Numerical simulations investigated the effects of thermal emittance, solar reflectance, and roof insulation on low-slope roof heat transfer for nonresidential buildings located in the 16 climate zones of California. The cooling and heating seasonal roof heat transfers are compared to data for low-slope roofs having 0.55 solar reflectance and 0.75 thermal emittance. Recommendations are provided that enable bare and acrylic-coated metal roofs to comply with California’s building efficiency standards.

Presented at Thermal Performance of Exterior Envelopes of Whole Buildings X – December 2007

Units: Dual