This roof paint blocks 97% of sunlight and pulls water from the air

A roof paint that can cool your home and pull fresh water straight out of the air? It’s within reach, as scientists scale up production of a new kind of paint-like coating that shields roofing from the sun’s rays and harvests dew from its surface.

Researchers at the University of Sydney and commercial start-up Dewpoint Innovations have created a nano-engineered polymer coating that not only reflects up to 97% of the sun’s rays, but also passively collects water. In tests, it was able to keep indoors up to 6 °C (~11 °F) cooler than the air outside.

That temperature differential results in water vapor condensing on the surface – like the fogging on a cold mirror – producing a steady trickle of droplets.

By Bronwyn Thompson