ORNL roof, attic design proves efficient in summer, winter

ORNL Roof System

A new roof system tested at Oak Ridge National Laboratory improves efficiency using controls such as a ventilation system that pulls air from the attic into an air space above the roof. (Photo courtesy of ORNL)

A new roof-and-attic system tested at the Oak Ridge National Laboratory keeps homes cool in summer and prevents heat loss in winter, a press release said.

Among the features designed to improve efficiency are a ventilation system that pulls air from the underbelly of the attic into air space above the roof, the release said.

“Heat that would have gone into the house is carried up and out,” says Bill Miller of ORNL’s Building Envelope Group. “And with a passive ventilation scheme, there are no moving parts, so it’s guaranteed to work.”

The release said the new roof system can be retrofitted with almost all roofing products.

“The heart of the design is a foiled, covered polystyrene insulation that fits over and between rafters in new construction or can be attached on top of an existing shingle roof system,” the release said. “Homeowners don’t have to remove old shingles, which saves money.”

It said attics can be retrofitted for about $2,000, and homeowners can save $100 per year. The system costs less than, and has the same payback period as, the spray foam used by many homeowners concerned about air leaking into their attics. The spray foam can cost $8,000, the release said.

It said Miller and his colleagues are working on designs with lower installation costs and greater overall cost-effectiveness.

A paper on the roofing system titled “Prototype Roof Deck Designed to Self-Regulate Deck Temperature and Reduce Heat Transfer” was published by the National Roofing Contractors Association. The authors were W. Miller, Stan Atherton, and Russell Graves of the University of Tennessee in Knoxville, and Billy Ellis of Billy Ellis Roofing.

Funding was provided by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy and Billy Ellis Roofing under a user agreement.


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  • mushroomcloud

    This is what Oak Ridge should be about and mix the info about the Manhattan bombs,,,,,,,,good job miller

  • CK

    2 words for 25 to 50% savings from your house ATTIC FOIL . It works great for less than a $1 per Sq.foot of attic space .

    • TJNoblemetals

      Go to Innovative Insulation in Texas. Buy rolls for about 20cents sq. ft.
      Get the double sided foil with Mylar strings and a small air bubble between. Can install it yourself on top of your current insulation. Pay for itself in 24 months.

  • CK

    Radiant Barrier works !

  • http://www.facebook.com/daniel.powers.336 Daniel Powers

    I have considered a radiant barrier on my existing home. Now at least have something else to compare with and see a cost/return rate comparison. Plus with energy cost going up all the time, 100 this year, might be 200 in down the road.

  • GoodIdeas

    I would like to see a better flow diagram with winter and summer flow arrows. The green convection and radiation arrows don’t seem to match the blue-to-purple airflow arrows. I don’t see which side the foil is on.

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