What Are The Different Types of Air Purifiers?

different types of air purifiers

As air pollution increases in many areas in the world increases, more and more people are being affected by allergens, pollutants, and irritants in the air they breathe. Also, as the population becomes more health conscious, people are paying more attention to things that have a negative effect on their health. This is why popularity in the different types of air purifiers has increase considerably in recent years.

There are many different types of air purifiers on the market. They are classified basically by the technology used to clean the air. In this article, we will look at what each of these different types of air purifiers is, how they work and where to place them for the best results.

A Look At The Different Types Of Air Purifiers

As mentioned, air purifier types fall into categories defined by the technology they use. Some popular types of air purifiers include:

  • HEPA
  • Activated Carbon
  • UV
  • Negative Ion
  • Ozone
  • Electronic Air Cleaners
  • Air-To-Air Exchangers.

Below we will look at each type of air purifier in more detail:

HEPA Technology

You may already be familiar with the term HEPA. That is an acronym for High-Efficiency Particulate Air. HEPA technology has been around for many years and HEPA filters have a very strict requirement. They are regulated to capture at least 99.97% of all particles measuring 0.3 microns or larger. These are particles that you cannot see as the human eye can only detect particles of 10 microns or greater. This means that the microscopic particles trapped in a HEPA filter will include extremely small particles including chemicals, bacteria, and viruses.

HEPA filters are made of a fine fiber-like material that is folded several times in an accordion configuration. The accordion shape results in a maze of fibers that create a large surface for the air purifier fan to push air through. As the air passes through the accordion maze of fibers, the tiny particles in the air get trapped in the filter.

Although HEPA air purifiers are the most effective at capturing airborne particles, they do not remove odors, chemicals, or gasses that are absorbed by other materials, such as activated carbon material (see below).

Activated Carbon Technology

Activated carbon has been in use since the early 1900s when it was used to purify water and to remove the color from sugar. It wasn’t until WWI when activated carbon was discovered to be useful in gas masks and to purify water and air during wartime.

Activated carbon is a processed form of carbon that is very porous, which results in a large surface area used for absorption. Activated carbon filters are an effective tool in trapping all kinds of pollutants from the air including gasses, tobacco smoke, and odors.

Individuals who suffer from Multiple Chemical Sensitivity (MCS) may find air purifiers with activated carbon filters are effective in absorbing formaldehyde (found in home furnishings including carpet), perfumes, and chemicals found in many household cleaning products.

Activated carbon filters can also remove smog, ozone, cooking fumes, pet odors, and more but are not as effective in capturing small airborne particles or allergens. They also have difficulties removing irritants that are not forced through the filter.

UV Technology

Since UV technology doesn’t do a very good job of removing airborne particles, it is typically used along with particulate filter systems. Where UV technology excels is in the elimination of germs such as bacteria and viruses.

Air purifiers using UV technology include a UV lamp and as the microscopic particles float by it, the UV rays cause either cellular or genetic damage to the microorganisms in the air. Oxygen and water found in the air can be converted into ozone and hydroxyl with a UV air purifier.

There is no denying that UV technology works well at eliminating viruses and bacteria but is best used with a filter system located before the UV light. Without a filter system, a large number of microorganisms will be hidden from the light by other particulates. The filter reduces the number of each. This is why air purifiers that utilize UV technology have a HEPA filter at the beginning of the cycle along with activated carbon. The final filtration stage is the UV light which kills bacteria and viruses that get through the filters.

Negative Ion

An ion is a positively or negatively charged natural particle. The charge they get comes from either adding or losing an electron. A negative ion is an oxygen atom that has gained an extra electron. A positive ion is the same atom but one that has lost an extra electron.

These negative ions are injected into the air. Because of the difference in electrical charge, negative ions attract airborne particles such as pollen and dust and will float in a room until they are too heavy and drop to attach to another surface like a wall or window.

Negative Ion Technology is far less effective than many other air purifier technologies as they primarily mask polluted air instead of cleaning it. This means that negative ion air purifiers do not absorb or dispose of harmful contaminants found in the air. They merely take airborne particles out of the air and transfer them to other solid surfaces within the room.

Eventually, these particles that have attached themselves elsewhere in the living space can become loose and recirculate in the space rather than be removed from the space altogether.


The gas known as ozone is produced by ozone air purifiers. Health professionals have argued about the harmful effects that ozone can have on us and as such, ozone air purifiers do not have approvals from regulatory government agencies. Exposure to ozone may irritate asthma conditions and levels that are excessive may even contribute to lung scarring. However, there are many different types of ozone air purifiers on the market with each differing by the amount of ozone they produce.

Ozone air purifiers may take months or years to react to chemicals found in an indoor environment which makes them virtually useless. And since ozone air purifiers do not remove airborne particles like pollen and dust, they also employ negative ion technology.

