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There are hundreds of portable indoor air purifiers on the market.  Finding the best one for your needs can be a daunting task.  Most air purifiers, particularly inexpensive models, only filter particulate matter but do nothing to remove gases, VOCs and odor.  If your goal is to remove as many of the most harmful contaminants as possible from your indoor air you need to look for air purifiers that remove both particulate and gaseous matter.


5 Things to Consider When Buying an Air Purifier


  1. Type of Filtration

Most filters are designed to remove either particles or gases.  A unit that does both will have two or more types of filters.  For example, a unit with only HEPA filtration will do nothing to eliminate gaseous pollutants.



HEPA stands for high-efficiency particulate air.  True HEPA filters are manufactured and certified to a standard in which 99.97% of all particles that have a size greater than or equal to 0.3 microns are captured.  But not all HEPA filters perform equally.  Some air purifiers with True HEPA filters can have different levels of efficiency and performance.  Keep reading to learn why efficiency is an important criteria when choosing an air purifier.


Sorbent Media

Sorbent media filters use material with very high surface area to capture gaseous pollutants.


Activated Carbon

This is the most common type of sorbent filter used in air purifiers.  Carbon can be very efficient at capturing gaseous pollutants but it does not destroy them.  According to the EPA, filters must be properly maintained to prevent the carbon from becoming saturated.  Once saturated, captured gases can break through and re-release into the air. Carbon is typically not as effective at removing low-weight aldehydes such as formaldehyde.

Some filters use chemisorption to stabilize gases and to help to target a variety of chemicals activated carbon cannot effectively remove.  Chemisorption occurs when a gas reacts with an agent that is impregnated into the sorbent media.


Earth Minerals

This is a proprietary type of sorbent media that is used in EnviroKlenz purifiers.  It is comprised of zinc oxide, magnesium oxide, and titanium dioxide.  The earth minerals adsorb, neutralize and breakdown the chemical compounds into basic, non-toxic elements.  This media also uses chemisorption to stabilize chemical compounds.



Ultraviolet Germicidal Irradiation uses UV lamps to kill or deactivate captured microorganisms such as bacteria, mold spores, and viruses.



Photocatalytic Oxidation (PCO) uses UV light and a filter coated with titanium oxide to convert harmful pollutants into harmless water and carbon dioxide.  PCO can be effective at transforming many pollutants but may produce chemical by-products, such as formaldehyde, and some may produce ozone.


PECO, photo electrochemical oxidation, is the proprietary technology used by Molekule.  PECO was developed based on similar principles as PCO, photocatalytic oxidation, but it uses a different type of UV light to begin the chemical reaction that breaks down the pollutants and claims to not produce ozone or chemical by-products.


Ozone Generators

Ozone generators produce ozone which react with chemical and biologic pollutants and break them down or destroy them. Ozone is a lung irritant and its production can produce harmful by-products.  No federal agency has approved ozone generators for use in occupied spaces.


  1. How Well Does it Remove Particulate Matter?

There are 3 factors that will help you compare different air purifiers ability to remove particulate pollution; efficiency, air delivery rate, and room size coverage.



This is the percentage of a concentration of particulate pollutants that are removed when they move through the unit.  For example, HEPA filters must have an efficiency of 99.97% for particles 0.3 microns and larger. Some manufactures will give a total efficiency percentage as well as percentages for different sized particles.  This is helpful because not all models are as good at removing smaller particles.


Particulate matter can be categorized based on its size.

Course particles (2.5 to 10 microns) include pollen and mold spores.

Fine particles, (0.1 microns to 2.5 microns) include household dust, bacteria, pet dander, and virus.

Ultra-fine (<0.1 microns) include some wildfire smoke, tobacco smoke, soot, and some virus.

If you are concerned about removing a particular contaminant, look for the efficiency for that size.  Make sure the unit removes a high percentage of pollutants in that size range.


