Impact of light-colored paint materials on discomfort in a building for hot-dry climate

Abstract

India is a tropical country with diverse climates, and thermal adaption plays a significant role in sustaining thermal comfort in non-conditioned buildings. Indoor air temperature is taken as the main parameter for thermal comfort in buildings, which is very high in western India and creates uncomfortable for occupant. Thermal comfort is a primary need inside the buildings from a human health perspective. Roof structure and the color of the exterior surface affect the thermal comfort of the buildings in a hot-dry climate. Roof contributes maximum heat gain towards the outdoor temperature wave amplitude and time lag in non-conditioned buildings during summer. Three commercially available reflective paints or coatings were selected and used in the simulation to assess the performance of a non-conditioned building. In this paper, we present the evaluation ofthe discomfort index (DI) and Tropical Summer Index (TSI) for the summer season (April and May).The comfort hours achieved using cool roof coatings were 12–17 hours more than the base case or conventional roof used in a hot-dry climate. The tropical summer index (TSI) was found adequate within its comfort range (27.5 °C) for roofs with surface coatings than a base case roof slab.