How does outdoor air enter a building?
Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house. Outdoor air enters and leaves a house by:
- natural ventilation, such as through open windows and doors
- infiltration, a process by which outdoor air flows into the house through openings, joints and cracks in walls, floors and ceilings, and around windows and doors.
- mechanical means, such as through outdoor air intakes associated with the heating, ventilation and air conditioning (HVAC) system; outdoor-vented fans that intermittently remove air from a single room, such as bathrooms and kitchens
For more information see Improving Indoor Air Quality .
- Who can I contact to have the indoor air quality tested at my place of employment?
- How much ventilation do I need in my home to improve indoor air quality?
- Has EPA issued specific recommendations on how frequently carpet should be cleaned?
- What can I do to improve indoor air quality in my home?
- What can I do to protect indoor air quality if I live in an apartment?
- How do I protect indoor air quality if I am remodeling my home?