How Important are Air Purifier Filters?

How Important are Air Purifier Filters?


Most air purifiers depend upon their filters in order to function. Air filters entrap particulates as air passes through them, cleaning the air you breath. These filters come in all shapes and sizes, and some are more effective than others. 

Are air purifier filters necessary? Yes, very much so. They are what your air purifier uses to actually clean the air! Otherwise, it’s about as useful as drinking water out of an empty glass.

Today, we will help you learn just how important your air purifier’s filters are, and about proper maintenance of the air filters.

Air purifier filters are very much important, as they are what allows the purifier to actually filter the air that passes through it. An air cleaner without filters is just an expensive fan, and an air purifier whose filters are caked thick is just a glorified piece of artwork. Either way, poor filter maintenance (replacing and cleaning of filters) renders your air purifier useless.



So why buy an air purifier that has filters? Well, right off the bat, they are a lot cheaper than the filterless alternatives. Even with the air filters that you will use over the years, it can still be more economical (and easier to budget for) an air purifier which depends on its filters. Filterless air purifiers commonly have grids or plates which will require cleaning, rather than replaced, but as we have already said, these are commonly pricier. The best kind of air filters that you can buy are called HEPA filters, which is an acronym for High Efficiency Particle Arresting.

HEPA filters are a specialized air filter that meets standards set in place by the US Department of Energy. These filters can capture particles in the air which are .3 microns in diameter, that’s about 1/167 the size of a human hair! Suffice to say, .3 microns is a lot smaller than anyone can see, but that doesn’t mean that things that small are not dangerous, like germs. HEPA filters are nearly twice as effective at screening the air of particulates, which would otherwise be inhaled by you. However, these filters are costlier than other air filters on the market.


When looking at air purifiers that require their filters to be replaced, it is important to see just what that means for you. Almost all the air purifiers out there, have filters you can replace yourself, without having to hire anyone to come into your home. However, the cost you will have to consider is how much all the replacement filters will cost. We found that many air filters cost at least $10 a piece, but most only need to be replaced about 4 times a year, costing you only $20 annually. Some filters last for a year or more, which makes them even more affordable. In the end, you have to see for yourself how affordable the replacement filters are.

If you would like to be walked through your own calculations on your annual air filters replacement cost, check out our post! How Do I Run the Numbers for Buying an Air Purifier? will take you step-by-step through the calculations you will need to make. This post also offers other guided equations for additional things you may want to calculate before making a purchase.


You’ve likely seen air purifiers that come with HEPA filters. Some companies simply tell you that their air purifier has a HEPA filter, while others go further into detail, describing the type of HEPA filter used. 

Some air purifiers claim to have a “True HEPA Filter” while others label themselves as “HEPA Type Filters”. Here, we will teach you what these two phrases mean, clearing away any uncertainty you will be feeling. 

Right off the bat, we’ll tell you plain and simple that a HEPA type air filter is NOT as good as a True HEPA filter. True HEPA filters are truly HEPA filters. HEPA type filters, on the other hand, are simply masquerading as the real thing.

Before we delve further into the differences between True HEPA filters and HEPA type filters, we need to go a little deeper into what a HEPA filter is. 

HEPA filters are special filters that utilize a dense fibrous material to clean the air. Many filters on the market also use materials like those in a HEPA filter, which is why some companies claim to have HEPA type filters. After all, they are made of similar materials right? 

As we are sure you know, just because something looks similar, or feels similar doesn’t mean they are the same thing. This holds especially true with air filters. Real HEPA filters are many times better than HEPA type filters. Read on below to see what makes HEPA filters special. 

HEPA filters have to meet stiff regulations set in place by the US Department of Energy (DOE). These regulations ensure that a HEPA filter can actually perform as well as they claim to. Long story short, this means that your filter will actually capture 99.97% of particles from the air. The particles captured will have to be .3 microns or larger, which, as we previously stated, is immensely small.

Now that we’ve established what a real HEPA filter needs to go through, let’s further disect the differences between true HEPA filters, and just HEPA type filters.

True HEPA filters meet the above regulatory requirements. The companies that manufacture them have put in the time and money to prove their filters are up to snuff. Not only that, they are also a lot better made, which is the only reason why they can pass the regulatory testing. This leads to these filters’ increased costs, which is why some people settle for just HEPA type filters. 

HEPA type filters are cheaper to manufacture for several reasons. The biggest reason being that they are of inferior quality. HEPA type filters don’t meet the government regulations that True HEPA filters do. HEPA type filters don’t function as well as True HEPA filters, and they won’t be as good at filtering the air either.


No, not all HEPA filters are the same. As we stated above, True HEPA filters are the only filters you should purchase, if you need really clean air. True HEPA filters will cleanse the air of 99.97% of particulates all the way down to just .3 microns. 

Be wary of air purifiers that claim to use HEPA type filters, as they are inferior to True HEPA filters. Companies use the phrase “HEPA type” in an attempt to trick people into thinking they are getting the real thing. 

Essentially, buying a HEPA type filter is like buying a pirated movie. It may be as good as the real thing (which is doubtful), but odds are, it doesn’t compare. It’s a lot simpler to just purchase the real deal, and get everything you are expecting.

If you are trying to save some money, then check out our article on finding affordable air purifiers that are worth the buy. There are some great deals out there on great air purifiers that have real HEPA filters, you’ll just have to dig a bit more than if you went the easy route. 


