Different Types and Sizes of Air Purifiers
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13 Different Types and Sizes of Air Purifiers That You Need to Know

Picking a wrong air purifier can be as bad as picking a wrong size shoes. It will still work, just not according to you needs. Like every other home appliances, air purifier comes in different shapes, sizes and set of features where each types of air purifier have a role of its own. What’s more the technologies used in an air purifier will have direct impact on its filtration performance and purifying efficiency. To give you a heads up on what to expect from an air purifier, we will be exploring the most common type of air purifiers (HEPA air purifier, odor eliminator) and other niche market models like ion generator and electrostatic air cleaner. We will also end each list with the pros/ cons and best place to use. Continue reading to learn more.

Short answer

HEPA, UV, Ionic, PCO, Electrostatic air purifier, Deodorizer, Ozone generator. Console, Desktop, Car, Tower, Permanent-filter, Whole house air purifier.

Long answer

On the whole, HEPA air purifier is the safest choice (certified filter) and most efficiency air purifier to purchase. If you need an air purifier that can capture smoke and odors, consider an HEPA air purifier with carbon filter. Likewise choose HEPA air purifier with UV/ Ionizer instead of a dedicated air purifier with one specific type of purification. The only type of air purifier that we do not recommend is Ozone air purifier as most ozone generator is not certified on safety and performance. Worst still improper use of an Ozone air purifier could have reverse effect on your health. As for picking the right size, rule of thumb is go with what you need (filtration performance), follow by price (including annual filter replacement cost) and lastly consider the size (overall dimension).

The Many Types of Air Purifier


HEPA air purifier

The popular one: HEPA air purifier is the most widely used and sought-after home air purifier in the world due to its proven filtration effectiveness. To qualify as a HEPA air purifier, the main filtration has to be HEPA which is essentially a mechanical filter that traps microscopic particles small as 0.3 micron through a fine mesh.

The best thing about HEPA air purifier is you know what you are getting. To qualified as a HEPA, the filter has to reach a certain industry standards (IEST, UL) and depends on which type of HEPA filter the air purifier is running on, the inferior HEPA-type filter has a 99% efficiency rate on particles as small as 2 microns while True HEPA filter has an efficiency rate of 99.97% at 0.3 microns or lower (see IQAir). With that HEPA air purifier is excellent against allergens like dust mites, pollen, mold, pet dander, germ and bacteria. A standard HEPA air purifier will also come bundled with a pre-filter that trap initial large particles like dust/ hair to prolong HEPA filter lifespan plus a carbon filter that solely focus on smoke/ odor based pollutants. Premium models will usually come equipped with Ionizer, antimicrobial coating or UV-light technology to further strengthen the filtration process.

Not everything is perfect with HEPA air purifier though. It’s very dependent on other filters to provide a complete filtration cycle. HEPA air purifier can be very costly depending on features, airflow performance and how many stage of filtration. Most HEPA filter also requires annual replacing and price varies from moderate to very expensive.

Rounding up, if you are looking for an air purifier and not entirely sure what to look for, start with HEPA air purifier (preferably True HEPA type) and branch out on the addon (Carbon filter, UV-light, Ionizer) and features later.

  • Easily available as it is carried by most big brands.
  • Proven and certified filter performance (a requirement to qualified as HEPA).
  • Excellent against dust, dust mites, pollen, mold, mildew, pet dander, virus, germ and bacteria.
  • True HEPA filter on average has a 99.97% efficiency rate against airborne particles as small as 0.3 microns.
  • HEPA-type filter on average has a 99% efficiency rate against airborne particles as small as 2 microns.
  • Works best with the additional support of Pre-filter and Carbon filter.
  • Relies on additional carbon filter to trap smoke and odor.
  • Most HEPA filter requires replacing quarterly/ annually and is considerably costly.

Carbon air purifier / Charcoal air purifier / Deodorizer / Odor eliminator / Odor removal

Activated Carbon air purifier / Charcoal air purifier / Deodorizer / Odor eliminator is the exact opposite of HEPA air purifier. One focus on non-gas based pollutants while carbon filter covers the other half. Most carbon air purifier use either Activated Carbon filter/ Granular Carbon filter while compact air purifier use carbon sheet or other equivalent filter. You will also find some carbon air purifier use HEGA filter although it is pretty uncommon.

As mentioned above, carbon air purifier focuses on smoke/ odor pollutants such as cooking smell, pet odor, tobacco smoke, chemical like radon, ammonia, chlorine, sediment and VOCs. As above pollutants are not covered by HEPA filter, Carbon filter works best as an addon filter to HEPA air purifier rather a dedicated odor removal for the same reason. Regardless of which types of air purifiers you go for, you will have to replace the carbon filter once it reaches its lifespan to avoid any interruption on the filtration.

