A new coating material developed by Stanford University engineers can be used to cool buildings by releasing building heat into space and also reflecting sunlight. The ultrathin multilayer material, only 1.8 microns thick, could lead to cooler buildings that require less air conditioning. The engineers called the technique photonic radiative cooling.
The material forces invisible, heat bearing light from objects and living things away from buildings into space at a precise frequency. Using this technique, the infrared light passes through the atmosphere without warming the air. Additionally the material acts a highly efficient mirror, reflecting 97% of sunlight. The engineers have developed this material to be cost-effective for large-scale applications and could lead to a reduction in demand for electricity.