1. Home

What Does An Air Purifier's Ionizer Do


Appliances in basement Jupiterimages/Stockbyte/Getty Images
Question: What Does An Air Purifier's Ionizer Do
What does the ionizer in an air purifier or cleaner do? Should I buy an air purifier that has one?
Answer: 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 to the grill work of your air cleaner, requiring frequent dusting.

If your HEPA filter 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 lifecyle of a HEPA filter can be greatly reduced. Check your air cleaner's operation manual for recommendations on how often to change your filters.

Negative ions are present in our environment, wherever the air is ‘stirred up’, especially around waterfalls, ocean surf, rivers and mountains. Positive ions are also present around us, in carpets, draperies and allergens in our home.

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. This has largely remained unproven.

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.

Promotional Feature: View this video series to learn how to take good care of your house.

©2014 About.com. All rights reserved.