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?


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?


Recommended Affordable Air Purifiers
Best of the Best! Budget Pick Also Great
Coway Airmega 300 Smart Air Purifier with 1,256 sq. ft. Coverage Germ Guardian True HEPA Filter Air Purifier for Home, Office, Bedrooms, Filters Allergies, Pollen, Smoke, Dust, Pet Dander, UV-C Sanitizer Eliminates Germs, Mold, Odors, Quiet 22 inch 3-in-1 AC4825 Coway AP-1512HH Mighty Air Purifier with True HEPA and Eco Mode in White
Coway Airmega 300 Germ Guardian AC4825 Coway AP-1512HH
1,256 sq. ft. Coverage
True HEPA filter
167 sq. ft. Coverage
True HEPA filter
361 sq. ft. Coverage
True HEPA filter
300 Dust | 340 Pollen | 310 Smoke
118 Dust | 125 Pollen | 108 Smoke
246 Dust | 240 Pollen | 233 Smoke

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