U.S. Department of Energy - Energy Efficiency and Renewable Energy
Building Technologies Office
Pollution Impact on Cool Roof Efficacy Research Project
The Department of Energy (DOE) is currently determining how pollution impacts the efficacy of cool roofs. The project specifically is focusing on the efficacy of white roofs in Northern India. The first phase of the project will take physical measurements to characterize the cooling and climate effects of white roofs. Results from this project will provide important guidance to policymakers and planners as they decide where cool roofs would have the greatest benefits.
The project involves the development of advanced surfaces and next-generation materials to improve solar reflectance of roofs; the ability to reflect the visible, infrared and ultraviolet wavelengths of the sun; reducing heat transfer to a building; reducing cooling costs; and saving energy. Material degradation will be simulated in order to understand, evaluate, and improve stay-clean coating prototypes.
This project is being undertaken between the Department of Energy, the Lawrence Berkeley National Laboratory, Dow Chemical, Owens Corning, and CertainTeed.
The goal of this project is to create American Society for Testing and Materials and International Organization for Standardization standards for rapid and calibrated accelerated aging of roofing materials.
Once standards are set, the DOE and its partners will collaborate with industry on several next generation material cooperative research and development agreements (CRADAs), with the aim of developing cool roofing products with superior solar reflectance. CRADA A would develop white elastomeric coatings that stay clean, CRADA B would focus on the development of low cost factory-produced cool asphalt shingles, and CRADA C would develop cool retrofit coatings for asphalt shingle roofs.
Benefits and Impacts
Retrofitting 80% of U.S. air-conditioned commercial buildings with conventional white roofs is estimated to annually save $735 million and 6.2 metric tons of carbon dioxide through energy conservation. Roughly 80% of the U.S. residential roofing market uses dark, hot asphalt shingles; upgrading these roofs would yield $14 billion in lifetime energy savings.