White roofs reduce surface temperatures more than 40 degrees compared to black roofs, study finds

Retrofitting a black roof surface to white reduced peak rooftop temperature in New York City by 43 degrees Fahrenheit, on average, during the summer of 2011, according to a new study published online at Environmental Research Letters. The study was the first long-term effort in New York to test how specific white roof materials held up and performed over several years.
March 21, 2012
2 min read

Retrofitting a black roof surface to white reduced peak rooftop temperature in New York City by 43 degrees Fahrenheit, on average, during the summer of 2011, according to a new study published online at Environmental Research Letters. The study was the first long-term effort in New York to test how specific white roof materials held up and performed over several years.

Widespread installation of white roofs, through the NYC CoolRoofs program, could reduce city temperatures while cutting down on energy usage and greenhouse gas emissions, said Stuart Gaffin, a research scientist at Columbia University. The options tested in the study included two synthetic membranes requiring professional installation and a white-paint coating that is being promoted by the city's white roof initiative.

The reflectivity and emissivity of the professionally installed white membrane coverings held up remarkably well after four years in use, the study found, while the painted surfaces were degraded after two years.

Several white roof membrane products that require professional installation are available for commercial facilities with flat roofs. Two of these options and a white-paint coating that is being promoted by the city's white roof initiative were tested in the study.

At Duro-Last, we applaud the results of the study. However, readers should be aware that there is a wide variety of choices available in cool roof materials.

Get the report at:
http://www.clickgreen.org.uk/research/data/123284-white-roof-tops-stay-far-cooler-in-the-summer,-new-study-confirms.html

About the Author

Drew Ballensky

Drew Ballensky is general manager of Duro-Last Roofing, Inc.’s central U.S. facility in Iowa and company spokesman for Duro-Last’s cool roofing, sustainability and architectural education programs. He is past-president of the Chemical Fabrics and Film Association and chairman of CFFA’s Vinyl Roofing Division. Drew earned his bachelor’s degree in industrial technology from the University of Northern Iowa and master’s degree in business administration from Florida State University. Drew has over 29 years experience in business and industry in various engineering and managerial capacities. He has worked in the U.S. and Canadian operations for a major international manufacturer of pre-engineered steel buildings, was a financial analyst with a major athletic apparel manufacturer and was an owner of a general contracting company.
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