You’ve probably considered an air purifier if you want to enhance the quality of your indoor air. Pollen and dust are two typical contaminants that these devices are quite efficient at decreasing and eliminating.

Ionizers are among the many options available on the market. Ionizers differ from typical HEPA filters in how they function, but are they any better? In reality, there have been significant debates over this approach of air purification.

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What Is an Air Ionizer?

Ionic filtration or ion generators are other terms for air ionisers. They function by releasing negative ions into the room, which bond to positive ions like dust.

Ionizers only release a cloud of negative ions, unlike typical air purifiers, which utilise a fan to bring air in. Ionizers are now divided into two categories: electrostatic precipitators and ion producers. Let’s look at it more closely.

Electrostatic Precipitators

Electrostatic precipitators are frequently marketed as stand-alone systems without a fan to pull in air. They use corona discharge to scatter ions. The ionisation of a fluid results in an electrical discharge. Negative ions attach to particles in the air and are collected on a flat plate with an opposite charge.

The collecting plate may then be simply removed and cleaned. Because you get to watch the unit in operation, this technique is popular. In comparison to ion generators and air purifiers, electrostatic precipitators are typically less expensive.

Ion Generator

Ion generators are more flexible and may be purchased separately. They might also be a standard component of air purifiers.

UV lamps or corona discharge are used to create ions in these ionisers. Many ion generators, unlike precipitators, do not have a collecting plate.

As a result, when ion generators are included in a filter air purifier, it usually does not have a collecting plate. Manufacturers frequently use this as a selling point because you won’t have to deal with a plate.

Where do the pollutants go if there is no location for them to be collected? Ion generators fail at this point. The particles become too heavy to float in the air once the negative ions have bonded to them.

When particles are unable to float in air, they will fall to the nearest oppositely charged surface. This means dust and other airborne contaminants will wind up on your bed, couch, walls, carpets, and other surfaces.

Worse, because the contaminants have now spread to other surfaces, you’ll have to clean more often.

Ozone Production

Ionizers really create ozone as a byproduct, which many householders are unaware of. The layer that protects humans from the sun’s UV radiation is known as ozone. However, as the Environmental Protection Agency puts it, “good up above, terrible nearby.”

When nitrogen oxide and volatile organic molecules react to the heat of the sun, ozone is produced. Ozone may be detrimental to human health at ground level. It can cause a variety of health concerns, the most common of which are respiratory difficulties. Smog is a common occurrence in many large cities throughout the world, and ozone is a major component of smog.

Indoors, air ionisers create ozone (if you have one in your home). Ionizers usually employ corona discharge to emit negative ions, as we discussed before. The gas produced by corona discharge, on the other hand, can be harmful to individuals and the environment.

You might be perplexed as to how these items are still being marketed. Regulations have been implemented. Despite this, many manufacturers neglect to notify their customers about the dangers of ozone exposure.

Consumer Reports put five of the most widely used ionisers to the test. The gadgets created more than 50 parts per billion (ppb) of ozone, according to the magazine. Any ozone exposure of more than 50 parts per billion (ppb) is regarded somewhat worrisome, especially for children, the elderly, and asthmatics.

How to Protect Yourself and Your Family

If you do decide to buy an ioniser, there are a few things to consider. Some companies strive hard to create ionisers with low ozone emissions. There are also air purifiers that have an ionising feature but don’t create ozone.

Any product that doesn’t include ozone in the description, on the other hand, should be avoided. Because they are afraid of losing customers, these firms are more inclined to conceal the facts.

We strongly advise you to seek for CARB-certified air purifiers with ionising capabilities. Because the unit is approved by the California Air Resources Board, you may be assured that it generates very little ozone. In order to be CARB approved, an ioniser must emit less than 0.050 parts per billion of ozone.

Effectiveness Of air Ionizers

The effectiveness of an air ioniser is determined on its kind. When compared to units without a collecting plate, those with one are more effective. This is due to the fact that they capture pollutants, whereas devices without collectors might make a mess.

When your gadget doesn’t have a collecting plate, you’re the only one who can make it work.

You might not notice any difference if you don’t clean your house or the space around the ioniser. The contaminants are then reintroduced into the air when the heavier particles are agitated — for example, when you sit down on the sofa or someone jumps on the bed.

Some of the most expensive air ionisers may cover up to 2,000 square feet.

