ANÁLISE DA REFLETÂNCIA E DO DESEMPENHO TÉRMICO DE TINTA REFLEXIVA APLICADA EM COBERTURA DE TELHAS DE FIBROCIMENTO

Abstract

In cities like Manaus where there is a predominance of high temperatures throughout the year and high solar incidence, it is necessary to search for strategies to reduce the thermal gains of the building, therefore, the use of roofs with low solar reflectance is one of the possible solutions. This work studied the solar reflectance of samples of fiber cement tiles with four types of coatings (painted with reflective paint, painted with white PVC paint, washed tiles and dirty tiles due to the action of time) and analyzed the effect of solar reflectance on the surface temperatures of two roofs. The reflectance of the samples was measured using the MiniScan EZ spectrophotometer and surface temperatures were measured using HOBO temperature sensors. The highest albedo was found in samples painted with white paint, with 85.9%, followed by samples painted with reflective paint with 82,6%. The washed and dirty tiles showed 76,3%, and 48,2%, respectively. In terms of surface temperatures of the tiles, it was found that the peak time of temperatures occurred at 12:43 pm on both roofs, and the surface temperatures on the roof with reflective and dirty paint were 52,9ºC and 62,1ºC, respectively, which gives a difference in surface temperature of 9,2ºC.