RESULTS OF RECENT WEATHERIZATION RETROFIT PROJECTS

Pacific Gas and Electric (PG and E) and the Bonneville Power Administration (BPA) have conducted studies in their respective service areas in order to evaluate the cost-effectiveness of certain conservation retrofits. Twenty houses in Walnut Creek, California, underwent an infiltration reduction program, similar to house doctoring. Ten of these houses also received additional contractor-installed measures. BPA retrofitted 18 houses at its Midway substation in central Washington. Retrofits made to the houses included: attic and crawlspace insulation, foundation sill caulking, storm windows and doors, increased attic ventilation, and infiltration reduction. Energy consumption and weather data were monitored before and after each set of retrofits in both projects. Leakage measurements were made by researchers from the Energy Efficient Buildings Program using blower door fan pressurization, thereby allowing calculation of heating season infiltration rates. An energy use model correlating energy consumption with outside temperature was developed in order to determine improvements to the thermal conductance of the building envelope as a result of the retrofits. Energy savings were calculated based on the results of the energy use model. As a check on these findings, the Computerized Instrumented Residential Audit (CIRA) load calculation program developed at Lawrence Berkeley Laboratory provided a theoretical estimate ofmore » the savings resulting from the retrofits. At Midway, storm windows and doors were found to save the most energy. Because the Midway houses were not very leaky at the beginning of the experiment, the infiltration reduction procedures were less effective than expected. In the Walnut Creek project, the infiltration reduction procedures did decrease the leakiness of the test houses, but the effect upon energy savings was not great.« less