Save Energy with a White Roof
A fascinating study reveals that white roofs could save 10 tons of carbon dioxide emissions. Hashem Akbari, a researcher at the Lawrence Berkeley National Labratory in California has conducted a study on whites roofs and their beneficial energy savings that is soon to be published in the journal "Climatic Change."
In an article "How white roofs shine bright green" dated October 2, 2008, The Christian Science Monitor reports on the study. Further details are found on one of their staff blogs, "bright green blog."
The concept in my mind is very simple--white roofs reflect heat, reducing the energy required to power air conditioners. In addition, as light is converted to radiant heat with a darker-colored roof, it is reflected back into the atmosphere increasing atmospheric temperatures, or global warming.
The Christian Science Monitor article indicates that the difference in temperature between air and a black-painted roof is almost 90 degrees, while the difference for a white-painted (titanium oxide) roof is nearly 0 degrees.
In places like Southern California, Florida and other southern-rim states, this make a lot of sense. And utilities apparently know it, as some offer rebates for the installation of white tiles. California has since 2005, required all flat roofs to be painted white. And in July 2009, California will require sloping roofs to be light-colored, if not white.
published: 16 Feb 2009
