Cool roofs may reduce the temperature of a surface exposed to the sun and decrease the energy consumption inside buildings. This type of technology works under two different principles; solar reflectance and thermal emissivity and there is a wide variety of products in the market with different initial and aged reflectance and emissivity values. Reflectance is the fraction of solar energy that is reflected by the roof, and this value decreases over time. Roofs with high initial reflectance and low aged reflectance are currently the most common scenario. In this paper, energy simulation software, Energy 3D and Oak Ridge Cool Roof Calculator were used to determine energy savings when using high albedo cool roof technologies with albedo values fewer than 70%. For this study, we selected the cities with the most solar radiation in the U.S.A. and those with rebates and incentives available and approved by the Cool Roof Rating Council (CRRC). Results show a significant difference between the values of solar reflectance and suggest supporting the application of high albedo coatings for substantial energy savings.

Sarada Kuravi