The process is called radiative cooling and consists of blocking sunlight to avoid heating. At the same time it radiates infrared light that is directed to the atmosphere, cooling down the device noticeably below room temperature.
It is a special isolation, called air gel, composed of polyethylene foam and that stands out for its simplicity, its lightness and its low cost. This material reflects the rays of sunlight, so they do not penetrate through it. The device blocks 90 percent of sunlight, protecting the underside so that it does not heat and at the same time allows 80 percent of heat rays to pass freely out. The test has been done in the torrid Atacama Desert, in Chile.
More details in the magazine Science Advances, thanks to an article by Arny Leroy and Evelyn Wang, as well as seven other researchers from MIT and the Pontifical Catholic University of Chile.
Redacción, N. (2019). Un sistema que proporciona refrigeración sin electricidad. [online] Noticias de la Ciencia y la Tecnología (Amazings® / NCYT®). Available at: https://noticiasdelaciencia.com/art/35031/un-sistema-que-proporciona-refrigeracion-sin-electricidad [Accessed 15 Nov. 2019].