A Comprehensive Guide to Mobile Air Purifiers

Growing up, I spent lots of time at my desk studying, and my mom would often nudge me to go outside to “breathe air.”  She also insisted that I open my window before bed and ventilate my room first thing in the morning. It was a given that the outdoor air was cleaner and fresher than the indoor air.  Nowadays though, with seasonal wildfires, this is not so true anymore.  So, to avoid wildfire smoke and feel safe about the air we breathe, we stay indoors a lot of the time. 

Ironically, indoor air may not be much cleaner either, especially without any air circulation.  Under the circumstances, an air filtering system may be of great help, but you must choose it wisely.  In this guide to mobile air purifiers, you will learn how to find the right air purifier for you.  You will also discover why I consider Austin Air and Air Doctor air cleaners some of the best.

Guide To Mobile Air Purifiers

Before becoming a full-time product researcher, I had worked at a wholesale bank in San Francisco as a financial analyst.  In 2012, in preparation for the arrival of my baby, I started looking for safe baby products.  Pretty soon I discovered that not all “natural” and “organic” baby products were truly natural and organic.  As I kept investigating, I learned very useful information for parents that I wanted to share with them.  That was how my blog I Read Labels for You was born.

For this guide, I looked into numerous air purifiers and did a comprehensive comparative analysis of six brands well known in the home air quality improvement area:

1. IQ Air
2. Air Doctor
3. Austin Air
4. Intellipure
5. EnviroKlenz
6. Molekule

Specifically, I contacted the companies, read the EPA guidelines to air cleaners, reviewed Consumer Reports, and used many other sources.  The purpose was to understand how portable air cleaners work and what media they must have to be effective.  And the goal was to form an informed opinion regarding purchasing and recommending the best air cleaning machine for individual needs.

The results of my comparative analysis are presented in a table whose highlights we will discuss today.  (Sign up to receive an email with the complete table.) 

Indoor Air Pollution

So, why is there so much talk about mobile air purifiers?  Is indoor air pollution really that serious? 

For starters, there are contaminants that originate inside the building from indoor sources:

Further, carbon monoxide, ozone, and radon affect indoor air quality.  Moreover, there are biological particles including bacteria, fungi, and pollen (source).

In addition to the indoor sources of air contamination, there are outdoor sources such as:

• traffic
• industrial activities
• wildfire smoke. 

The pollutants from these sources can seep into homes through vents and air conditioning systems. (Learn more in my blog post Does Wildfire Smoke Get Into Your House?.)

There is a body of research that sees a correlation between air quality in residential areas and health.  Reportedly, poor indoor air quality can be especially harmful to youngsters, the elderly, or people with chronic respiratory and cardiovascular diseases.  And smoke in the air can cause an increased risk of cancer due to its carcinogenic components, including benzene and PAHs. 

The latest research focuses on the potential harms of fine (2.5 microns) and ultrafine (0.1 microns) particulate matter found in outdoor air pollution, including wildfire smoke. Specifically, studies show that maternal exposure to fine and ultrafine particulate matter adversely impacts birth outcomes and children’s respiratory and immune systems, brain development, and cardiometabolic health. Scientific evidence suggests that due to their small size, ultrafine particles exert higher toxicity than larger particles, including pulmonary/systemic inflammation, heart rate variability, and blood pressure. Furthermore, recent studies found a strong correlation between short-term exposure to fine particulate matter (PM2.5) during wildfires and increased COVID-19 cases and deaths. 

Effect Of Mobile Air Purifiers On Indoor Air Quality

Per the US Environmental Protection Agency, the two most effective ways to decrease home air pollution are:

1. reduction of the sources of pollutants and
2. ventilation with clean outdoor air. 

As for air purifiers, they can be an effective way to make the air safer in your home.  Especially, when the air outside is more polluted than the air inside due to wildfires, for example.  (Read my post to learn how to protect your health from smoke in the air.)

It is important to note that air purifiers cannot remove all pollutants from the air.  (By the way, technically, air purifiers should be called “air cleaners.”  However, since even these home appliance manufacturers refer to them as “air purifiers,” this post uses both terms interchangeably.)  Thus, be sure not to adopt an “all or nothing” approach.  In other words, any air cleaner is better than nothing (given it does not add more pollutants to your house).

Also, note that whole-house air filtering systems (which attach to your HVAC system) deal with particulates only, not with gases or odors.  For gases and odors, you would need a mobile air purifier/cleaner with a significant amount of activated carbon (e.g., Austin Air air cleaners).

