With support from the USDOE’s Building America program, researchers evaluated eight homes built to ENERGY STAR Homes Northwest™ standards; four each in marine and cold climates. The location of the ductwork varied (inside versus outside conditioned space) as did the floor insulation strategy (floor cavity insulation versus perimeter insulated crawlspace.) Using field testing data as inputs, three energy simulation software models were used to evaluate energy use. The research design compares simulation models based on foundation type, duct location and duct insulation levels. Energy use for an ENERGY STAR Homes Northwest home was also compared to a base case Washington Code home. Utility savings, builder pricing and simple consumer affordability issues are presented.

The research may help ASHRAE, builders, code officials, homebuyers, and building-science and energy-policy stakeholders who are working with new energy efficient single-family residential construction. 

 Presented at Thermal Performance of Exterior Envelopes of Whole Buildings X – December 2007

Units: I-P