Air purifiers with activated carbon are the best option for dealing with volatile organic compounds (VOCs), gasses and odors in a home. You generally need a lot of carbon (and other sorbent material) to make a significant dent in the problem.
This list of air purifiers looks at those with the highest amount of sorbent material – starting at 30 lbs and going down to 12 lbs.
Activated carbon is the main material used to combat VOCs, but in order to deal with formaldehyde and acetaldehyde you want to look for options that include Zeolite, Potassium Iodide, or Potassium Permanganate.
Some of the brands have smaller units down to 6.5 lbs of carbon.
What to Look for in a Good Air Purifier:
High Amount of Sorbent Material – If you want activated carbon to absorb VOCs, the number of pounds of carbon is key. Zeolite, Potassium Iodide, and Potassium Permanganate extend the range of VOCs covered.
Ideally “True HEPA” – which is 99.97% of particles done to 0.3 microns.
Around 5 ACH (air changes per hour) – The CFM will tell us how many air changes we can get in a space. You want at least 1 ACH, and up to 5 ACH for sensitive folks or highly polluted areas.
Other Comparisons – How loud they are (dB), the cost of replacing filters, and year established (so you can feel certain they will be around to replace filters and parts).
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What are Air Changes Per Hour (ACH)
Air change per hour is how many times you are “replacing” the air in the room per hour, this is a key area of comparison with air purifiers.
How Do You Calculate the ACH From a Unit’s Specs – You need the CFM to calculate ACH. CFM stands for Cubic Feet Per Minute, this is the capacity of the unit to move air – how much air it moves through the machine. I have two calculators here to properly size these units based on CFM.
What Does Activated Carbon Absorb?
Air filters with activated charcoal will remove most volatile organic compounds (VOCs) and odors. Carbon is especially effective against organic compounds as well as gasses like Chlorine (CARB, HSW).
You can use this when you have odors or new materials offgassing.
What are its limitations?
Carbon is not that great at removing formaldehyde, acetaldehyde and dichloromethane. Austin Air with Zeolite and Potassium Iodide showed better reduction in formaldehyde, acetaldehyde and dichloromethane in an independent test.
Additives such as Potassium Permanganate will remove most mercaptans (the ‘smell’ of natural gas) and other odorous gases related to gas, such as hydrogen sulfide. (CARB)
What Does HEPA Filter?
HEPA air filters can theoretically remove at least 99.97% of dust, dust mites, pollen, pet dander, mold, particulates from smoke, bacteria, some viruses, and any airborne particles with a size of 0.3 microns or larger (EPA, PudMed).
Top Brands of Air Purifiers with High Activated Carbon
1. AllerAir
Alongside Amaircare, this has the highest amount of carbon mix with a very high CFM (the highest on the list) to move air through so much carbon.
AllerAir is a very hefty home air filter with the highest amount of carbon on the market (alongside Amaircare). The Vocarb sorbent mix is the best for higher pollution levels, VOCs, chemicals (formaldehyde etc.), fumes and odors. But you can mix and match filter types inside the unit. They have over 40 blends of carbon for specific pollutants. However what’s in the mix is a trade secret so we don’t know what’s in them and that means we can’t fully evaluate its effectiveness. A UV light is optional.
This is also the highest CFM option on the list so the fan can pull through so much carbon.
Coverage: In 900 sq ft you get 5 air changes per hour running on high.In 2700 sq ft you get 1 air change per hour. Good for small, medium and large rooms.
Colors: It comes in White, Black and Tan. Special order: Pewter, Copper
Filter replacement costs: Carbon Filter 2-5 years $172; Super HEPA 2 years $131; Pre-filter 3 months $132
Cons: No change filter indicator. You need to undo screws at the bottom to change the main filters. We don’t know what’s in the carbon mixes so we can’t fully evaluate its effectiveness.
AirMedic Pro 5 HD MCS is made for people with multiple chemical sensitivities (MCS) – They burn-in the motor by running and offgassing it for 6-8 hours. It has 24lbs carbon and is dB 35-60 @1ft.
