Dive summary:

• The Oak Ridge National Laboratory has released data from its testing of a new roof design – reported in Construction Dive in September – that creates a passive circulation pattern to help keep homes cooler in the summer and warmer in the winter.
• Estimates are that the design can be used in a retrofit for about $2,000 that will have a return of about $100 per year in reduced utility bills. Spraying foam to seal an attic gets a payback of roughly $462 per year but has an upfront cost of about $8,000.
• "The system improves efficiency using controls for radiation, convection and insulation, including a passive ventilation system that pulls air from the underbelly of the attic into an inclined air space above the roof," Oak Ridge Lab said.

From the article:

Oak Ridge National Laboratory released findings from field tests of a roof and attic system that aims to improve the energy efficiency of residential buildings. ...