Clean Air Delivery Rate (CADR)

This measure tells you the volume of air that can be filtered by an air purifier in one minute. The higher the CADR, which is expressed in cubic feet per minute (cfm), the more air can be processed in a room in a given timeframe and the larger the room it can clean.  The CADR is based on running the unit at the highest fan speed.  Generally speaking, a delivery rate of 250 cfm is considered very good.


While CADR is one metric to look at, it has limitations.  It is only a measure of particulate pollution and tells you nothing about a unit’s ability to remove chemical VOCs, gases or odors.  Additionally, it favors units that perform well very quickly but not necessarily over a longer period of time.


Room Size

Most manufacturers provide an estimate of how large a room the unit can clean.  These calculations are usually based on a room with an 8ft. ceiling.  If you have a higher ceiling, the coverage will be less than stated.  You may need multiple units if your room is larger the recommended room size.


  1. How Well Does it Remove Gases?

There is no standard for comparing how well air purifiers remove gases.  If comparing air purifiers brands or models that each use activated carbon, the ones with more carbon weight will generally be more effective.  Those that also use chemisorption will be more effective at destroying formaldehyde and other VOCs.  For brands and models that use other technology, you will need to reply on third-party testing to assess their performance.


  1. Test Results and Reviews

When reading testing results on manufacturers websites make sure the data is independent third-party tested with specific information on who conducted the testing and under what parameters.  The greater the transparency around the testing, typically, the greater confidence you can have in the results.  Consumer reviews can also be helpful but be aware that most of the reviews that compare different air purifiers evaluate larger particle removal and not removal of fine particles or gases.  Make sure you understand what is being evaluated.


Unfortunately, even independent third-party testing cannot always be trusted.  A stunning report by Wirecutter revealed that the makers of Molekule were advised by the NAD, an investigative division of the Better Business Bureau, to remove claims of “independent” testing from their marketing because much of the testing was done at labs which had received sponsorship from the company or where the founder was a director.


There is currently very limited independent research available and more is needed to compare air purifiers that claim to remove chemicals and gases.


  1. Price

Models that I am recommending here range in price from $699 to $1299.  Most units that removes gases as well as particles are more expensive because they use multiple filter technologies.


Recommended Air Purifiers

I have only evaluated air purifiers that remove both particulate and gaseous pollutant because this website is dedicated to eliminating toxins.  Most air purifiers do nothing to remove some of the most dangerous pollutants in your indoor air such as VOCs and gases from cooking combustion.  If your primary interest is removing large molecule allergens like pollen there are many lower-cost options not covered here.


I recommend 4 popular models that rate well against all of the criteria outlined above.  If you are looking at a brand or model not listed here, you can compare it against the criteria to better understand how it stacks up. Check back often as I will continue to update testing data as well as add new brands and models.


EnviroKlenz Mobile Air System

Technology:    True HEPA filter

   Earth Minerals material

   UVGI (for UV Model)

Room Size:      Maximum 1000 sq. ft.

Efficiency:        99.99% for particles >0.3 microns

Air Delivery:    250 cfm

Price:               $699 without UV, $799 with UV.

Filter Replacement Cost:  Earth mineral filter ($99) every 6 months, HEPA filter ($150) every 2 to 3 years.


Testing and Reviews:

EnviroKlenz provides extensive laboratory testing results on their website that compares their product with IQAir, BlueAir and Molekule. The testing shows the unit to be very effective at removing a range of VOCs.  Additionally, they submitted a unit for review to Vacuum Wars, an independent review and comparison channel on YouTube.  It is not a laboratory, but it does conduct an unbiased chamber test.  They claim it could be the best on the market.


Bottom Line:

EnviroKlenz is a very powerful unit that effectively cleans both particulate and gaseous pollutants.  It is a simple, no frill model made with a powder coated metal housing.  Some readers on this site have reported quality control and customer service concerns though the EnviroKlenz website shows very positive reviews.  The UV model provides extra protection against virus, mold and bacteria.


