A study to optimize the potential impact of residential building energy audits

Abstract

The Colorado College Energy Audit and Retrofit Program is a non-profit organization that teaches students the science and mechanics involved in energy audits and retrofit work through service–learning and community-based research projects. This approach represents a “win–win” scenario where the college contributes to maximize learning and minimize costs to the community. The method of identifying homes for energy audits has evolved from responding to homeowner requests to a proactive approach aimed at targeting older low-income neighborhoods and working with existing neighborhood associations. Recent work on the Mill Street Neighborhood in Colorado Springs, Colorado is presented in which a sample of homes (N = 14) received thermal audits, complete with blower door tests and Energy-10 computer modeling. The results are tabulated, analyzed, and extrapolated over the entire 145 homes in the neighborhood. The normally distributed ACH n values and the skewed distributions of R aver values and building sizes are discussed. A method of identifying unusual occupant behavior, relative to the building quality, is presented where the Home Heating Index is compared to a Building Thermal Performance Index (R aver/ACH n ). Estimates from extrapolation of the data predict that an investment of $146,500 USD in retrofit materials will yield a total annual neighborhood savings in energy, utility costs and GHG emissions of 9.1 × 106 kBtu (9.6 × 109 kJ), $64,000 USD and 555 US tons (5.0 × 105 kg), respectively, providing a simple payback time of 2.3 years. This efficient method of neighborhood energy audits provides data that could support neighborhood renewal grant proposals to purchase materials for follow-up retrofits and supports municipal demand-side management programs.