Molecular Confinement Engineering Induced Super Thermostable and RT‐Adjustable Gel for Tri‐Heat‐Channeled Smart Window

Abstract Thermochromic hydrogel‐based smart windows hold great potential for building energy‐saving. However, most of thermochromic hydrogels possess high response temperatures (RT) and poor size stability under heat, resulting in limited energy‐saving performance for smart windows. Here, a printable thermochromic gel (PNC) is reported with low thermal shrinkage and tunable RT for smart windows applications via molecular confinement engineering. The RT of PNC gel is well within the comfort temperature zone of the human body and can be modulated (26.5–31.5 °C) by the introduced support networks. Importantly, the resultant gel exhibits a super transmittance (95%) in visible light and an outstanding modulation (87%) for sunlight. Based on PNC gel, a tri‐heat‐channeled smart window is fabricated using a multilevel thermal regulation strategy that couples conduction, radiation, and evaporative cooling. The tri‐heat‐channeled smart window demonstrates outstanding daytime cooling (10 °C lower than conventional windows) and can cut off 30% of annual heating, ventilation, and air‐conditioning (HAVC) energy consumption. Furthermore, a novel smart window is designed with invisible shutters that appear only when needed. This work offers novel clues for constructing versatile gels and innovative smart windows for building energy‐saving.