Long-term performance of high-reflectivity exterior panels

Paint performance was assessed over time with respect to surface contamination and degradation of reflectivity through environmental exposure tests. Test panels were coated with high-reflectivity or conventional paints. One set of test panels was coated with high-reflectivity paint on site or in-factory at the manufacturing stage by a newly developed heat curing paint method. Following environmental exposure, this heat curing paint method was evaluated for its long-term performance in thermal conditioning, and durability, as well as for possible performance enhancement with the addition of a photocatalyst. Solar reflectivity of the panels was degraded by exposure to ultraviolet light, adhesion of airborne contaminants, and exposure to high temperatures and precipitation. Newly developed high-reflectivity heat curing paint was just as durable as conventional heat curing paint. In addition, panels coated with a photocatalyst in-factory achieved a high level of solar reflectivity for a longer period compared to panels coated with conventional paint in-factory and high-reflectivity paint on site.