Low-cost and Transparent Cooling Films with Solar Selective Nanoparticles for Building Energy Saving

Abstract

As a passive cooling technology with no energy consumption and no pollution, radiative cooling has shown huge energy saving potential. However, its application in building glass still faces great challenges due to the contradiction between transparency and cooling performance. In this work, we combined solar regulation and radiative cooling to develop the promising solar selective films. Spectral analysis shows that solar selective films presented the emissivity of 92.2% in the mid-infrared band (8~13 μm), a blocking rate of 78% in near-infrared band (780~2000 nm), and an average transmittance of 63.7% in visible band (400~780 nm), resulting in a considerable indoor temperature drop of 11 ℃ in summer. Meanwhile, energy consumption analysis demonstrated that solar selective films can reduce the energy consumption of air-conditioner by 11.5%~25% in different regions and the corresponding payback periods are only 0.16~0.72 years. More striking, the developed films presented the facile preparation process and superior stability, indicating the great application potential in reducing energy consumption of buildings.