Assessment of the impact of cool roofs in rural buildings in India

Increasing roof reflectance reduces absorption of solar radiation, roof surface temperature and heat ingress into the building. This leads to an increase in indoor comfort and reduction in room air temperature that in turn results in energy saving by reducing AC demand. To assess this impact of cool roofs on buildings in rural and peri-urban areas of India, a study was performed on two un-conditioned school buildings in Hyderabad (ZPH School) and Nagpur (VNHM School). Two classrooms of same size, function, and occupancy from both the school buildings were monitored for a period of ten weeks starting from March 2014 till May 2014. The data from the experiments and their analyses showed promising results. The average reduction and peak reduction in indoor air, roof underdeck and roof overdeck surface temperatures are 2.1 degrees C, 5.0 degrees C and 12.3 degrees C and 4.3 degrees C, 10.0 degrees C and 26.3 degrees C respectively for the room with white roof as opposed to grey roof in ZPH School and 1.5 degrees C, 4.0 degrees C and 9.5 degrees C, and 3.3 degrees C, 4.2 degrees C, and 25.2 degrees C respectively in VNHM School. The results from the experiment prove that white roof has a significant effect in reducing the indoor air temperatures in buildings due to reduction in outdoor and indoor roof surface temperature. (C) 2015 Elsevier B.V. All rights reserved.