The best value for comprehensive filtration: True HEPA, 15 lbs of Carbon, plus Potassium Iodide and Zeolite for more chemical coverage of formaldehyde.
15 lbs of Activated Carbon Impregnated with Potassium Iodide and Zeolite
250 CFM
True HEPA (Removes 99.97% of all particles larger than 0.3 microns and 99% of all particles larger than 0.1 microns)
dB 50-66 3-5ft
EST early 90s
This is one of the most well trusted brands in air purifiers. The high level of sorbent material eliminates a wide range of gases, chemicals, VOC’s and formaldehyde (the Potassium Iodide + Zeolite works best on formaldehyde). This broad-spectrum adsorption makes it the best choice for people exposed to smoke from wildfires. The unit itself is all metal (apart from the wheels).
Coverage: In 400 sq ft you get 5 air changes per hour (running on high).In 2000 sq ft you get 1 air change per hour. Great for high turnover in small and medium sized rooms with still a 1 ACH in large rooms.
Colors: Black, Dark Blue, White, Tan. The Baby’s Breathe Model comes in Pink and Baby Blue (but does not have pounds of carbon).
Filter replacement: HEPA/carbon pre-filter 3-5 years $360. A more realistic life expectancy for the filters is 2 to 4 years, with the carbon likely becoming saturated before the HEPA filter. Still, the filters are protected by a 5 year pro-rated guarantee.
Cons: Not the quietest air purifier on the list. There is no concrete way to tell when the filters are actually saturated and should be changed other than when you start to smell the carbon offgassing. Both carbon and HEPA filters are attached so if one is maxed out you need to replace both.
The Healthmate is the slightly more affordable option at $715. The difference is it doesn’t have Potassium Iodide for formaldehyde reduction.
Healthmate Jr comes in regular and Plus, $415 and $465. They both have 6.5 lbs of granular carbon/zeolite and the Plus model also has the Potassium Iodide. It has 125 CFM.
This might be one of the best-known brand names in air purifiers. Lots of people swear by it even though the amount of carbon is lower than the others the additives make it efficient.
The addition of Alumina impregnated with Potassium Permanganate to the Carbon adds protection against contaminants such as hydrogen sulfide, sulfur dioxide, nitric oxide, and formaldehyde.
Coverage: In 500 sq ft you get 5 air changes per hour (running on high).In 2500 sq ft you get 1 air change per hour. Good for small, medium and large rooms.
Colors: MultiGas comes in white with blue stripe, HealthPro (pictured above) in white or wood look.
Filter replacement: Multigas cartilage 2 years $400; Post Filter 2.5 year $129; HEPA about a year (on 10 hours a day on speed 3) $109; optional Filter Pads $79. Color-coded lights indicate when a filter change is needed.
Cons: It’s large and not particularly aesthetic. The filter costs are somewhat high.
Their HealthPro Plus, $899, comes with 5 lbs of carbon, is 40 to 300 CFM and that gets you 2 air changes/hr in 1125 sq. ft, dB 25 to 59
You can buy the HealhPro and Multigas directly through the IQAir website or on Amazon
4. Amaircare
Dependable true HEPA particle filtration. This is the lowest cost option with the highest level of carbon (alongside Allerair) for medium sized rooms.
Up to 30 lbs of carbon, depending on the option you choose
265 CFM
True HEPA
dB 43 to 61 @ 6 ft
EST 1994, Made in Canada
This all metal construction is well liked by those with chemical sensitivities. It’s the lowest cost option with a very high level of carbon.
They also have the following filter options for a wider range of filtration: Formaldesorb option for formaldehyde, Acitisorb for nitric and hydrochloric acid, Multisorb for a mix of VOCs. They don’t say what is in these sorbent mixes but presumably they are adding to the carbon.
