Warm in Winter and Cool in Summer: Scalable Biochameleon Inspired Temperature-Adaptive Coating with Easy Preparation and Construction

The highly reflective solar radiation of passive daytime radiative cooling (PDRC) increases heating energy consumption in the cold winter. Inspired by the temperature-adaptive skin color of chameleon, we efficiently combine temperature-adaptive solar absorption and PDRC technology to achieve warm in winter and cool in summer. The temperature-adaptive radiative cooling coating (TARCC) with color variability is designed and fabricated, achieving 41% visible light regulation capability. Comprehensive seasonal outdoor tests confirm the reliability of the TARCC: in summer, the TARCC exhibits high solar reflectance (similar to 93%) and atmospheric transmission window emittance (similar to 94%), resulting in a 6.5 K subambient temperature. In the winter, the TARCC's dark color strongly absorbs solar radiation, resulting in a 4.3 K temperature rise. Compared with PDRC coatings, the TARCC can save up to 20% of annual energy in midlatitude regions and increase suitable human hours by 55%. With its low cost, easy preparation, and simple construction, the TARCC shows promise for achieving sustainable and comfortable indoor environments.

Automated summary

This study combines temperature-adaptive solar absorption and passive daytime radiative cooling (PDRC) technology to achieve warm in winter and cool in summer. The temperature-adaptive radiative cooling coating (TARCC) with color variability is designed and fabricated, showing high solar reflectance and atmospheric transmission window emittance in summer, and heat absorption in winter. It has the potential to save energy and increase suitable human hours.