A weather-resistant daytime radiative cooler based on fluorocarbon resin

Daytime radiative cooling (DRC) technology is used for cooling by reflecting sunlight and radiating the heat to outer space. It does not require energy for cooling, and there is no pollution. In this study, a double-layer DRC structure was prepared using the doctor's blade method. The upper layer was a fluorocarbon resin (FEVE), while the bottom layer was a silver layer. The average reflectivity in the solar radiation band and the average emissivity in the atmospheric window were 0.933 and 0.945, respectively. Without considering non-radiative heat transfer, the cooling power was calculated as 128.75 W/m2 under direct sunlight and for the ambient temperature of 27 °C. When the material was used as a radiative cooler in Tianjin, China, the average temperature drop from 10:00 a.m. to 2:00 p.m. was 5.1 °C. The proposed polymer cooler is cost-efficient, easy to fabricate and commercially feasible. In addition, its good weather resistance makes it possible for radiative coolers to be used outdoors for a long time, which will greatly promote the wider practical application of DRC.