Posted by Big Gav
MNN has a post on the use of white painted roofs to reduce peak electricity demand and make urban areas cooler - Cool roofs: Basking in reflected glory.
The U.S. Department of Energy is encouraging the use of reflective paint and "cool roofs" to increase the energy efficiency of homes and commercial buildings. The move could reduce electric bills by 10 to 20 percent, because structures use less air conditioning when they absorb fewer of the sun's rays.
White or light-colored roofs can also cut down on what's known as the "heat island" effect that can make urban areas so dreadfully uncomfortable in the summertime. And lots of cool roofs decrease peak demand for electricity on summer afternoons, easing the strain on power plants and reducing the chances of brownouts and blackouts.
The EPA says those "islands" in cities with more than a million people can be 2 to 6 degrees warmer than surrounding areas. In the evenings, that can sometimes jump to as much as 22 degrees!
That steamy scenario adds to energy use, increases pollution and greenhouse gas emissions, and can contribute to heat-related illnesses.
Paint companies are coming up with a variety of products to help alleviate the heat.
Hyperseal products both lighten roofs and do a double dose of recycling. The primer is made from recycled rubber; the topcoat contains tiny balls of recycled glass.
"It's a great way to get rid of rubber, and it improves the quality of the paint," says Hyperseal's R.C. Autry. "It's like making paint with inner tube toughness."