Filter Vs. Filterless Air Purifier (Detailed Comparison)

  • Author: Irene Batres
  • Date: September 26, 2022
  • Time to read: 7 min.
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Have you ever thought about getting an air purifier?

Maybe you’ve wondered about filter vs filterless air purifiers? Or whether or not air purifiers are effective at all?

Then you’ve come to the right place!

This article will carefully consider both filter and filterless air purifiers so that you can determine which one is right for you. 

So, let’s get right into it!

Filter Vs. Filterless Air Purifier Comparison

There are a wide variety of air purifiers out there for you to choose from.

Depending on the type of pollutants that you may want to target, there might be certain air purifiers that make more sense for you and your needs.

In general, we can divide air purifiers into two main categories: filter or filterless.

In short, filter air purifiers rely on one or more filtration media to take out pollutants from indoor air, whereas filterless air purifiers clean the air with different technologies that seek to perform the same essential function as filter air purifiers—that is, of course, to purify your indoor air. 

Air Purifiers With FiltersFilterless Air Purifier
Cost$50 – $1000 +$100 – $550+
Pollutants targetedAllergens, dander, smoke, unpleasant odor ( via a carbon filter)Bacteria, viruses, other pathogens and microoganisms
NoiseModerate to highQuiet
MaintenanceRoutine maintenance ( changing or washing of filters)Minimal (typically every year or two at most)
Energy useModerate to highMinimal
CoverageTypically 1,00 sq. ft. at most ( For HEPA filters)Up to 3,500 sq. ft. (for ionizers)

Do Filterless Air Purifiers Work?

In general, filterless air purifiers do work, but not all are created equal. There are four main types currently on the market:

  • Ionic – Sometimes referred to as “ionizers,” these purifiers release negative ions. Why? These ions attack particle pollutants by reversing their charge, making them drop to surfaces below (like furniture or all the way to the floor).
  • UV – These purifiers employ UV (ultraviolet) light to help clean your air. Microorganisms—viruses, mold, bacteria, etc.—don’t stand a chance against UV light, making these quite effective.
  • Ozone-based – These purifiers are a bit controversial because they generate ozone gas to cleanse your air of pollutants, but the ozone gas itself might be harmful.
  • PCO – Photocatalytic oxidation—that’s some mouthful. PCO for short, these purifiers utilize this process to produce ions that obliterate pollutants in your air.

Are Filterless Air Purifiers Good?

Filterless air purifiers can be quite good at cleaning the air, despite their lack of filters. Depending on the pollutants you would like to target, they can prove even more adept at purifying your air than regular filter purifiers. 

Like air purifiers in general, filterless air purifiers are good for you because they help remove pollutants that can be harmful to your health, particularly if you have medical issues including respiratory ailments.

Our Top Pick For Filterless Air Purifiers

Our top choice for filterless air purifiers are ionic air purifiers, also known as ionizers or electrostatic precipitators.

These purifiers are excellent because they don’t require replacement filters due to their lack of filter, to begin with. They are also quite energy-efficient and effective at sanitizing the air.

What Are Air Purifiers With Filters?

Just as there are multiple types of filterless air purifiers, there are different kinds of filter air purifiers. These are the four main types currently on the market:

Filter Verses Filterless Air Purifier
  • HEPA purifiers – By far the most common form of air purifier out there, HEPA filters work incredibly well to remove pollutants in your air. This makes HEPA purifiers true to their name, as HEPA filter stands for “high-efficiency particulate air” filter.
  • Activate carbon – These purifiers use activated carbon in their filters. Like many water filters, these work by absorption—when pollutants hit the filter, they don’t pass through because they’re trapped by the carbon filter.
  • Electrostatic – Not unlike ionic purifiers, electrostatic purifiers depend on electricity to ionize pollutants. In addition, they usually use a filter as well to collect the particles that have been electrically charged. In this way, they’re a blend of filter and filterless technologies.
  • Metal filter – These air cleaners typically use a metal (aluminum is a common choice). These filters work well to trap larger pollutant particles, so they’re frequently found in HVAC and exhaust duct systems. They can also be found as an additional component of other filtering systems like HEPA or carbon filters.   

Our Top Pick For Filter Air Purifiers

We recommend HEPA filter air purifiers as the best option among filter air purifiers. 

HEPA filters must remove up to 99.97% of particles that are a size of at least 0.3 microns according to U.S. regulations.

Air cleaners with HEPA filters are quite trustworthy and particularly beneficial for asthma sufferers and people triggered by allergens such as pet hair and dander.

Do Air Purifiers Need Filters?

