Choosing a portable air purifier

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Air purifiers, also referred to as portable air cleaners, can help improve indoor air quality by removing small particles that can be a risk to your health. While air purifier filters can help capture some pollutants (particles, pollen, dust), the best way to improve indoor air is to remove the source of the pollutants and to ventilate with clean, outdoor air. Before opening windows or doors, check the Air Quality Health Index to know the outdoor air quality conditions in your region.

Follow these tips to choose the best air purifier for your home.

  • Look for a unit tested by Consumer Reports or certified by the Association of Home Appliance Manufacturers (AHAM). Check for this certification:
  • Measure the dimensions of the room where you will use your air purifier and calculate the square footage. Device ratings assume an 8-foot ceiling. If your ceilings are higher than 8 feet, you will need an air purifier rated for a larger room.
  • Look for the suggested room size and the clean air delivery rate (CADR) on the AHAM label. Choose an air purifier sized for the room in which you will use it.
    • The CADR describes how well the machine reduces tobacco smoke, dust and pollen. The higher the number, the more particles the air purifier can remove.
    • Calculate the minimum CADR required for a room: as a general guideline, the CADR of your air purifier should be equal to at least two-thirds of the room's area.
      • For example, a room with the dimensions of 10 feet by 12 feet has an area of 120 square feet. It would be best to have an air purifier with a smoke CADR of at least 80.
  • Follow manufacturer instructions for placement and operation to ensure good airflow. Generally, higher fan speeds and longer run times will increase the amount of air filtered.
  • Clean or replace filters as often as recommended by the manufacturer.
  • Avoid devices that produce ozone as ozone can impact your health. The California Air Regulatory Board (CARB) lists units that have passed testing for ozone emissions.
  • Consider selecting a unit with a lower noise rating.

More information to consider when choosing a portable air purifier

  • Many devices use high-efficiency particulate air (HEPA) filters. How well the unit works depends on both airflow and filter efficiency.
  • Some devices may also include an activated carbon or other absorbent filter. These may help to remove gases such as volatile organic compounds (VOCs).

Using an air purifier to filter wildfire smoke

Wildfire smoke can get inside your home through windows, doors, vents, air intakes and other openings. This can make your indoor air unhealthy. The fine particles in smoke can be a risk to health.

Those who are most vulnerable to the health effects of wildfire smoke will benefit the most from using an air purifier in their home. People who are at a higher risk of health problems when exposed to wildfire smoke include:

  • seniors
  • pregnant people
  • infants and young children
  • people who work outdoors
  • people involved in strenuous outdoor exercise
  • people with an existing illness or chronic health conditions, such as:
    • cancer
    • diabetes
    • mental illness
    • lung or heart conditions

You can use an air purifier in a room where you spend a lot of time. This can help decrease the fine particles from wildfire smoke in that room.

Wildfire smoke is most similar to tobacco smoke so use the tobacco smoke CADR as a guide when selecting an air purifier. For wildfire smoke, look for an air purifier with the highest tobacco smoke CADR that fits within your budget.

For more information on keeping your indoor air clean, visit

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