One of the description points for an air purifier used by home appliance manufacturers is clean air delivery rate (CADR). This is a measurement of how much clean air an air filter can produce per minute. However, I consider this criterion imperfect mainly because it measures performance in the first 20 minutes and doesn’t take ozone emissions into consideration.  Hence, I believe the following criteria to be more important for an effective air cleaner:

• It should have a True HEPA filter for particulate matter.
• There should be a filter for gases, and the best is activated carbon.
• It should not emit ozone.

HEPA Filters In Air Cleaners

To start with, High Efficiency Particulate Air (HEPA) filters trap particles moving through them by means of a fine mesh of dense fibers.  

According to the US Department of Energy (DOE) standard, a HEPA filter must trap 99.97% of all particles 0.3 microns in diameter.  Under the European standard, the filter rating, e.g., H13 or U16, indicates its efficiency – the higher the number, the better the filter (source).  

When you shop for mobile air purifiers, look for True HEPA as opposed to “HEPA type” or “HEPA like” filters.  Let’s see which of the surveyed brands use HEPA filters.

While IQ Air calls their filters “Hyper HEPA,” their efficiency seems to be no different from “regular” HEPA used in Austin Air air cleaners and EnviroKlenz – 99.97% at 0.3 microns. 

The Ultra HEPA filter in Air Doctor (at 0.003 microns) should be effective for catching ultrafine particles such as mycotoxins and viruses.

As for Intellipure and Molekule, they use their own technologies, and one of their downsides is that they produce ozone.  Read on to see why ozone is a no-no in an air filtering system.

HEPA Filters Do Not Capture Gases Or Eliminate Mold.

While HEPA filters can remove some mold spores suspended in the air, they do not deal with the mold source.  In addition, especially in humid climates, the captured mold particles can thrive on moisture and dust in the tightly spaced fibers of HEPA filters.  Potentially, they can grow in the filter and re-disperse themselves in the air.  Therefore, it is critical to use professional help to get rid of mold before using an air cleaner.

Also, HEPA filters cannot stop VOCs, carbon monoxide, ozone, or other gases that are too small for them.  That is why the right air purifier should have a carbon filter, too.

Activated Carbon In Air Purifiers

According to the EPA, activated carbon is the best medium in mobile air purifiers to filter gases.  However, “activated carbon filters can be effective, provided there is a large amount of material used in the filter” (source).  Thus, the consumer education website AirPurifiers.com states that a carbon filter should contain at least five pounds of activated carbon.

How much carbon do the surveyed brands use?

As you can see, Austin Air purifiers have the biggest amount of activated carbon, by far – 15 pounds.  The closest to this number is 12 lbs in one of the IQ Air models, and 5 lbs in another. 

So, what exactly does activated carbon do as a filter medium?

Specifically, activated carbon adsorbs molecules from harmful chemicals and gases to its surface.  

Some carbon filters also feature zeolite and potassium permanganate.  By absorbing smoke, gases, chemicals, and odors, they increase efficiency to the filtering system (source).  

Additionally, for a carbon filter to remove formaldehyde, it should be impregnated with potassium iodide or blended with active alumina.  To clarify, these elements, added to the tiny spaces within the carbon, neutralize formaldehyde.  In other words, it is not the carbon itself that removes it.  Therefore, to reduce formaldehyde, you would need to get one of Austin Air air cleaners – Healthmate Plus – that has potassium iodide, the substance that neutralizes formaldehyde.

Ozone-Generating Mobile Air Purifiers

Since 2010, the California Air Resources Board (CARB) has been testing portable air purifiers sold in California following the adoption of California’s Air Cleaner Regulation (AB 2276).  The goal is to ensure that air filtering systems meet certain ozone emission and electrical safety standards.  Thus, electronic air cleaners must comply with an ozone limit of 0.05 parts per million (50 ppb). 

To explain, CARB refers to air cleaners as “electronic” when they use ionizers, PCOs, UV light etc.  Such air purifiers may be capable of generating small amounts of ozone or ions, but not more than 0.05 ppm.

Alternatively, “mechanical” air cleaners use only physical filtration, such as pleated or HEPA filters. 

What is wrong with ozone?

According to the EPA, ozone can damage the lungs, and even low amounts can cause chest pain, coughing, shortness of breath and throat irritation.  Moreover, ozone may deteriorate chronic respiratory diseases, such as asthma, and compromise the body’s ability to battle respiratory infections.