All in all, most standalone deodorizer/ odor eliminator can only cover its respective field. Unless you are entire sure this is what you need, a HEPA air purifier with carbon filter would be the perfect all-in-one solution against household pollutants.

  • Most Odor eliminator/ Standalone carbon air purifier is priced between cheap to inexpensive.
  • Excellent against cooking smell, pet/ diaper odor, tobacco smoke, vapor gas, ozone to chemical like radon, ammonia and VOCs.
  • Uses either Carbon sheet, Granular Carbon filter or HEGA.
  • Works best as an addon filter to HEPA air purifier.
  • Does not capture dust, dust mite, pet dander, pollen, mold or any types of germs and bacteria.
  • Like HEPA filter, most Carbon filter requires replacing quarterly/ half-yearly and is considerably costly.

UV air purifier / Ultraviolet air purifier / Ultraviolet Germicidal Irradiation Cleaner / UVGI cleaner

UV air purifier / Ultraviolet air purifier/ Ultraviolet Germicidal Irradiation Cleaner / UVGI cleaner is an advanced purification technology used in many different products from bottle sterilizer, lighting and water purifier. The ultraviolet radiation from UV lamps will effectively eliminate biological irritants most notably germ, bacteria and viruses. The entire process is 100% safe, eco-friendly and certified by many different agencies.

Unlike HEPA or Carbon filter, Ultraviolet/ UVGI cleaner covers all types of airborne particles including smoke and odor. It’s also very effective in killing microorganism like germ and bacteria. The only issue is most home UV model have limited capacities therefore it will take longer time or higher UV exposure to kill off stronger resistance irritants. Another common issue is UV light efficiency drop gradually upon use. You will need to replace the Light bulb according to its lifespan or prior to that to maintain its filtration efficiency.

To sum up, UV air purifier/ Ultraviolet Germicidal Irradiation Cleaner might not be a great independent air purifier due to is limited purifying capacities, as a last-stage/ complementing filtration system, we can hardly say no to it.

  • Proven eco-friendly technology used in Hospital and other healthcare center.
  • Capture all types of airborne particles including dust mite, pet dander, pollen, mold, germ, smoke and odor.
  • Effective against microorganisms i.e. germ and bacteria.
  • Works best as a last-stage filtration to HEPA air purifier.
  • Effectiveness deteriorate over-time and not as effective against any other airborne particles.
  • Ultraviolet purification takes longer time to eliminate large amount of airborne irritants.
  • UV lamp/ Ultraviolet light has a moderate lifespan and replacement cost varies between low to high.

PCO cleaner / Photocatalytic Oxidation Cleaner / Photocatalyst air purifier

Like Ultraviolet technology, PCO air purifier/ Photocatalytic Oxidation Cleaner is also the new kids on the block when compare with HEPA filtration. What makes it tick is the Photocatalytic Oxidation (PCO) technology that uses broad-spectrum UV light to reacts with a thin film of titanium dioxide, resulting oxidization on microorganisms/ chemicals which then be absorbed on catalyst’s surface. In simple words, it’s essentially a photocatalysis process.

Proven and certified technology (based on research from NASA), the highlight of Photocatalytic Oxidation Cleaner filtration is it can tackle a broad range of airborne contaminants as small as 0.001 microns. Very effective against germ and bacteria where even small viruses fall between 0.004 to 0.1 microns, way within the PCO filtration category. Rather than a standalone air cleaner, PCO technology works best as an additional filtration to HEPA air purifier.

Again like UV technology, Photocatalytic Oxidation effectiveness will degrade upon use where the outcome is incomparable with brand-new set. Oxidation process also differ on room temperature or dealing with different types of chemicals. Lastly the UV-light has a moderate lifespan and the replacement cost is between reasonably inexpensive to expensive.

To conclude, PCO is 100% safe technology that can destroy the smallest possible microorganisms at 0.001 microns. It’s less effectiveness against large quantity of irritants and the short usage lifespan makes it less compelling as a dedicated air purifier.

  • Proven and certified technology which often used to cleanse pesticides from fruits/ vegetables.
  • Eradicate broad range of airborne particles as small as 0.001 microns.
  • Works best as an addon filtration to HEPA air purifier.
  • Filtration performance decrease on a gradual basis where is incomparable with a brand-new unit.
  • Performance varies depending on external factors (room temperature, presence of chemicals) and quality of the UV-light.
  • Moderate lifespan and replacement cost varies between low to high.

