Buyers Guide & Information

Best Filterless Air Purifiers

These filter free systems provide safely provide clean air in your home.

Besides the fact that filterless air purifiers work to catch particles that HEPA systems cannot, they also make it so that you do not have to do the work or go to the expense of changing filters.

Many filterless air purifiers are quite affordable—under $500, or even under $100. Moreover, they do not require replacement filters or washing of filters, so you save time and money.

Most filterless air purifiers do not use much energy and require only minimal maintenance. When it comes to loudness: filterless air purifiers range from absolutely silent to soft white noise.

Quick Guide – Our Top Picks


Best For Dust

Airfree Filterless
Airfree Filterless

Our Top Pick

Air Oasis 1000G3
Air Oasis 1000G3

Smallest Model

Airfree Tulip
Airfree Tulip

How Do Filterless Air Purifiers Work?

  • Ionization method:
    Ionizers release ions—usually negative, but sometimes both positive and negative—into the air to neutralize pollutants.
  • Electrostatic precipitation:
    Electrostatic precipitators work similarly to ionizers, except the ionization process happens inside the apparatus.
  • Heat sterilization/Thermodynamics method:
    In the apparatus’s core ducts, air is heated to about 400⁰F until organic molecules are reduced to carbon dioxide and water. This method kills most germs.
  • Ozone generation:
    Ozone generators destroy air contaminants, and your body’s cells—dangerous. (Some ionizers incidentally produce ozone, but at safe levels, especially if you follow user instructions.)
  • UV-C rays method:
    UV-C rays are great for sterilization—killing all categories of microbes. However, in air purifiers, UV rays are typically used for PCO described below.
  • Photocatalytic oxidation:
    PCO uses a UV-absorbent molecule (usually titanium dioxide) and UV rays to chemically change particles. NASA developed the technology, but others have created their own variations, such as AHPCO©, used by Air Oasis.

Filterless Air Purifiers Compared

ModelAreaFilter TypePrice
Air Oasis 1000G3300 sq. ft.AHPCO/ UV-C, Bi-Polar ionizationCheck Amazon
Airfree Filterless650 sq. ft.Thermo dynamic TSSCheck Sylvane

Check Amazon

Airfree Tulip450 sq. ft.Thermodynamic TSSCheck Sylvane

Check Amazon

TREKOO 166 sq. ft.Ionizer, ozone generatorCheck Amazon
IonPacific Ionbox500 sq. ft.IonizerCheck Amazon
AirocideNAPCO/UV-CCheck Amazon

Choosing Filterless Air Purifiers

Air Purification Technology

The most important thing to realize about filterless air purifiers, no matter the technology used, is that they do not actually take any matter out of the air. They can only electrochemically process particles and kill microorganisms. For some people, this solves the problem; others might need a HEPA filter instead of, or along with, a filterless unit.

Room Size vs. Coverage Area

Many filterless air purifiers come with a reported coverage area, usually in sq. ft. This could include multiple rooms if doors are open. However, if you have extreme air pollution or very high ceilings, consider a unit with a higher coverage area than the floor space you have.

Particle Removal Capacity

Most filterless units have a particle removal rate—99% or more for those reviewed here—or ionizing filterless air purifiers have a number of ions produced per second. Clean Air Delivery Rate (CADR) ratings generally do not apply to filterless units, but some filterless units come with CADR values. CADR is the cubic footage of air per minute (CFM) in which particles are eliminated.

Modes of Operation

Most filterless air purifiers have at least 3 modes: low, medium, and high. Often these are just different fan speeds to draw air into the apparatus. Some have sensors to detect air quality or human presence, triggering the purifier to run. Most of the time, you just intuitively select the mode you want. However, if you have an air purifier that produces ozone, avoid toxicity hazards by acting on user manual instructions.

Noise Level

Almost all filterless units are quiet. Heat sterilization units are entirely silent. Ionizers and photocatalytic units, even on the highest mode, create white noise that many users find soothing.

Build Quality & Aesthetics

Most filterless air purifiers come in black or white and have a sleek, compact, modern shape. Most have some sort of lighting with operation. Sometimes the lighting apparatus is substantial, with 5+ options, but in such cases, there is always the option to turn the light off, too.

