Based in Manchester, Marie is one of the writers at HouseFresh and our resident dust expert. She works together with our in-house researchers and our Managing Editor to produce in-depth articles offering practical advice on how to tackle indoor air quality issues.
Our verdict:
While there are various types of air cleaning technology, they’re certainly not all created equal.
Many kinds of tech can remove harmful particles such as mold spores and VOCs like formaldehyde, but a few also come with serious disadvantages. These include producing chemical by-products such as ozone and carbon monoxide and high energy costs.
For the most effective and safest choice, however, your best bet is to look for a cleaner that uses a fibrous media filter (particularly HEPA) and adsorbent media filter (activated carbon) technology. This will help to ensure that harmful particles are eliminated while pungent odors are kept at bay.
You may already be using or thinking about buying an air purifier for your health and home. After all, they have many advantages, from relieving asthma and allergy symptoms to destroying bacteria. Yet it can sometimes seem a bit mysterious as to what they do and how they work.
On top of all this are the various types of technology used in air purifiers. Luckily, we’re on hand to break it all down. Below you’ll find detailed information about the eight kinds of tech, including fibrous media filters and ionizers.
We’ll also give our verdict on what we believe is the best technology as of 2022.
Air cleaning Technology #1: Fibrous Media Filter
This mechanical filter traps harmful, airborne particles into its dense fibrous media filter. It’s able to do this through a maze-like and mesh-type structure. The thickness of the filter, as well as its absorbency, affects its efficiency.
According to the Environmental Protection Agency, there are different fibrous filters, but the most popular is HEPA, which can remove “at least 99.97%” of harmful particles.
| FIBROUS MEDIA FILTER | |||
| Targeted Air Pollutants | Advantages | Disadvantages | |
|
Bacteria Viruses Mold Pollen Smoke |
✅ Very effective at trapping microscopic airborne particles ✅ Safest air cleaning technology ✅ Can be combined with other forms of purification ✅ Do not have any harmful by-products |
❌ Filter needs to be replaced regularly ❌ Pollutants that are deposited in the filter often create secondary air pollution ❌ Efficiency is reduced if the filters are excessively loaded ❌ Ineffective at removing odors |
|
“Backed by decades of academic research and creates no chemical by-products. Even lower grades of HEPA can capture small particles when combined with a fan. This type of technology is our key recommendation for those looking to remove particulate pollutants from their home.”
Air cleaning Technology #2: Adsorbent Media Filter
Adsorbent media filters effectively neutralize odors, VOCs and gases by a chemical process called adsorption. This means that as air flows through the cleaner, toxic gases stick to the adsorbent material in the filter.
Activated carbon is widely used as a material and successfully releases clean, purified air.
If you’re still unsure how activated carbon filters work, don’t worry; you can check out our thorough guide here.
| ADSORBENT MEDIA FILTER | |||
| Targeted Air Pollutants | Advantages | Disadvantages | |
|
Gas |
✅ Absorbs multiple types of gases and volatile organic compounds (VOCs) ✅ Reduces various household odors ✅ No harmful by-products so it is safe to use around the home ✅ Can be added to other purifiers for dual benefit e.g. HEPA |
❌ The filter gets overloaded and saturates fast ❌ High costs to replace filters ❌ Its effectiveness varies on gas types ❌ The adsorption process is reversible so gases cannot be permanently trapped ❌ Extra expense of buying additional purifier |
|
“The only technology that has no additional emissions of by-products. It’s backed by decades of research, and its low cost means it’s the main technology we recommend for those looking to remove odors, VOCs and gases from their home.”
Air cleaning Technology #3: Ionizers (Ion generators)
Ionizers are electronic and work by creating a static charge around the various airborne pollutants inside your home. After releasing negative ions, these ions then attach themselves to airborne particles, making them heavier.
Eventually, the contaminants are collected into charged plates or simply fall to the ground. The particles can attach themselves to various household surfaces like furniture and walls.
| IONIZERS | |||
| Targeted Air Pollutants | Advantages | Disadvantages | |
|
Dust Pollen Allergens Mold spores Ash Soot |
✅ Able to operate at low power ✅ Simple maintenance required ✅ No need to replace filters ✅ Generally quieter than fibrous filters such as HEPA ✅ Removes particles with high efficiency ✅ Durable and easy to maintain ✅ Effectively removes dry and wet impurities from the air |
❌ Often produces ozone, which is harmful to health ❌ Slow air filtration process ❌ May create a mess as the particles can settle on surfaces ❌ Essentially just moves particles around your room rather than removes them ❌ Often produces chemical by-products including ozone and nitrogen oxide ❌ Higher energy cost ❌ Ineffective at removing odors and gases ❌ Not recommended for home use and is better for industrial purposes |
|
“Ionziers can generate a lot of Ozone and Nitric Oxide which can lead to a ton of health problems. We do not recommend air purifiers that use this technology.”
Air cleaning Technology #4: Ultraviolet Germicidal Irradiation (UVGI)
UVGI is electronic and works by applying Ultraviolet (UV-C) light, or lamps, to destroy airborne microbes such as dust mites, mold, viruses and bacteria.
