(Last Updated On: September 11, 2023)

Guide to Ionizers in Air Purifiers

What do Ionizers in Air Purifiers do and do I Need This Technology?

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By Mark Vander Berg

12 min read

When you hear the word ionizer, it can be easy to assume that it is something you want to have as a feature in your air purifier. In some cases, this technology can be useful, but it is important to know more about this technology in order to make the best air purifier decision for your particular needs. For example, air ionizers should not be the only technology used in an air purifier to “purify” air. Yes, we know that sounds confusing, but we will explain.

First, we need to be in-synch with what air ionization is, what it can do, and how it does it.  Simply put, air is drawn into an air purifier and it passes through an ion generation field.  Loosely put, during this process some molecules become electrically charged.  Lastly, these charged particles are emitted with the clean exhaust air and attach themselves to particles in the air. These charged particles attract and begin to clump together with other particles.

This results in two things happening: First is that these enlarged particles become easier to trap in the HEPA filter the second time they pass through the unit – which is a win-win as we have cleaned the air and captured the particles in the air purifier. Second that can happen is that these now larger particles are heavier and they naturally fall to the ground – which we consider this a win-lose. 

The good news is that the air is cleaner, but the bad news is that the dirt particles are now dispersed on the floor, on you bed, on your couch, on you piano, and more.  Granted, you could vacuum the particles up with a good HEPA vacuum, but the more likely occurrence is that you kick up these particles, putting them back in the air every time you sit down on the couch. This is not an optimal resolution. The preference is to have particles not just removed form the air, but also removed from the environment, captured by the air filter.

Some Ionizers can generate ozone, and ozone is not good for your lungs. This isn’t as common of an occurence as it used to be, but it is still something to keep in mind. For this reason, you will want to make sure that the air purifier unit you want is CARB (California Air Resources Board) Certified. This certification is the most stringent anti-ozone certification available. If it is approved, you can rest assured that the device produces only safe/low amounts of ozone.  Therefore, we only recommend CARB certified units when ever an ionizer is included.

Ionizers are effective and can improve an air purifier unit’s performance by nearly 10%.  They can also emit clean, fresh air into your space. However, we do fully understand why some folks would prefer to do without. In that case, we would lean towards a CARB certified unit that has an on/off ionizer. In other words, you get to choose when to use the ionizer or not.  Choice is a great thing.


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Ionizers are a nice incremental technology that certainly can improve your air purifier experience. Combine that with on/off capability and CARB certification, and you will have access to a safe experience whenever you wish it.

Air Purifier ExpertAbout the Author: Mark Vander Berg

Mark Vander Berg is the Chief Product Expert at AirPurifiers.com. Mark has decades of experience in air purifier engineering. In addition to engineering and product design, he has also done extensive research and testing of many air purifiers and continues to do so for AirPurifiers.com.