Deciding on an air purifier is a big decision, so you’ll need reliable information. You need the facts because you don’t want to buy an inferior product that won’t work as advertised. You also don’t want to spend a small fortune maintaining your purifier. Sadly, many purifiers end up costing more to maintain over five years than the original cost!
How to Buy the Best Air Purifier
In this article, you’ll learn a few critical facts about indoor air pollutants, how air purifiers work and which is the best air purifier.
So whether you’re looking for the best air purifier for smoke, mold, VOCs, pet dander, allergies, dust or asthma, this is your best air purifier buying guide. By the time you finish this article, you should know which air purifier you’re going to buy.
Why You Want an Air Purifier that Removes Both Types of Indoor Pollutants
Indoor air pollutants fall into two categories. For your health, it is important to control both types. And, it’s good to remember, indoor air is 2 to 5 times more polluted than outdoor air (EPA.GOV).
Fine & Coarse Particulate Matter (PM) – includes dust, cooking and tobacco smoke, pollen and plant spores, animal dander, dust mites, molds, bacteria, and viruses. Exposure to Fine PM has been linked to many health risks including premature death (EPA.GOV).
Gaseous Pollutants or Volatile Organic Compounds (VOCs) – These can come from flooring, gas cooking stoves, carpets, upholstered furniture, paint, adhesives, cleaning products, pesticides, new construction, electronics, and sadly enough air fresheners. One of the most prevalent VOCs in the home is formaldehyde, a known carcinogen.
Results from research show that VOCs from materials and finishes, cleaning products, personal care products and other consumer products result in increased risk of asthma, pulmonary infections, and allergies (Mendell 2007). Some chemicals may have health impacts at extremely low levels; studies have found that exposure to very small traces of VOCs in homes and schools can disrupt the endocrine system (hormones), gene activation, and brain development.
The best air purifiers reduce PM and VOCs. Reducing these in your home is important to your health.
Isn’t My HVAC System Filtering My Indoor Air?
You’re probably thinking that your HVAC system has air filters that you change every 1-3 months, so aren’t they filtering your indoor air?
While it is true that your HVAC has in-line air filters, these filters were really designed to protect your furnace and air conditioning system from dust and other large airborne particles. They will not remove fine PM or VOCs.
How to Remove Dangerous PM From Your Home
The best solution for removing indoor PM is a HEPA filter. In order to trap the finer, more dangerous particles that can travel deep into the lungs and cause health problems, you need a filter that incorporates a High-Efficiency Particulate Arrestance (HEPA) filter. True HEPA medical filters remove at least 99.97% of all airborne particles 0.3 microns in diameter or greater.
When buying an air purifier look for true HEPA medical filters. If the description doesn’t say HEPA medical filter, don’t buy it. Pay attention to the number of sq. ft. of HEPA medical filter. The higher the sq. footage of filter, the longer the filter will last and the higher the value to you.
How to Remove Unhealthy VOCs From Your Home
VOCs are generally so small they cannot be removed by HEPA filters. To remove these pollutants, you need a material called a “sorbent” which is a highly porous substance that can adsorb or bind with VOCs on a molecular basis across a large internal surface area.
The most common adsorbent (not a typo – there really is a word adsorbent) material used in air filters is activated carbon. One pound of activated carbon has a surface area equal to about 125 acres. Another adsorbent is the alumino-silicate crystal structure known as “zeolite”.
Activated carbon and zeolite have different pore sizes and structures, and when used together, they can adsorb a greater range of chemicals. Finally, there are “chemisorbents” that are designed to remove specific chemicals and impregnated into the filter.
When evaluating air purifiers, pay special attention to the adsorbents. Adsorbent materials have a finite capacity, so the more activated carbon and/or zeolite present in your filter, the greater the capacity to remove VOCs and the longer the life of the filter.
Compare the number of pounds of activated carbon in air purifier filters. Determine if the filter has added adsorbents and chemisorbents. The best air purifiers have many pounds of activated carbon along with adsorbents and chemisorbents.
