Thermal analysis of a building in hot and dry climate: a detailed study

Abstract

Active cooling is quickly becoming a necessity in hot-dry climates prevailing across large sections of the world, where the equivalent solar temperature can rise above 70 °C in the summer. The cooling demand, within the structure depends on various components of building, some of which may be directly exposed to sunlight. While a few mitigating technologies that reduce this energy ingress have been proposed, quantitative analyses leading to policy prescriptions are largely missing. This research is aimed at identifying the building elements primarily responsible for the energy ingress by focusing on a specific apartment located in a hot and dry climate (in western India). A comprehensive resistance–capacitance (RC) model inclusive of all of the building components has been used for this purpose. Among other insights, this model shows that while a heat ingress largely occurs through the roof, the installation of the Brick Bat Koba waterproofing and sand bedding and reflective tiles lead to a reduction in energy ingress. However, these two mitigating strategies are not adequate for achieving thermal comfort during summer and the presence of brick bat Koba and sand bedding worsens the situation by preventing the indoor environment from cooling down sufficiently during the night. As potential solutions, we propose the usage of nocturnal ventilation using fresh ambient air, which helps to reduce the indoor temperature during the night, concomitantly reducing the energy consumption attributable to air-conditioning. These insights are expected to lead to the adoption of best practises and ultimately to the development of regulatory guidelines.