As noted above, negative ion technology essentially just attracts dust in a room instead of cleaning the air by trapping the dust.

One plus to ozone air purifiers is that they may inhibit the growth of some biological agents but do not clean air.

Electronic Air Cleaners/Central Air Cleaner

An electronic air cleaner can remove up to 99.98% of allergens in the air you breathe in your home. It does this through the use of HEPA filters and positively charged ions. This system works with your furnace or air conditioner to provide air purification of your complete home.

Essentially, an electronic air cleaner keeps the air that flows through your home’s HVAC system clean and safe. The air first goes through the HEPA filter where particles as small as .3 microns are trapped. The ions then neutralize any remaining impurities.

This type of system does an excellent job of removing everything from dust and dander to allergens, viruses, bacteria, fumes, and smoke. However, this is not a do-it-yourself project as you will require a professional installer to get one connected to your HVAC system. In addition to that added cost, the filters will have to be replaced regularly and the ionizing wires or collector cells will have to be cleaned at least monthly.

The benefits of an electronic air cleaner far outweigh these added expenses by providing you with clean air in your home free of any airborne particles.

Air-To-Air Exchangers

An air-to-air exchanger is as the name implies. It exchanges old, stale air from inside your home with fresh, healthy air. These units also permit you to control both temperature and humidity with the use of energy recovery ventilators.

An example of this is when you are exchanging air during the cooler winter months. The ventilators trap the heat from the old stale air and uses it to warm up the fresh, clean air that will replace the air you are removing. In warmer months, the exchanger cools and dehumidifies the air before pushing it inside.

How Does An Air Purifier Work?

As mentioned above, air purifies work in different ways depending on the type of purifier. However, they essentially are an air sanitizer that cleans the air that you breathe.

Some use an air filter that removes particles such as pollutants, allergens, and toxins. Some air purifiers trap the particles and then neutralize them. The neutralized, or sanitized particles are no longer harmful to your health.

Do Air Purifiers Actually Work?

types of air purifiers

Well, as mentioned above, it does depend on the type of air purifier that you use. They can be very effective at doing the job they were created to do. However, it is unlikely that an air purifier will be able to remove or neutralize all airborne particles in your home.

This is because many of these particles will be attached to soft surfaces around your home including carpets, bedding, and furniture. Other particles will be attached to surfaces such as walls and windows. However, by combining an air purifier in your home with a filter system, you will be able to effectively eliminate particles ranging from allergens and mold to smoke, and indoor toxins.

The size of the air purifier will also impact the effectiveness of cleaning the air in your home but are much better than just having a filter system in place.

Where To Place An Air Purifier

There are a few considerations to keep in mind when placing an air purifier in a room. Here is a quick review of things to keep in mind for air purifier placement:

Place It Near The Worst Pollutant

To properly address how do air purifiers work, you need to put them where they will be the most effective. In other words, the air purifier should be where the highest concentration of air pollution exists. To narrow down your search, use your eyes, nose, and allergic reactions to help guide you.

Place It Three To Five Feet From The Ground

There are many different types of air purifiers that are portable enough for you to do this. Air circulation typically moves horizontally (from door to door) and vertically, from floor to ceiling. By placing the unit on a counter, nightstand, table, or desk, you are exposing it to all these airflow directions.

Place It Where The Highest Airflow Exists

How do air purifiers work? If you place one near a window, or a doorway, or along the walls where air naturally moves, you will be able to make that air purifier perform to its best ability. That means, for one to do its job properly, it needs to be where airflow is at its highest.

Do Not Place It In A Corner

The airflow is at its lowest in a corner, so it just makes sense to not place your air purifier in the corner of any room.

Do Not Block It

Obstacles of any kind will restrict airflow and as it has been pointed out already, for the unit to work properly, it needs unrestricted air circulation.

Do Not Place It In High Humidity Locations

The high humidity levels in places such as bathrooms or near cooking appliances translate to heavier air. This is problematic for air purifiers.

Do Not Place It Near Electronics

Electronic devices like a stereo, television, or microwave oven may be harmful to the function of an air purifier. This is why you should not place your unit near electronics of any kind.

Move The Air Purifier Around For Better Results

One way to improve how an air purifier works is to not keep it in the same place all the time. With the guidance provided in the above tips, you should be able to identify the best locations in each room of your house where the air purifier can provide the most benefit.


Do air purifiers actually work? Yes, they do. But there are a few things to consider, such as you need to have the right one for your specific needs and it has to be placed in the right location to do its job.

It important to take care of our health, and a big part of that is improving the quality of the air we breathe. With more pollution in the air around us, there has never been a more important time to do some research on the different types of air purifiers on the market and determine which one you need.

With these matters taken care of, you should be able to live comfortably and breathe clean, good-quality air within your home.

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