Affordable retrofitting methods to achieve thermal comfort for a terrace house in Malaysia with a hot–humid climate

Abstract

Although various cooling approaches have been proposed to overcome the thermal discomfort in residential buildings, tropical developing countries still lack affordable and effective retrofitting methods. The objective of this study was to evaluate the effectiveness of an affordable retrofitting method with high-density polyethylene (HDPE) nets as roof covers for shading over the roof, supported by full day free-running ventilation, and heat insulation above the ceiling of residential buildings in hot–humid climate regions to overcome the thermal discomfort. Field measurements were carried out in a corner terrace house in Malaysia, from September to December 2018. The roof cover with HDPE nets maintained a consistent surface temperature at the roof tiles and reduced the convective heat flux by approximately 70–80% in the attic and 88% in the room. Further, it improved the compliance (acceptability: 80%) of the whole-day mean operative temperature in the room (hot–humid climate) by 10%. The roof cover can effectively provide thermal comfort in residential buildings in Malaysia, which has a hot–humid climate. Alongside active cooling with the ceiling fan, required comfortable indoor temperature can be reached under the hot–humid climate, particularly during the night-time. Furthermore, the zero-energy-consuming, low-cost low-technology roof cover method is very suitable for low-cost houses with roof tile in hot–humid climate regions.