Intelligent electrochromic photothermal regulation for integrated building energy saving

As the demand for energy-efficient buildings surges, it is of utmost importance to develop efficient and integrated intelligent energy-conservation technologies. This research presents a comprehensive intelligent energy-saving system that combines electrochromic dynamic photothermal regulation windows (DPRW) with selective dynamic radiative cooling regulators (SDRCR) using electrochromic technology. The DPRW enables independent solar transmittance modulation (ΔT = ∼92%/∼82% at the visible/near-infrared band) and mid-infrared emissivity switching (Δε = ∼0.6), leading to a temperature ∼14 °C lower than that of normal windows. The SDRCR provides customizable colors while guaranteeing selective emissivity modulation (Δε_max= 0.6/0.64) within the atmospheric transparent windows (8–13 µm, 16–23 µm), facilitating dynamic thermal management with a temperature regulation of ∼5 °C for cooling/insulation and overcoming static radiative cooling limitations. EnergyPlus simulations suggest a potential annual energy saving of up to 99.5 MJ m⁻²and ∼80% reduction in cooling energy consumption in hot climates. This study is the first to introduce electrochromic technology into an integrated building system and offers a novel solution for intelligent buildings through multi-band spectral control, achieving a balance among energy efficiency, aesthetic flexibility, and environmental adaptability.