There are two types of UVGI filters. One is designed for cleaning in the air, while the other is intended to disinfect surfaces. Both of these can get rid of harmful organisms. However, surface cleansing is believed to destroy more airborne contaminants because it has a shorter exposure time.
| ULTRAVIOLET GERMICIDAL IRRADIATION (UVGI) | |||
| Targeted Air Pollutants | Advantages | Disadvantages | |
| Microorganisms Viruses Bacteria Fungi Mold spores Dust mites |
✅ Deactivates germs effectively
✅ Easy to maintain and operate ✅ Wide range of uses, particularly in medical settings as an antibacterial disinfect method ✅ Unique purification because it targets airborne microorganisms rather than non-living particulates |
❌ High possibility it will produce ozone
❌ Risk of injury as uncovered UV-C ray is harmful to human eye ❌ Kills microbes but doesn’t eliminate them from the air ❌ Requires high electric power ❌ Some mold and bacteria spores are resistant to UV radiation |
|
“There is a clear danger with UV radiation for skin and eyes. Ozone can interact with VOCs and cause EVEN more pollutants. Due to this, we advise you to avoid UVGI/UVC-based air purifiers.”
Air cleaning Technology #5: Photocatalytic Oxidation (PCO)
The electronic PCO process transforms gaseous pollutants and toxins into harmless by-products such as water and carbon dioxide. The purification is achieved by an oxidation process using titanium oxide as a catalyst and UV light as an igniter.
Photocatalysis means that light makes the catalyst do its job. Light provides the energy that allows the catalyst to work. After the ultraviolet light shines onto the catalyst, this converts water in the air into a form that changes pollution molecules into safer substances.
| PHOTOCATALYTIC OXIDATION (PCO) | |||
| Targeted Air Pollutants | Advantages | Disadvantages | |
| Carbon monoxide
Sulfur dioxide Nitrogen dioxide Formaldehyde |
✅ PCO neutralizes a large variety of gaseous contaminants
✅ Uses low energy permanent UV light ✅ Particularly helpful for people who suffer from asthma and allergies ✅ Instead of just trapping pollutants, PCO completely transforms the harmful chemicals and effectively kills them |
❌ Often produces chemical by-products su ch as formaldehyde and ozone
❌ Slow filtration process ❌ May fail to deactivate all pollutants and could activate irritations ❌ Catalysts have a limited lifetime, reducing their cost-effectiveness |
|
“An interesting technology but still very far off from being useful in commercial air purifier devices. There are clear issues with its practical usage even after decades of research studies.”
Air cleaning Technology #6: Plasma
An electronic filter, plasma technology transforms gaseous pollutants by breaking their chemical bond. It does this by utilizing electrical arcs with both positive and negative electrical charges.
A high-voltage discharge ionizes any harmful gases in the environment. The thermal plasma air cleaners can generate a high-temperature plasma flame to effectively break down all the toxic gases in your surroundings.
| PLASMA | |||
| Targeted Air Pollutants | Advantages | Disadvantages | |
| Formaldehyde
Benzene Sulfur dioxide Nitrogen oxides |
✅ High filtration efficiency
✅ Plasma can be combined with other air filtration methods ✅ Easily deactivates and destroys harmful microorganisms ✅ Able to eliminate odors such as cooking |
❌ Often produces harmful chemical by-products such as carbon monoxide, ozone, and some organic gases
❌ Unable to remove particle pollutants ❌ Due to the variety of plasma technology, it can be confusing as to how it works ❌ Not considered to be as effective as HEPA filtration |
|
“Studies show that cold plasma technology is promising, but there is still a lot unknown about this technology as it may generate unwanted byproducts like ozone and other chemicals. Still needs a lot more research.”
Air cleaning Technology #7: Intentional Ozone Generator
Ozone generators are electronic and work by deliberately producing ozone using UV light or corona discharge. This enables them to break down gases and volatile organic compounds.
These devices essentially take in oxygen from the air and give it a strong electrical charge, allowing the oxygen molecules to rearrange themselves and form ozone. The ozone is then released from the machine into the air. When the ozone hits molecules such as smoke, it attaches itself to pollutants and destroys them.
| INTENTIONAL OZONE GENERATOR | |||
| Targeted Air Pollutants | Advantages | Disadvantages | |
| Gas
VOCs Formaldehyde Carbon monoxide Sulfur dioxide |
✅ It neutralizes all kinds of indoor gases
✅ Particularly effective at removing pungent odors ✅ May be used for professional and commercial cleaning purposes |
❌ Not suitable for residential or occupied spaces
❌ Ozone is harmful to home appliances and building materials ❌ It can cause lung irritation and other health problems ❌ Takes months to react with chemicals in the air, and often leaves by-products that are just as bad as the original chemicals |
|
“Ozone is a very problematic gas and should be avoided when looking for an air purifier.”
Final Thoughts
Now that you’re more clued-up about the different types of air cleaning technology, you probably want to know which is best at purifying your home?
We highly recommend devices that use fibrous media filters, especially HEPA. This is hands down the most effective, not to mention the safest, purification method for removing particulates. Equally, adsorbent media filters that use activated carbon are also excellent choices for eliminating odors.
For a more comprehensive look at the best purifying technology for 2022 (and the worst), check out our guide here.
SOURCES
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Environmental Protection Agency. (2022). Ozone Generators that are Sold as Air Cleaners. epa.gov
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Smith, D. (2020). Kaiterra. 5 Types of Home Air Purifiers: Pros, Cons, and How They Work. learn.kaiterra.com Woodford, C. (2022). Explain That Stuff. Photocatalytic air purifiers. explainthatstuff.com