Field investigation and performance evaluation of sub-ambient radiative cooling in low latitude seaside

With the breakthrough of daytime radiative cooling, more and more efforts have been devoted to this promising technology. However, most of the studies are conducted in arid mid-latitudes, and few reports in humid areas fail to achieve effective cooling. This technology seems difficult to extend to humid low latitudes. To explore the radiative cooling performance in low latitudes, this work sought out cooling materials suitable for low latitudes from the scalable radiative cooling materials and investigated the cooling performance in low latitudes from modeling and experiment. The experimental results demonstrated that in low latitude seaside, a maximum temperature drop of 6.5 °C was achieved under solar irradiation of 750 W/m2. Even with the relative humidity of over 75%, the temperature drop of 4.9 °C and the cooling power of 50 W/m2 was achieved. Additionally, compared with the mid-latitudes, humidity and solar radiation in low latitudes have more impact on the cooling performance. Finally, the radiative cooling potential in China was further investigated and the results revealed that radiative cooling technology can meet the solar peak cooling demand of 65% areas in China alone. Our work broadens the application regional scope of radiative cooling technology to the seaside in low latitudes.