Investigation of attic insulation effectiveness using actual energy consumption data

The effectiveness of attic installation was determined using actual energy consumption and weather data for 34 single family residences. For each residence, linear regression was used to determine the actual winter energy consumption rates for 2 years before and 3 years after the installation of attic insulation. Comparison of the pre- and post-installation energy consumption rates confirmed the effectiveness of attic insulation. Sufficient agreement between postinsulation predicted and actual consumption rates indicated that the insulation degradation factors has no gross effect and that estimates of heat loss through the ceiling based on the simple conductive heat loss model are adequate.