Ionic air purifier / Ion generator / Negative Ion air purifier

The next 2 list we will be focusing on electronic air cleaners which is the complete opposite of mechanical filter. Starting with Ionic air purifier / Ion generator / Negative Ion air purifier, airborne particles like dust mite, pollen are electrostatically charged through the machine dispersion of ions. The increased weight of charged particles will then adhere to any nearby surfaces thus reducing the numbers of airborne irritants in the air.

The good thing about Ionization purification method is it uses zero filter so you would not have to spend any extra dollar on filter replacement. The entire process is also safe even though a minimum amount of ozone will be produced (model dependant). The bad thing is Ion generator requires additional filtration support to complete the whole purification cycle as the charged pollutants will still be stuck in a room as oppose in a filter. It also cannot handle smoke and odor based irritants e.g. from fire burning or litter box.

In short, Ion generator is not an amazing air purifier unless it is paired with mechanical filter like HEPA. Regardless what technology jargon used by different brands, if there is any mentioned of the word ion, it’s an Ionizer.

  • Charged all types of airborne particles and allergens including dust mite, pet dander, pollen, mold and germ.
  • Does not rely on filter thus no costly replacement filter needed.
  • Works best as an addon filtration to HEPA air purifier.
  • Rarely find as a standalone unit. Requires additional filtration for it to work.
  • Does not eliminate airborne particles but rather stuck them to the wall and floor.
  • Smoke and odor typically is not included in the Ionization list.
  • Produced ozone although it’s usually at minimum to moderate level.

Electrostatic precipitators air purifier / Electrostatic air cleaner / Electronic air cleaner

As part of electronic air cleaner branch, Electrostatic precipitators air purifier / Electrostatic air cleaner / Electronic air cleaner is the exact replica Ion generator except in comes with the addition of collector plate. Through the process of Ionization, the Electrostatic precipitators air purifier will release negative ions to the air and charge with positive ions particles. Charged airborne particles will then be collected via a flat plate similar to how filter works.

The merit of a collector plate is you would not have to vacuum the room to officially get rid of the irritant particles. You do however have to clean the collector plate on a regular basis to maintain its effectiveness. Electrostatic precipitators also produce slight ozone but not at an alarming level.

In summary, Electrostatic precipitators can work without the reliance on other filter, its overall effectiveness, price factor and the availability makes it a less obvious choice than a standard HEPA air purifier.

  • Electrostatically charge and capture all types of airborne particles including dust mite, germ, pollen and mold.
  • Permanent collecting plate that does not require replacing.
  • Best used together with HEPA air purifier.
  • Not cheap and also not as common as HEPA air purifier.
  • Requires constant cleaning on the collector plate in order to remove the stuck particles.
  • Does not capture smoke and odor based pollutants.
  • Produced ozone but at an insignificant level.

Ozone generator / Ozone *NOT* air purifier

The controversial one: Ozone generator / Ozone *NOT* air purifier has never been loved by any government agencies or air quality website including yours truly. Reason for that is the sheer number of harmful ozone it produced that works completely opposite of what an air purifier supposed to achieve.

Ozone generator often market on its filtration capacities in eradicating microorganism like mold, bacteria and viruses. Studies shown ozone actually does nothing in removing dust or any other airborne particles (See CARB website). Same goes with smoke and odor where many believe ozone generator is a great odor eliminator, true is ozone only mask them and decrease one’s sense of smell so you cannot distinguish any bad odors. High concentrated level of ozone would also trigger asthma and cause permanent damage to your lungs.

In conclusion, never consider an Ozone generator as your air purifier due to the adverse health risk it brings. Despite many manufacturers best effort in marketing it as air purifier/ air cleaner, there is no official regulation or proven facts on its purifying effectiveness. We recommend users to examine an air purifier specification first before putting down your money.

  • NONE. Period.
  • Unregulated, unproven technology therefore not carried by major brands.
  • Does not remove dust, pollen, mold or any other airborne particles. Known to react with existing chemicals to form even more toxic airborne pollutants.
  • Mask odor instead of removing them. Will also damage one’s sense of smell.
  • Inhaling excessive amount of Ozone is can aggravate asthma and caused permanent damage lung.

Console air purifier / Large room air purifier / Full-size air purifier

Among the different types of air purifier below, Console air purifier/ Large room air purifier/ Full-size air purifier is the pinnacle of all (including whole-house purifier). With a bigger overall dimension, console air purifier typically comes with extra filtration ranging from 2 to 6-stage. It also utilizes bigger, better grade filters that you would not typically find in a compact air purifier. Advanced technologies like Ionizer also available in most console air purifier. Airflow distribution, purifying coverage and CADR also score better in general. Last but not least, the latest and newest features is always available in a full-size air purifier.

