Researchers at the University of Sydney have developed a new roof coating that could transform how buildings stay cool and source water. The study, published in Advanced Functional Materials, shows how this paint can both reflect sunlight and harvest moisture, allowing rooftops to act as natural coolers and water collectors.
A Dual-Purpose Design
The research team designed the coating to reflect up to 97% of incoming sunlight, preventing roofs from heating up under hot conditions. Instead of absorbing heat like typical roofing surfaces, this paint actively deflects solar radiation, keeping building interiors cooler without heavy reliance on fans or air conditioners.
The paint also draws water vapor from the air, even when humidity levels are relatively low. Once collected, the moisture can be condensed into small amounts of usable water. This feature could provide households and community centers with a passive way to gather fresh water, especially in regions where water is scarce.
Ideal for Hot and Water-Stressed Regions
Because the coating applies just like regular paint, builders and homeowners can use it without specialized equipment or major construction changes. By reducing cooling demand, the paint helps lower energy use and eases strain on power grids during heatwaves. At the same time, its water-harvesting function offers a sustainable source of supplemental water for areas facing drought and rising temperatures.
As climate challenges increase, architects and urban planners may adopt this technology to support greener and more resilient cities.
