Air Ionizers: What to Know Before You Buy

Is an air ionizer right for you? We uncover what they are, how they work and their potential benefits and drawbacks.

We’re all spending a lot more time inside these days, so it’s no surprise that concerns about maintaining good indoor air quality are top of mind for many families. While outdoor air may be smoggy or hazy with environmental impurities, the air we breathe inside our homes is just as important to our health and safety.

Today, filtration, air purification and sterilization advancements seem to be rolling out at breakneck speed. But did you know that air ionizers have been around since the early 1900s? The concept originated from the work of scientist Alexander Chizhevsky, who studied aero-ionization in biology. Decades later, British electrical engineer Cecil Alfred “Coppy” Laws developed the first air ionizer for home use.

Even with their long history, there’s still an air of mystery surrounding ionizers. Many factors must be considered to determine if an ionizer is appropriate for your particular situation. Although we aren’t encouraging or discouraging the use of ionizers, we can certainly help you understand more about them.

What Is an Air Ionizer?

An air ionizer is an air purifying device that releases negative “ions” (an atom or group of atoms with a positive or negative charge) into the air.

Unlike air purifiers and sanitizers that use fans and filters (HEPA or carbon) to trap harmful contaminants within the device, an ionizer “zaps” impurities as they float around the room, attacking the molecules and neutralizing them.

How Do Air Ionizers Work?

Ionizers use electrostatic charging plates that produce negatively charged ions. These ions attach themselves to tiny airborne particulates, like cigarette smoke and other toxins, as they move through the air.

“Once the bond is made between these ions and particles,” says Michael Clark, founder of, “the particles become too heavy to stay in the air, which results in the contaminants falling onto the floor or sticking to surrounding surfaces.”

Places around the house like carpet, floors, furniture and drapes — all positively charged from static electricity — draw in negatively charged particles. (It’s the perfect example of how opposites attract!) Then the particles stay there until they’re vacuumed away.

What Are the Benefits and Drawbacks of an Air Ionizer?

When deciding whether an air ionizer is right for you, it’s important to weigh the pluses and minuses.

Advantages of air ionizers

  • Effective against fine micro-organisms such as smoke, soot and other tiny particulate matter, all the way down to 0.1 microns;
  • Fanless and quiet to run;
  • Typically compact for portability;
  • Economical and easy to maintain.

Air ionizer limitations

  • Less effective on large particles that trigger allergies and asthma such as dust, pollen and pet dander;
  • Won’t destroy odors, tamp down gaseous toxins (VOCs) or remove viruses and germs;
  • Scatters particles that can be reintroduced into the air;
  • May emit ozone, a lung irritant, as a secondary byproduct.

Many states regulate the amount of ozone an ionizer may emit. Daniel Tranter, supervisor of the indoor air unit at the Minnesota Department of Health, recommends an ionizer meet the UL 867 standard certification for electrostatic air cleaners, or preferably the UL 2998 standard certification for zero ozone emissions. The California Air Resources Board offers a list of air purifier devices that give off dangerous amounts of ozone.

Note: To learn more about how you can improve your indoor air quality, the Environmental Protection Agency (EPA) offers a free technical summary that focuses on air cleaners for residential use.

Types of Air Ionizers

Air purification terms and technologies can be confusing. So can sorting through the different types of air ionizers on the market. Here’s our breakdown:

Fanless Air Ionizers

Fanless air ionizers are quiet and energy-efficient. However, an ionizer without a fan doesn’t circulate air as quickly, so it could take longer to purify a room.

Air Ionizer With Fan

This type of ionizer blows air around the room quickly so it cleans much faster. The fan also promotes good ventilation, although it tends to be noisier and consumes more energy than a fanless ionizer.

Electrostatic Precipitator Ionizer

The first electrostatic air ionizers were marketed for home use in 1954. They work by collecting attracted particles onto a positive-charge plate, rather than scattering the particles around the room. They use a lot of energy and the plate needs to be cleaned frequently, but you don’t have to vacuum up the particles.

Bipolar Ionizer

Often delivered through an in-duct HVAC system, bipolar ionization (also referred to as needlepoint bipolar ionization) is an air-cleaning technology that disperses positively and negatively charged ions into a space. Like a regular ionizer, it causes molecules to cluster, making them easier to clean out of the air.

Combo Air Purifier and Ionizer

Many manufacturers offer add-on air purifiers to their ionizers to boost air filtration rates. A HEPA filter can remove up to 99.97 percent of particles 0.3 microns or larger.

How Much Do Air Ionizers Cost?

A decent home air ionizer can cost between $40 to $200. Those with HEPA filters, fans and other upgraded features will be on the pricier end.

Before buying an air ionizer, Tranter recommends following guidelines set by the Association of Home Appliance Manufacturers (AHAM). Their portable air cleaner certification program lists all certified cleaners with their CADR (clean air delivery rate) values on its website. If you’re interested, you can even try making a DIY portable air cleaner of your own.

If you buy an air ionizer, make sure it’s appropriate for the size of the space. And, of course, follow the manufacturer’s instructions.

Toni DeBella
Toni DeBella is a culture and lifestyle writer, reviews expert and DIYer covering everything from pest control to pool cabanas to painting to container gardening. For over a decade, Toni was the owner of a successful faux finishing, mural and children’s furniture business before moving to a career in writing. She lives in a medieval hill town in Italy, where her bicycle “Raoul” serves as her primary mode of transportation.