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Allergy season is here, but air purifiers can help ease your suffering

We sort out these cleaning machines and clear the air on why you might want one in your home.


Dyson's line of air purifying fans control air pollutants in style.  

Sarah Tew/CNET

Allergy season is ramping up, and if the eye-itching, nose-running time of year is getting you down, air purifiers could be the answer. Air purifiers, sometimes referred to as air cleaners, work to keep your home's climate healthy by removing polluting particles such as dust, pollen, pet dander and even mold spores. These air cleaners are often packaged as portable units and fans. Here's how they can help you breathe easier.

Read more: 4 clear signs you have seasonal allergies

What do they do? 

Portable air purifiers and air filters remove pollutants from the air. Indoor air pollutants fall into two main categories:

  • Particulate matter: This includes biological pollutants like mold spores, dust mites, bacteria, pet dander and viruses.
  • Gaseous pollutants: Things like paints, varnishes, adhesives and pesticides. Especially dangerous gaseous pollutants are sometimes referred to as volatile organic compounds or VOCs.

Air purifiers work to filter these contaminants out of your air. Anyone sensitive to allergens or with asthmatic symptoms might benefit from an air purifier. Of course, it's hard to imagine anyone who wouldn't be better off with a cleaner atmosphere inside their home, and air purifiers can certainly play a helpful role in improving indoor air quality.


Vacuuming your home regularly is a good way to stay ahead of accumulating dust and allergens.

Colin West McDonald/CNET

An air purifier isn't a replacement for keeping your home clean and ventilating it when possible, however. The most effective way to manage pollutants in your air is to avoid introducing these airborne particles in the first place. 

Preventive measures like not smoking indoors, vacuuming regularly, allowing fresh air in on occasion and keeping solid surfaces sanitized are still the best ways to combat indoor air issues and reduce air pollution inside your home.

How do air purifiers work? 

Air purifiers remove these pollutants from the air using one of three common methods: filtration, electrostatic precipitation and ionizing. However, the EPA warns about the risk of ozone created by some electrostatic and ionizing air purifiers. Using filter-based air purifiers is widely considered healthier and more effective than ozone generators, so that's the method we'll focus on here. 

The most effective form of air filtration (and likely the one you've heard the most about) is a HEPA (high-efficiency particulate absorber) filter. Models with filters pull in your home's air and move it through the filter with a circulating fan. When the air moves through each filter, any pollutants, particles or airborne allergens are caught in the filter. The clean air is then pushed back out into your space. HEPA filters do a better job here than a standard air filters because they can catch finer particles and purify the air more thoroughly. 

Buying tips

Air purifiers range from under $100 to well over $1,000, and the major difference is typically the amount of air (how many square feet) it is able to effectively purify. Most models are designed to sit on the floor, but you can find tabletop models and even wall-mounted designs for air filtration. Read the descriptions carefully to be sure you get an air filtration system big enough to fit your room and tackle your allergies, but remember that a larger model will likely also use more energy.

Now playing: Watch this: Dyson bundles a fan, heater and air purifier into one,...

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There are a few ways to be confident you're picking a good air purifier. You might see the abbreviation and value for "CADR" on an air purifier's packaging, which stands for "clean air delivery rate." That's a measure of how quickly the air purifier can deliver clean air. The higher the CADR, the more quickly the air pollutants are removed, though some manufacturers have suggested this lab testing method isn't an accurate simulation of how air filtration would work in an average home. Dyson even came up with its own testing method, called the Polar test.

Air purifiers are also measured by the MERV scale (minimum efficiency reporting value), where the lowest rating is 1 and the highest is 20. HEPA filters rate between 17 and 20. If you're in the market for an air purifier, look for a higher score on this scale if you're looking to solve serious asthma and allergy issues.

We haven't tested air purifiers at CNET, but there are a host of well-reviewed and popular models available online. Here are a few notable options from Amazon: 

If dust, allergens, pet dander and other pollutants are taking over your home or if allergies are driving you crazy, try a good deep clean and consider air filters or air purifiers to improve the indoor air quality of those extra irritating spaces.

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