Northwest wall moisture study: A field study of excess moisture in walls and moisture problems and damage in new Northwest homes.

摘要

The Pacific Northwest Electric Power Planning and Conservation Act, signed into law December 5, 1980, mandated regionwide energy conservation practices. Under the act, the Bonneville Power Administration (BPA) is required to identify and implement cost- effective electric energy options and programs for the Pacific Northwest. The Residential Technology Section in the Division of Resource Management supports current residential energy conservation programs and designs and conducts various research and development projects, of which this project is one. Concern has been expressed about whether the higher levels of wall insulation in new, energy-efficient homes causes unacceptably high levels of moisture or moisture damage within walls. This study was conducted in three phases. In the first phase, a pool of homes built to the Model Conservation Standards (MCS) were identified in the fall of 1986. Letters explaining the project were sent to 257 homeowners. The owners of 124 homes agreed to participate. Each of the 124 houses was inspected and the occupants were interviewed. An effort was made to select houses likely to have the worst moisture problems. Wall cavities of 86 selected homes were opened during the winter of 1987 since the potential for moisture condensation is greatest in the winter. In the second phase, 28 homes with very wet walls in the first phase were reopened during the summer of 1988 to check for drying. In the third phase, the 16 homes that still had wet walls in the summer of 1988 were reopened again in the winter of 1989. Moisture mitigation measures were installed in these homes and they were reopened again in the spring. Field data was collected during each phase and analyzed to produce this report. 18 refs., 1 fig., 14 tabs.