Potential of hybrid radiant cooling with infrared-transparent membranes to improve thermal comfort in hot and humid climate

Abstract

• Condensation risk limits radiant cooling in a hot and humid climate. • Infrared-transparent membranes prevent condensation on radiant cooling surfaces. • Radiant surface at 4 °C below dew point reduced discomfort hours by 3–6%. • Experiments-modeling should target lower radiant surface temperatures. • Solar gains significantly affected radiant cooling effectiveness. Condensation risk has limited the deployment of radiant cooling systems for improving thermal comfort in hot and humid climates. Infrared-transparent membrane films emerged as a viable alternative to improve hybrid radiant cooling by preventing moisture condensation. This case study assesses the potential of membrane-assisted radiant cooling in a rural school building in Santa Lucia, Atlántico (Colombia), a location with a hot and humid tropical climate throughout the year. The study evaluates different cooling strategies, including natural ventilation, mechanical ventilation, hybrid radiant cooling, and membrane-assisted radiant cooling using EnergyPlus® software. Results for a radiant surface temperature of 4 °C below the dew point show that membrane-assisted radiant cooling could reduce annual discomfort hours by 3–6% compared to conventional radiant cooling. Further experimental and modeling studies should focus on the lowest achievable temperature below the dew point without condensation. Our results suggest that radiant cooling with infrared-transparent membranes is a potentially cost-effective alternative for improving thermal comfort in rural school buildings in hot and humid climates.