Paint-Like Polymer Promotes Passive Cooling

A new porous polymer coating, developed by engineers at Columbia University, acts as a spontaneous air cooler that can be created, dyed, and applied like traditional paint.

The paint-on finish is meant to be an easier application than other products enhancing a structure's efficiency through Passive Daytime Radiative Cooling (PDRC). Treehugger.com reports, "The trick is to develop a surface with a high thermal reflectance, so that it doesn't heat up, and a 'high thermal emittance that maximizes radiative heat loss,'" and that cooling without need for power makes PDRC highly valuable as an energy-efficient solution.

Passive radiative cooling is straightforward; if there are no clouds at night you get really cold because as Robert Bean has explained, our bodies lose heat to cold surfaces, and space is really cold. The Persians used it centuries ago to make ice. Passive Daytime Radiative Cooling (PDRC) is a little harder to comprehend, because while space is still cold, in the daytime the sun is hotter.