Mechanically Robust and Spectrally Selective Convection Shield for Daytime Subambient Radiative Cooling

• Published in: ACS applied materials & interfaces Vol. 13; no. 12; pp. 14132 - 14140
• Main Authors: Zhang, Ji, Zhou, Zhihua, Tang, Huajie, Xing, Jincheng, Quan, Jiayou, Liu, Junwei, Yu, Junrong, Hu, Mingke
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 31.03.2021
• Subjects: Energy, Environmental, and Catalysis Applications; radiative cooling; composite film; mechanically robust; spectrally selective; convection shield
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.0c21204

As a passive cooling strategy, radiative cooling is becoming an appealing approach to dissipate heat from terrestrial emitters to the outer space. However, the currently achieved cooling performance is still underperforming due to considerable solar radiation absorbed by the emitter and nonradiative heat transferred from the surroundings. Here, we proposed a mechanically robust and spectrally selective convection shield composed of nanoporous composite fabric (NCF) to achieve daytime subambient radiative cooling. By selectively reflecting ∼95% solar radiation, transmitting ∼84% thermal radiation, and suppressing the nonradiative heat transferred from warmer surroundings, the NCF-based radiative cooler demonstrated an average daytime temperature reduction of ∼4.9 °C below the ambient temperature, resulting in an average net radiative cooling power of ∼48 W/m2 over a 24 h measurement. In addition, we also modeled the potential cooling capacity of the NCF-based radiative cooler and demonstrated that it can cover the cooling demands of energy-efficient residential buildings in most regions of China. Excellent spectral selectivity, mechanical strength, and weatherability of the NCF cover enable a much broader selection for the emitters, which is promising in the real-world deployment of direct daytime subambient radiative cooling.