Yttria-stabilized zirconia coating for passive daytime radiative cooling in humid environment

Abstract

Passive daytime radiative cooling is a promising new field for solving the energy shortage all over the world. The performance of daytime radiative cooling is limited by several factors such as non-radiative heat transfer, outdoor-environment erosion and atomsphere humidity. We propose in this work a 8 wt% yttria stabilized zirconia (8YSZ) coated SiO2 (glass)/Ag radiative cooler for improving daytime radiative cooling performance. Numerical results show that the proposed radiative cooler can achieve a cooling power of 95.1 W/m2 under direct AM1.5 solar irradiation and dry environment. In addition, the cooler temperature can drop by 10.3 ℃ below the ambient under direct solar irradiation and 1 m/s wind speed. We also evaluate the cooling performance of the proposed structure under different humidity and it is remarkable to find that the 8YSZ coated radiative cooler can boost the net cooling power under high humidity, compared to that without 8YSZ coating. This proposed structure may have potential practical applications in daytime radiative cooling due to its fantastic corrosion resistance, anti-degeneration and adaptability to high as well as rapidly changing humidity.