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arXiv · 1803.07906

Daytime passive radiative cooler using porous alumina

Yang Fu·Jiang Yang·Yishu Su·Wei Du·Yungui Ma
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Abstract

We report a daytime passive radiative cooler using chemically fabricated porous anodic aluminum oxide (AAO) membranes. Effective medium theory (EMT) has been applied to analyzing the optical properties of the air-doped porous medium. The composite structure is specifically optimized so that it has a high absorbance (emittance) in the far-infrared atmospheric window and nearly no loss in the solar spectrum. The calculated emittance is well reproduced in the experiment by our AAO sample. The fabricated porous membrane shows a potential cooling power density of 64 W/m2 at ambient (humidity = 75%) under direct sunlight irradiance (AM1.5). Experimentally, the sample is cooled by a 2.6C temperature reduction below the ambient air temperature in the sunlight. This performance shows little variance at night. The AAO approach proposed here may provide a promising way to produce low-cost and efficient radiative cooler in large scales for feasible energy conservation.

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Yang Fu, Jiang Yang, Yishu Su, Wei Du, Yungui Ma. 2018-02-28. Daytime passive radiative cooler using porous alumina. https://arxiv.org/abs/1803.07906

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