy consumption and ultimately, about sustainability.
- Abordagem para a avaliação do desempenho térmico de Data Centers baseada em novos índices (EUED, TWI e PDD) envolvendo elementos psicrométricosPublication . Santos, Alexandre Fernandes; Gaspar, Pedro Miguel de Figueiredo Dinis OliveiraCom a ascensão do mercado de Data Centers (DC), os gastos mundiais com infraestrutura de DC devem chegar a 200 biliões de dólares em 2021, que é um aumento de 6% em relação ao esperado para 2020 [1]. A eficiência energética nestas instalações de elevado consumo de energia é fundamental. Já existem metodologias para mensurar essa eficiência, como seja o índice PUE (Power Usage Effectiveness). Porém, este índice, apesar de importante, não reflete de forma integral a eficiência. Nesta tese, são apresentados os valores de PUE para 38 Data Centers a serem localizados em 37 cidades brasileiras e 1 cidade (Chicago) dos Estados Unidos da América, e comparada a eficiência deste índice com um novo criado, o índice de Eficiência no Consumo de Energia em fase de projeto (EUED - Energy Usage Effectiveness Design). A métrica do EUED, ao invés de considerar a potência como elemento de comparação, usa a energia. O PUE é apenas mensurado com mais precisão no campo em forma de energia, ou seja, kWh/kWh, de acordo com as condições externas das 8760 horas anuais. Este método possibilita ao Investidor, com os dados do ASHRAE Weather Data Viewer, fazer simulações em múltiplas cidades com o intuito de selecionar o local ideal para localizar um Data Center. Este poderá ainda simular o consumo de energia anual do Data Center, considerando as variações ao longo do ano da temperatura de bolbo seco e temperatura de bolbo húmido coincidentes do ar. Os consumos de energia com a infraestrutura, que consistem no somatório do consumo de energia com os equipamentos de ar condicionado, equipamentos de Tecnologias de Informação, iluminação e outros, nas diferentes cidades simuladas, fornece uma diferença de mais de 1,21% de São Paulo em relação a Curitiba e de 10,61% de Rio de Janeiro em relação a Curitiba. Os índices obtidos com aplicação do índice EUED foram respetivamente, de 1,25 [(kWh/ano)/(kWh/ano)] para Curitiba, 1,26 [(kWh/ano)/(kWh/ano)] para São Paulo e de 1,38 [(kWh/ano)/(kWh/ano)] para Rio de Janeiro, providenciando uma diferença de 16,86% para Curitiba, de 16,19% para São Paulo e de 10,31% para Rio de Janeiro em relação ao PUE COA (Power Usage Effectiveness - Constant Outdoor Air). Utilizando um método transparente ao projetar um sistema de energia com baixo impacte ambiental, o TEWI (Total Equivalent Warming Impact), corresponde a uma métrica do impacte do aquecimento global dos equipamentos com base no total de emissões diretas e indiretas, relacionadas a uma correlação equivalente dos gases com efeito estufa durante a operação do equipamento e a eliminação dos fluidos refrigerantes no fim da vida útil. Foi constatado que o consumo anual de energia de sistemas de Aquecimento, Ventilação e Ar Condicionado é aproximado para as duas cidades com condições climáticas similares, mas o TEWI é extremamente diferente, sendo em Chicago (EUA) de 1.781.566,043 [kg CO2/10 anos] e em Curitiba (Brasil) de 667.042,128 [kg CO2/10 anos]. Corresponde um gasto anual em Chicago relativamente a Curitiba de mais de 267%. Assim como o TEWI, numa visão holística dos processos, também foi criado o índice de Impacte Total da Água (TWI - Total Water Impact), em que os usos direto e indireto de água são utilizados para comparar sistemas de condensação a ar e a água num sistema de refrigeração. Para tal foram simulados chillers de condensação a ar e a água e foi obtido para uma capacidade de 200 TR (Toneladas de refrigeração), um consumo superior de 5% no sistema com condensação a ar e na capacidade de 500 TR, um consumo superior de 25% no sistema de condensação a água. Ou seja, à medida que a potência de refrigeração aumenta, verifica-se uma alteração da melhor eficiência no consumo de sistemas com chillers com condensação a água para sistemas com chillers com condensação a ar. Porém, à medida que surgem novos padrões, a eficiência do chiller está a tornar-se cada vez mais importante, pois chillers de rolamentos magnéticos