Coverage: In 400 sq ft you get 5 air changes per hour (running on high).In 2000 sq ft you get 1 air change per hour. Good for small and medium sized rooms, though you still get 1 ACH in large rooms.
Colors: Black or White.
Filter replacement: Pre-filters + VOC media/year (12 lbs) $119; HEPA Filter 2-5 years $200. The HEPA is rated at 2-5 years when the prefilter is maintained. Touch pad control panel indicates when each filter needs to be replaced.
Cons: You need a screwdriver to change the filter.
This has a very high amount of carbon and a high CFM for large areas (and fairly quiet for that CFM), but no additives to increase formaldehyde removal and no True HEPA filter.
No True HEPA filter, the HEPA filter captures 1 micron and greater
dB 28.1 – 62.3 @6ft.
EST 2004
This little unit has a very high CFM (second highest on the list) so it’s good for large spaces. The C600 has a lot of carbon, though you would have to get the C600 DLX to get the Potassium Permanganate (for the most formaldehyde and smoke abatement).
It has all metal housing and can work well for chemically sensitive folks.
Coverage: In 700 sq ft you get 5 air changes per hour (running on high).In 2500 sq ft you get 1 air change per hour. Good for small, medium, and large rooms.
Colors: Black, Cream, White.
Filter replacement: Carbon filter 2-3 years $350; Post filter 1 year $100; Pre-filter 6-12 months $40; filter 1-2 years $60
Cons: No true HEPA filter. It will capture airborne particulates 1 micron and greater, but does not have the ability to capture sub-micron particles. No filter change indicators. Replacing the filters requires some work – the C600 needs to be turned upside down and the unit weighs 49 lbs.
Corinne Segura is a Building Biologist Practitioner with 8 years of experience helping others create healthy homes.
Buy me a kofi to support the research behind this blog.
Reader Interactions
Comments
Mindysays
Are there any filters that can be put on an HVAC system to do the same thing as these air purifiers? I have the filters that catch mold but is there anything better? Thanks!
Moved into a completely renovated apartment. In NYC.
Cheap materials & sub par workmanship.
Can you recommend an air purifier for a small bathroom 5X7 or 6X8. That would absorb formaldehyde, VOC’s & other chemicals.
We have had really hot weather for days now 90+. The smell is apparent half of the time.
I have allergies & It hurts my sinuses – temples.
Thank you.
Salvatore Chiarelli
I recently bought a Blueair 211i Max air purifier. It has a combined HEPA & carbon filter. I would like to lower the levels of ozone in our apartment as well as reduce the PM levels. How can I tell if the carbon portion of that filter is activated or not? (I have read that activated carbon filters can reduce ozone levels. Will non-activated carbon work, too?)
Hi Corinne! Wonderful article. Can you recommend which air purifiers would be best for minimizing wildfire smoke in the air? I’m in NJ and we’re getting slammed. Thank you!
there are a couple on this list that have smoke specific sorbent material mixes and are good for smoke like Austin air. but I’m not sure how many you would need to do better than 6 fousts.
I live within 50 miles of a newly built factory. Since the factory I’ve had a continuous headache and foul taste in my mouth. This article was very informative and pretty much gave me all the information I needed. I especially like the detailed information about VOCs and different types of filters needed for different VOCs.
Do any of these purifiers have an indicator of when the filter needs to be changed? Given the wide variation of levels of pollution it’s hard to trust their standard range. I also don’t want to change filters more than necessary.. It would be helpful if they offered an indicator of when the filter was maxed out. I hope newer models start to do that.
Wow, this blog really helped me out! As someone with terrible allergies, finding the right air purifier can be a real headache. The comparison chart made it easy to see the differences between each model and decide which one would work best for me. Plus, the additional information about activated carbon technology was super enlightening. Thanks for doing the research so I don’t have to!
In order to make the list it needs to contain a lot of carbon. That’s the only way it’s effective against VOCs. Air doctor only contains 2.2 lbs of carbon which is very little. It doesn’t make the cut. On the other hand if you only want HEPA and don’t need the carbon then just go for any brand with true HEPA, the cheapest one will do (as long as the CFM is adequate).
