Energy demand is growing significantly worldwide to create thermal comfort in buildings. Air-conditioning is contributing to energy consumption at a massive scale in the residential and commercial sectors. The roof is one of the most critical components of the building envelopes, and it achieved maximum heat gain in summer, and it covered nearly 20–25% of overall urban surface areas. In this respect, cool roofs are considered one of the sustainable solutions to maintain thermal comfort in buildings. The results achieved from the literature review indicate that cool roof application reduced energy use in the buildings and a useful tool to mitigate Urban Heat Island (UHI) effect. This paper summarizes cool roof thermal performance with different types of surface coatings in different climatic zones for buildings with additional benefits, limitations, and recommendations for future research work. The results of this review can be helpful for engineers, researchers, dwellers, and architectures to have a good understanding of the benefits of cool roofs to mitigate energy consumption demand in dwelling in a sustainable, cost-effective, and energy-efficient way. The average energy-saving effect of the roof is expressed from 15% to 35.7% in different climatic zones (Temperate, Tropical, Composite, Hot and Warm-Humid) as per the literature survey results. Also, the average roof surface temperature reduction is possible from 1.4 ˚C to up to 4.7 ˚C using cool roof technology.

Mohan Rawat, R. N. Singh, A study on the comparative review of cool roof thermal performance in various regions, Energy and Built Environment, Volume 3, Issue 3, 2022, Pages 327-347, ISSN 2666-1233, https://doi.org/10.1016/j.enbenv.2021.03.001.