002 Assessment of Radiative Cooling Potential through Climate Indicators and Energy Simulation

Abstract

Rising global temperatures are amplifying the need for energy-efficient buildings as cooling demand escalates worldwide. Conventional air-conditioning is carbon-intensive, prompting interest in radiative cooling materials that passively reflect solar radiation and emit heat to the sky. This study combines building energy simulation with climate-based indicators to evaluate their performance in eleven cities across China and Japan. Three façade types were examined: conventional absorptive, typical radiative cooling, and an idealized high-reflectance, high-emissivity surface. Results show that the ideal façade can lower wall temperatures by up to 20 °C, reduce diurnal heat flux by 60–80%, and cut annual cooling demand by 5–80 kWh/m², depending on climate. To extend applicability, three indices—Weather Structure Index, Diurnal Temperature Index, and Composite Climate Applicability—were introduced. Regression analysis validated the composite index as a reliable predictor of energy savings. Findings highlight that radiative cooling is effective not only in hot-humid climates but also in clear, cold regions, providing a robust, climate-informed framework to guide low-carbon building design.