Replacing your air purifier’s filters ensures several things. Here are a few reasons to always replace your filters:

-Increased air purifier life

-Efficient air filtration

-More germs in the air


Keeping your air filters clean ensures that your air purifier doesn’t have to work harder than it is designed to. If you let your machine get choked up with everything it is filtering out of the air, it may impact you unit’s lifespan. If you fail to replace or clean you filters, you will also find yourself with less clean air coming out of your air purifier, since less air can be cycled through. This also results in more particulates (germs, dust, etc.) being left in the air you are breathing, since they cannot be captured.


There are several different filter types for air purifiers. Here are some of the most common that you will likely see:

-Fabric Filters

-Carbon Filters

-HEPA Filters

-Pre Filters

Fabric filters are just that, filters made from fabric. Many of these can be washed, and they do a great job at filtering your home. Carbon filters are used to neutralize odors and allergens, normally with activated charcoal. Impregnated carbon filters work much like their activated carbon counterparts, but they are treated in a way that they capture aerosol particulates, which are proven to harm your health. HEPA filters are specialized filters which capture over 99% of the particulates in the air that passes through them. They are great for people with allergies.

Pre filters remove the largest particles in the air before they can clog up the rest of your filters. This allows for a longer lifespan for the rest of your filters. We strongly recommend finding an air purifier with a pre filter because of the attached savings that they provide. The lifespan of your air purifier’s main filter is greatly increased when pre filters are present, which is very beneficial.

If you would like to learn more about pre-filters, see our post that is all about the importance of pre-filters! Pre-filters are ideal if you want to maximize every dollar that you invest into an air purifier.


Air purifiers that use UV light to sanitize the air do need air filters as well. The UV light simply kills the particulates in the air, like allergens and pathogens, they do not take them out of the air completely. In fact, many of these UV air purifiers are rendered largely ineffective because the air they are cleaning passes through them too quickly to be properly sanitized.

We recommend purchasing air purifiers with HEPA filters since these filters do the best at capturing microscopic particulates. By having a HEPA filter in addition to your UV sanitizer, you are ensuring the best possible air quality in your home. The HEPA filter captures the neutralized particles and the allergens and pathogens that survived the UV light. This makes this filter invaluable.

One air purifier filter types that I’m really happy and excited about is actually water! Literally water! Believe it or not, water is a great filter type, and it’s a lot easier to “replace” its filter too! If you’d like to read up on water-based air purifiers, check out one of these articles that I wrote on them!

What is a Water Based Air Purifier? | The Pros & Cons of Water Air Revitalizers

What Is the Best Air Purifier That I Can Buy? | Water Based Air Purifier Buying Guide

What Does a Water Air Purifier Do? | The Surprising Benefits of Using Water as an Air Filter

Frequently Asked Questions

What Exactly Do Pre Filters Do?

Your Air Purifiers Pre Filter stops larger particulates from entering your main filter. It is designed in a way that allows only the smallest particles through it. Your main filter (the one that does capture the smallest particles) doesn’t have to work as hard. By stopping the largest particles from entering the main filter, the pre filter ensures your main filter can work harder, longer. Saving you money in the long run. We recommend spending a little bit more to buy an air purifier with a pre filter.

What Other Kinds of Air Purifiers Are Out There?

There are several kinds of air purifiers in production, the most common of which relies on replaceable or washable filters. Some air purifiers also use UV light, heat, and static electricity. All of these systems address similar issues, and just utilize different technologies to achieve a similar end result. We recommend doing your own homework or visiting our other post which further details the types of air purifiers.

What are Ozone Generating Air Purifiers?

These machines work like normal air purifiers, by with one major caveat, they also release a gas known as ozone. Small amounts of ozone are not dangerous, in fact, that clean smell you smell during a lightning storm is actually ozone! Air cleaners with ozone generators are great for sterilizing a room, but you had best keep the room vacated.

Can Air Purifiers Take Care of Cat Hair?

Yes, air purifiers take care of cat hair, dog hair, and hare hair! They can capture stuff a lot smaller than that too, including pet dander. Air purifiers cut down on common odors that plague pet owner’s homes. Now you can have your furry family members indoors and not have to worry about what guests will smell.

What do Air Purifiers do?

Air purifiers take out numerous things from the air you breath which can be harmful to your health. This may include particulates that come from car’s tailpipes, or airborne pathogens, or just dust and pollen. Depending on what you are susceptible to, air purifiers can be your fix!

Do Air Purifiers Help Me with My Asthma?

Asthma attacks are commonly caused by dust and other particulates in the air entering an asthmatic person’s lungs, air purifiers remove these invisible hazards. By removing the microscopic matter from the air, the cleaners keep it out of one’s lungs. Effectively stopping future asthma attacks. Air purifiers are commonly bought by people with any breathing difficulties to ensure easy breathing into the future.

How do Air Purifiers Work?

There are several different methods that are utilized in air purifiers. These include carbon and fabric filters, static electricity, screens, heat, UV light, and more. The air purifying machines run their surrounding air through themselves. They sift out all of the particulates in the air and capturing them. The resulting air that they release is freshly cleaned.

Jonathon Silva

Jonathan Silva is our longtime Air Purifier Essentials author. He has been writing on air purification technologies for his entire professional career.

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