September 24, 2001—In a recent study, Sarnafils white, reflective EnergySmart roof membrane reduced the average summertime daily maximum roof surface temperature of a retail store in Austin, Texas from 168 F to 126F. The total air-conditioning energy use was thereby reduced by 11% and peak air-conditioning demand fell by 14%. This 100,000-square-foot building is predicted to save about $65,000 over the life of the roof.
In this study, sponsored by the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE), the Heat Island Group at the Lawrence Berkeley National Laboratory measured and analyzed summertime air-conditioning energy savings and power-demand reduction of a large retail store in Austin, Texas that was retrofitted with a reflective Sarnafil roof membrane.
It is estimated that the Sarnafil cool roof would save over 60 megawatt-hours per year; the total annual energy- and peak-demand savings are estimated at $7,200. The total discounted savings over the expected life of the roof are estimated to be $60,000 to $70,000.
The State of California is the first to offer cash rebates for companies to replace dark roofing surfaces with highly reflective surfaces, such as single-ply vinyl roof membranes. The incentives, offered through the California Energy Commission (CEC) Cool Roof Retrofit Program, apply to low-slope roofs on non-residential or multi-family buildings that are mechanically cooled in the summer. The program offers financial incentives to replace dark roofs reflecting less than 30% of sunlight with non-metallic “cool roofs” reflecting at least 65%.
Additional studies by the Florida Solar Energy Center and the U.S. Environmental Protection Agency (EPA) confirm that reflective roofs made of polyvinyl chloride (PVC or vinyl) membranes or other single-ply materials can reduce utility costs of air-conditioning by as much as 50%. And cooling demand in the peak hours—the most costly—can be reduced by 10-15%, reducing demand on the grid. According to the EPA, $40 billion is spent annually in the United States to air condition buildings—about 1/6 of all electricity generated in the United States each year.
For more information or a copy of the EPA study, contact Sarnafil or call 800/576-2358.