arrefecidos a água em ambientes com temperatura elevado apresentam baixo valor de NPLV (Non-standard Part Load Value), certamente levando no futuro a índices de TWI mais baixos do que os de chillers arrefecidos a ar. De forma a simplificar a visão de eficiência num Data Center, foi criado um novo índice denominado Data Center de Design Perfeito (PDD - Perfect Design Data Center). Este índice facilita a visualização de um Data Center perfeito, utilizando uma classificação em ordem crescente. Para tal, foram criadas tabelas qualitativas para classificação de eficiência energética de DC a partir desse índice. Nas 37 cidades simuladas, aquela que apresentou melhor índice PDD, com o valor de 0,803 [(kWh/ano)/(kWh/ano)], foi a cidade de Curitiba e aquela que apresentou o pior índice PDD, com o valor de 0,694 [(kWh/ano)/(kWh/ano)], foi a cidade de Natal. Apesar das simulações terem sido realizadas para as principais 37 cidades brasileiras, este método pode ser replicado para qualquer local do globo, podendo gerar ao Investidor de Data Center, tabelas de decisão com as simulações energéticas. Este método apresentase como sendo o único que faz uso da psicrometria para decisão de instalação de um Data Center, fazendo uso de sistemas free cooling, adiabáticos ou de ar condicionado com variação do COP de acordo com a admissão do ar no condensador. O impacto dos índices PDD e EUED para um Data Center é equivalente ao IPLV (Integrated Part Load Value), para a escolha de um equipamento de ar condicionado.
- Best Practices on HVAC Design to Minimize the Risk of COVID-19 Infection within Indoor EnvironmentsPublication . Santos, Alexandre Fernandes; Gaspar, Pedro Dinis; Hamandosh, Aseel; Aguiar, Eliandro; Filho, António Carlos Guerra; Souza, HeraldoThe spread of Coronavirus is causing in the society all around the world a considerable degree of fear, worry and concern and particularly among healthcare workers that are at increased risk for infection. This paper gathers the strategy/guidelines to reduce the contamination in Intensive care unit (ICU) and in all the hospital environment. The ASHRAE and REHVA guidelines applied the UV-C Lamps, Pressure control filtration, Restroom actions and Humidity control to reduce the coronavirus disease (Covid-19) in ICU. The role of infection control in the design of hospitals is increasing every day. This paper highlights the role of heating, ventilating and air-conditioning minimizing the risk of infection from airborne transmission within the built environment through the application of best practices.
- New Data Center Performance Index: Perfect Design Data Center - PDDPublication . Santos, Alexandre Fernandes; Gaspar, Pedro Dinis; Souza, HeraldoData Centers (DC) are specific buildings that require large infrastructures to store all the information needed by companies. All data transmitted over the network is stored on CDs. By the end of 2020, Data Centers will grow 53% worldwide. There are methodologies that measure the e ciency of energy consumption. The most used metric is the Power Usage E ectiveness (PUE) index, but it does not fully reflect e ciency. Three DC’s located at the cities of Curitiba, Londrina and Iguaçu Falls (Brazil) with close PUE values, are evaluated in this article using the Energy Usage E ectiveness Design (EUED) index as an alternative to the current method. EUED uses energy as a comparative element in the design phase. Infrastructure consumption is the sum of energy with Heating, Ventilating and Air conditioning (HVAC) equipment, equipment, lighting and others. The EUED values obtained were 1.245 (kWh/yr)/(kWh/yr), 1.313 (kWh/yr)/(kWh/yr) and 1.316 (kWh/yr)/(kWh/yr) to Curitiba, Londrina and Iguaçu Falls, respectively. The di erence between the EUED and the PUE Constant External Air Temperature (COA) is 16.87% for Curitiba, 13.33% for Londrina and 13.30% for Iguaçu Falls. The new Perfect Design Data center (PDD) index prioritizes e ciency in increasing order is an easy index to interpret. It is a redefinition of EUED, given by a linear equation, which provides an approximate result and uses a classification table. It is a decision support index for the location of a Data Center in the project phase.
