Cool Roofs Help Indian Slums Beat Extreme Heat:

In an attempt to assist residents cool down prior to the hottest time of the year, hundreds of roofs in the informal settlements of Gujarat have been painted with a white reflective coating over the last two months.

The effort, which encompasses 400 households in Ahmedabad, is part of a cooling movement aimed at studying the effects of indoor heat on a person’s health and economic wellbeing in developing regions, and how “cool roofs” can be beneficial.

Aditi Bunker, an epidemiologist from the University of Heidelberg in Switzerland, said, “Home is where people have come to find shelter and respite against external elements,”. Her project is funded by the UKs Wellcome Trust.

“In this Positionality people are living in precarious housing conditions wherein one ought to be sprotected is further exposing them into problem of heat.”

In terms of amenities and infrastructure, the Vanzara Vas slum in Narol has two thousand single-roomed, non ventilated houses. Most of the residents in the project like Nehal Vijaybhai Bhil believe that they are now starting to feel the impact of the improvement work.

“I have noticed that the heating on my refrigerator is no longer running and the “cooling” function is working as it should. I sleep much more soundly and am now spending less on electricity,” said Bhil, whose roof was painted in January.

According to a 2022 article in Environmental Research Letters, heatwaves which overturned the world by three times prior to the industrial revolution, had nearly a 1 in 10 chance of happening every decade.

Bunker and her group is doing a remarkable job in blocking the sun's radiation from being absorbed by using highly reflective white pigments on roofs like titanium dioxide and preventing it from being released back into the atmosphere.

“There is no insulation shield above these low socio-economic households to stop the heat transfer from getting through hence why these families cannot cope with the scorching heat”, Bunker remarked.

Before participating in Bunker’s experiment Arti Chunara used to just make her roof out of plastic sheets and place grass on top.

Along with her family, there were some days in which she sat outside for the majority of the day and came inside only for two to three hours when the heat was manageable.

During the course of one year, scientists in Ahmedabad will gather health and indoor environmental data from participants with cool roofs as well as those without to latter to form a comparison in a study conducted in Ahmedabad.

Other study locations include Burkina Faso, Mexico, and Niue, South Pacific, encompassing various regions with different construction materials and climates.

As Bunker noted, the initial findings from the Burkina Faso trial exhibit that cool roofs were able to lower the indoor temperature in houses with tin and mud roofs by 1.2ºC and further lowered the temperature in houses with tin roofs by 1.7ºC over the course of two years, which later on decreased the residents' heart rates.