Simulação termoenergética e análise econômica do uso de telhados frios em uma residência unifamiliar

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: O uso de telhados frios é uma estratégia passiva para reduzir a carga de resfriamento das edificações e sua utilização tem potencial de mitigar o fenômeno Ilha de Calor. Este trabalho objetiva analisar o desempenho termoenergético e a viabilidade econômica do uso de telhados frios em uma edificação unifamiliar, localizada no Rio de Janeiro – Brasil. Foram selecionados dois tipos de telhas, de fibrocimento e de cerâmica, ambos foram analisados na cor natural e na cor branca. Foi realizada a medição da refletância solar e da emitância térmica, bem como o cálculo do Índice de Refletância Solar. A análise termoenergética foi realizada por meio do software EnergyPlus. A análise econômica foi realizada através dos indicadores financeiros: Valor Presente Líquido, Taxa Interna de Retorno e payback. O telhado frio de fibrocimento reduziu em até 60% o ganho de calor na cobertura e o telhado frio de cerâmica reduziu até 55%. A análise econômica mostrou-se viável para o cenário proposto com um payback inferior a 5 anos para as telhas de fibrocimento e inferior a 13 anos paras as telhas cerâmicas.ABSTRACT: The use of cool roofs is a passive strategy to reduce the cooling load on buildings and its use has the potential to mitigate the Heat Island phenomenon. This work aims to analyze the thermoenergetic performance and economic viability of using cool roofs in a single family building, located in Rio de Janeiro - Brazil. Two types of tiles, fiber cement and ceramic, were selected, both were analyzed in color natural and white. The measurement of solar reflectance and thermal emittance was performed, as well as the calculation of the Solar Reflectance Index. Thermoenergetic analysis was performed using the EnergyPlus software. The economic analysis was carried out using the financial indicators: Net Present Value, Internal Rate of Return and payback. The cool fiber cement roof reduced the heat gain in the roof by up to 60% and the cold ceramic roof reduced up to 55%. The economic analysis proved to be viable for the proposed scenario with a payback of less than 5 years for fiber cement tiles and less than 13 years for ceramic tiles.info:eu-repo/semantics/publishedVersio

Far infrared microsensor based on transversal gradients

In this work we report finite element method simulation, design and fabrication process of an uncooled thermal infrared detector with high-sensitivity. The device is based on the differential association of thermocouples (Cu/constantan), shaped appropriately in order to increase the thermoelements density, deposited onto silicon substrates to provide further integration with silicon technology. The Si substrate is back-side etched with Deep Reactive-Ion Etching (DRIE), creating regions with different thickness under each thermoelement in order to improve the thermal gradient. On the wafer front side, a constantan serpentine is potentiostatically electrodeposited following the parameters obtained from reference 1. Thermocouples are formed by plating copper pad upon the constantan layer. The device is covered by a porous gold layer (black–gold), prepared byevaporating in inert atmosphere, that works as an efficient absorber in the far infrared spectral region [2]. The major advantages expected from the micromachined sensor are the small dimensions, low power consumption, low cost, high sensitivity, good accuracy and resolution in the far infrared spectra. The application of this sensor could be in the demand of on-line monitoring for thermal confort, in heat transfer control for industrial processes and for CCD far infrared cameras