When choosing an air purifier, the most important factor to consider is the type of filter. Prices range from around $30 for small, basic purifiers to $800 or more for models that purify large spaces and come with all the bells and whistles. You’ll also need to factor in the cost of replacement filters as you’ll need to regularly switch them out to keep your air purifier in top performance.
Compare, type, cost and features when finding the right purifier for you.
Data obtained August 2020. Prices are subject to change and should be used only as a general guide.
What is an air purifier?
Air purifiers use filters to remove common pollutants and allergens from the air. People with allergies and asthma most commonly use air purifiers to help reduce the number of irritants in the air.
What can an air purifier do?
Remove allergens, including pollen and dust
Help those with asthma breathe more clearly by removing irritants
Get rid of odor and contaminants from smoke
Decrease allergic reactions to pet dander and fur
Types of air purifiers
Air purifiers can come with several types of filters, and some models include multiple filter types. Not all filters are created equal.
PECO filters. Photoelectrochemical oxidation (PECO) filters are some of the latest air purifying options. These filters can remove and even destroy some harmful compounds that other filters can’t trap.
HEPA filters. High-Efficiency Particulate Arresting (HEPA) filters are considered to be one of the most effective filters at targeting common allergens. HEPA filters remove at least 99.95% of allergens and pollutants.
Activated carbon filters. These filters use activated charcoal to clear smoke, chemicals and odors from the air. However, they don’t filter allergens and bacteria and need to be replaced frequently.
Ozone filters. These filters can help remove odors, including the smell of smoke, but they don’t remove allergens or pollutants.
Ionic filters. Ionic filters use an electrical field to remove pollutants from large areas. While they are somewhat effective, they produce ozone — another type of pollutant — and release it into the air.
Ultraviolet (UV) filters. UV filters can kill bacteria. However, for it to work, most bacteria need to be exposed for an extended period of time – much longer than most purifiers allow.
True HEPA filters vs. HEPA-Type filters
A True HEPA filter adheres to the standards set by the US Department of Energy (DOE), while HEPA-Type or HEPA-Like filters don’t necessarily conform to any set of standards. These are marketing terms that don’t guarantee specific filtration capacity.
True HEPA filters should remove 99.97 percent of all airborne particles that are 0.3 microns in size, according to the DOE. When shopping for an air purifier with a HEPA filter, make sure it is a True HEPA filter, rather than HEPA-Type or HEPA-Like, to ensure its effectiveness at cleaning the air around you.
How to compare air purifiers
When choosing an air purifier, consider the following factors:
If the purifier is too large for your room, it uses more energy than it needs. If it’s too small, the purifier is ineffective. Look for a model that matches the footprint of the rooms you want to use it in. If you have a large, open space, you might need to get multiple purifiers and place them in opposite ends of the room.
An air purifier that can automatically check the air quality of the room and adjust settings accordingly allow you to set it and forget it. Otherwise, you’ll have to manually adjust the settings throughout the day.
Some air purifiers sound like a loud tower or pedestal fan, while others have a quiet hum similar to a refrigerator. To be the most effective, the air purifier should run all day, so look for a model that’s quiet enough to be on in the background throughout the day and night.
Most models require you to replace the filters regularly — although some UV and ionic models don’t have any filters at all. Activated carbon filters need to be replaced more often than other filter types, typically around once every three months.
Filter prices can range from around $10 to $100 or more. Consider buying replacement filters when you buy the purifier to avoid additional shipping costs.
Filter replacement indicator
Some models include an indicator or light that tells you when you need to replace your filter and can help you avoid using your air purifier while it’s not working.
If you plan to keep the air purifier in your bedroom, look for a model with a sleep setting that shuts off or dims lights and maintains a quiet fan setting while you sleep.
A sensor light can tell you what the air quality is as soon as you enter a room.
Antimicrobial agents can stop mold from growing within the air purifier and extend the life of the filters.
Look for a purifier with multiple, adjustable fan speeds to save energy and avoid unnecessary noise.
Three tips for air purifier maintenance
Check out our top tips to get the most out of your air purifier:
Replace the filters regularly. While replacement filters add significantly to the lifetime cost of the air purifier, a purifier without working filters is effectively useless. Make sure to replace the filters at the recommended times, which is between three to twelve months for most filter types.
Consider where to put it. If you work from home or spend most of your time at home, a purifier in your office or living space can make a lot of difference. If you’re out of the house a lot, a unit in your bedroom will have a more significant impact. It might be convenient to move the purifier from room to room, so look for one that’s light enough to carry. Alternatively, consider getting units for each room.
Keep it running. To be the most effective, the purifier should be running as much as possible – with all windows and doors closed.
How did we choose these products?
We specifically chose products in a wide price range and with various types of filters. To narrow our search, we conducted our own research to determine some of the most popular models, factoring in third-party reviews and our personal experiences with some of these products.
An air purifier could be a sensible buy if you’re looking to reduce the amount of dust, dander, mold and other allergens and potentially harmful particles from an indoor space. Just be sure that the size of the air purifier you choose is a good fit for the size of the room it’ll be in.
Sarah Brandon is an editor at Finder. She has a degree in Psychology from New York University and loves learning about why people do what they do. Sarah has researched and written about a wide range of topics, from pool fences to private jets to personal loans. But no matter the subject, her number one priority is figuring out what information our readers need to make the best decisions.
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