Should You Get A Filter Or Filterless Air Purifier?

Many people are used to the super-popular HEPA filters and thus are led to believe that all air purifiers use filters. As shown by the different filterless air purifiers outlined above, however, not all air purifiers require filters. 

Related Post: Best Air Purifiers Under $150

Similarities Between Filter And Filterless

Regardless of whether or not they have a filter, air cleaners or purifiers both use technology to make your air safer to breathe.

“Air cleaner” is sometimes used to refer specifically to filter purifiers (like HEPA filter purifiers), whereas “air purifier” is sometimes used to refer to filterless air purifiers (like ionizers). 

Differences Between Filter And Filterless 

The main difference between these purifiers is rather obvious: one has a filter and the other does not.

Filter purifiers use one or more filters, whereas filterless purifiers lack a filter but utilize another form of technology to purify your air. 

Whether or not a filter or filterless model makes more sense for you depends on your needs, which will be covered in the section below. 

Related Post: What Is A Pre Filter In An Air Purifier?

Should You Get A Filter Or Filterless Air Purifier?

Here are the pros and cons of both filter and filterless air purifiers to help you decide what’s best for you: 

Pros of filter air purifiers

  • Great for odors, dust, dander, and various other microorganisms and allergens
  • Potentially safer as pollutants are trapped inside with the filter(s)
  • No production of ozone, which is an irritant (particularly for asthma sufferers)

Cons of filter air purifiers

  • Not necessarily as effective at sanitization of germs, viruses, and bacteria 
  • Limited coverage area relative to filterless purifiers
  • Require more energy than filterless purifiers
  • More maintenance required due to replacing filters
  • More noise compared to filterless purifiers 

Pros of filterless air purifiers

  • Best for sanitizing germs, viruses, and bacteria 
  • Better coverage area relative to filter purifiers
  • Require less energy than filter purifiers
  • Less maintenance required (no replacing filters)
  • Less noise compared to filter purifiers 

Cons of filterless air purifiers

  • Not as effective at handling odors and larger particles like pet hair
  • Potentially not as effective because particles are released rather than trapped
  • They can produce ozone, which is an irritant (particularly for asthma sufferers)

Final thoughts – filterless air purifiers vs. HEPA filter purifiers

So, filterless vs. filter air purifiers—what’s best for you?

First, we should note that the above listing of pros and cons gives a little bit of a distorted picture.

It’s not that filterless purifiers are necessarily much better than filter purifiers. In the end, they both have positive and negative attributes, and which one you choose depends on your own needs and preferences.

Ultimately, the key difference lies in the pollutants that you wish to target.

If you don’t have pets and aren’t as concerned about removing allergens and odors, then a filterless air purifier will probably do the trick just fine.

If, on the other hand, you have pets and want your purifier to take on allergens, odor, and pet hair, then a filter system is best for you.

Another factor to consider is that HEPA filters create zero by-products and are thus perfectly safe for everyone. Ionic and other filterless purifiers produce ozone, which might cause health issues, particularly for people with pre-existing respiratory issues.

While HEPA filters alone don’t capture odors, many of them come with activated charcoal filters as well, which do an excellent job of eliminating foul odors. 

Another issue with HEPA filters to consider is that they follow the “razor-and-blades” model, that is, they require an initial base product and then continual replacements (the filters), which will increase your overall cost with time. 

Speaking of cost, that’s another key consideration for many, which is understandable.

Depending on the size of the room where you would place your new air purifier, you will need to select a purifier that is up to the task.

As discussed, filterless purifiers tend to cover much more ground—or rather air—because they don’t need to physically receive and filter pollutants.

Once you’ve decided to opt for a filter or filterless air purifier, and ensured that it provides proper coverage for the room in question, you’ll still have quite a range of options.

HEPA purifiers can range from as little as $50 to thousands of dollars. Remember to also factor in the replacement filters that you’ll need to purchase.

Filterless purifiers can vary widely in price as well, from options under one hundred dollars to around five hundred dollars. or more.

In general, HEPA purifiers are more popular and more widely produced, making them potentially easier to get your hands on.

No matter what you choose, we hope this guide has helped answer your air purifier questions and allows you to make a more informed decision about whether a filter or filterless air purifier is right for you.

Looking For Air Purifier Guides?

If you’re looking for more air purifier resources, consider checking out our other posts on air purifiers.

irene mills author of freshairdevices


Irene Batres is eager to help others create an indoor allergen-free home. She has years of experience testing out air purifiers, dehumidifiers, and other products designed to help with indoor air quality. Learn more about me.