White roofs keep cities cooler - official

ERJ staff report (DS)

New York - A long term research project shows that pale roofing materials are better than dark-coloured ones. Research published in Environmental Research Letters reports on a long term test of city buildings roofed with TPO, EPDM and asphalt comparing the effects of high- and low-albedo (reflectivity) colourings.

The project took ordinary dark coatings on New York City buildings and painted them white. After three years, the researchers found, “The EPDM membrane shows evidence of low emissivity; however this had the interesting effect of avoiding any 'winter heat penalty' for this building. The painted asphaltic surface shows high emissivity but lost about half of its initial albedo within two years of installation. Given that the acrylic approach is such an important 'do-it-yourself', low-cost, retrofit technique, and, as such, offers the most rapid technique for increasing urban albedo, further product performance research is recommended to identify conditions that optimise its long-term albedo control.”

The paper: Bright is the new black-multi-year performance of high-albedo roofs in an urban climate is authored by S R Gaffin, M Imhoff, C Rosenzweig, R Khanbilvardi, A Pasqualini, A Y Y Kong, D Grillo, A Freed, D Hillel and E Hartung and published in Environmental Research Letters Volume 7 Number 1.

This is an external link and should open in a new window. If the window does not appear, please check your pop-up blocking software. ERJ is not responsible for the content of external sites.

Abstract from Environmental Research Letters