How to Choose an Air Purifier
When looking for an air purifier, you want to make a few considerations. First, what are you trying to filter? Is it just pet hair and dust or do you want to be covered against outdoor air pollutants? What about VOCs and fumes from the garage? Mold and pathogens? Do you need whole-house or just a few rooms?
HEPA is a great place to start. HEPA filters remove 99.97% of particles ≥0.3 microns. That means even fine particulate matter from outdoor pollution is removed. However HEPA alone won’t clean odors, VOCs, and gases. So a three-stage setup is best. A three-stage filter includes a pre-filter (for hair and dust), a (true) HEPA filter, and then a (preferably thick) layer of activated carbon. Indoor air can contain a mix of particles and gases from sources like cooking, cleaning products, fragrances, building materials, and outdoor pollution, which is why both particulate filtration (HEPA) and gas adsorption (activated carbon) are important when choosing an air purifier.
CADR is another thing to consider. CADR is the Clean Air Delivery Rate. The higher the CADR, the more air it’s going to clean. You want your air purifier CADR to be at minimum two-thirds of your square footage of the room. So if your room’s 300 square feet, you want a CADR of 200 for the purifier in that room. You also want to consider the ACH rate – how many times per hour the purifier will circulate the air through its system. Making sure your CADR is at least two-thirds of your room area will circulate the air 4-5 per hour, which keeps it nice and clean under most circumstances.
Now, you also want to make sure that the purifier is actually doing what it claims to do. So you want to look for AHAM certification (AHAM Verifide). AHAM Verifide certification ensures that the air purifier has the CADR that it claims to have. That way you can be sure that you’re getting what you pay for.
Finally, one consideration is ozone. You want a purifier that doesn’t put out a lot of ozone (O3), preferably none. Then there are other more personal considerations: budget, warranties, style, noise, cost of filter replacements, etc. Energy Star certification will ensure you’re getting the most filtration for your energy bill.
Here are some of the best air purifiers that we could find. But keep in mind, any air purification is better than none! You’ll find a lot of humble brands on our guide here but some of the fancier options we see promoted in the wellness world may be absent. Scroll down for a link where we discuss all of the brands we reviewed and why some didn’t make it on our guide. The good news is, you don’t have to spend thousands of dollars to get a decent unit.
Note: most air purifiers will bear a Prop 65 warning due to chemicals in the motherboard, packaging, or cord, and don’t pose a risk unless the unit is on fire or something.
Our Vetting Criteria
Published CADR and/or AHAM Verifide certification
Our Picks
Medify Air $69.99 – $3,999 depending on size
15% off CODE: NBN15
Info:
Three-stage filter with a pre-filter, HEPA filter, and a thick activated carbon layer. Check individual listings for CADR.
Certifications:
All units AHAM Verifide
Ozone:
Company claims Medify purifiers with ionizers are tested and verified zero ozone.
Windmill Air $349
Info:
Three-stage filtration with pre-filter, HEPA, and activated charcoal.
CFM (Airflow): 111 CFM on Whisper to 388 CFM on Boost
CADR (CFM): Smoke (286), Dust (284), Pollen (343), PM2.5 (260)
Rated Room Size (Sq. Ft.): 442
Certifications:
ETL
Energy Star
AHAM Verifide
Blue Air$84.99 – $699.99
Info:
Three-stage filtration with pre-filter, HEPA, and activated charcoal
CADR varies on model, refer to listings to choose the right one for your space
Certifications:
AHAM Verifide
CARB certified
EnergyStar rated
Levoit $49.99 – $449.99
Info:
Three stage filtration with pre-filter, HEPA, and activated charcoal
CADR varies on model, refer to listings to choose the right options for your space
Certifications:
AHAM Verifide
IKEA Air Purifiers $59.99 – $284
Info:
Three stage filtration (pre-filter, HEPA, activated charcoal)
Best suited for small spaces
This one is adorable!
Certifications:
AHAM Verifide
Bionaire $64 – $139 (on Amazon here)
Info:
CADR varies from model to model
Three to six stage filtration options depending on model
Certifications:
AHAM Verifide
NOTE: Some models with UV filtration may generate small amounts of ozone (below 50 ppb) sensitive individuals may want to avoid the options with the UV as part of the filtration.
Honeywell $69.95 – $319
Info:
CADR varies from model to model
Three-stage filtration
Certifications:
AHAM Verifide
Bosch (can purchase at Lowe’s)
Info:
CADR varies from model to model
Four-stage filtration (pre-filter, HEPA, charcoal, antibacterial layer)
Details vary from model to model.
Certifications:
AHAM Verifide
EnergyStar
Note: Use CADR ratings to figure out room size, not the published “covers X square feet,” as these are often overstated. Take CADR value and multiply by 1.5 to calculate recommended square footage coverage.
Non-Certified Options
Austin Air $345 – $1,145
Austin air does not have AHAM Verifide certification so there’s no proof or verification behind their claims. (Ie, might not cover the square footage as marketed.) However their filter design is so robust that I opted to include it in a “non-certified” category. They have a 4-stage filter system with up to 15 lbs of activated carbon. Having a THICK activated carbon/zeolite stage really helps to remove VOCs and other smaller particles and gasses that a standard three-phase system can.
Alorair Commercial Air Scrubber $399 – $499 (can find deals if you watch Amazon)
If you have a lot of square footage that you want cleaned FAST, this is the most cost-effective solution. This is more powerful than any of the air purifiers above. It’s a commercial-grade unit used in mold remediation, flood remediation, and during construction. I personally (hi this is Stephanie) bought one for our production department to protect our production area from possible air pollution or accidental smoke on the heating elements. I also got one for my house. My boyfriend’s always either tinkering in the garage or working with art supplies and that means lots of VOCs and other stuff in our home’s air. I’ve had a Dyson air purifier and a couple others and they can’t seem to keep up with cleaning the air. Nothing compares to this commercial scrubber. It’s loud, it’s not pretty, it’s very basic but it clears all the fumes and smells fast. AHAM Verifide doesn’t apply to commercial units, only residential so this doesn’t have this certification. But it has three-stage filtration with a MERV-10 pre-filter, HEPA, and activated charcoal. CADR value is 550, so it would clear 800+ square feet in 15 minutes. I’m sure it will come in handy during wildfire season.
Don’t See your Favorite Brand?
Here’s a writeup of the air purifiers that we looked out and why they didn’t make the cut. Like we said, any air filtration is usually a good thing, so don’t be dismayed if yours didn’t make the list. Most of your favorites are still good. We only included options with AHAM Verifide certification (other than the last two). We wanted the options on our guide to be able to prove what they say they do! (It’s kind of like saying a product’s organic without organic certification – we want the proof!)