Since 2008, California has required whole dwelling mechanical ventilation compliant with ASHRAE Standard 62.2. A field study was undertaken to measure ventilation system airflows, air pollutant concentrations, and exhaust fan use in these homes to determine if the ventilation systems are providing acceptable indoor air quality, as intended. Concentrations of fine particulate matter (PM2.5), NO2, NOX, and formaldehyde were measured inside and outside of 70 homes over one-week periods. The homes were characterized for air leakage and the air flows of all ventilation systems were measured and monitored during the study. The results show, when operating, the installed ventilation systems provided adequate flow to meet the standard and that pollutant levels were below acceptable limits, except for formaldehyde, which exceeded California’s very stringent reference exposure level, but was well below the WHO standard. Significantly, most of the systems were not operating when researchers arrived at the study homes. This raises serious issues regarding operational requirements and configuring and labeling of ventilation system controls.
Building America is supporting a similar, but greatly expanded, field study to collect data on indoor air quality (IAQ), ventilation and IAQ controls in new homes in four U.S. climate zones. Field teams are measuring ventilation equipment airflows and installing sensors to monitor exhaust fan use and indoor air quality parameters over a week-long period. Roughly half of the study homes will have ventilation systems intended to comply with ASHRAE Standard 62.2. We will present a detailed list of air pollutant and other data collection targets for this study. The data from these studies will inform builders and manufacturers, as well as industry ventilation standards and code provisions, to better protect indoor air quality and health as building infiltration is reduced to save energy.
Learn more about this Building America research from Lawrence Berkeley National Lab researchers.
Click here to learn more.