How to Choose a Room Air Purifier

Nothing is as critical to your health, and even survival, as clean, fresh air. But as homes and office buildings are built to be increasingly airtight and energy efficient, they are also becoming more filled with indoor contaminants such as:

  • Tobacco smoke
  • Dust
  • Pet dander
  • Fumes from cleaning supplies and air fresheners
  • Off-gassing from carpets, paint, upholstery and other furnishings
  • Radon and carbon monoxide
  • Pollen, mold and airborne allergens
  • Bacteria and viruses

According to the Environmental...MORE Protection Agency (EPA), indoor air can be many times more polluted than the outdoor air, even in urban areas. As the majority of people spend far more time indoors than outside, the health risks of indoor air pollution are a serious concern. Your bedroom is particularly important, as you spend so many hours there, and bedrooms tend to be prime breeding grounds for dust mites and other allergens.

What is an Air Purifier?

Air purifiers, or air cleaners, are electronic devices that draw in room air, pull it through a system of filters that trap airborne contaminants, and then blow out fresh, clean air. When buying an air purifier, always check the rating for room size, which will be indicated on the package. Ideally, choose a unit that can handle a room slightly larger than the one where you will be using it.

Types of Filters

There are several types of air purifier available, differing in the kind of filter used to remove airborne particles. Many air purifiers combine filter types for heightened performance.

  • Activated carbon: These filters are good for removing smoke, gases or odors from the air, but do little for dust or allergens. Many air purifiers make use of activated carbon for odor control, while using another type of filter for particles. The carbon filter needs periodic replacement.
  • HEPA filters: High-efficiency particulate arresting filters can remove over 99% of the airborne particles measuring 0.3 microns or larger from the air. This means dust, pollen, mold spores, most bacteria and pet dander cannot pass through. HEPA filters are excellent for those with allergies or respiratory conditions, and are the most popular type of air purifier. While some HEPA air purifiers claim to have a “permanent” filter that only needs occasional vacuuming, in reality, it’s very difficult to vacuum the filter thoroughly enough to really get it clean. More often, HEPA filters are replaced periodically – anywhere from every few months to once a year, depending on usage.
  • Prefilter: Many air purifiers use a prefilter to catch the largest particles before they reach the main filter. A prefilter saves wear and tear on your more expensive main filter, so you will need to change it less often.
  • Electrostatic: These devices pull air through an electronic field, creating an electrical charge that traps particles on a charged metal plate. Not effective against bacteria, electrostatic devices are good for allergens, dust and some gases and odors. The collection plates require periodic cleaning, but there are no filters to replace.
  • Ionizing: Ionizers are usually used in conjunction with a filtered device. An ionizer discharges electrons into the air, which attract dust and other particles. These larger “clumps” of particulate matter are easier for the air purifier’s filter to trap. However, the particles can also fall onto nearby carpet, fabric or upholstery.  Be aware, however, that some ionizers also emit ozone, which is irritating to your lungs, and can cause asthma symptoms in those especially susceptible to respiratory symptoms. Ozone is also dangerous to pet birds or other small pets.

As buildings become more energy-efficient, electric bills go down, but discomfort due to indoor pollution goes up. Removing airborne particles, gases, allergens and other irritants from your bedroom will help you sleep better, feel better and live better.

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    Holmes Desktop Air Purifier for small rooms.
    Photo from Amazon.

    If your tiny bedroom (up to 10 –by-11 feet) requires an air purifier small enough to sit on your bedside table, check out the Holmes Desktop Purifier. Its HEPA filter gets rid of airborne particles that might stir up allergies, while its charcoal filter keeps your bedroom smelling fresh and clean. You can even choose between positioning it on its bottom or on its side for further space-saving convenience.

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    Hamilton Beach TrueAir Pet Air Purifier
    Photo from

    If you share your bedroom with furry family members, then you know that although Rover and Fluffy are good company, they can be a source of pungent pet odor. Add pet dander to the mix, and your allergies and sinus issues can flair out of control. The Hamilton Beach TrueAir Compact Pet Purifier combines a permanent HEPA filter that traps airborne allergens and particles with a zeolite filter that absorbs unpleasant smells. The TrueAir is compact enough to fit in any room, but powerful enough to...MORE handle filtration for a room up to 140 square feet.

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    GermGuard air purifier kills airborne germs.
    Photo from

    While a HEPA filter will remove most bacteria from the air, viruses are often smaller than even a HEPA filter’s capabilities. If you’re particularly concerned about illness, or have a family member with an impaired immune system living in your home, you can add a little bit of peace of mind with an air purifier that not only catches airborne germs, it kills them as well. The GermGuardian 3-in-1 Air Cleaning System has both a HEPA filter to catch airborne irritants and UV-C light technology to...MORE actually kill most bacteria, viruses and mold spores. Plus, a charcoal filter helps eliminate unpleasant smells.