SF-98-06-1 -- High-Albedo Roof Coatings-Impact on Energy Consumption PDF

Recent tests conducted on a 12,000 ft² single-story building used as an educational center identified high roof temperatures as a significant problem. The galvanized roof frequently reached temperatures above 180°F. Considerable heat energy reached the nonventilated attic, resulting in temperatures as high as 105°F during the peak of summer. Although the HVAC units were equipped with insulated return ducts, these temperatures increased energy conduction through the duct insulation and through the ceiling insulation into the conditioned space. The roof was coated on March 28 and 29, 1995, with a high-albedo acrylic coating developed to control thermal gain and rust. Tests show installation of the thermal-control roof coating reduced the peak roof temperature to 120°F and significantly decreased the energy flow through the roof and ceiling. Tests show that the high-reflectivity roof coating reduced HVAC energy consumption in a range from 8.7% to 27.5%, depending on the solar radiation and the ambient temperature.

Units: I-P