Get a cooler roof
Global warming and ozone worries are nothing new to most of us. But who knew the color of your roof could be depleting the ozone layer?
Jeff Luvall, senior research scientist at NASA, has researched the effect sunlight has on the temperatures of dark surfaces like roofs. Luvall found that on a normal, sunny day, the temperature of a light-colored shady sidewalk was 70 degrees. Inches away on a slightly darker though sunny patch of grass, the temperature was an uncomfortable 90 degrees.
We all know it's hotter in the sun than in the shade. But it's Luvall's next measurements that will shock you: The dark asphalt street next to that grassy patch was a scorching 123 degrees; that's nearly 20 degrees above the temperature that causes the human body to suffer heatstroke.
Now for the good news: the white stripes painted on that street were 10 degrees cooler than the surrounding dark asphalt. Inside your house, 10 degrees is the difference between being comfortable and turning on the air conditioning.
Naturally, houses sheltered by a dark roof are going to be hotter and require more energy to cool them. Dan Varvais of the National Coatings Corporation says that his company's light-colored roofs repel the sun's heat rather than absorb it, making homes cooler and requiring less energy used to keep them comfortable.
This cool roofing technology begins with a base of reflective materials, which are coated with polyurethane foam. An acrylic coating containing UV-blocking pigments is then sprayed on top of the foam. Much like people wearing sunscreen, these light-colored roofs provide protection from the sun's light by reflecting it away from the house.
These high-tech roofs cut down on landfill waste, too. They last longer than conventional roofs, and since the installation is much like the application of paint, it's sprayed directly onto the existing roof.
