What Does an Air Purifier's Ionizer Do?

A look at a popular air purifier feature

Lasko Wind Curve 2551 Tower Fan with Ionizer
Lasko Wind Curve 2551 Tower Fan with Ionizer. Photo Courtesy Amazon

What does the ionizer in an air purifier or cleaner do? Should I buy an air purifier that has one and is it worth the extra cost? Many air purifiers or cleaners have built-in, independent ionizers that help to trap airborne particles, to more efficiently clean the air in your home. However, their usefulness can be hampered if the HEPA filter in your air purifier requires changing.

When the air cleaner’s ionizer is turned on, voltage is applied to a series of built-in needles, creating electrons which are discharged into the air.

When these electrons attach to air molecules, ions are formed.

These negative ions are dispelled into the room where they attach to dust, pollen, cigarette smoke and pet dander to form larger particles, which can more easily be trapped by your air cleaner's filters. However, these particles can also descend to the floor to be vacuumed later, or attach to positively charged surfaces in the room and the grill of your air cleaner, requiring frequent dusting.

If your HEPA filter requires cleaning or is close to the end of its lifespan, particles may not be filtered but may be returned to the room. For this reason, the ionizer should be turned off until the filter is changed. If your home has more than the average amount of allergens such as animal dander or smoke, the usual lifecycle of a HEPA filter can be greatly reduced.

A household with multiple pets should expect to replace their air purifier's filter monthly, if not more.

Check your air cleaner's operation manual for recommendations on how often to change your filters, but do keep in mind that these guidelines are based on average home air quality and may not take pets into consideration.

Some could argue that an ionizer also freshens the air in a positive and healthy way.

Negative ions are present in our environment, wherever the air is ‘stirred up,' especially around waterfalls, ocean surf, rivers, and mountains. Think of how you feel or breathe close to a waterfall. It's quite energizing, similar to the air right after a rainfall.

Many people believe that negative ions promote wellness, and as such, provide additional benefits when there are more negative ions than positive ones in the air we breathe. It has largely remained a wellness strategy and scientifically unproven. On the other hand, positive ions are also present around us, in carpets, draperies, and allergens in our home.

In summary, ionizers enable your air purifier to work more efficiently, helping you breathe better, as long as your filters are changed as required, and the particles that have settled on surfaces in your home, are vacuumed or dusted frequently.

The Honeywell HFD-120-Q Quiet Clean Tower Air Purifier (shown) is a good example of an air purifier with an ionizer, plus it has very good features for the price.

Ionizers are also available as individual air quality machines and are also included built-in features in some air circulating fans, such as the Lasko 2551 Wind Curve Platinum Tower Fan featured.

This type of feature in a fan would help to freshen the air, as it recirculates it around the room to make you more comfortable.