Nano-coating cools roofs and harvests water from the air

Australian researchers have developed a nanoengineered cooling paint that uses passive radiative cooling to reflect most of the sun, keeping rooftops cooler and reducing building energy use, while also condensing moisture from humid air to harvest water. Early field tests showed solar reflectivity up to 96% and roof temperatures up to 6°C cooler than the surrounding air, with a Sydney trial suggesting up to 34% in cooling energy savings. In trials on a 200 m2 roof, about 74 liters of water per day were harvested. The paint is being considered for commercialization, but durability, performance in cloudy weather, upfront costs, and the lack of standardized testing remain challenges.”,