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What is a Pre-filter on an Air Purifier?

As of late, there has been a growing concern over how well protected we are at home. This doesn’t just refer to home security systems but also attacks by microscopic offenders. We’re talking about airborne contaminants, but an air purifier equipped with the right types of filters should help ease any lingering worries.

What is a Pre-filter?

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The best air purifiers come with multi-level filtration systems, starting with a pre-filter. In this short guide, we’re focusing entirely on what pre-filters are, their purpose, and how to maintain the pre-filter to ensure better air purification at home.

What is a Pre-filter?

The “pre” label in pre-filter should give you a slight indication of what it is. Basically, a pre-filter is an air purifier’s first line of defense when removing airborne particles from the air. To be more specific, the pre-filter traps the largest particles such as hair and dust.

What is a Prefilter?

In most air purifiers, the next filtration step is passing air through a HEPA filter to capture finer, microscopic particles to stop them from going airborne.

If a pre-filter weren’t in place, the HEPA filter would bear the brunt of the force, take in all contaminants large and small, and become clogged a lot more quickly, ultimately requiring more frequent washing and replacing.

To put it simply, the pre-filter is not an air purifier’s main filter, but it keeps the main filter unclogged for longer by stopping larger particles from passing through the system.

Pre-filter vs. Activated Carbon Filter

Some pre-filters are physically attached to an activated carbon filter so they can be one in the same. However, in most cases, they are kept apart for maintenance purposes, and they also have very different functions.

What is an Air Purifier Pre-Filter?

Pre-filters trap larger particles from making their way into the HEPA filter, whereas an activated carbon filter, a.k.a. activated charcoal, is a porous filter designed to trap finer particles as well as odor molecules. The best air purifiers come with both a pre-filter and an activated carbon filter for better purification performance and odor removal.

Maintaining the Pre-filter

In general, pre-filters are washable, reusable, and never require replacements. Maintaining the pre-filter is a simple task that involves vacuuming the filter to remove accumulated dust and lint or sending it through a gentle wash, rinse, and dry cycle.

Do I Need A Pre-Filter

Make sure the pre-filter is thoroughly dried before placing it back into the air purifier.

If the pre-filter is physically attached to an activated carbon filter, the only difference is that you will need to replace the entire filter later on. On average, a combination pre-and-carbon filter can remain fully functional for up to six months. Check with the manufacturer of your air purifier to see how long the carbon filter lasts and where you can purchase replacements.

Other Filter Types

For obvious reasons, the best air purifiers should not rely solely on a pre-filter to make indoor air more breathable. Here is a list of other filter types you should consider when looking for the most appropriate air purifier for your home.
True HEPA Filter
Activated Carbon Filter
UV-C light

Do I Need Pre-Filters for My Air Purifier?

Air Recommended Air Purifiers

Our Pick Perfect for bedrooms, playrooms, and living rooms, the Coway Airmega AP-1512HH is one of the best-performing, most durable, and most economical purifiers we’ve tested.

Most Popular The Levoit Core 300 air purifier has some strong suits, but in our opinion it falls short of carving out a meaningful niche for itself. Its ideal use would be in a small bedroom occupied by someone who is sensitive to noise.

Also Great With high end air cleaning performance and a whisper quiet fan, the Winix 5500-2 is the perfect combination of power and finesse. It cleared airborne particulates out of our smokey testing room faster than any other model.

Best of the Best If you have a large space you want to remove irritants from, We recommend the Airmega 400S. All of Coway air purifiers do an excellent job of attacking indoor pollutants, and we highly recommend any of them. The 400S is designed to accommodate large room sizes.

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If you have any questions or comments, please add them below in the comment section. Similarly, please let us know if you spot any mistakes or omissions. Thanks!

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About the author

Hi I’m Alex, founder of HouseholdMe.com and I’d like to say thank you for dropping by. Like most of you, the first thing I look at before buying something online is reviews or buying guides. By reading what other people say will help me gauge whether or not a product is good or not.  I am trying to help people find answers, solve problems, and get inspired.

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