Study of Ventilation Practices and Household Characteristics in New California Homes; Final rept

摘要

A survey was conducted to determine occupant use of windows and mechanical ventilation devices; barriers that inhabit their use; occupant perception of and satisfaction with indoor air quality (IAO); and the relationships among these factors. A questionnaire was mailed to a stratified random sample of 4,972 single-family detached homes built in 2003, and 1,448 responses were received. A convenience sample of 230 houses known to have mechanical ventilation systems resulted in another 67 completed interviews. The results are: Many houses are under-ventilated: depended on the season, only 10-50 percent of houses meet the standard recommendation of 0.35 air changes per hour; Local exhaust fans are underutilized. For instance, about 30 percent of households rarely or never use their bathroom fan; More than 95 percent of households report that indoor air quality is 'very' or 'somewhat acceptable,' although about one-third of households also report dustiness, dry air, or stagnant or humid air; Except in households where people cook several hours per week, there is no evidence that households with significant indoor pollutant sources get more ventilation; Except in households containing asthmatics, there is no evidence that health issues motivate ventilation behavior; Security and energy saving are the two main reasons people close windows or keep them closed.