Analysis of Thermal Effects of Roof Material on Indoor Temperature and Thermal Comfort

The indoor thermal comfort is one of the key factors in designing an energy-efficient sustainable building. In the tropics, ensuring indoor thermal comfort using air conditioning systems is the primary cause of the high energy consumption of buildings. This thermal comfort is greatly affected by the characteristics of the building envelope material, including the roof. Zinc roofing sheet is the most common roofing material used in Indonesia because of its lightweight and easy installation. However, it is corrosive, and it has a high thermal conductivity that can lead to overheating in the room. In order to improve indoor thermal comfort, it is necessary to find alternative, environmentally friendly building roofing materials. The purpose of this experimental study is to analyze and evaluate the effect of the type of roofing material on rooms’ temperature profile and indoor thermal comfort level. Temperature measurements are carried out for three consecutive days on three prototype buildings with the one-twenty scale with different roofing materials: zinc plate, bamboo, and sugar palm fiber called Ijuk. In each building, four temperature sensors connected to a temperature data logger are placed at the rooftop surface, attic zone, bedroom, and living room. The measurement results show that the type of roofing material has a significant impact on the indoor temperature profile and comfort level both day and night. Considering the thermal performance shown by the results of the study, Ijuk can be a rational choice as a roofing material for residential houses in tropical climates