Low-cost radiative cooling blade coating with ultrahigh visible light transmittance and emission within an “atmospheric window”

By Cheng Ziming, Wang Fuqiang, Gong Dayang, Liang Huaxu, Shuai Yong. 2020

133 citations recorded by the source corpus.

Abstract Radiative cooling is a passive means of cooling that does not require the consumption of additional energy and has broad application potential. While experimental spectral measurements have been conducted, the daylighting of buildings, photovoltaic (PV) cells, and vehicles has seldom been considered. Here, we use spectrum-selective coatings to resolve the competing demands of daylighting (or appearance) and radiative cooling. A simple liquid blade-coating method that was inexpensive, convenient, and scalable was used to achieve radiative cooling with ultrahigh transmittance in visible light and excellent cooling performance. Resonant polar dielectric SiO2 microparticles with optimized volumetric fractions and diameters were randomly mixed into an acrylic resin and manually bladed at room temperature with natural evaporation drying. Spectrometry results showed that a mean visible light transmittance >91.3% was achieved, which was much higher than reported in previous studies; a mean emittance >93.7% within the “atmospheric window” was also reached. Over four days testing of a silver-plated aluminum sheet in a populous area at sea level, we achieved a maximum sub-ambient decrease in temperature of ~8.7 °C and a maximum cooling power of 108.49 W/m2.

Subfields: Atomic and Molecular Physics, and Optics, Civil and Structural Engineering, Environmental Engineering

View Paper: https://www.semanticscholar.org/paper/9f76ab0d5e9aef2e5cd1746c8c0b1f1450fc9cba