Principle and Application of Air-Layer Integrated Radiant Cooling Unit under Hot and Humid Climates

Radiant cooling systems offer several advantages over conventional air-cooling systems, such as better thermal comfort, quieter operation, and less air ductwork. However, their application is limited owing to high condensation risk, particularly in hot and humid climates. To reduce this risk and enhance the cooling capacity, an air-layer-integrated radiant cooling unit (AIRCU) is developed. The unit uses an infrared transparent membrane to seal a dry-air layer between the membrane and the radiant cooling surface, separating the radiant cooling surface from the air-contact surface. Here, we report a comprehensive study on the AIRCU, including (1) suitable membrane materials; (2) a method for estimating the membrane temperature; (3) the feasible range of the radiant cooling surface temperature; and (4) the cooling capacity and thermal comfort under different humidity environments. The experimental and numerical analysis results demonstrate that AIRCU is a potential alternative cooling system for hot and humid climates.