Price Vs. Usage

HEPA filters work on 0.3-micron or larger particles. If you suspect that your problem is smaller particles, then a filterless unit might be a much better value for you. These smaller particles include VOCs (volatile organic compounds—formaldehyde, ethylene, or paint fumes), some odorants (tobacco, cat litter), some mycotoxins (mold particles), pathogens (bacteria and viruses), and some allergens.

6 Best Filterless Air Purifiers Reviewed

1. Air Oasis 1000G3

Best Filterless Air Purifier
Coverage Area300 sq. ft.
Filtration Technology UsedAHPCO/UV-C, Bi-Polar ionization
Electricity ConsumptionNot given
Noise LevelNot given
Particle Removal Rate99%

The 1000G3, part of Air Oasis’ G3 series of UV-ionic units, is the best filterless air purifier, overall: It comes at a reasonable, mid-range price; has top technology; and gets rid of almost all odorant particles. Furthermore, unlike the others following on this list, the 1000G3 also purifies surfaces.

At 14.13 inches tall and 3 lbs., the 1000G3 is effectively portable for traveling. It has a spacy and angular modern look with a honeycombed blue light on its top surface.

The most common complaint about this unit is that, for some users, it does not get rid of allergens; all the while, many users claim that it does. The probable reason for the discrepancy is that the 1000G3 does not filter out particles. Instead, it electrochemically changes them, using ions—here, both positive and negative—and a kind of photocatalytic oxidation. G3 units neutralize odors and deactivate mycotoxins, bacteria, viruses, VOCs, and some allergens.

These units do not actually remove any material from the air. If you want a filtered air purifier from this brand, consider the iAdaptAir® line, which has true HEPA and carbon filters, along with ionization. Air Oasis units do not produce registerable amounts of ozone.

A Better Home Innovations reviewer says, “We put this in the area where the kitty litter was, and…less than 24 hours, that smell was gone.”


  • Kills microbes/pathogens
  • Sleek, modern, compact design
  • Purifies surfaces, along with air
  • Lifetime warranty
  • Works on variety of odors


  • Not effective for absolutely all particle types
  • Relatively small coverage area

2. Airfree Filterless

Best Filterless Air Purifier for Dust
Coverage Area650 sq. ft.
Filtration Technology UsedThermodynamic TSS (heat sterilization)
Electricity Consumption52 W
Noise Level0 dba
Particle Removal Rate99.99%

The Airfree Filterless line—including this unit, the Iris 3000, as well as the P1000 and P2000 and Onix 3000—use thermodynamic TSS core technology to kill pathogens and deactivate dust and odorants. The Iris 3000 is arguably the best filterless air purifier for dust.

It has no fan, so it makes no noise. It is portable for travel, at 10.4 inches high and 3.5 lbs., and covers the area of a standard room.

Regrettably, this unit is not Energy Star certified. However, some users might appreciate that it is made in Europe and tested by ISO 17025 laboratories. This Airfree Filterless comes at an affordable price, with a decent 2-year warranty—and it works on a whopping 99.99% of air contaminants. It has an attractive exterior, as well, with changeable lighting—an option of 9 different colors (the light can be switched off, too). Some users report that it puts out some heat, so it might be best for large, somewhat drafty rooms.

Because the Airfree Filterless uses heat sterilization to deactivate particles, there is no ozone or ion production. In fact, this unit might even remove some ozone. There is also no need for a fan to draw air in, so the unit is essentially silent. Users confirm that Airfree Filterless units take tobacco smoke out of the air and reduce the need to manually dust. reviewer reports, “…Love that there is no filter, no maintenance and it is noiseless but the best part is all the particles, bacteria, etc. that are being eliminated from the air I breathe.”


  • Affordable
  • Cute, modern exterior with light options
  • Reduces ozone
  • Kills pathogens of all kinds
  • Essentially silent


  • Puts out some heat in room
  • Not effective for all particle types

3. Airfree Tulip

Best Small Filterless Air Purifier for Bedrooms
Coverage Area450 sq. ft.
Filtration Technology UsedThermodynamic TSS (heat sterilization)
Electricity Consumption44 W
Noise Level0 dba
Particle Removal Rate99.99%

The Airfree Tulip 1000, much like the Iris 3000 above, uses thermodynamic TSS core technology—heat sterilization at 400 F—to process every kind of air pollutant. Like other Airfree units, this one has no fan, so it is silent; it works on 99.99% of air contaminants, and it has a 10-color-option light on top that can be turned off.