Air Purifier vs. Air Ionizer

The way air purifiers and air ionisers remove pollutants from the air is the primary distinction. However, there are several other differences between the two air cleaners:

Filter vs. No Filter

HEPA filters are commonly seen in air purifiers. These are available in a variety of quality levels, from HEPA-type to genuine HEPA. Filtered devices use a tiny engine to draw air in, which is then passed through several filters. Filtration stages, such as two-stage or three-stage, are commonly used to describe how many filters a device contains.

You’ll very certainly discover an activated carbon filter in addition to the HEPA filter. This filter collects both smells and gases like VOCs.

After passing through the filters, the air is redistributed back into the atmosphere. Some gadgets do this from the rear, the top, or all four sides. Smart features like an auto mode that detects the air and automatically adjusts the temperature are common.

Ionizers, on the other hand, release electrically charged ions into the air that bond to contaminants. The contaminants are then collected by an oppositely charged plate or left on any available surface in the room.

Coverage of the Area

Filtered air purifiers clean an area of up to 1,000 square feet, with some covering much more. This, however, is dependent on the unit’s size, so always read the description.

Air ionisers, on the other hand, may cover huge areas of up to 2,000 square feet. However, there is a limited selection, and they are often more expensive. The majority of air ionisers are designed for spaces up to 600 square feet.

Maintenance and Costs

Air purifiers are not inexpensive. Even so, there are budget-friendly choices. Filtered air purifiers, on the other hand, are more expensive than ionisers owing to the extra filters and functions.

Air purifiers with filters are significantly more expensive to operate and maintain. For the gadget to function properly, the filters must be replaced on a regular basis. Some air purifiers include washable or reusable filters, thus this is usually done every six to twelve months.

Ionizers, on the other hand, don’t have any filters, therefore there’s nothing to change. Wiping the collecting plate is the only maintenance you’ll have to undertake (if applicable). If there isn’t a plate, you’ll be cleaning and dusting the house more frequently.

Design Alternatives

Ionizers come in a variety of shapes and sizes, with the majority of them being thin and vertical. Most ionisers are likewise small and designed to fit into nooks or other hidden spaces.

Air purifiers with filters, on the other hand, come in a variety of sizes and forms. The unit’s size is generally proportional to the amount of space it covers. Smaller units are ideal for smaller spaces like offices and nurseries.

Should You Buy an Air Ionizer?

It is entirely up to you whether or not to purchase an ioniser. However, given the dangers and the aforementioned considerations, we do not suggest it for everyone.

Not only do they risk releasing ozone into your home, but they’re also less effective than filtered units. If your ioniser doesn’t have a collecting plate, you’ll end up with dusty surfaces that need to be cleaned.

Despite the fact that manufacturers promote ionisers to asthmatic patients, specialists advise against it. In reality, the gadget is more likely than pollution to produce irritation, symptoms, and attacks owing to the creation of ozone.

Filtered air purifiers with an optional ioniser are available; these seldom create large amounts of ozone. The ionising function, on the other hand, isn’t as effective as a genuine ioniser. These extra functions are occasionally included in air purifiers to justify a higher price.

Frequently Asked Questions

Air Ionizer Bottom Line

Despite the fact that they create ozone as a byproduct, air ionisers have been on the market for decades. The electrostatic precipitator is the most common of the two types of ionisers. This kind captures air pollutants using a collecting plate.

Pollutants, on the other hand, are frequently left lingering on nearby surfaces. As a result, allergens and pollutants continue to harm us even after we exhale them.

We don’t suggest ionisers in general, but if you do decide to buy one, make sure it’s certified. Look for low-zone emissions and maybe a CARB certification in the description.


  • Air Filters And Air Cleaners: Rostrum By the American Academy Of Allergy, Asthma & Immunology Indoor Allergen Committee. (2010, January 1). PubMed Central (PMC).
  • List Of CARB-Certified Air Cleaning Devices | California Air Resources Board. (n.d.). List of CARB-Certified Air Cleaning Devices | California Air Resources Board.
  • CDC – NIOSH Pocket Guide To Chemical Hazards -Ozone. (2019, October 30). CDC – NIOSH Pocket Guide to Chemical Hazards -Ozone.
  • Corona Discharge – Wikipedia. (2013, April 1). Corona discharge – Wikipedia.
  • Ground-level Ozone Basics | US EPA. (2015, May 29). US EPA.
  • Electrostatic Precipitator – an Overview | ScienceDirect Topics. (n.d.). Electrostatic Precipitator – an overview | ScienceDirect Topics.

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