Phase change thermostat for all-day temperature-adaptive thermal regulation

The increasing energy consumption in buildings exacerbates the worldwide energy shortage and environmental pollution problems. To reduce the energy consumption, emerging thermal management technologies such as radiative cooling, thermal insulation, and phase change thermal regulation have been used in building envelopes. Most recently, aerogel-based tunable daytime radiative supercoolers have been proved to be an ideal candidate for energy consumption savings. Herein, a phase change material (PCM) enhanced thermostat for energy-efficient buildings is designed to go beyond the limitation of insulating radiative coolers. Compared to cutting-edge aerogel coolers, the proposed phase change thermostat featuring latent heat storage and release is capable of dynamically adjusting its thermal regulation performance along with the change of the environmental temperature, further absorbing the heat during the daylight for cooling and releasing the stored heat at night to suppress overcooling. The phase change thermostat with low thermal conductivity, high solar reflectance, considerable infrared emissivity, and high energy storage density shows great potential for all-day temperature-adaptive thermal management in energy-saving buildings.