Draft Environmental Impact Statement on New Energy-Efficient Homes Programs: Assessing Indoor Air Quality Options: Volume 1

摘要

BPA has underway marketing and incentive programs to encourage the construction of new energy-efficient homes that comply with Model Conservation Standards (MCS) developed by the Northwest Power Planning Council. These homes are designed to have lower infiltration rates than current building practices provide, which is likely to contribute to increased levels of indoor air pollutants, and may adversely affect the health of occupants. BPA's current and past new homes programs maintained ventilation rates comparable to those found in current practice homes by requiring balanced mechanical ventilation. BPA now proposes to give builders and consumers more flexibility by increasing the options for protecting indoor air quality in its new homes programs. This proposal is the impetus for this Environmental Impact Statement (EIS), which was prepared for BPA by Pacific Northwest Laboratory. BPA is preparing this EIS to assess whether techniques such as dehumidifiers and air cleaners, pollutant source control, and mechanical ventilation with various control options maintain indoor air quality comparable to that found in homes built using current practices. Although many pollutants are potentially of great concern, our analysis concentrates on radon and formaldehyde. It is based on measured concentrations of these pollutants and measured ventilation rates, in both current practice and energy-efficient homes. Ventilation was measured using fan pressurization tests, which measure only air leakage, and perfluorocarbon tracer gas (PFT) tests, which account for ventilation from mechanical devices and occupant behavior in addition to air leakage. We used these data to estimate pollutant concentrations and lifetime cancer rates under four alternative actions. Under all of the alternatives, radon had a much greater effect than formaldehyde. (ERA citation 12:023466)