%0 Journal Article %A Ruijiao Miao %A Ravi Kishore %A Sumanjeet Kaur %A Ravi S Prasher %A Chris Dames %B Cell Reports Physical Science %D 2022 %G eng %N 7 %P 100960 %R 10.1016/j.xcrp.2022.100960 %T A non-volatile thermal switch for building energy savings %U https://linkinghub.elsevier.com/retrieve/pii/S2666386422002417 %V 3 %8 07/2022 %! Cell Reports Physical Science %X

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 $0.045 W m^{- 1} K^{- 1}$ , 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.