How air purifiers work
What a portable air cleaner can and cannot do.
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Air purifier or air cleaner?
EPA says portable air cleaners are also known as air purifiers or air sanitizers. It says they are designed to filter the air in a single room or area. Central furnace or HVAC filters are designed to filter air throughout a home.
What they filter
EPA says most filters are designed to filter either particles or gases. It says many air cleaners contain two filters, one for particles and another for gases, while others have only one filter, usually for particles.
What they cannot do
EPA says portable air cleaners and HVAC filters can reduce indoor air pollution, but they cannot remove all pollutants from the air. It says no air cleaner or filter will eliminate all of the air pollutants in your home.
What comes first
EPA says the most effective ways to improve your indoor air are to reduce or remove the sources of pollutants and to ventilate with clean outdoor air. It says filtration can be an effective supplement to source control and ventilation, and that filtration does not replace the need to control pollutants and ventilate.
Do air purifiers work?
EPA says most portable air cleaners and furnace or HVAC filters can filter particles from the air, and some can filter the fine particles of greatest health concern, called PM2.5. It says the longer the air cleaner runs, the more air it filters. We do not say whether one is worth it for you.
Health effects, plainly
EPA's answer to whether air cleaners can improve health is "Possibly." It says several studies using portable HEPA air cleaners have demonstrated small improvements in cardiovascular and respiratory health, and that the improvements are typically small and not always noticeable to the individual, although they may be measureable by health professionals. We do not say any air purifier will improve your health. Talk to your doctor about any health question.
FAQ
General information only. An air purifier is not a substitute for ventilation, for removing the source of a pollutant, or for medical care. Read and follow the maker's manual. The California Air Resources Board strongly advises against the use of ozone generators in spaces occupied by people or animals. If you have asthma, allergies, or heart or lung disease, talk to your doctor. During wildfire smoke, follow local officials and be ready to evacuate. In an emergency, call 911.
Next: HEPA Filters
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