8 Most Common Types of Air Purifier With Pros and Cons

1. HEPA Air Purifier

Acronym for High Efficiency Particulate Air is a safe and proven technology used since the 1940s to filter airborne particles without producing any harmful byproducts like ozone. A certified HEPA filter must meet The American Society of Mechanical Engineers (ASME) and the United States Department of Energy (U.S. DOE) standard of trapping at least 99.97% of particles equal to or greater than 0.3 μm (micrometer). The true HEPA filter also has to reach stringent IEST and UL industry standards.

There are two common types of HEPA filters in the market. The inferior HEPA-type filter with a 99% efficiency rate on particle removal as small as 2 microns. The better True HEPA filter with a 99% efficiency rate on particle removal as small as 0.3 microns.

How it works: The inner fan will pull air into the HEPA air purifier filtration. The accordion shape, weaving fiberglass-made HEPA filter traps particulates that pass through via interception, impaction, or diffusion. This includes dust mites, mold, pollen, pet dander, bacteria, and viruses that our naked eyes cannot see. The HEPA air purifier will distribute purified, clean air with most particulates trapped. The more air cycles through the filter in an hour, the faster clean air can be achieved.

A typical HEPA filtration in an air purifier will consist of a pre-filter and an activated carbon filter. The initial pre-filter will trap large particulates like dust or hair. The activated carbon filter will focus on smoke/odor-based pollutants not captured by the HEPA filter. Premium models even come with an additional ionizer, antimicrobial, or UV light (more on this later).

Also known as: HEPA air cleaner, HEPA machine

Should I get one: Yes, you should, as it is the most popular and sought-after residential air purifier in the world. HEPA air purifiers can go as low as $30 or as high as $1000, depending on features, airflow level, and numbers of filtration. However, most HEPA filter requires replacing annually and can be costly in the long run. HEPA filter also does not trap smoke particles. You will need an additional carbon filter to absorb smoke, odor, and chemical gases. That being said, the HEPA machine is the undisputed BEST air purifier type, and we highly recommend it.

2. Activated Carbon Air Purifier

A century-old technology has existed since the early 1900s to purify water and later air. Carbon filters are compressed, solid block carbon with thousands of molecular-sized pores. The high absorbent ability enables an air purifier with an activated carbon filter to effectively absorb smoke, chemical gases, and odors. It will make the indoor air much more breathable without any unpleasant smell. Great for people with Multiple Chemical Sensitivity (MCS) and asthma or impaired immune system.

There are different grades of activated carbon filters. Thin carbon sheets or baking soda filters are generally less effective than a full-sized activated carbon filter. The bigger the surface area for adsorption, the more effective and longer-lasting the filter lifespan.

How it works: By pulling the surrounding air into its filtration, the chemical adsorption activated carbon filter will absorb smoke particles from cooking, cigarettes, household cleaning products, diapers, or pet odors. Stronger toxic fumes like formaldehyde, CO, radon, ammonia, chlorine, sediment, smog, ozone, and VOCs will be absorbed as well. Odor eliminator carbon air purifier is best used in places that reek like a kitchen, toilet, basement, or smoking area.

Also known as: Odor eliminator, Charcoal air purifier, Deodorizer, Odor removal

Should I get one: Only consider one if smoke and odor are your only concern. Carbon air purifiers cannot capture non-smoke particles like dust, mold, and pollen. Carbon filter also requires replacing quarterly or annually, depending on the filter material. It works best as an add-on filtration rather than a standalone unit like a HEPA air cleaner.

3. UV Air Purifier

UV air purifiers irradiate ultraviolet light to kill harmful germs, bacteria, and viruses. It is used in hospitals and medical equipment. UV purification technology can be found in many household products, including bottle sterilizers, lighting, and water purifier. The disinfection process is 100% safe, certified, and regulated by many different agencies including FDA. UV-C radiation can pass through the air without creating ozone. Low doses (without direct contact) will not cause any burns and damage human tissues.

How it works: As biological pollutants are drawn and pass through the air purifier’s tube, the Ultraviolet light radiates a spectrum of wavelengths that kills cells and alters the DNA through molecules reaction. The pathogens like mold, bacteria, and viruses dead or dormant without the ability to multiply. The effectiveness of sanitization is highly dependent on the wattage and the time of exposure.

