Guidelines for improving the energy efficiency of roofs and attics are documented fromresearch conducted for the Department of Energy (DOE) Building Technologies Office. The results of combined analytical and experimental studies were used to benchmark computer tools, which in turn, were used to simulate homes in hot and cold climates. Simulations of adding floor and roof insulation, above-deck ventilation, radiant barriers, cool-color shingles, and metal or tile roofs; sealing the attic floor and the duct system; and making the attic a semi-conditioned space (sealed attic) were performed to compute the cost of energy savings. Results are prioritized to help building owners make an informed economic decision when contemplating roof and attic retrofits. Sealing the attic floor is a top retrofit option. The approach of making the attic a semi-conditioned space (sealed attic) and exploiting a newprototype roof assembly — an insulated and ventilated roof — are good options for retrofit work but have paybacks ranging from 15 to 25 years. A new sealed attic concept is proposed, and computations show its simple payback is about 10 to 12 years in hot and cold climates; its first cost is significantly reduced from that of a spray foam approach. For new construction the best option is to keep the ducts out of the attic, make sure the attic floor is sealed to limit whole-house air leakage, and add at least the code level of insulation to the ceiling.
Presented at Thermal Performance of Exterior Envelopes of Whole Buildings XII, December 2013
Citation: Thermal Performance of Exterior Envelopes of Whole Buildings XII
Product Details
- Published:
- 2013
- Number of Pages:
- 13
- File Size:
- 1 file , 3.3 MB
- Product Code(s):
- D-BldConf13-44