IQAir GC MultiGas

Technology:    True HEPA filter

   Activated Carbon (12lbs.)


Room Size:      Maximum 1240 sq. ft.

Efficiency:        ≥ 99% for particles ≥ 0.3 microns

   ≥ 95% at ≥ 0.003 microns

Air Delivery:    780 cfm

Price:              $1299

Filter Replacement Cost:  Prefilter ($78) every year, Gas cartridges ($295) every 2.5 years, Post-filter sleeves ($95) every 2.5 years


Testing and Reviews:

IQAir does not provide testing data on their website but the testing on the EnviroKlenz website shows that this is extremely effective at removing formaldehyde.  The Allergy Buyers Club rates it as the category winner for VOC and chemical removal because it is able to deliver excellent fine and ultra-fine particle removal as well as address specific chemicals and gases.


Bottom Line:

This is a top-of-the-line unit that does an excellent job of removing particles, even the most concerning fine and ultra-fine particles, as well as a range of chemicals, gases and odor.


IQAir HealthPro Plus

Technology:    True HEPA filter

   Activated Carbon (5lbs.)


Room Size:      Maximum 1125 sq. ft.

Efficiency:        ≥ 99.97% for particles ≥ 0.3 microns

   ≥ 99.5% at ≥ 0.003 microns

Air Delivery:    780 cfm

Price:              $899

Filter Replacement Cost:  Prefilter ($69) every 1.5 years, V5-Cell filter ($99) every 2 years, HyperHEPA filter ($199) every 4 years


Testing and Reviews:

Allergy Buyers Club rates this as the category winner for HEPA air purifiers.


Bottom Line:

Compared to the IQAir GC MultiGas, this model is even more efficient at fine and ultra-fine particle removal but not as powerful against chemicals, gases and odor.  If you are concerned about smoke, virus or other ultra-fine particles, this might be the model for you.  Note: Only the HealthPro Plus model removes gas, while the HealthPro model does not.


Austin Air Healthmate Plus

Technology:    True HEPA filter

   Activated Carbon (15lbs.)


Room size:      Maximum 1500 sq. ft.

Efficiency:       99.97% for particles ≥0.3 microns

   95% for particles ≥0.1 microns

Air Delivery:    400 cfm

Price:               $715

Filter Replacement Cost:  Replacement Filter ($360) every 5 years.


Testing and Reviews:

Austin Air purifiers are sold on many sites and have positive consumer reviews.  There is a lack of independent testing showing how it compares to the other recommended units but based on its technology and efficiency at removing particles, it is a solid choice.


Bottom Line:

This is a simple but well-made unit by a company that has been around for a long time and stands behind their products.


Why I Don’t Recommend Molekule

I own a Molekule and purchased it because of the extensive third-party testing they provide on their website.  The data shows compelling performance against VOCS, mold, bacteria, and virus, and provides evidence that no ozone or by-products are emitted.  Experts have verified these results.

Consumers love the product.  Repeat purchases are 200% which means people who own a unit are happy enough to go back and buy additional units.

Consumer reviews that have rated Molekule poorly only test for a short period of time and Molekule’s testing shows strong results over longer periods.

So, why don’t I recommend it?

As I mentioned above, makers of Molekule were advised an investigative division of the Better Business Bureau, to remove claims of “independent” testing from their marketing because much of the testing was done at labs which had received sponsorship from the company or where the founder was a director.  If the results of the data cannot be trusted there is no compelling reason to buy this product over the other recommended models.  It is possible that its new technology performs as well as the manufacturer claims and as the test results show, but based on this disappointing news, it’s a safer bet to chose the proven technology in one of the recommended units.


For chemically sensitive individuals, you may want to also look at which has a good overview of different media and purifier components that may cause a reaction.  Additionally, make sure you understand the return policy for the unit you plan to purchase so if you are not able to tolerate it you have the option of sending it back.


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