Air-to-air heat exchanger performance

Abstract

The performancesof air-to-air heat exchanger (AAHX) systems in 38 residences are evaluated using data collected as part of Bonneville Power Administration's Residential Standards Demonstration program. The primary goal of this analysis is to characterize the AAHX system use patterns and to determine the thermal performance of the installations. The results of the study showed that on average AAHX systems were operated approximately seven hours per day over the 1985/1986 heating season with a mean thermal efficiency of 52%. The lower-than-expected AAHX system utilization suggests that design ventilation rates are not being supplied and the combination of low utilization and thermal efficiency results in low annual energy recovery attributable to the AAHX system. Until the issue of low utilization is addressed, conservation planners must view the benefits of including AAHX systems with caution.