Numerical study of the integrated heat transfer of a condensation-free radiant cooling panel covered with multiple interlayer infrared membranes

Radiant cooling panels have been widely used because of their energy efficiency, high thermal comfort, and ability to improve indoor air quality. However, low cooling capacity and condensation become the key problems that limit the application of radiant cooling panels, especially in hot and humid areas. Aiming at improving the cooling capacity and reducing condensation risk, this study proposed a new condensation-free radiant cooling panel structure with multiple air layers. A two-dimensional heat transfer model of the radiant cooling panel with multiple air layers was established. Numerical methods were used to investigate the effects of the number and thickness of air layers on the cooling capacity and temperature uniformity of the radiant cooling panel. The number and thickness of the air layers were also optimized to maximize the cooling capacity and condensation resistance. The results showed that the optimum number and thickness of air layers were 2 and 10 mm, respectively. In an environment of 28 °C and a relative humidity of 50%, the cooling capacity and radiant heat flux of the optimized radiant cooling panel were 169.42 W/m² and 138.69 W/m², respectively. The results were improved by 25.7% and 30.5% compared to a panel with a single air layer, respectively. This study demonstrated a high-performance radiant cooling structure with multiple air layers having improved cooling capacity and reduced condensation risk and will be beneficial to radiant cooling panel applications, especially in hot and humid regions.