The AirDoctor is a huge marketing scam. When you hold the carbon VOC filter up to the light you can see large gaping holes where there’s no carbon.
There is truly nothing special about the product. It’s overpriced, which is why the manufacturer constantly appears on health webcasts with discount offers.
Yes, I do have one, but I use an IvisiClean instead as the filters are better.
Mindy says
Are there any filters that can be put on an HVAC system to do the same thing as these air purifiers? I have the filters that catch mold but is there anything better? Thanks!
Corinne says
if you want a lot of carbon you have to buy a separate whole house unit that you duct into your HVAC
June says
Great article. Which one of these would you recommend for removing the cat smell/pet odor in general?
2000sq ft two-storey house.
Corinne says
I would target the source with enzyme cleaners
Salvatore Chiarelli says
Great article !
Moved into a completely renovated apartment. In NYC.
Cheap materials & sub par workmanship.
Can you recommend an air purifier for a small bathroom 5X7 or 6X8. That would absorb formaldehyde, VOC’s & other chemicals.
We have had really hot weather for days now 90+. The smell is apparent half of the time.
I have allergies & It hurts my sinuses – temples.
Thank you.
Salvatore Chiarelli
Corinne says
for something a bit smaller EL Foust is good.
Vic says
I recently bought a Blueair 211i Max air purifier. It has a combined HEPA & carbon filter. I would like to lower the levels of ozone in our apartment as well as reduce the PM levels. How can I tell if the carbon portion of that filter is activated or not? (I have read that activated carbon filters can reduce ozone levels. Will non-activated carbon work, too?)
Corinne says
You’d have to ask them if it’s activated carbon
Alexandra says
Hi Corinne! Wonderful article. Can you recommend which air purifiers would be best for minimizing wildfire smoke in the air? I’m in NJ and we’re getting slammed. Thank you!
Corinne says
there are a couple on this list that have smoke specific sorbent material mixes and are good for smoke like Austin air. but I’m not sure how many you would need to do better than 6 fousts.
JenWren says
I live within 50 miles of a newly built factory. Since the factory I’ve had a continuous headache and foul taste in my mouth. This article was very informative and pretty much gave me all the information I needed. I especially like the detailed information about VOCs and different types of filters needed for different VOCs.
Do any of these purifiers have an indicator of when the filter needs to be changed? Given the wide variation of levels of pollution it’s hard to trust their standard range. I also don’t want to change filters more than necessary.. It would be helpful if they offered an indicator of when the filter was maxed out. I hope newer models start to do that.
Corinne says
I mention that in the article
John Corso says
Super helpful. Many thanks
Pamela Kilsdonk says
What’s the best air filter for new carpet in a 1500 square ft apartment?
Corinne says
that’s what this post is about, just check the section about coverage.
Amelia Davis says
Wow, this blog really helped me out! As someone with terrible allergies, finding the right air purifier can be a real headache. The comparison chart made it easy to see the differences between each model and decide which one would work best for me. Plus, the additional information about activated carbon technology was super enlightening. Thanks for doing the research so I don’t have to!
Sara says
Why is Air Doctor not on this list? Thanks.
Corinne says
In order to make the list it needs to contain a lot of carbon. That’s the only way it’s effective against VOCs. Air doctor only contains 2.2 lbs of carbon which is very little. It doesn’t make the cut. On the other hand if you only want HEPA and don’t need the carbon then just go for any brand with true HEPA, the cheapest one will do (as long as the CFM is adequate).
Gene says
The AirDoctor is a huge marketing scam. When you hold the carbon VOC filter up to the light you can see large gaping holes where there’s no carbon.
There is truly nothing special about the product. It’s overpriced, which is why the manufacturer constantly appears on health webcasts with discount offers.
Yes, I do have one, but I use an IvisiClean instead as the filters are better.