Air ionizers vs. air purifiers, which should you buy?

Heating, Cooling & Air Quality

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The difference between air ionizers and air purifiers

When you want to make the air in your home cleaner, you can opt for an air ionizer or air purifier. An air ionizer is a type of air purifier. Still, in this instance, we’ll use the term “air purifier” to refer to HEPA air purifiers and the term “air ionizer” to refer to ionic air purifiers.

Air ionizers use negatively charged ions that transfer their charges to air pollutant particles in the environment, causing them to stick together and eventually fall to the floor. They can then be vacuumed up. Air purifiers use a fan to suck air in the room into them and physical filtration to trap pollutant particles.

Air ionizers

An air ionizer is a type of air purifier that removes pollutant particles — such as dust, pollen and pet dander — from the air by releasing negatively charged ions. These ions impart their negative charge to airborne particles, causing them to stick together. 

Once enough pollutant particles have stuck together, they become too heavy to remain in the air and fall to the floor, where they’ll be picked up the next time you vacuum. Some models feature oppositely charged plates to attract these particles when they pass through the ionizer.

Air ionizers tend to be cheaper than HEPA air purifiers covering similar square footage, which is a plus if you’re on a tight budget.

What you’ll love about air ionizers

  • Air ionizers tend to have larger coverage areas than HEPA air purifiers. The most powerful ionizers can clean air in rooms up to 3,000 square feet, whereas powerful HEPA purifiers tackle just half that area.
  • Because they don’t use physical filters, you don’t have the cost or maintenance of replacing or cleaning filters. 
  • Ionizing air purifiers tend to be more affordable than their HEPA counterparts. 

What you should consider about air ionizers

  • Some air ionizers emit ozone, which is considered an air pollutant, so you might get rid of some pollutants in your air but gain others.
  • Air ionizers don’t trap particle pollutants; they just get them to drop out of the air.

Top air ionizers

Ivation 5-in-1 Air Purifier

Ivation 5-in-1 Air Purifier

This multi-purpose air ionizer uses ionic technology to purify the air and features a HEPA filter to mechanically filter out and trap tiny particles that a standard ionizer might miss. Available at Amazon

Envion Ionic Pro 500 Sq. Ft. Ionic Air Purifier

Envion Ionic Pro 500 Sq. Ft. Ionic Air Purifier

This nifty machine can clean the whole air volume in a medium to large room as many as three times in an hour. Available at Best Buy and Amazon

Plixio Portable Odor Eliminating Plug-in Ionic Air Purifier

Plixio Portable Odor Eliminating Plug-in Ionic Air Purifier

Despite the extremely compact size of this machine, which is about the size of a plug-in fragrance diffuser, it can take on spaces of up to 150 square feet. Available at Amazon

Air purifiers

Air purifiers use HEPA filtration systems to remove and trap airborne particles. HEPA filters can trap at least 99.97% of all particles down to the size of 0.3 microns. 

This includes mold spores, pollen, dust, bacteria and viruses. HEPA air purifiers are ideal for anyone who suffers from environmental allergies, such as hay fever or dust allergies. You can find some basic air purifiers for around $50, but we’d recommend paying at least $100-$200 for a quality model. Top-end HEPA air purifiers can cost more than $1,000.

What you’ll love about air purifiers

  • Air purifiers trap allergens and other pollutant particles in the air, so they won’t stick to your home surfaces or be able to re-enter the air.
  • HEPA air purifiers don’t emit ozone, unlike most air ionizers, so you don’t need to worry about them affecting your air quality.
  • You can buy air purifiers with washable filters, so there’s no need to spend money on replacement filters.

What you should consider about air purifiers

  • You’ll need to either buy new filters to replace old ones or clean the filters and replace them, depending on your chosen model.
  • Air purifiers tend to cover a smaller area compared to air ionizers.
  • HEPA air purifiers can’t remove odors or chemicals from the air unless they also incorporate an additional activated carbon filter.

Top air purifiers

Dyson Pure Cool TP01 HEPA Air Purifier & Fan

Dyson Pure Cool TP01 HEPA Air Purifier & Fan

Not only is this an effective air purifier that’s suitable for large rooms, but it also looks like a piece of modern art, so it won’t detract from the appearance of your room. Available at Home Depot, Bed Bath and Beyond and Amazon

Alen BreatheSmart FLEX HEPA Air Purifier

Alen BreatheSmart FLEX HEPA Air Purifier

This high-end HEPA air purifier runs quietly and cleans the air in spaces up to 1,100 square feet. Available at Home Depot and Amazon

Honeywell True HEPA200 Air Purifier

Honeywell True HEPA200 Air Purifier

This reliable HEPA air purifier comes from a reputable brand and is suitable for large rooms up to 310 square feet. Available at Home Depot and Amazon

Should you get an air ionizer or an air purifier?

Objectively, HEPA air purifiers do a better job of cleaning the air and trapping pollutant particles than ionic air purifiers, so we’d usually recommend an air purifier over an air ionizer, especially if you have allergies. You might, however, consider an air ionizer if you need to clean the air in a large space on a low budget.

Lauren Corona is a writer for BestReviews. BestReviews is a product review company with a singular mission: to help simplify your purchasing decisions and save you time and money.

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