By Dr. Lisa M. Gartland Cool roof coatings offer managers expanded opportunities for both energy savings and better performance. They reflect much of the sun's energy, allowing the roof surface to stay cooler and transfer less heat to the building. Demonstration projects have shown the coatings can save an estimated 20-70 percent of a building's cooling energy.
Coatings can save money, increase comfort and help reduce air pollution and reroofing needs.
But there are technical and industrial challenges in the way of widespread adoption of coatings as a roofing standard. For more on coatings standards and research, see sidebar below. Cool roofing properties Roofing materials have two properties that help them stay cool in the sun. The first is solar reflectivity, sometimes called albedo, which indicates how much light and heat from the sun bounces off their surface. The coolest materials have reflectivities of 50 percent or higher, which means they only absorb 50 percent of the sun's energy.