With outstanding purifying performance and coverage, some compromisation has to be made and it’s in the form of size. On average full-size/ console air purifier is at least 20% – 30% bigger and heavier too. Price factor also gets bump up between moderate to very expensive. Same goes with annual filter replacement which on premium range, it could cost as much as a brand-new air purifier. Overall noise level and power consumption is also on higher tier.

Despite all of that, it’s no brainier to go with a full-size air purifier if filtration depth is your first priority. This is also the best option for asthmatic, MCS person or anyone including children allergic to airborne irritants.

  • Multi-stage filtration varies from 2 to 6-stage.
  • Equipped with higher grade filters and technologies e.g. True HEPA, antimicrobial, Ionizer.
  • Support the widest possible purifying coverage.
  • Stronger airflow and dust/ pollen/ smoke CADR.
  • Availability of advanced features like remote control, Auto mode, air quality sensor.
  • Price range varies from moderate to very expensive.
  • Moderate to very high annual filter replacement cost.
  • Bulkier and heavier than compact/ tower air purifier.
  • Overall higher noise level and power consumption.

Compact air purifier / Table top air purifier / Desktop air purifier / Small room air purifier

Whether is a Compact air purifier, Table top air purifier, Desktop air purifier or Small room air purifier, these types of air purifiers will have the following characteristic: a) small and lightweight enough to fit in most places b) Inexpensive although not necessarily cheap c) easy to use. Let’s start with the size, the small dimension of a table top air purifier means it will fit practically anywhere and this includes your working desk cluttered with all sorts of documents. You do have to place the air purifier as close to you as possible due to the limited purifying coverage, nonetheless noise level will be kept at a lower tier (not completely silent mind you) to avoid being a constant annoyance. Likewise, power consumption is also low at all speed as the airflow distribution will be rather limited. The second most obvious advantage of compact/ small room air purifier is the very cheap price tag due to the limited performance and functionality. The upside to that is of course filter replacement cost would be very affordable too as the bundled filters tend to be lower grade e.g. HEPA type filter and smaller. Another advantage of a compressed body is the air purifier will have low learning curve therefore it is very straightforward to use without any complicated features.

In short, a compact/ small room air purifier is deal for a person that is allergic to dust or other airborne irritants in a small confined area. It is also a stepping stone for someone that wanted to give air purifier a go before investing on a full-size air purifier.

  • Entry-level price tag (cheapest to own).
  • Low annual filter replacement cost.
  • Easy to use with low learning curve.
  • Fits anywhere and easily bring around when on the go.
  • Produce less noise and uses less power.
  • Use smaller filters with limited number of filtration.
  • Usually not great against microscopic particles (HEPA-type filter based) and strong chemicals.
  • Small purifying coverage and weak airflow distribution.
  • Limited set of features.

Car air purifier / Portable air purifier

Car air purifier is gaining its traction as more and more people is spending their precious time in a car. First off, it’s inexpensive to own although not as cheap as a compact/ desktop air purifier. This is especially true on models that utilize only 1 type of purification (e.g. Ionizer) which incidentally also has the advantage of zero filter replacement cost. On to usability, all car/ portable air purifier operates via a plug and play system or a single on/ off button. It is uncommon to find any more adjustment or features in the machine. Performance wise do not expect too much from a car air purifier, it does capture dust plus other allergens although at a slower pace and not microscopic HEPA grade. It is also not great against smoke and odor. Noise level is low and so is the power consumption. Most car air purifier is powered by either a 12 volt power outlet or USB.

All in all, if car is your daily commute and you often stuck in a traffic jam, a portable/ car air purifier would be the ideal product to bring fresh air when you are on the move. Keep in mind that even with an air purifier in place, you should never smoke in car as most car air purifier does not hold enough capacity nor speed to capture tobacco smoke.

  • Inexpensive although not necessarily cheap.
  • One-off cost as most models does not rely on filters.
  • Plug and play.
  • Compact and compatible with older or newer car.
  • Very silent operation. Works quietly in the background.
  • Low power consumption. Typically powered by 12 volt outlet or USB.
  • Single filtration purification. Most models use only Ionizer.
  • Limited purifying capacity. Poor against microscopic particles, smoke and odor.
  • Most models only come with 1 speed with no other controls or functionality.

