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Can Thermal Nonreciprocity Help Radiative Cooling?
Run Hu1,2, Zihe Chen1, Sun-Kyung Kim2
1School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Abstract:
Radiative cooling has witnessed substantial progress while its performance is constrained by the thermal reciprocal Kirchhoff's law. Violating Kirchhoff's law to pursue nonreciprocal radiative cooling seems promising; however, the energy conservation requirement and radiant flux integrated over the entire hemisphere make the nonreciprocal benefit insignificant. This commentary discusses the practical limits of nonreciprocal radiative cooling and points toward the future direction of directional radiative cooling.
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