Dynamic glazing with switchable solar reflectance for radiative cooling and solar heating

Abstract

Dynamic control of sunlight entering a building through glazing panels (e.g., windows, curtain walls, and skylights) is essential for reducing building energy consumption. Here, we demonstrate a dual-mode glazing panel with switchable reflectance (89% versus 17%) via reversible electrodeposition of a silver film on a transparent glass of the glazing. In cooling mode, the silver film-coated glazing, functioning as a radiative cooler, achieves net cooling power of 20–60 W/m 2 on a summer day with direct solar irradiance of 560–970 W/m 2 . In heating mode, transparent glazing absorbs only 13% and allows ∼70% of sunlight to shine through, providing a net heating power of around 400 W/m 2 on a winter day with solar irradiance of 540 W/m 2 . Simulations show that employing such dynamic glazing panels in a medium-size office building (∼5,000 m 2 ) could save up to 23% annual heating/cooling energy consumption under the local climates of 15 U.S. cities. • Reflectance-switchable glazing panel via reversible silver electrodeposition • Heating-mode glazing panel allows ∼70% of sunlight transmission in cold weather • Cooling-mode glazing panel achieves a net cooling power of 20–60 W/m 2 in hot weather • Dynamic glazing panel can save up to ∼23% annual HVAC energy consumption By reversibly depositing a silver film on a transparent glass substrate, Zhao et al. demonstrate a reflectance-switchable glazing panel for solar heating and radiative cooling. The dynamic glazing panel can significantly reduce heating/cooling loads of buildings and is promising for applications such as skylight windows, transparent roofs, and ceiling walls.