Tower air purifier / Mini Tower air purifier

Tower air purifier/ Mini Tower air purifier is the slimmer cousin to a full-size air purifier with identical specification and performance. Depending on the size and shape of a tower air purifier, a good spec tower air purifier normally comes with at least 2 to 4-stage filtration. Airflow delivery rate, CADR and purifying coverage would be at decent tier as well. Last of all features like Ionizer, Auto/ Sleep mode, air quality monitors, remote control is also available on specific models. When doing an apple to apples comparison between a tower and console air purifier, tower air purifier will often lose out on airflow or CADR output, smaller filters but gains the advantage of lower price tag and of course slimmer body.

If pricing and size is your number 1 concern, a compact air purifier would outdo a tower air purifier on these 2 factors not to mention the lower annual filter replacement cost. That said, tower air purifier is the closest possible option to a full-size air purifier without carrying the bulkiness.

  • Take up less space with its slim and tall body profile.
  • Multi-stage filtration.
  • High-grade filter but typically smaller than console’s filters.
  • Availability of technologies e.g. True HEPA filter, Ionizer.
  • Moderate to wide purifying coverage.
  • Average to high airflow performance and CADR.
  • Availability of features like remote control, Auto mode, air quality sensor.
  • Price range varies from inexpensive to expensive.
  • Moderate to high annual filter replacement cost.
  • Bulkier and heavier than compact/ tower air purifier.
  • Overall moderate to high noise level and power consumption.

Permanent-filter air purifier / Washable-filter air purifier / Reusable air purifier

Permanent-filter/ permanent air purifier comes in different shapes and form. As long as the main filter can be reuse multiple times, we categorize it under this group. Due to the size differences, a tower air purifier with permanent filter will have a better filtration rate than a tabletop permanent, air purifier. The number one advantage of a permanent air purifier that relies only on one purification method is of course no costly filter replacement. You will save up a lot (especially for bigger models) in long-run. Still, nothing is perfect. The flipside of using a permanent filter air purifier is the slightly higher price compare with like-for-like model. Filtration depth, airflow delivery rate and purifying coverage would also lose out to similar price model that uses conventional mechanical filter.

Bottom line, permanent air purifier is ideal for people that do not mind paying the extra cost for a weaker filtration as they know in couple of years’ time it will be more cost-effective. Also perfect for busy folks that do not want get tied down to an air purifier on a schedule basis.

  • Hassle-free operation without have to stock up on replacement filters.
  • One-off fee with no recurring cost (for model that only utilize one filter).
  • Permanent filter requires cleaning regularly to maintain its filtration efficiency.
  • Permanent filter tends to be less effective against microscopic particles e.g. germs and viruses.
  • Slightly more expensive with weaker purifying performance compare with a like-for-like non-permanent filter model.

Whole house air purification / Whole-house air filter / Central air purifier

Commonly found in hospital and nursery home, whole house air purification / Whole-house air filter / Central air purifier is not your typical air purifier. It is usually hidden on top of the ceiling or behind the wall. There are few types of system that provide different level of filtration depth but in general central air purifier works in the same way.

The upside of installing a whole-house purification system is the central air purifier can cover a lot of ground, literally every corner of the room. It takes up zero of your exterior space as most central air purifier is installed within the ceiling or together with your heating or cooling system. Whole-house air purifier also works anonymously in the background without you ever know its presence. As for the simpler whole-house air filter (a basic filter installed at the home ventilation input/ output), there is no power usage involvement thus it will not create extra burden on your electricity bill.

If there is up there’s bound to be down. To kick start with whole-house air purification system, you will need field expert/ professional to install the system that might require some part of renovation and of course money. Filter maintenance/ replacement can be very tricky as the filter placement is usually at an unreachable spot. Another common issue is most whole-house system has very basic filtration which cannot trap ultrafine particles like germ and bacteria.

In conclusion, whole house air purification system might not be the perfect choice simply for the complicated and costly setup, it can still serve a very important role against the never ending airborne pollutants invasion. The anonymous operation will also compliment well to any existing air purifier.

  • Complete house purifying coverage that covers every corner of the room.
  • Does not take up any interior space as it is inter-linked with home heating or cooling system.
  • Operates automatically and silently in the background.
  • Does not use any electricity (for Whole-house air filter) as it trap airborne particles that flows in or out of the home ventilation system.
  • Works best with the addition of console air purifier.
  • Expensive and requires professional installation as it is usually attached to home vent system.
  • Troublesome filter maintainence/ replacement on congested or damaged filter.
  • Most system has less thorough filtration that does not trap tiny, ultrafine particles.

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