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Air Purifier Buying Guide

It’s one of your most popular questions: Which air purifier (also known as a “Portable Air Cleaner”) is best for the home? Our Air Purifier Buying Guide will help you take action to solve your indoor air quality challenges, and guide you in selecting an effective appliance for your home’s needs.

STEP 1: Fight the source of your indoor air quality challenges

Air purifiers can offer a great boost to the quality of the air in your home, but for best results you’ll have to “clear the air” by tackling the cause of the problem first. Here are some of the most common indoor air quality challenges facing Ontario homes:

Although dust is found everywhere, it can be controlled, both at the source and through regular cleaning.

  • Vacuum using a central vacuum system or one with a High Efficiency Particulate Air (HEPA) filter at least once a week.
  • Where possible, replace carpeting with smooth flooring.
  • Regularly clean items with damp cloths that collect dust and dirt. Common dust collectors include: television and television stand, electronic equipment, coffee table, bookcase or shelving unit, paintings hung from the wall, lamps and lampshades, and blinds.
  • Regularly vacuum soft furniture such as sofas and cushions to remove food crumbs, pet dander and dust mites. If possible, vacuum or wash curtains.
  • One part lemon juice with two parts vegetable oil makes a safe furniture and floor polish.
  • Regularly replace furnace filters and vacuum your heating vents.

Mould can be found almost anywhere there is moisture.

  • Keep the indoor humidity level less than 50 per cent—humidity can be measured by a hygrometer (an instrument that measures humidity) available at hardware stores
  • If your basement is damp, use a dehumidifier
  • Stay indoors when mould levels are high
  • Avoid or reduce activities such as cutting grass, raking leaves, camping and working with compost
  • Use an air conditioner to filter out mould spores and to reduce dampness indoors. Replace the filter regularly.
  • Reduce clutter in your home, especially in the basement. Allowing air to move freely will reduce the chance that mould will grow.
Tobacco smoke

Do not allow smoking in your home or vehicle. The smoke from even one cigarette will eventually reach all areas of your home and can linger for a very long time.

Smoking tobacco indoors can exposure you to high levels of smoke. Exposure to smoke can:

  • Trigger asthma symptoms which can be severe
  • Increase the amount of asthma medication you need to take
  • Lead to more trips to your health-care provider, emergency department, and hospital


Wood smoke

Smoke from wood fireplaces and wood stoves contains:

  • Particulate matter
  • Sulphur oxides
  • Nitrogen oxides
  • Volatile organic compounds
  • Carbon monoxide
  • Formaldehyde
  • Benzene

If possible, replace wood stoves with other sources of heat. Wood burning appliances with advanced technology can reduce your exposure to smoke. Only burn clean, dry wood.

For more information refer to A Guide to Residential Wood Heating.

STEP 2: Consider your room’s needs

First, you’ll need to determine the appropriate size of the device relative to the size of your room.

Check the device’s “Clean Air Delivery Rate” (CADR) label, which shows the amount of air that can be cleaned in a certain room size. The CADR can range from 10 to 450, and the higher the number, the more air it can process.

STEP 3: Consider the quality of the device’s filter

Once you have removed the source of the problem and determined your room’s needs, it’s time to consider the make-or-break features of the device’s filter system. Look for:

  • A HEPA (high-efficiency particulate air) filter
  • A filtering system that includes activated charcoal, which can be particularly helpful in reducing some VOCs emitted from building materials
The hype about HEPA

HEPA is a type of mechanical air filter. It works by forcing air through a fine mesh that traps harmful particles. We recommend frequent vacuuming using a device with a HEPA filter in order to keep dust under control!

Look for an air purifier device that uses the same HEPA technology. Your weekly vacuuming will remove particles from your floor, carpet, soft furnishings and draperies. Meanwhile, your purifier device can take care of airborne particles, too!

STEP 4: Other features to consider

  • Check the level of noise when the system is operating.  Some devices have “night modes” that reduce the sound and display brightness.
  • Consider how easy it will be to change the filter. You’ll need to monitor the filter regularly and clean or replace it according to the manufacturer’s instructions. Some devices offer built in notifications that will alert you when it’s time to change the filter!
  • Do you love data? Some devices allow you to link phone apps to the device, giving you real time updates on your home’s air quality.
  • Some devices do double duty as cooling fans or heaters.
No zone for Ozone

Check that the device you’re considering does not generate ozone or ultrafine particles. Ozone generators should never be used inside a home. They intentionally produce ozone gas into the air. Ozone is a lung irritant which can cause difficulty breathing, headaches, throat irritation, and coughing. While these devices have some commercial applications, they should not be used in residential settings. The Canadian Standards Association (CSA) does not approve ozone generators for use in homes. Health Canada has received complaints from consumers having lung problems when using ozone generators.

More questions about indoor air quality?

Talk to a Certified Respiratory Educator. It’s free and confidential through our Lung Health Line: 1-888-344-LUNG (5864).  You can also email or start a livechat through lungontario.ca.