We recently had the roof on our house replaced/rebuilt. Since we live in the southwest (New Mexico) summer heat gain is a BIG issue. We chose a Galvalume finish metal panel (aka Pro-panel) to replace the brown asphalt shingles.
While I've always known that an asphalt shingled roof (or attic) is a hot place to be in the summer, until I did some research I had no idea how much of a heat sink they are.
The 'Autumn Brown' asphalt shingles on our roof had a Solar Reflectance of 9.6% and Infrared Emittance of 91%. The new 'Galvalume' metal roof has a Solar Reflectance of 60.9% and Infrared Emittance of 25%. While we didn't choose the most efficient metal panels available, they are Energy Star rated.
I've posted an article on our new roof with links to Cool Roof calculators and solar efficiency data on roofing materials here -
Cool Roof: Pro-Panel vs. Asphalt Shingle | EcoDaddyo.com.
What sort of roof do you have and are you looking into cool or green roofing materials?
Tim