Passive directional sub-ambient daytime radiative cooling

被引：243

作者：

Bhatia, Bikram ^{[1
]}

Leroy, Arny ^{[1
]}

Shen, Yichen ^{[2
]}

Zhao, Lin ^{[1
]}

Gianello, Melissa ^{[1
]}

Li, Duanhui ^{[3
]}

Gu, Tian ^{[3
]}

Hu, Juejun ^{[3
]}

Soljacic, Marin ^{[2
]}

Wang, Evelyn N. ^{[1
]}

机构：

[1] MIT, Dept Mech Engn, Cambridge, MA 02139 USA

[2] MIT, Dept Phys, Cambridge, MA 02139 USA

[3] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA

来源：

NATURE COMMUNICATIONS | 2018年 / 9卷

关键词：

SOLAR; TEMPERATURES; PERFORMANCE; EMITTANCE; NIGHT;

D O I：

10.1038/s41467-018-07293-9

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Demonstrations of passive daytime radiative cooling have primarily relied on complex and costly spectrally selective nanophotonic structures with high emissivity in the transparent atmospheric spectral window and high reflectivity in the solar spectrum. Here, we show a directional approach to passive radiative cooling that exploits the angular confinement of solar irradiation in the sky to achieve sub-ambient cooling during the day regardless of the emitter properties in the solar spectrum. We experimentally demonstrate this approach using a setup comprising a polished aluminum disk that reflects direct solar irradiation and a white infrared-transparent polyethylene convection cover that minimizes diffuse solar irradiation. Measurements performed around solar noon show a minimum temperature of 6 degrees C below ambient temperature and maximum cooling power of 45 Wm(-2). Our passive cooling approach, realized using commonly available low-cost materials, could improve the performance of existing cooling systems and enable next-generation thermal management and refrigeration solutions.

引用

页数：8

共 48 条

[31] RADIATIVE COOLING EFFICIENCY OF WHITE PIGMENTED PAINTS [J].