How about on the sides of my brick house, which also get very hot in
the summer? If it's clear, then the beautiful brickwork should still
show through... or is that hoping for too much?
How rooftop color helps or hurts energy efficiency changes with the weather.
White roofs bounce sunbeams from buildings and reduce air-conditioning needs in the summer. In colder weather, black roofs absorb more of the sun’s heat, helping to keep tenants cozy in the winter. Conversely, black rooftops on hot days may have you cranking up the A/C.
In locales that experience all the seasons, both dark or white tops have drawbacks when it comes to heating and electric bills.
Enter the fast-food smart roof.
United Environment & Energy scientists have developed a roof coating that can switch from transmitting to reflecting heat by controlling infrared light levels.
When applied to asphalt shingles, the coating decreased rooftop temperatures in warm weather between 50 and 80 percent. In cooler conditions, the coating raised roof temps up to 80 percent.
The researchers convert cooking oil into a liquid polymer. After application, the liquid hardens into a plastic. Altering the polymer’s composition fine tunes the coating for flipping the reflect-transmit switch at specific temperature points, possibly to coincide with regional climes. Further, the plastic can range in color from clear to black, for a custom-designed outer decor.
Lead researcher Ben Wen, who is also the company’s vice president, says in a statement:
It will help save fuel and electricity and reduce emissions of volatile organic compounds from petroleum-based roofing products. In addition, it will provide a new use for millions of gallons of waste oil after it is used to cook french fries and chicken nuggets.
Presented at the American Chemical Society meeting last month, the roof coat might be available commercially in about three years.
In the meantime—just in case you were thinking of it—Wen warns not to pour raw cooking oil on your roof. It won’t work, it’s smelly and it’s a fire hazard.
Images: Ben Wen, Ph.D.
Via: CNet
