High Performance Transmission‐Type Daytime Radiative Cooling Film with a Simple and Scalable Method

Abstract Transmission‐type radiative cooling textiles represent a vital strategy for personal thermal management. However, traditional preparation methods based on heat‐induced phase separation face significant challenges regarding cost, environmental impact, and optical performance. Herein, a novel preparation method is devloped by blending mid‐IR transparent solid styrene ethylene butylene styrene (SEBS) with solid polyethylene (PE), enabling the creation of pores through dissolving SEBS. Consequently, large‐scale production of transmission‐type radiative cooling films at the meter scale are achieved, exhibiting 95% solar reflectivity and 80% mid‐IR transmittance. Moreover, this method reduces costs by 68% and diminishes CO 2 emissions by 92%. Under sunny and cloudy conditions (solar irradiance ≈730 and 280 Wm − 2 , respectively), the film‐covered simulated skin demonstrates sub‐ambient cooling effects of ≈4 and 3 °C. Given its exceptional passive cooling capabilities, low‐cost, and scalability, this film holds great potential for industrial and personal applications.