Also known as: UVGI cleaner, Ultraviolet Germicidal Irradiation Cleaner

Should I get one: No other than a pluggable version or addon to a HEPA air purifier. Although UV air purifiers can permanently eradicate germs, removing large pollutants like dust and smoke takes a long time. The effectiveness will deteriorate over time as the ultraviolet light intensity weakens. Without a multi-stage filtration system, microorganisms may get shaded from the light and recirculate back into the air. UV lamp also has an average lifespan (usually around 20,000 hours), and replacement can be expensive in the long haul.

Here are the finest Ultraviolet light powered air purifiers that you should get your hands on one.

4. PCO Air Purifier

PCO air purifier is a proven and 100% safe technology based on research from NASA. The highlight of Photocatalyst technology is it can eradicate contaminants as small as 0.001 microns ( nanometer). 300 times smaller than what a HEPA filter can remove at 0.3 microns. Even the smallest viruses fall between 0.004 to 0.1 microns.

How it works: Through photocatalytic oxidation, the PCO air purifier pulls air in and passes through the internal chamber. The combined UVC irradiation with titanium dioxide formed hydroxy radicals and super-oxide ions that break down pathogens by damaging their cellular structure and DNA chromosomes. The particulates will then be converted into harmless water molecules or carbon dioxide, absorbed on the catalyst’s surface. In simple words, it’s a photocatalysis process that accelerates the natural decomposition of organic matter.

Also known as: Photocatalyst Air Purifier, Photocatalytic Oxidation Cleaner, PCO Cleaner

Should I get one: It depends on a few major drawbacks. It is not the cheapest air purifier type, and so is the UV light bulb replacement. Another issue is photocatalytic oxidation effectiveness will degrade over time as the UV irradiance and titanium dioxide drop. The oxidation process also varies at room temperature and with different types of chemicals. It is not great at dealing with large particulates above PM10 and gaseous pollutants. Rather than a standalone unit, a PCO air purifier works best as a supplement filtration.

5. Ionic Air Purifier

An air ionic air purifier is a device that uses a high voltage generator to charge molecules in the air electrically and causes the particles to fall. Most commercial and residential ionizers in the market generate negative ions or anions. It is the gold standard as negative ions are safe, natural, and produce biochemical reactions that boost mood chemical serotonin. A chemical nerve cell that helps alleviate depression, relieve stress and increase daytime energy.

Air Ionizer is the complete opposite of a mechanical air purifier. Its ionization method does not rely on filters; therefore, it is more eco-friendly. You would not have to spend any extra dollars on filter replacement. Take note that an ionizer is not an ozone generator. Some manufacturers would mislead the buyer but naming their Ozonator as “ionizer.” Unethical business practice.

How it works: Air ionizer charges and disperses millions of negative ions into the air. The released negative ions will magnetically bond with other electrostatically charged positive ion particles. The bonded ions will eventually become too heavy to remain in the air and fall to the ground or adhere to bed, sofa, window, tabletops, draperies, walls, etc. This resulted in a reduced density of irritants in the air as the ionization cycle continued.

Also known as: Air Ionizer, Ion generator, Negative Ion air purifier, Chizhevsky’s chandelier

Should I get one: No other than a pluggable ionizer to complement your main filtration. An ionic air purifier does not eliminate airborne particles but rather causes them to fall and get stuck on the ground or wall. If nothing is done, the particulates will scatter all over the place and could stir back up in the air when disturbed. An ionizer is also known to be less effective compared with other purification technologies. It may produce ozone at a very minimal level that is certified safe by the California Air Resources Board (CARB).

Here are our best negative ion generators reviewed that can serve as standalone or complement your primary filtration.

6. Electrostatic Precipitators

Electrostatic Precipitators emit and charge ions, resulting in the airborne particles dropping. It uses the same ionization technology but comes with a collector metal plate that attracts charged particles. The merit of a collector plate is you do not have to vacuum daily to remove dropped particles attached to the surface area in a room. It is essentially the step-up version of an ionizer with health benefits.

How it works: Through the force of an induced electrostatic charge, the Electrostatic Precipitator diffuses ions in the air. By charging particles in the room, airborne particles like dust, pollen, mold will merge and fall from the increased weight. The fallen particles will be collected by a charged plate rather than attracted to other surface areas in a room. The bigger the collector’s plate, the more particles will be collected by the Electrostatic Precipitator, thus less risk of particles being resuspended into the air.

