Using energy audits to investigate the impacts of common air-conditioning design and installation issues on peak power demand and energy consumption in Austin, Texas

This study presents an analysis of a unique dataset of 4971 energy audits performed on homes in Austin, Texas in 2009-2010. We quantify the prevalence of typical air-conditioner design and installation issues such as low efficiency, oversizing, duct leakage, and low measured capacity. and estimate the impacts that resolving these issues would have on peak power demand and cooling energy consumption. We estimate that air-conditioner use in single-family residences currently accounts for 17-18% of peak demand in Austin, and we found that improving equipment efficiency alone could save up to 205 MW, or 8%, of peak demand. We estimate that 31% of systems in this study were oversized, leading to up to 41 MW of excess peak demand. Replacing oversized systems with correctly sized higher efficiency units has the potential for further savings of up to 81 MW. We estimate that the mean system could achieve 18% and 20% in cooling energy savings by sealing duct leaks and servicing their air-conditioning units to achieve 100% of nominal capacity, respectively. Although this analysis is limited to the City of Austin, understanding the methods described herein could allow electric utilities in similar climates to make better-informed decisions when considering efficiency improvement programs. (C) 2011 Elsevier B.V. All rights reserved.