However, the Tulip is made for medium-small rooms, making it the best small filterless air purifier for bedrooms. Its compact build and lightweight—13.3 inches tall and 2.4 lbs.—make it portable for travel. Furthermore, its smooth, elongated, streamlined shape looks good anywhere.

Despite its unobtrusive exterior and lack of emissions (no ozone, no ions), the Tulip works on bacteria, viruses, dust mites, mildew and mold toxins, organic odorants like tobacco, and pet and plant allergens. Like other Airfree air purifiers, it has a respectable 2-year warranty. Regrettably, it is not Energy Star certified but ultimately does not use much power. It does have a host of safety features, such as heat-sensitive resistors and fuses, tilt sensing systems, and voltage- and current-limiting devices. Furthermore, users do not complain of excess heat production, as they do with the Iris 3000 above.

A Sylvane reviewer says, “I got this for cat hair and it is helping me breathe better at night. Sleep is good now.”


  • Great value for cost
  • Cute, modern exterior with light options
  • No ozone or ions emitted
  • Kills all kinds of pathogens
  • Essentially silent


  • Not effective for all particle types

4. TREKOO Upgraded Air Purifier

Best for Lounge Rooms
Coverage Area166 sq. ft.
Filtration Technology UsedIonizer, ozone generator
Electricity Consumption10.8 W
Noise Level20 dba
Particle Removal Rate1 million negative ions/second

Despite its small size, the TREKOO Upgraded Air Purifier is an unusually powerful odor-remover, making it the best for living rooms. It can remove tobacco product fumes, perfume, kitty litter smell, bathroom odors, and lingering cooking odors. It is also antibacterial. Most users find that it makes a noticeable difference within minutes.

The TREKOO comes with wall-mounting hardware and a UL-listed power adapter. Many choose to mount it on the bathroom wall, but you can just set it on a tabletop, too. Some users report that it produces a “hotel-room smell”—most are happy about this.

There is reason to be cautious with such an efficient ozone producer/ionizer: It can produce threshold-harmful levels of ozone (maximum is 0.075 ppm.); however, instructions do say to leave the room while it is in the highest mode. Some users are confused by the usage and the instructions. This is not made to run 24/7. It has Toilet, Room, Manual, Sleep, and Auto modes with different ozone/ion production levels and 3 fan speeds to accommodate different situations, and it has Person/No-Person modes linked to sensors that detect someone in the room. All of this is designed to keep ozone to a safe concentration.

Unlike many others on this list, it does make some noise; however, most users still find it very quiet. To reduce ozone and further neutralize odors, the TREKOO contains a nano-activated-carbon filter that can last up to 15 years—nearly a permanent filter.

A YouTube reviewer remarks that “…It’s similar to what hospitals use…these can cost a whole lot more; I was actually very surprised at this unit…”


  • Great value for cost
  • Wall-mount hardware included
  • Unobtrusive and quiet
  • Variety of modes
  • Works fast


  • Produces ozone
  • Somewhat complicated usage

5. IonPacific Ionbox

Best Portable Filterless Air Purifier
Coverage Area500 sq. ft.
Filtration Technology UsedIonizer
Electricity Consumption1.5 W
Noise LevelNot given
Particle Removal Rate20 million negative ions/second

The IonPacific Ionbox 20m is the best portable filterless air purifier on the market. At under $100, this purifier has a 1-year warranty and access to helpful customer service. It comes with an electrostatic discharge (ESD) brush to clean the intake/output grids—this helps if the unit starts making undue noise.

The Ionbox is powerful for its 4.8 oz.—as its name suggests, it puts out 20m negative ions/second, which allows it to impact the air of a medium-sized room quickly. Users report relief from allergies, litter box odors, tobacco smells, vehicle exhaust, and cooking odors. The company even promises that it works on pathogens—bacteria and viruses. It is both CE and RoHS certified and produces only negligible ozone.

The Ionbox is not just compact; it also is chargeable by USB (meaning you can connect it to a smart device or laptop; also, its adapter works for 110-V or 220-V connections, so you do not need a voltage converter when traveling.