Also known as: Electrostatic air cleaner, Electronic air cleaner

Should I get one: It depends. An electrostatic precipitator is a good choice as it can remove airborne particles without reliance on other filters. The filter-free setup means there is no filter replacement cost to incur. However, its air cleaning effectiveness, particularly on smoke and odors, is under par. You have to clean the internal collector plate regularly to remove the trapped particles. Lastly, an electrostatic precipitator will produce a very insignificant amount of ozone, even though it is within the FDA safety limit.

7. Ozone Generator

The controversial one: Ozone generator is not approved by any health professionals or government agencies. It is notorious for exasperating respiratory issues, irritating the lungs, and damaging tissue. For years, manufacturers have been pushing hard to the public, making false statements on how safe and effective ozone generator is in removing airborne allergens. Some manufacturers would even market their ozone generator as an air cleaner to mask it from public backlash. The “anti air purifier” counter what it is meant to do.

How it works: An ozone generator produce ozone (O_₃) through the Silent corona discharge method. Electrically discharge and split oxygen molecules (O2) into a single atom. The single atom will reattach to other oxygen molecules to form ozone. In other words, O + O2 =O3. Once the “cleaning” process has started, you will need to stay away from the room for at least a couple of hours until the ozone clears off. Because every ozone generator emits a different amount of ozone, the isolation duration may vary.

Also known as: Ozonator, Ozonizer, Ozone *NOT* air purifier

Should I get one: Never consider an Ozone generator due to the irreversible health effects it brings. In theory, it will destroy strong odors that are normally irremovable. In reality, ozone will only mask them by decreasing one’s sense of smell so that you cannot distinguish any bad odors. Ozone reacts with existing chemicals to form even more toxic pollutants. It is ineffective against dust, mold, and pollen, as large airborne particles take a long time to react with ozone. Ozone generators may also inhibit the growth of biological agents. Lastly, most Ozonator in the market is unregulated and not carried by major brands. The aftermath of ozone is not worth the risk.

Go the opposite route. opt for the very best ozone-free air purifiers currently on sale in the market.

8. Air Exchanger

An Air Exchanger is an appliance that manages the home’s ventilation by exhausting stale air out and pulling fresh air in. The continuous renewal of fresh air keeps indoor air clean and free from airborne allergens. Air Exchanger helps regulate the room temperature by retaining indoor air warm during the winter and cold air during the summer. It maintains the home humidity level at a comfortable 30 to 50 percent, effectively halting mold and mildew from thriving.

How it works: Via the internal motor fan, stale air from home will be warmed up and exhausted via a small passageway of the heat recovery core. Likewise, fresh air from outside will be pulled into the house via the heat recovery core passageway. An air exchanger is typically connected to the central ductwork, so fresh air will circulate throughout the home, including the living room, bedroom, kitchen, and basement. You can find an Air-To-Air Exchanger installed by default in newer homes as it works well with an existing HVAC system.

Also known as: Air-to-Air Exchangers, Air Heat Exchanger

Should I get one: No, if your sole purpose is to clean the indoor air. Air Exchanger does not guarantee clean air as it exchanges indoor air with outdoor air. The outdoor air may be more polluted and comprises toxic fumes and microscopic particles that the machine cannot filter. It is also very bulky, expensive, and difficult to install without the help of an HVAC expert. You will be better off with a console air purifier with a HEPA filter.

Which is The Best Type of Air Purifier?

After comparing so many different types of air purifiers, HEPA air purifier is the safest and most effective type to capture airborne particulates. If you need to deal with smoke particles, go with a model with a carbon filter addon. Here are the best air purifiers money can buy right on.

• Best overall air purifier - Coway AP-1512HH Mighty Air Purifier
• Best value air purifier - Winix 5500-2 Air Purifier
• Best smart air purifier - Dyson Pure Cool Tower Fan Air Purifier
• Best HEPA air purifier for allergies - Blueair 605
• Best affordable air purifier - TREDY TD-1500 Air Purifier
• Best midrange air purifier - Honeywell HPA300 Air Purifier
• Best air purifier for big spenders - IQAir Healthpro Plus Air Purifier

Find out more information about our latest best air purifier reviews here.