Portable Air Cleaners
Portable high efficiency HEPA air cleaners can help an HVAC system by removing fine particulates from the air. HEPA filters with activated charcoal or alumina, especially those impregnated with potassium permanganate or zeolite will absorb gases in the smoke, including oxides of nitrogen (NOx) and some of the volatile organic compounds (VOCs) such as benzene. These filters are more expensive and need more frequent replacement.
Do not use ozone generators, personal air purifiers, or electrostatic precipitators and ionizers that produce ozone. Ozone is a respiratory irritant that can aggravate asthma and other lung diseases. Consult the California Air Resource Board Consumers' Air Cleaner Portal for more information on devices certified to avoid ozone exposures.
Proper size, installation, and maintenance are critical for portable air cleaners to be effective.
- Air cleaners should filter at least two or three times the room volume per hour.
- The package should indicate the unit's airflow rate, the room size it is suitable for, its particle removal efficiency, and perhaps its Clean Air Delivery Rate (CADR), a rating that combines efficiency and airflow.
- The Association of Home Appliance Manufacturers (AHAM) maintains a certification program for air cleaners. The AHAM seal on the box lists three CADR numbers; the higher the numbers, the faster the unit filters the air. Choose a unit with the highest number.
- Consumer reports has evaluated air cleaning devices and has produced a buying guide.
- Place the unit(s) away from doors, windows, and foot traffic; and away from walls or corners, so that air can easily reach the unit.