Compared with traditional static insulation, a thermally switchable building envelope could reduce annual heating and cooling loads by intermittently coupling to the outside environment when beneficial. Here, we demonstrate a voltage-actuated, contact/non-contact thermal switch that meets the unique challenges of this application. The switch is non-volatile, consuming electricity only briefly while switching and none to hold steady state. The switch ratio is 12, the off state has a low effective thermal conductivity of $0.045\mathrm{W}{\mathrm{m}}^{-1}{\mathrm{K}}^{-1}$, comparable to fiberglass insulation, and the performance is stable over 1,000 switching cycles. Numerical simulations using real-world climate data show that combining this thermal switch with a thermal storage layer in a building envelope can yield annual energy savings of 9%–55% (heating) and 17%–76% (air conditioning), depending on the climate zone. The greatest benefits are realized when the exterior temperature crosses well above and below the desired interior temperature within a single 24 h period.

与传统的静态绝缘相比，可热转换的建筑围护结构可以在有益的情况下通过间歇性地与外部环境耦合来减少年度供暖和制冷负荷。在这里，我们展示了一种电压驱动的接触式/非接触式热敏开关，可应对该应用的独特挑战。该开关是非易失性的，仅在切换时短暂消耗电力，而不会保持稳定状态。开关比为 12，关断状态的有效导热系数低$0.045\mathrm{W}{\mathrm{米}}^{-1}{\mathrm{ķ}}^{-1}$，可与玻璃纤维绝缘材料媲美，1000 次以上开关循环性能稳定。使用真实世界气候数据的数值模拟表明，将此热开关与建筑围护结构中的蓄热层相结合，每年可节省 9%–55%（供暖）和 17%–76%（空调）的能源，具体取决于气候区。当外部温度在单个 24 小时内远高于和低于所需的内部温度时，可以实现最大的好处。