Enhanced radiative cooling with <i>Janus</i> optical properties for low‐temperature space cooling
Meng Yang, Yijun Zeng, Qingyuan Du, Haoyang Sun, Yingying Yin, Xiantong Yan, Mengnan Jiang, Chin Pan, Dazhi Sun, Zuankai Wang
Abstract
Abstract Passive daytime radiative cooling that could provide sub‐ambient cooling emerges as a promising technology to reduce household energy consumption. Nonetheless, prevailing studies are predominantly focused on surface cooling, often overlooking its adaptability to enclosed spaces with active cooling technologies. Here we present a multilayer radiative cooling film ( J ‐MRC) with Janus optical properties in the mid‐infrared region, consisting of the nanoporous polyethylene films, the polyethylene oxide film, and silver nanowires. The top side of the J ‐MRC functions as a conventional radiative cooling material to supply sub‐ambient surface cooling, while the bottom side with low mid‐infrared emissivity transfers limited heat via thermal radiation to the low‐temperature enclosures. Our experiments validate that the J ‐MRC possesses an enhanced space cooling performance in comparison to the conventional radiative cooling film. This work provides a valuable design concept for radiative cooling materials, thereby expanding their practical scenarios and contributing to reduce the carbon emission.