- Refrigeration of COVID-19 Vaccines: Ideal Storage Characteristics, Energy Efficiency and Environmental Impacts of Various Vaccine OptionsPublication . Santos, Alexandre Fernandes; Gaspar, Pedro Dinis; Souza, Heraldo J. L. deThis article considers the ideal storage conditions for multiple vaccine brands, such as Pfizer, Moderna, CoronaVac, Oxford–AstraZeneca, Janssen COVID-19 and Sputnik V. Refrigerant fluid options for each storage condition, thermal load to cool each type of vaccine and environmental impacts of refrigerants are compared. An energy simulation using the EUED (energy usage effectiveness design) index was developed. The Oxford–AstraZeneca, Janssen COVID-19 and CoronaVac vaccines show 9.34-times higher energy efficiency than Pfizer. In addition, a TEWI (total equivalent warming impact) simulation was developed that prioritizes direct environmental impacts and indirect in refrigeration. From this analysis, it is concluded that the cold storage of Oxford–AstraZeneca, Janssen COVID-19 and CoronaVac vaccines in Brazil generates 35-times less environmental impact than the Pfizer vaccine.
- Evaluation of the Thermal Performance and Energy Efficiency of CRAC Equipment through Mathematical Modeling Using a New Index COP WEUEDPublication . Santos, Alexandre F.; Gaspar, Pedro Dinis; Souza, Heraldo J. L. deAs the world data traffic increasingly grows, the need for computer room air conditioning (CRAC)-type equipment grows proportionally. The air conditioning equipment is responsible for approximately 38% of the energy consumption of data centers. The energy efficiency of these pieces of equipment is compared according to the Energy Standard ASHRAE 90.1-2019, using the index Net Sensible Coefficient Of Performance (NetSCOP). This method benefits fixed-speed compressor equipment with a constant inlet temperature air-cooled condenser (35 C). A new method, COP WEUED (COP–world energy usage effectiveness design), is proposed based on the IPLV (integrated part load value) methodology. The IPLV is an index focused on partial thermal loads and outdoor temperature data variation for air intake in the condenser. It is based on the average temperatures of the USA’s 29 major cities. The new method is based on the 29 largest cities worldwide and with datacenter- specific indoor temperature conditions. For the same inverter compressor, efficiencies of 4.03 and 4.92 kW/kW were obtained, using ASHRAE 90.1-2019 and the proposed method, respectively. This difference of almost 20% between methods is justified because, during less than 5% of the annual hours, the inlet air temperature in the condenser is close to the NetSCOP indication.
- Measuring the Energy Efficiency of Evaporative Systems through a New Index - EvaCOPPublication . Santos, Alexandre Fernandes; Gaspar, Pedro Dinis; Souza, Heraldo J. L.Evaporative systems are probably the oldest technology for thermal comfort. However, they are still an essential technology in the food industry, environments for thermal comfort, and even for cooling data centers. Standards have been improved to compare the energy efficiency of this type of equipment. Using AHRI concepts with temperature data from the 29 most populous cities in the world, an EvaCOP index was created from temperatures that are easier to simulate than current parameters. The index parameters were tested in a laboratory located in Curitiba (Brazil). EvaCOP values of 45.58 and 25.77 W/W were found in the calculation in two different simulated equipment and compared with the compression cycle systems that in the most efficient machines is around 6.29 W/W.