DESEMPENHO TÉRMICO DE UMA COBERTURA VERDE TESTADA EM BANCADA EXPERIMENTAL

Abstract

Roofs located in tropical countries are exposed to intense solar radiation, which affects the necessary cooling load in conditioned buildings and thermal comfort in non-conditioned ones. Reducing thermal gain by using a cover is one way to decrease energy expenditure and provide thermal comfort to users. Therefore, this work analyzed the thermal performance of a green roof through an experimental workbench, built in the city of Florianópolis (Brazil), which can admit eight small-scale covers simultaneously. The internal temperature of the experimental bench was maintained at 23.5 °C and the covers were instrumented with temperature and heat flow sensors. The study took place from July to September 2017. The results showed that the use of the green roof reduced superficial temperatures when compared to a fiber-cement tile roof. As far as the heat flux is concerned, the green roof reduced diurnal thermal gains and nocturnal thermal losses. Throughout the analysis, the green roof reduced the gains by 81% and prevented thermal losses by 53%. By this study, it was possible to confirm that the use of green roofs is effective and can improve the thermal performance of buildings located in subtropical areas.