It’s long been known that a white roof makes a building cooler. Studies have shown that a white roof’s net energy savings is around 20%, and for homes in the United States alone that equals more than $1 billion dollars savings a year on air conditioning costs.
Now, research from the Lawrence Berkeley National Laboratory in California has revealed what effect millions of white rooftops could have on the environment. A 1,000 square foot area of rooftop painted white or covered in white roofing material has about the same one-time environmental impact as cutting 10 tons of carbon dioxide emissions. Impressive!
So with that in mind, if the estimated 360,000 square miles of urban rooftops and pavement we have covering the planet were white or light colored, that would result in a one-time reduction of 44 billion tons of carbon dioxide (CO2) entering the atmosphere. Or it would be about the same as taking all the earth’s automobiles off the road for 11 years. Now that’s really impressive!
This spring Energy Secretary Steven Chu took part in the climate change symposium in London and said that the U.S. administration is ready to do some global whitewashing and would like to make every roof an energy-reflecting white. A Nobel laureate in physics, Chu says this simple idea is “completely benign” and yet it will help to keep buildings cooler and reduce energy use from air conditioning while it reflects sunlight back away from Earth — something that can have benefits individually, locally, and globally.
Michael Sasse, owner of Commonwealth Roofing Corporation, tells us that the cost of going with a “cool roof” usually isn’t much more (if any) than a typical darker roof. Asphalt shingles with a white or light tint are roughly the same cost as other shades. And for covering flat commercial roofs, Michael is a big fan of the white PVC roof system by Duro-Last®. “We’ve represented Duro-Last® for years and they have an excellent environmental reputation. It is an Energy Star product that will reduce the electricity load for air-conditioning and is one of the most effective products tested by the EPA.”
Michael reports that buildings covered in Duro-Last Cool Zone® roofing have seen up to a 40% reduction in energy consumption. That has obvious benefits for the individual building owner, but by reflecting solar gain away from the building, it also helps reduce the local “heat island” effect. This is the phenomenon where temperatures can be several degrees higher in urban areas because of so much heat-absorbing dark roof material and road pavement.
Finally, besides the direct global benefit of reducing buildings’ cooling costs, an efficient system like Duro-Last® compounds this global benefit with reduced energy consumption in its manufacturing process, transportation burden, and installation costs. A longer service life than competitive dark roofs means the roof will need to be replaced less often, plus, when it does come to the end of its useful life, it’s recyclable.
So is it time to start thinking about making our roofs white? According to our Secretary of Energy, yes! Chu says we need a “new revolution” in energy generation to cut fuel consumption and emissions. And Michael Sasse adds, “Many ‘Green’ ideas come with substantial costs or changes of lifestyle. With roofing’s ‘White = Green’ principles, though, doing the right thing really comes quite easily and can be a lot less expensive.”
For more information contact Michael Sasse, (502) 459-2216
Commonwealth Roofing Corp.
