Air purifiers — they’re everywhere. But how do you choose? What do you need to take into consideration when choosing one? How do you avoid getting the wrong thing? And how do you navigate all of the options and features that each one has? If you are asking yourself any of these questions, this guide will help you avoid the five most common mistakes that people make while choosing air purifiers.

One quick reminder is that an air purifier is not intended to replace your home or office’s HVAC system. Buildings still need effective HVAC systems in order to keep the air flowing and the air quality at an acceptable level. An air purifier can target the air in specific spaces or rooms and provide an additional level of filtration and air cleaning.

1. Choosing the Cheapest Model

With so many online buying options, it’s easy to think that you can get a high-quality air purifier at a low cost. Product descriptions can get confusing, and it’s hard to even know if you’re purchasing from a reputable company. Unfortunately, any model under $100 is likely not worth your time researching and is not much more than a room fan. Above the $100 price point, read the labels very carefully. Many products will say that they have a HEPA-like filter, which is not a true HEPA filter. True HEPA (High-Efficiency Particulate Arresting, or High-Efficiency Particulate Air) filters are certified to remove 99.97% of all microscopic airborne particles as small as 0.3 microns in size. The micron size is important as it is the smallest size particle that can get into your lungs.

The U.S. Department of Energy (DOE) sets these standards. (Visit High-Efficiency Particulate Air [HEPA] Filter Test Facility [FTF] to read their standards.) And while the DOE or the United States Environmental Protection Agency (EPA) do not recommend specific brands, there are two organizations that do: the Association of Home Appliance Manufacturers (AHAM) [Certified Room Air Cleaners] and the Asthma and Allergy Foundation of America (AAFA) [Air Cleaners]. Aside from Curated, these are the best places to start your search.

2. Not Paying Attention to Square Footage, CADR, or ACH

These three things are key to understanding what you are getting in your air purifier and if it will work for your needs. As a purifier expert, I know this is where things can start to get confusing, which is why here at Curated, we do all of the research for you. Feel free to skip this part if you don’t want to get into the textbook science of it all, and just contact an expert instead.

Square footage (sq. ft.) is the most obvious one. You need to figure out the square footage of the space you need purified. For a one-bedroom apartment, you may be able to get one unit that will cover the whole space. But for a multiple-floor house, purchasing several units will likely be your best bet. Verify that the unit you are looking at can cover the space that you need it to.

Some purifiers can cover a larger space than they are certified for. This is where we get into Clean Air Delivery Rate (CADR) and Air Changes Per Hour (ACPH or ACH). The Environmental Protection Agency and Centers for Disease Control and Prevention suggest using a CADR rating to choose the correct air purifier. (For an in-depth read in response to air filtration during COVID, visit Ventilation in Buildings.) CADR was created by AHAM and scores the units on how efficient their filters are and how much airflow the unit produces. CADR determines what size room the purifier is best suited for, so you don’t necessarily need something with the highest CADR for a smaller space. Each purifier can also have multiple CADR ratings based on what type of particle it is filtering. If you have a specific concern that is affecting the air quality in your home, make sure you look at the CADR rating for that concern.

Because it's easier to explain how big of a space your air purifier is best suited for instead of explaining CADR, a lot of companies will use ACPH in their marketing campaigns. This is because ACPH needs can vary from person to person. If you have a person that is highly allergic to dust mites, for example, you will want the purifier you purchase to change the air in the room four to six times per hour. However, if you’re a relatively healthy person, and your HVAC is working well, you may only need the room to be changed twice per hour.

A great example is that Rabbit Air states for “normal residential use” you only need two ACPH, which means the A3 can cover a room up to 1,070 square feet. If you are an allergy sufferer Rabbit Air recommends four ACPH; this means the A3 will only cover 535 square feet. So, if your indoor air quality and outdoor air quality are generally good, and you don’t suffer from allergies, you may be able to save some money and get a purifier that covers a larger space with less ACPH.

3. Overlooking Your Personal Health Needs

This may seem obvious, but in today's world where 66% of Americans fear they won’t be able to pay for health care, it is common for people to overlook their personal health needs. Sure, it makes sense to save money where you can, but buying a cheaper air purifier that does not do what you need it to is a big mistake. Numerous tests show that air purifiers can help relieve the symptoms of allergy sufferers and asthmatics. And it's not surprising that during COVID many companies are looking to purchase air purifiers to enhance the cleanliness of the air in their workspaces. While it is true that air purifiers will not cure your medical issues, speaking from personal experience, I do know that they make a difference.

The best air purifiers target a variety of different needs, and there are even models that have specific filters for specific allergens, such as filters that target just pet dander, smoke, or VOCs. And as we learned before, some purifiers are certified by the AAFA that have been proven to help with asthma and allergy symptoms. Symptom alleviation can prevent continuous visits to the doctor and sometimes infections. You can also use an FSA, HSA, or HRA to pay for a purifier, if it is deemed medically necessary.

4. Mistaking Ionizers and Ozone Generators as Air Purifiers

In the realm of air cleaning, there are not only air purifiers but also devices that are marketed as ionizers or ozone generators. Ozone generators produce ozone, which solves odor issues and can remove bacteria, viruses, and other organisms. The fresh smell right before a thunderstorm or during a fresh rain is the smell of ozone. You can see why it might be tempting to buy a machine that can produce that smell and do all of those things.

However, ozone is not meant for humans to breathe, and it can damage the lungs and worsen asthma. The caveat to ozone generators is that many of them state to leave the room while the generator is running, so it is a well-known fact that you or your pets or plants shouldn’t be anywhere near it. And the ozone levels needed to actually be effective at any of those things are well beyond what we should be inhaling. Also, they won’t fix the issues that are causing the mold in the first place.

An ionizer works by producing an electric charge that attracts particles to surfaces using the electric charge. The idea then is that either you can vacuum or dust the particles, or, if your air purifier has an ionizer, the ionizer on the purifier will attract the particles to the filter. Sounds good, right? Well, the only issue is that a waste product of ion production is ozone. The EPA does not recommend ionizers or ozone generators and has not seen any evidence that they truly work. Plus, they can often produce more ozone than is stated on the box.

There are air purifiers that do come with an ionizer option. If you are concerned about producing any additional ozone in your home, you can opt to not use the ionizer, or you can look for an air purifier with an ionizer that is considered safe per the EPA recommendation of emissions of 0.05 parts per million of ozone.

5. Not Taking Into Account the Need for Replacement Air Filters

Unfortunately, air purifiers are not “set it and forget it.” To keep them running at an optimal level, some maintenance needs to be done, including, for most purifiers, switching out the filters. The time that each filter is good for varies per unit and whether you run it in auto mode or at its highest fan speed. If you’re constantly running your purifier at the maximum speed, the filters are doing more work and will need to be replaced more frequently. Be sure to follow the specific guidelines on your purifier for when to replace each of its filters.

If cost is a concern, you can save some money by choosing a specific air purifier over another. Let’s take a look at the A3 again. RabbitAir recommends replacing the filter on the A3 every 12 months if you run the purifier all the time. The replacement filter pack for the A3 at this point in time costs a little over $100. In contrast, Austin recommends replacing their Air Healthmate Purifier filters every five years! And the Healthmate filter pack costs under $300. For two air purifiers that are relatively the same price upfront, you will save a little under $300 over a five-year time period going with the Healthmate.

Shopping for air purifiers can be a daunting process, especially if you have health concerns. Hopefully, these five tips will give you a great starting point. And if you would rather have someone research for you and pick the right product for your needs with no loss of time or worry on your end, please contact me or another Air Purifier Expert here at Curated.com.