Next Generation Roofs and Attics for Homes
- ORNL
Prototype residential roof and attic assemblies were constructed and field tested in a mixed-humid U.S. climate. Summer field data showed that at peak day irradiance the heat transfer penetrating the roof deck dropped almost 90% compared with heat transfer for a conventional roof and attic assembly. The prototype assemblies use a combination of strategies: infrared reflective cool roofs, radiant barriers, above-sheathing ventilation, low-emittance surfaces, insulation, and thermal mass to reduce the attic air temperature and thus the heat transfer into the home. The prototype assemblies exhibited attic air temperatures that did not exceed the peak day outdoor air temperature. Field results were benchmarked against an attic computer tool and simulations made for the densely populated, hot and dry southeastern and central-basin regions of California. New construction in the central basin could realize a 12% drop in ceiling and air-conditioning annual load compared with a code-compliant roof and attic having solar reflectance of 0.25 and thermal emittance of 0.75. In the hot, dry southeastern region of California, the combined ceiling and duct annual load drops by 23% of that computed for a code-compliant roof and attic assembly. Eliminating air leakage from ducts placed in unconditioned attics yielded savings comparable to the best simulated roof and attic systems. Retrofitting an infrared reflective clay tile roof with 1 -in (0.032-m) of EPS foam above the sheathing and improving existing ductwork by reducing air leakage and wrapping ducts with insulation can yield annual savings of about $200 compared with energy costs for pre-1980 construction.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Building Technologies Research and Integration Center (BTRIC)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 978803
- Resource Relation:
- Conference: ACEEE Summer Conference, Pacific Grove, CA, USA, 20080817, 20080822
- Country of Publication:
- United States
- Language:
- English
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