How Much Cooler Is A White Roof

While white roofs may shave electric bills in hot summer months studies suggest they increase winter heating bills.

How much cooler is a white roof.

Similarly if your roof experiences winter problems like ice dams your roof color probably isn t the primary culprit. In cooler climates think detroit or toronto the issue is less straightforward. Cool roofs can be made of a highly reflective type of paint a sheet covering or highly reflective tiles or shingles. Such a roof can be reasonably expected to be some 50 to 60 degrees cooler than a dark color asphalt shingles roof.

Switching to a white roof can actually reduce energy use by about 20 percent in hot sunny weather according to the lawrence berkeley national laboratory heat island. The benefits of a white roof. Turns out painting your roof white would be. White roofs will stay white.

False white roofs attract and retain dirt easily which quickly diminishes some of the positive aspects of the membrane. Standard or dark roofs can reach temperatures of 150 f or more in the summer sun. A cool roof under the same conditions could stay more than 50 f cooler and save energy and money by using less air conditioning. So although your building may be cooler it s not doing much to decrease global warming.

However and here is the big kicker a properly ventilated attic space let me say that again properly ventilated was a 2 degree average difference. Unless routine maintenance and power washing is completed a white roof will often dull and look. What they found was surface temprature hand to shingle was approximately 20 degrees warmer if black. Dark roofs may have a small snow melt effect but not a sizeable one.

During the maximum internal temperature increase hours of 7 00am 5 00pm a white roof is 6 97 cooler more energy efficient than a non white roof. The question is by just how much. Some scientists say white roofs can increase heating costs more than they save on a c costs. Atmosphere a white roof should act like a natural anti warming device while also reducing your energy costs by keeping your house cool in the summer.

The 50 year life cycle cost analysis found that even the most inexpensive kind of green roof with no public access and consisting of only sedum or prairie grass costs 7 per square foot more than black roofs over 50 years while white roofs save 2 per square foot compared to black roofs. The white powder actually reflects away much of the sunlight so the dark roof underneath cannot absorb heat and melt the snow.