On top of that, AirPurifiers.com states that “while ozone generators can be effective under certain conditions, their general use in home settings is still ill-advised due to the health risks they pose.”

Mobile Air Purifiers I Use At Home

In my open floor living room (which is about 1,000 square feet), I use both an Austin Air Healthmate Plus air purifier and an Air Doctor 5500, and here is why.

“Austin Air” Air Purifiers

First, Austin Air carries air purifiers for spaces of various sizes. Namely, they carry:

• Austin Air Healthmate and Austin Air Healthmate Plus (for larger spaces, like a living room)
• Austin Air Healthmate Junior and Austin Air Healthmate Plus Junior (for smaller spaces, like a bedroom), and
• Austin Air It Air Purifier (for small personal spaces like a small office, RV, or boat).

Second, all these models feature a True HEPA filter that removes 99.97% of all particles at 0.3 microns and larger and 95% of all particles at 0.1 microns and larger. 

Third, the Austin Air Healthmate and Healthmate Plus models have an activated carbon medium (15 lbs in standard units and 6 lbs in Junior units).

In addition to activated carbon, the Healthmate Plus model contains potassium iodide impregnated carbon and zeolite that are especially good at removing PAHs, VOCs, and formaldehyde, typical of wildfire smoke and new construction.

As for the Austin Air “It” unit, it has an option for a VOC Carbon Wrap add-on that also adsorbs VOCs, chemicals, gases, and odors. 

Next, the California Air Resources Board tested Austin air purifiers for ozone emissions and found that they had none. 

Above all, you need to replace filters in Austin air cleaners only every 5 years, and the filters are interchangeable.  This means any Austin Air replacement filter will fit your unit model. Email me to buy an Austin air purifier or a replacement filter with a discount and free shipping.

“Air Doctor” Air Cleaners

I was also impressed with the Ultra HEPA filter in Air Doctor air purifiers.  It removes 100% of airborne particles at 0.003 microns and should be effective at filtering ultrafine particles such as mycotoxins and viruses (COVID-19). 

The virus that causes COVID-19 is approximately 0.125 micron (125 nanometers) in diameter (source). Austin Air removes 99.97% of all particles larger than 0.3 microns and 95% of all particles larger than 0.1 microns. That means it provides good protection from the virus.  But the Air Doctor Ultra HEPA™ is certified to filter the particles down to 0.003 microns.  This means that if you are buying an air purifier solely for coronavirus, you might want the Air Doctor Ultra HEPA™.  (You can get it from me with a discount.)

Note that CARB classifies Air Doctor air cleaners as “electronic,” meaning they can emit ozone. Therefore, I do not recommend using the ionizing setting in these units to avoid ozone emissions.

Conclusion: How To Select The Right Mobile Air Purifier?

Select An Air Purifier That Has A True HEPA Filter For Small Particulate Matter And At Least 5 Lbs Of Activated Carbon For Gas Removal.

In sum, I consider the following factors crucial when selecting an effective air purifier:

• An effective air cleaner should have a True HEPA filter capturing at least 99.97% of particles at 0.3 microns.
• It should have at least 5 lbs of activated carbon for gas removal.
• The air purifier should be tested by CARB and found not to emit ozone. Alternatively, just don’t use the ionizing setting on the unit.

I believe Austin Air air cleaners combine these factors well.  That’s why I decided to become an Austin Air dealer.  Personally, I own an Austin Air Healthmate Plus model because it is designed specifically to handle wildfire smoke.  In addition to 15 lbs of activated carbon, it features potassium iodide and zeolite to remove VOCs, formaldehyde, benzenes, gases, and odors. Email me to buy an Austin Air unit with a discount and free shipping.  

In addition to the Austin Air unit, I own an Air Doctor 5500 unit that features an Ultra HEPA filter to capture particles at 0.003 microns, including mycotoxins and certain viruses. Having two air purifiers in our open floor living room of about 1,000 square feet seems like a good idea. Follow my link to purchase an Air Doctor unit with a significant discount.

As for proprietary technologies used by Intellipure, EnviroKlenz, and Molekule, I choose to avoid those.  First, CARB tested them and found them to emit ozone.  Second, a lot remains unclear when it comes to new technologies.

Browse the I Read Labels For You blog for updates on my latest research. Also, visit my shop, check out my e-books, and book a consultation with me for advice on healthy living.

Download The Free Guide!

5 Powerful Steps To A Non-Toxic Home

Join our informed consumer community and get our free guide the “5 Powerful Steps To A Non-Toxic Home”.

SUBSCRIBE