Self‐Adaptive Colored Radiative Cooling by Tuning Visible Spectra

Abstract

Traditional radiative cooling leads to overcooling in the winter season and increases the total energy consumption of buildings. And, the super white color limits its practical applications. In this work, a bilayer coating consisting of a polydimethylsiloxane (PDMS)@thermochromic dye film as the top layer and a super white polytetrafluoroethylene film as the bottom layer is designed to achieve self‐adaptive colored radiative cooling by tuning visible spectra. The mass ratio of PDMS to the black thermochromic dye is 1: 0.04 to balance the solar heating and radiative cooling performances although the thermal emittance is constant (0.95). The designed black adaptive coating can achieve modulations of visible and solar reflectance from 0.36 to 0.91 and from 0.62 to 0.92, respectively. And its net power can switch from 331 W m−2 at −10 °C for heating to 70 W m−2 at 50 °C for cooling down. In the indoor and outdoor experiments, it is shown that adaptive coatings can achieve heating performance in a cold environment while cooling performance in a hot environment. Further energy consumption calculation indicates that adaptive coatings can save 5%−44% of energy consumption in different climates. Various colors and critical transition temperatures can be regulated by different thermochromic dyes for various scenarios.