Paint could help cities stay cool
You probably have a favourite way to keep cool in hot weather – perhaps sipping a cold drink, having a swim or retreating to a shady spot. However, did you know that a fresh lick of paint on a building could also help you to beat the heat?
In a recent study in Singapore, researchers painted the roofs and walls of two rectangular buildings and the pavement in between them. The team used a paint containing a substance that reflects the Sun’s heat. Another pair of buildings were not painted, so the researchers could make a comparison.
The paint works by reducing the amount of heat that buildings absorb, because the heat is reflected away instead. Absorbed heat is later released, warming up the interior of a building and the surrounding area. Over two months, the researchers measured the conditions in the two areas. They found that the special paint had a big impact. At the hottest time of the day – around 4pm – the street that had buildings coated in it was as much as 1.5°C cooler than the street without the paint.
Over a 24-hour period, 30% less heat was released from the buildings and the pavement in the painted area. Professor Ng Bing
Feng, who worked on the study, said the findings show paint “can be a promising way to make urban areas (towns and cities) cooler and more comfortable”. The scientists who conducted the study hope it could reduce the need for indoor airconditioning, which uses lots of energy.