Do Filterless Air Purifiers Work?

There are a lot of misconceptions about filterless air purifiers. Many people doubt its capability in providing clean, fresh air even though it is scientifically proven. In this post, we will address the many common questions including how it works, the maintenance cost, and the efficiency in cleaning the air? We will also compare the pros and cons of owning a filterless air purifier VS filter one. Read on to find out why a filter-free air cleaner is beneficial to you and your family member.
Short answer
Filterless air purifier works!


Do Filterless Air Purifiers Work?

Filterless air purifiers will work effectively and efficiently in purifying indoor air. Through various filter-free technology, it can remove a wide range of airborne particles like dust, pet dander, mold spore, pollen, bacteria, and viruses. It can also remove bad odors from cooking, pets, cigarette, and chemical fumes like VOCs, radon, ammonia, asbestos, benzene, formaldehyde. Without having to pay for recurring filter replacement costs, you will save a lot of money in the long run. Last but not least, filterless air purifiers are energy efficient, zero maintenance, and operate silently at all speeds. You will breathe better, live healthier, with fewer allergy symptoms.

Barring ozone generators, most filter free air purifiers are ozone-safe or are way below the ozone emission limit set by California Air Resources Board (CARB). Below are the many types of filter-free air purifiers that can provide you with clean, healthy air.

  • Ionization – AKA air ionizer or negative ion generator. Create an electrical static field that charge airborne particles in the area. The charged particles will fall and adhere to the nearest surface like wall, sofa, cabinet, or floor. You will then need to vacuum and clean the house to remove the fallen particles.
  • Electrostatic precipitatorDiffuse ions like an ionizer but with the added collector plate. It removes airborne particles by inducing a high-voltage electrostatic field. The heavier electrostatically charged ions particles will drop and attract to the collector plate.
  • Ultraviolet light – AKA UV air purifier or UV sterilizer. Emit a broad wavelength of electromagnetic UV radiation to disinfects bacteria, viral viruses, and other pathogens from reproducing.
  • Photocatalytic oxidation – AKA PCO machine. A NASA developed technology that cleans the air without relying on any filter. Eliminate bacteria and viruses through the photocatalysis combination reaction of broad-spectrum UV light and titanium dioxide.
  • Thermodynamic sterilization – Airfree patented filterless technology. Sterilize 99.9% of bacteria, viruses, and other microorganisms through high temperatures over 400°F.
  • Ozone generator – We do not recommend buying one. Ozone generator or Ozonator emits millions of ozone into the air to neutralizes odors and allergens by splitting oxygen molecules into single atoms. The single atoms will then merge with oxygen molecules to create ozone. Inhaling ozone can aggravate asthma, damage lung tissue cells, and other respiratory problems.

Filter VS Filterless Air Purifiers

Filterless air purifiers are gaining traction for a good reason. It is safe, cost-efficient, and proven on its filtration performance. While there are many benefits of owning one, there are also drawbacks compared with a conventional air purifier with HEPA filter. To assist you in your buying journey, here are the pros and cons of a filterless air purifier.


  • Noiseless operation – Most filter-free air purifiers do not rely on a motor fan to draw air in hence is it completely silent during the entire operation. Without the noise distraction, you can run it all day in the bedroom, office, and living room.
  • Zero maintenance – Utilizing hassle-free filter-free technology like ionizer or UV-light that does not need cleaning. A standard filter requires interval upkeeping to remove the trapped contaminants like dust. Great for busy folks that do not have the time to maintain an air purifier.
  • Economical – Filter-free air cleaners are much more cheaper compared with a HEPA air purifier. Without having to periodically replace the HEPA filter and carbon filter, you will save a lot of money in the long-run.
  • Reliable and proven technologyFilterless air purifiers are safe to use around children, pets, allergies, and asthma sufferers.
  • Kill bacteria and virus – Rather than trapping them in the filter. Technologies like UV-light, Photocatalytic oxidation, and Thermodynamic sterilization eradicate microorganisms permanently with zero chance of escaping.
  • Energy-efficient – Filterless air purifier uses very little energy as there is no motor fan involved. You can leave it running for days and will not see an increase in your electricity bill.
  • Sleeker design – Most air purifiers with no filter are compact and lightweight because it does not have to account for the filter space. Perfect if you have very limited interior space as it can fit on a bedstand or top of the cabinet.
  • Simple operation – Most filter-free air purifiers are just plug and play model with a dead simple control.


  • Limited options – There are not many options to choose from compared with a HEPA air purifier with filter.
  • Single filtration – VS multiple filtrations found in an air purifier with HEPA filter. The multi-level filter air purifiers can cover a wider range of airborne pollutants.
  • Weaker performance – In general, filterless air purifiers are less effective than a HEPA air purifier in removing harmful airborne particles and smoke. Filter-based air purifiers can cover a much wider area with higher air changes per hour. Ideal for a person with breathing difficulty or severe respiratory diseases.
  • Limited recognition – Only filter air purifiers are certified by the Association of Home Appliance Manufacturers (AHAM).

To summarize, both types can improve indoor air quality but the pros of owning a filterless air purifier clearly outweigh the cons. Here are the key differences between a filter and a filterless air purifier.

FeaturesAirfree Onix 3000
Filterless Air Purifier

Filter Air Purifier
PricingStarting from $40Starting from $60
Noiseless OperationYesNo
Zero MaintenanceYesNo
Ozone SafeYes (Except for ozone generator)Yes
FiltrationSingle (Active)Multiple (Passive)
Asthmatic SufferersSuitableSuitable
Kill Bacteria and VirusYesNo
One-touch OperationYesNo
Advanced HEPA filtrationNoYes

What Is The Best Filterless Air Purifier?

Not all air purifiers need filters to clean the air. Some models are better-priced, while some are more effective or energy-efficient. The best filterless air purifier can ensure you're breathing clean, fresh air without producing any harmful ozone. Through extensive research and testing, here are our top 8 residential air purifiers without filter you can buy right now.

  • GermGuardian GG1100
  • GermGuardian GG1000
  • Airfree Lotus
  • Airfree T800
  • Clarifion GL-139
  • Airfree Iris 3000
  • Airocide APS-300
  • Air Oasis 1000G3

For full unbiased reviews and specification comparison, head over to our latest best filterless air purifier page.

Max Fernandez

A loving father and a dedicated reviewer for airfuji.com with more than 1000 air purifiers under his belt. Max Fernandez is also one of the million patients currently suffering from asthma. Feel free to nudge him if you have any questions.
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