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Whole House Air Quality Improvement Strategies > Adequate Ventilation

Proper ventilation ensures that adequate fresh, outdoor air flows into a home, which helps to both control moisture and reduce indoor air pollutants such as particulate matter, biological contaminants, and harmful gases. Outdoor air can enter a home in three ways: infiltration, natural ventilation, and mechanical ventilation. Infiltration refers to outdoor air entering a home through openings and gaps in the building’s structure. (Movement of air out of the home in this manner is called exfiltration.) Natural ventilation refers to the movement of air in and out of a home through opened windows and doors. Mechanical ventilation systems use ducts and fans to control the flow of fresh air.

Air movement associated with infiltration and natural ventilation depends on temperature and pressure differences between the indoor and outdoor air and on the airtightness of the building structure. Uncontrolled infiltration reduces energy efficiency and increases moisture levels, which can be remediated through air sealing and moisture barriers. Natural ventilation may not be adequate in all situations, especially during windy or extreme weather.

Mechanical ventilation devices range from localized exhaust fans used in kitchens and bathrooms to whole-house ventilation systems that exhaust stale air and circulate fresh outdoor air uniformly throughout a house using fans and ducts. To learn about the different types of whole-house ventilation systems and how they work, visit this link. Consumers can consult with an HVAC (heating, ventilation, and air conditioning) contractor to determine which ventilation system would best meet their needs.

In addition to improving indoor air quality, ventilation systems combined with ceiling fans, window fans, and whole house fans can be used to cool buildings in hot weather, which saves energy and reduces cooling costs.

For more information on ventilation, visit the following links:


Whole House Air Quality Improvement Strategies > Air Cleaners

In addition to controlling the sources of pollutants and improving ventilation in a home, consumers can use air cleaning devices to remove particulate matter and harmful gases from indoor air. For whole-house air filtration, certain air cleaning devices can be installed in the ductwork of a home’s central heating, ventilation, and air conditioning system. Portable room air cleaners can clean the air in a single room or in specific areas. Refer to the U.S. Environmental Protection Agency’s Guide to Air Cleaners in the Home for detailed information on the different types of air cleaning devices and how they work.

For more information on air cleaners, visit the following links: