What is 3M Passive Radiative Cooling?

Passive Radiative Cooling is a natural phenomenon that only occurs at night in nature because all nature materials absorb more solar energy during the day than they are able to radiate to the sky. At night, the surrounding environment cools the material to a temperature that is below the dew point or below freezing to form frost. This explains why you may see frost on your car windshield in the morning, even after the air temperature is above freezing. 3M’s Passive Radiative Cooling Film (PRCF) reflects enough solar energy to allow passive radiative cooling to occur during the day.

While the concept has been known for centuries, 3M scientists only recently applied their experience in multi-layer optical films and materials science to develop a solar reflective film with passive radiative cooling capabilities. With careful selection of materials, they have optimized a property called selective emissivity which enables PRCF to radiate heat into the sky in the precise infrared wavelength known as the atmospheric window. PRCF enables 24/7 supplemental cooling and 10-20% energy savings when integrated with building refrigeration and HVAC systems. It can also be applied to other surfaces such as bus shelter roofs to passively cool them during the day and at night.