Sub-ambient radiative cooling with wind cover

Abstract

With the breakthrough of daytime radiative cooling, more and more efforts have been devoted to this promising clean energy technology. However, there still lacks systematic research on the impact of wind cover on radiative cooling performance. This work firstly reviews the existing wind cover material and non-radiative heat exchange models. Subsequently, the great impact of the wind cover on cooling performance is demonstrated theoretically and experimentally. The results indicate that in the high temperature and humidity area, the difference of daytime maximum temperature drop with and without wind cover can reach about 2.3 K, while the nighttime difference is significantly greater. Additionally, the tilt strategy and wind cover strategy are employed to achieve a maximum daytime average temperature drop of 4.2 K in Tianjin, China. Furthermore, this work continues to investigate the impact of the wind cover on radiative cooling potential of various areas in China, and the results reveal that wind cover has a greater impact on the radiative cooling potential in Northwest China and 85% of China's areas can achieve radiative cooling performance with wind cover. This work provides a detailed evaluation of radiative cooling potential with and without wind cover in China.