SunGuard: A Roofing Tile for Natural Cooling--PowerLight Corporation, 2954 San Pablo Avenue, Berkeley, CA 94710; 510-540-0550
Mr. Thomas L. Dinwoodie, Principal Investigator
Mr. Thomas L. Dinwoodie, Business Official
DOE Grant No. DE-FG03-99ER82862
Amount: $749,899

Maintaining a cool roof deck can significantly reduce air conditioning costs in cooling-dominated climates while reducing humidity build-up and other moisture problems within the home. A preferred method of cooling roof decks is by natural convection, which should have wide market acceptance for residential applications compared with reflective or other methods. This project will develop novel residential roofing technology that accomplishes significant roof deck temperature reduction through strictly passive means. The technology integrates cool-ing load avoidance and humidity removal to reduce building cooling loads. Phase I optimized product construction and validated product performance under full-scale system testing. A system prototype was constructed for independent testing and validation at a national laboratory. The prototype reduced heat flow through the roof on a typical summer day by 90 percent. In Phase II, design enhancements will be developed and incorporated. These include a roof mounting system to facilitate installation, improved material and processing specifications to reduce fabrication costs, and enhanced convection for improved thermal performance. Critical product certifications and commercial partnerships will be obtained.

Commercial Applications and Other Benefits as described by the awardee: The passive cooling technology targets residential roofing for roof slopes of 2:12 and higher, representing 77 percent of the residential roofing market. With just 5 percent market penetration, the nation would save over 35 million barrels of oil per year, with annual environmental savings of 18.6 million tons of carbon dioxide, 80 kilotons of nitrogen oxides, and 178 kilotons of sulfur oxides.