Clean Air Delivery Rate (CADR) Doesn’t Tell the Whole Story (so don’t be fooled)
The CADR is flawed. CADR measures (1) an air filter’s effectiveness at removing specific particles-dust, pollen, and smoke; and (2) the volume of air cleaned during a 20-minute test.
Sounds great, right? Well, there’s more to the story.
There are good reasons to look beyond these numbers when deciding which air filter to buy. First, the CADR standard only tests for particle filtration and does not consider VOC removal which is critical for clean air.
Second, the range of particles tested is from 0.1 to 11.0 microns, but it does not specify results at removing smaller particles vs. larger particles, just overall removal.And, we know that the Fine PM is the most damaging to our health, it is important to know the air filters efficiency at removing these finer particles.
So, when comparing air purifiers, don’t bother using the CADR to decide. Why? Because an air purifier could have a very good CADR, but it could be failing to remove the most dangerous contaminants like Fine PM and VOCs.
What Does CFM Mean for Clean Air?
CFM is a measure of how many cubic feet/minute the air purifier handles. The higher the CFM, the more air changes per hour and the cleaner your air.
Here’s the formula to understand how many times an hour your air is changed/cleaned based on the air purifier’s CFM cleaning rate:
(CFM x 60 min) / (room height x width x length in feet)
Example: (400 CFM x 60 min) / (9′ x 40′ x 30′) = 2.2 changes/hour
Compare a lower CFM rating of 250:
(250 x 60) / (9′ x 40′ x 30′) = 1.4 changes/hour
The higher CFM rating of 400, cleans the air 36% more often than the lower rated version.
The air purifier you buy should have a high CFM to be most effective at cleaning your air.
Air Purifier Reviews – A Look at the Best
We searched the marketplace for air purifiers that could effectively remove PM and VOCs. We scoured the spec sheets on literally dozens of air filters and spoke with the manufacturers. We also looked at a lot of “best-rated air filters” web sites (most are pushing one particular brand, certainly not the best). What we found was just a lot of plain old bad or misleading information.
Most of the companies that claimed their filters removed VOC’s were actually using filters “impregnated” with activated carbon and not a true carbon filter.
Kind of disappointing, right?
If you are serious about removing VOC’s and gasses from your indoor air, you’ll want an air filter that measures their activated carbon in pounds, not ounces.
Ultimately, we found only a handful of companies that were making air purifiers that used significant amounts of both true HEPA medical filters and activated carbon in their filters. We included those in the final air cleaner rankings and reviews listed below.
Look at the 5 Yr Filter Costs!
If you bought a Blueair 503 with SmokeStop, you’d pay a whopping $1490 in filters over five years. Compare that to the Austin Air Healthmate Plus at a fraction of the cost ($353).
Why We Recommend Austin Air Cleaners
Clearly, in terms of performance and long-term value, no other air cleaner manufacturer really comes close to Austin Air. As you can see from the chart above, the Austin Air Cleaners are ranked at the top in size of HEPA filter, number of pounds of Activated Carbon, added Chemisorbents, amount of air cleaned per minute (CFM), filter life and total five-year cost of ownership.
In fact, the Austin Air machines are the only ones who have a five-year filter cost LESS than the initial purchase price. That means the disparity in the total cost of owning those other machines is only going to INCREASE the longer you own them!
The more closely you look at Austin Air Cleaners, the more impressed you will become. In addition to having a large HEPA filter, pounds of Activated Carbon, additional VOC/gasses removal capability, great air cleaning power and the lowest cost of ownership, the other benefits include:
- Austin Air unit is well-designed. By vacuuming the outside of the case, you are also vacuuming the pre-filter. This allows Austin Air to project an overall filter life of up to 5 years
- Only company to offer any type of filter warranty and it’s a full five years
- Made in the USA for more than 30 years
- Made with highest quality materials certified to not off-gas; powder coated all metal housing
- Designed and built for continuous 24/7 operation
- Chosen by the US Government (after extensive independent testing) to fulfill the largest deployment of air cleaners in American history
- Selected by FEMA and The Red Cross to address serious indoor air quality concerns after 9/11