Cool Paint

A revolutionary new paint has been developed that cools a building using the sun – and the stronger the sun, the cooler it gets! Dubbed SolCold, it’s based on a principle known as anti-Stokes fluorescence in which the amount of energy emitted by an atom or molecule is greater than the amount of energy it absorbs. The key is to selectively absorb the proper wavelengths of energy so that the net reaction causes a cooling effect.

The researchers came up with a two-layer approach that, once applied to the surface of an object, is no thicker than a business card. The outer layer filters out much of the sun’s broad spectrum to absorb infrared energy (or heat) while the inner layer emits higher energy photons (light). Unlike existing cooling paints that lower heat absorption simply by scattering the energy absorbed, the new material actively lowers temperatures by pulling energy out. In simulations, it has been demonstrated that applying the paint to a roof could reduce the temperature on the top floor of a building by up to 10 degrees Celsius (about 18 degrees Fahrenheit). The material could also be used to cool objects in space by conducting excess heat from solar radiation and equipment away from the surface.

SolCold currently costs about $300 to cover an area of about 100 square meters. The team is currently raising funds with plans to conduct pilot tests on buildings within the next two years.