In fact, all IonPacific air purifiers have high-tech aesthetics and functionality. The ionNight has an LED nightlight, the ionFan is a USB-chargeable and highly portable fan, and the ionMi takes portability in an ionizer even further—it is wearable.

A Walmart reviewer says, “…It cleared the burned broccoli smell out of my kitchen in no time!…Great product, highly recommended by my healthcare practitioner…. Compact and can be placed anywhere.”


  • Good customer service
  • Simple to use
  • Great value for cost
  • USB chargeable
  • 110V/220V AC adapter


  • Sometimes malfunctions quickly
  • Slight noise

6. Airocide

Best Filterless Air Purifier for Allergies
Coverage AreaNot given
Filtration Technology UsedPCO/UV-C
Electricity ConsumptionNot given
Noise LevelNot given
Particle Removal Rate100% organic pollutants/pathogens

The best filterless air purifier for allergies is the Airocide line, especially the Airocide APS-200. It uses titanium dioxide, UV-C photocatalytic oxidation (PCO) developed by NASA. NASA uses this process to neutralize ethylene (a VOC produced by plants) out of a space vessel’s air to facilitate in-space gardening.

Consistent with its origins, Airocide has a modern, space-age look that suggests a special ornament, rather than an air purifier. It is relatively large at 18.7 inches long and 9 lbs. However, it is still within a portable size range.

Airocide takes out VOCs, bacteria, mold, and dust particles; it is especially useful with organic matter. Therefore, many allergy suffers and asthmatics find relief with this unit, as do electronics-owners who cannot seem to get rid of dust.

There are not many official stats with this unit. However, users corroborate that the unit works for medium to large-sized rooms. The bedroom is the recommended space; its sound is a potentially soothing white noise.

Its control buttons are touch-sensitive icons. It is made to run 24/7, but you have the power to turn it up or down, and it can down-throttle automatically for nighttime use.

It does not produce ozone; however, the internal magnets of the unit can present a choking hazard, so this is best used in an adult household. Some users report confusion about getting a replacement reaction chamber, which is needed annually, but the Airocide APS-200 Replacement Chamber Kit for $140 does the job.


  • 5-year warranty
  • Neutralizes all organic particulates
  • Very modern aesthetic
  • Top PCO/UV-C technology


  • Expensive
  • Needs replacement reaction chambers

Filterless vs. Filtered Air Purifiers

Filterless units need less maintenance but do not remove matter from the environment. However, they are better suited to kill germs and neutralize small odorants and organic (biological) particles.

Filtered air purifiers are especially great for more substantial dust particles, and so they might help with house cleaning, alleviate allergies, and reduce odors. You do not always have to buy replacement filters—it is easy to find an affordable and effective air purifier with a true HEPA washable/permanent filter, too.

In conclusion: Severe allergy and asthma sufferers should consider using both filtered and filterless systems together.

People Also Ask (FAQ)

Is it safe to keep this type of air purifier on at all times?

It depends on the model, so follow user instructions—but in most cases, yes.

Do the purifiers that use the ionization method kill germs?

Yes, ionizers kill germs, but heat sterilization/thermodynamic purifiers are better for this.

How do I know which size air purifier to get?

Look at the reported coverage area and compare it to the area of the room/open space where you want to put the air purifier. Most filterless units work for one, average-sized room.

Are the UV-C lights inside the filter-free air purification unit safe for humans?

Direct exposure to UV-C light is dangerous, so no one should tamper with the internal components. However, inside the apparatus, UV-C lights are safe.

How long do filter-free air purifiers last?

The least expensive and/or smallest might last no more than 1 year. However, medium- or high-priced units can last 5 years or more.

Can my filterless air purifier handle pet odors and cigarette smoke?

Yes, almost all are great for pet odors and cigarette smoke.

What steps can I take to make filterless air purifiers last longer?

Keep water and direct exhaust fumes away from the air purifier. Also, gently brush dust buildup from intake/output areas.


The Air Oasis 1000G3 (#1 on this review list) is ideal because it combines two highly effective filterless technologies, PCO and ionization; furthermore, it comes at a reasonable price and is made for an average-sized room. Therefore, it is the perfect bet if you are not sure which is best for you.