"A relatively new class of roof coatings has been shown to save significant amounts of cooling energy. Cool roof coatings reflect away the bulk of the sun’s energy, allowing the roof surface to stay cooler and transferring less heat to the building underneath. Demonstration projects have shown these coatings can save between 20 and 70% of the cooling energy used in a building. These coatings also have the potential to save money, reduce air pollution and reduce the need for re-roofing. There are still technical and industrial challenges in the way of the widespread adoption of these coatings as the roofing standard. This paper discusses all aspects of cool roof coatings and their implementation, from the technical to the sociological."

Numerous projects have studied the impact of cool roof systems on roof surface temperature and cooling energy use. All studies confirm that cool roof coatings reduce surface temperatures by 50-80° F and save significant amounts of cooling energy during summer months. The chart below shows results from five studies conducted in California and Florida.¹ The albedos (reflectivities) of all rooftops were raised by 40 to 60 percentage points to a "very high albedo" rating. Regardless of the amount of roof insulation, all buildings showed significant reductions of 25-67% in cooling energy usage.

1 Akbari, Bretz, Hanford, Kurn, Fishman, Taha and Bos, "Monitoring Peak Power and Cooling Energy Savings of Shade Trees and White Surfaces in the Sacramento Municipal Utility District (SMUD) Service Area: Data Analysis, Simulations and Results". Lawrence Berkeley Laboratory Report # LBL-34411, December, 1993.