Architectural coatings and temperature adaptive radiative cooling strategies applied in ten climate zones in China: Annual energy consumption reductions and potentials

Abstract

This research evaluates the energy-saving potential of high-reflectivity building materials, including four coating types—normal (absorptivity 0.8, emissivity 0.8), cooling (absorptivity 0.2, emissivity 0.9), supercooling (absorptivity 0.05, emissivity 0.95), and Temperature-Adaptive Radiative Cooling (TARC) materials across 49 representative cities within ten climate zones in China using computational fluid dynamics simulations combined with the Demand.ninja energy consumption model. The results reveal that optimal solar absorptivity varies significantly between different climate zones, with higher absorptivity benefiting colder regions and lower absorptivity benefiting hotter regions. Urban microclimate simulations confirm that low solar absorption materials effectively reduce wall temperatures during the daytime and boost overall cooling energy savings, despite a slight increase in ambient air temperature. Building height-to-width ratios also influenced energy efficiency, with the best performance observed at a ratio of unity for both cooling and supercooling materials. Additionally, tests on the Temperature-Adaptive Radiative Cooling (TARC) materials demonstrate that TARCs offer significant energy-saving advantages, achieving an annual saving of 23.1 billion kWh across China by effectively balancing heating and cooling demands across different seasons. This superior performance is primarily attributed to TARCs’ ability to mitigate increased heating energy demands often associated with conventional cooling materials, especially in regions with substantial winter heating needs. Present research has highlighted the importance of climate-specific building material strategies and the potential of innovative materials like TARC for reducing energy consumptions, and this could favour the low carbon urban development.