Radiative Warming Glass for High‐Latitude Cold Regions

Abstract Traditional window glazing, with inherently adverse energy‐efficient optical properties, leads to colossal energy losses. Energy‐saving glass requires a customized optical design for different climate zones. Compared with the widely researched radiative cooling technology which is preferable to be used in low‐altitude hot regions; conversely in high‐latitude cold regions, high solar transmittance (T_sol) and low mid‐infrared thermal emissivity (ε_MIR) are the key characteristics of high‐performance radiative warming window glass, while the current low‐emissivity (low‐e) glass is far from ideal. To address this issue, Drude's theory is used to numerically design a near‐ideal film with specified electron density (n_e) and electron mobility (µ_e). The fabricated hydrogen‐doped indium oxide (IHO) could achieve high T_sol (0.836) and low ε_MIR (0.117). Energy‐saving simulations further reveal a substantial decrease in annual heating energy consumption up to 6.6% across high‐latitude regions (climate zones 6 to 8), translating to a corresponding reduction in CO₂ emissions (20.0 kg m⁻²), outperforming 1165 high performance commercial low‐e glass. This radiative warming glass holds the promise of making a significant contribution to sustainable building energy savings specifically for high‐latitude cold regions, advancing the goal of carbon neutrality.