An ionizer is, by far, the most misunderstood air purification technology. With good reason. Most sites who publish ionizer reviews mistakenly group “purifiers” into an overly broad ionizer category. We assume that they do this because they don’t fully understand basic chemistry (anions, cations, etc.). To further complicate things some manufacturers over generalize and skew the science behind ionizing air purifiers. And, they really don’t like to be called out on it. But, don’t worry we’ll do our best to explain things and hopefully avoid upsetting any (litigious) manufacturers.
First, a few words on Ozone Generators
We have to tackle this one first. Companies (and review sites) who pass off an ozone generator as an ionizer are… (to keep things civil) not doing you any favors. Ozone is a potentially harmful substance and should only be used by those who fully understand its pros, and cons.
Beyond that ions and Ozone are apples and oranges as far as science is concerned. Ozone is a molecule that comprises three Oxygen atoms. Ions (both positive and negative charged) cover a much broader scientific concept. However we do want to point out is that electron transfer to molecular oxygen forms ozone in its gaseous phase. So there is a bit of an association, but not one that would justify grouping ozone generators into the same category as ionizers.
We could go on and on about the responsible use and marketing of ozone producing devices, but we’ll just draw the line at: never confuse a ionizer with a ozone generator. And, to those of you who are thinking “hey… ionizers create ozone as a by product of ionization,” you are correct. However, many electronic devices produce ozone. Ionizers in purifiers typically produce well under the recommended 50 ppb (parts per billion) guideline. Contrast that with the fact that the California Air Resource Board tested a generator that, in two hours, created concentrations of 300 ppb.
One more thing…Ozone may harm indoor plants. It also damages rubber, electrical wire insulation and textiles/artwork.
We’ve established that an ionizer and an ozone generator are not the same thing. But, we now have a more important question to answer. How does an ionizer work?
Before we get into ionizers in purifiers let’s look into the claim that ions improve air quality.
The basic claim…
The basic theory used by some of the less reputable sites and manufactures is pretty simple. Ions carry a negative or positive charge. That charge makes particles stick together. Kind of like a magnet or static electricity. So far that’s actually pretty acurate. Unfortunately, from there things get a little outlandish. Evidently, according to them, the ions are distributed from the device and spread through your home hunting down airborne dust, allergens and mold. The particles are either “destroyed,” fall to the ground, or land on any grounded surface.
And the Salt Lamp
The worst offender of this misapplication of science is the himalayan salt lamp. It’s bad enough that we wrote an entire article addressing the claims sellers and “reviewers” make. In short, the claim with those is that the “heat” from a light bulb causes the salt to release “ions.” Which in turn make you happier and purify the air in your home. Pretty outlandish when you actually take a moment to think about how that could work.
Purifiers that emit ions into the room
Unfortunately, some use the same basic idea but apply it to electronic purifying appliances. There are numerous studies and consumer watchdog groups who back up the notion that this does not work.To make things worse there isn’t much anyone can do about it. As long as a company avoids claiming an actual health benefit; the FDA is unable to do anything about an appliance that’s meant to improve your quality of life and the air in your home.
You’re probably thinking that you should avoid ionizers all together. That’s not the case at all. You just need to understand how they work before you buy into the hype.
Types of Ionizers Used to Purify Air
|Ion Generator||EP (Electrostatic Precipitator)|
|Used in...||Stand Alone Purifiers or Feature of a Purifier||Filterless and/or Fanless Purifiers|
|Ozone (03) Emissions||Typically low levels (less than 50 or 70 ppb)||Higher levels produced|
|How the work||Ions are released and mix with air charging airborne particles||Charged particles stick to metallic plates|
|Where does dust go||Either trapped in a filter or sticks to household surfaces||Collects on plates inside the machine|
How Ionizers Improve Air Quality… and More
So here’s the part where we tell you that there are some good guys out there. If you want to see some of them reviewed check out our ionizer equipped purifier guide. There are actually some pretty awesome options out there that use science to their benefit. Not as marketing hype.
Ionized particles, then HEPA
Ionizers used inside a purifier help improve a HEPA filters chances of capturing even the smallest particles. Basically what happens is that ions (+ or -) are released inside the machine. From there they mix into the air attaching themselves to whatever they can. Once they’re charged they’ll stick to anything with an opposite charge. Kind of like dust on a TV screen. They’ll stick to other particles, making them easier to capture. And, some will even stick to the filter if the charge attracts them.
Ions exist outside of air purifiers and silly marketing claims. They’re one of the building blocks in the natural world. For example NaCl (aka Sodium Chloride) is an Ionic Compound. There are also Covalent compounds but they’re not as central to this discussion. So when mother nature says “hey lets make some salt (NaCl)!” she needs to figure out how to make Sodium (Na) stick to Chloride (Cl). Enter electrostatic force and ionic bonds. Without rehashing too much from your past science or chemistry class…sodium has an electron and chloride needs one. When sodium is ionized by a force greater than 5.14 eV that exchange can be made. Which bonds the substances together creating salt (Na+Cl=NaCl).
Expanding on that concept the next question should be “how are electrons gained and lost in nature?” Some examples include radiation, sunlight, and moving air/water. That’s why you can detect the presence of ions near a waterfall. You might not have known it, but last time you were near a waterfall that sense of “freshness” was created by a huge ion generator.
You can find myriad studies out there on the impact charged ions make (reduced depression, for example). It’s been a focus of studies for almost a century. Unfortunately, you can find just as many products claiming to leverage that proof to sell their products.
So the intent of this article wasn’t to dissuade you from purchasing a product from a reputable company. We just wanted to give you a foundation to sort out fact from fiction when reading air purifier ionizer reviews. It’s hard, we’ve definitely struggled at times to look at a purifier and figure out if the included ionizer was a gimmick, a dangerous Ozone generator, or an actual tool to help improve function.
So regardless of whether you’re reading a ionizer review on our site or someone else’s keep what we mentioned above in the back of your mind. We’ll do our best to keep things above board, but a little skepticism on your end is a valuable tool.