The best air purifiers use high-efficiency particulate air (HEPA) filters.
Clinical studies suggest that a well-maintained air purifier using HEPA filtration can alleviate the symptoms of asthma and allergies. However, these same studies caution that: "Dirty filters themselves can become a source for air contamination." In other words, air purifiers are only effective if they are properly maintained.
Do Air Purifiers Filter Smoke?
There is mixed data on whether an air purifier is effective at filtering smoke. Some studies say that the fine particulates in smoke (linked with cancer) can be filtered. Other studies say that filtering doesn't work. Those who are exposed to wildfire smoke (or secondhand tobacco smoke) may benefit from an air purifier, but there is no substitute for a smoke free home.
Air Filters and Coronavirus Protection
According to the U.S. Environmental Protection Agency, “When used properly, air cleaners and HVAC filters can help reduce airborne contaminants including viruses in a building or small space. By itself, air cleaning or filtration is not enough to protect people from exposure to the virus that causes COVID-19. When used along with other best practices recommended by CDC and others, filtration can be part of a plan to protect people indoors.” Avoid electrostatic or ionic air purifiers. These ionic devices produce ozone, a respiratory irritant.
What Is a True HEPA Filter?
Beware products that are marketed as “HEPA grade”, “HEPA like” or “HEPA style.”
A true HEPA filter must have "a minimum particle removal efficiency of no less than 99.97 percent for 0.3-μm particles," according to the U.S. Department of Energy. This standard is important. HEPA filters were designed in the 1940s to protect those who were working on the Manhattan Project. Today, nuclear facilities still use HEPA filters. So do hospitals, laboratories and other clean facilities.
How Much Does a Good Air Purifier Cost?
A good air purifier (with verified, above-average reviews) costs approximately $127, according to a 12-month analysis of price trends. Those same HEPA units cost around $74 while on sale: an average discount of 42%.
Don't buy an air purifier unless you're certain that you can buy replacement filters for a reasonable price. Some Amazon customers who bought off-brand air purifiers were horrified to learn that the replacement filters they needed cost as much as the unit itself!
Lastly, don't expect a portable air purifier to clean an entire home or apartment. A review published in Current Allergy and Asthma Reports concludes that portable filters are only effective in a single room.
A Note About Plastic Smells and Burning Smells
During initial usage, some air purifiers smell like plastic (for example, models made by Philips). However, an air purifier that emits a burning smell is a potential fire hazard: Unplug it and contact the manufacturer.
Here are the best affordable True-HEPA air purifiers for the money:
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1. Holmes 4-Speed True HEPA Air Purifier
Good Value: $119 | Great Deal: $76
Check Current Price on: Amazon | Walmart
Holmes' air purifier is easy to operate and it dramatically improves air quality and circulation, according to several online customers. Many reviewers caution that this unit is loud, even at the lowest setting; others say that the front filter door would not stay closed. Some customers use this unit as a white noise machine.
2. LEVOIT LV-H126 Air Purifier with True HEPA Filter
Good Value: $56 | Great Deal: $47
Check Current Price on: Walmart
Levoit's compact air purifier runs quietly and reduces odors caused by mildew, cooking and cigarette smoke, according to several online customers. Some reviewers say that the unit makes a rattling noise.
3. Vornado CYLO 50 Air Purifier
Good Value: $100 | Great Deal: $65
Check Current Price on: Best Buy | ABT | Home Depot
This Vornado air purifier is a good choice for smokers, pet owners and allergy sufferers, according to several online customers. Some reviewers say this unit is expensive relative to its cleaning capacity (100 sq. ft.).
4. Honeywell HPA100 True HEPA Allergen Remover
Good Value: $113 | Great Deal: $84
Check Current Price on: Amazon | Best Buy | B&H
Honeywell's HEPA purifier is effective at removing allergens like dust and pet dander, according to several online customers. Many reviewers say this unit is noisy, even on low settings; others say it smells like plastic.
5. Winix 5500-2 Air Purifier with True HEPA
Good Value: $159 | Great Deal: $100
Check Current Price on: Amazon | Home Depot | Walmart
Winix's mid-sized air purifier reduces odors and improves air quality, according to several online customers. Many reviewers say the unit's LED lights can disrupt sleep; others wish that replacement filters were cheaper.
6. Germ Guardian Air Purifier With True HEPA Filter
Good Value: $104 | Great Deal: $84
Check Current Price on: Amazon | Walmart | Home Depot
This affordable air purifier is effective at reducing allergens, smoke and cooking odors, according to several online customers. Many reviewers say this unit operates loudly enough to disrupt sleep, even at its lowest setting; others were disappointed that the air intake is on the back of the unit (i.e. it can't go against a wall).
7. Coway (AP-1512HH) Mighty Air Purifier with True HEPA
Good Value: $191 | Great Deal: $88
Check Current Price on: Amazon | Walmart
Coway's AP-1512HH air purifier is beloved by most customers (and is Wirecutter's top pick for several years in a row). Some reviewers say this unit is loud on its highest setting; others say the LEDs are bright for a dark bedroom. Most customers agree that Coway's air purifier is effective and cheap to maintain.
8. Okaysou AirMax 8L 5-in-1 True HEPA Air Purifier
Good Value: $100 | Great Deal: $70
Check Current Price on: Amazon
This compact air purifier is easy to operate, runs quietly and is effective at removing smells and allergens, according to several online customers. Some reviewers wish the replacement filters were cheaper.
9. Pure Enrichment PureZone 3-in-1 True HEPA Air Purifier
Good Value: $90 | Great Deal: $64
Check Current Price on: Amazon
This air purifier is quiet, effective and easy to use, according to several online customers. Many reviewers were bothered by the bright lights on this unit (and that these lights can only be turned off at the lowest fan speed). Other customers say their unit produced a plastic smell or grew louder over time.
10. Honeywell DH-HPA060 HEPA Air Purifier
Good Value: $65 | Great Deal: $45
Check Current Price on: Amazon | Walmart
Honeywell's budget air purifier is compact, easy to assemble and it removes pollen, dust and other allergens from the air, according to several online customers. Most reviewers (even happy ones) say this air purifier runs loud and isn't ideal for a bedroom; others caution that the carbon filters must be replaced often.
11. HomeLabs True HEPA H13 Filter Air Purifier
Good Value: $78 | Great Deal: $60
Check Current Price on: Amazon | Walmart
HomeLabs' air purifier is inexpensive to maintain and it's effective at reducing allergy symptoms, according to several online customers. Some reviewers wish this unit was better at combatting smoke and pet odors; others say the fan is noisy. Many customers caution that this air purifier is only effective in small rooms.