14.04.2021

​Heat-Reflecting Paint Keeps Things COOL Without Air Conditioners

The paint would absorb nearly no solar energy and send heat away from the building, replacing the need for air conditioning, according to the researchers. Without the building heating up, air conditioning wouldn’t have to kick on. The paint would not only send heat away from a surface, but also away from Earth into deep space where heat travels indefinitely at the speed of light. This way, heat doesn’t get trapped within the atmosphere and contribute to global warming. Earth’s surface would actually get cooler with this technology if the paint were applied to a variety of surfaces including roads, rooftops, and cars all over the world, the researchers say. The new white paint reflects 95.5% sunlight and efficiently radiates infrared heat. Calcium Carbonate, an Earth-abundant compound commonly found in rocks and seashells, is used as the paint’s filler, allowed the formulation to behave essentially the same as commercial white paint but with greatly enhanced cooling properties. These calcium carbonate fillers absorb almost no ultraviolet rays due to a so-called large “band gap,” a result of their atomic structure. They also have a high concentration of particles that are different sizes, allowing the paint to scatter a wider range of wavelengths. Cutting down on air conditioning also means using less energy from coal, which could lead to reduced carbon dioxide emissions. Credit: WASTE ED