AIVC Contributed Reports

Ventilation Behavior and Household Characteristics in New California Houses

1.3 MB

P.N. Price and M.H. Sherman (Ernest Orlando Lawrence Berkeley National Laboratory)
AIVC Contributed Report 10, 2008, 144 pp

A survey was conducted to determine occupant use of windows and mechanical ventilation devices; barriers that inhibit their use; satisfaction with indoor air quality (IAQ); and the relationship between 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.

Results:
- Many houses are under-ventilated: depending on season, only 10-50% of houses meet the standard recommendation of 0.35 air changes per hour.
- Local exhaust fans are under-utilized. For instance, about 30% of households rarely or never use their bathroom fan.
- More than 95% of households report that indoor air quality is “very” or “somewhat” acceptable,” although about 1/3 of households also report dustiness, dry air, or stagnant or humid air.
- Except households where people cook several hours per week, there is no evidence that households with significant indoor pollutant sources get more ventilation.
- Except 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.

Key words: Indoor Air Quality, IAQ, mechanical ventilation systems, ventilation standards, indoor pollutants, asthma, windows, natural ventilation, thermal comfort.