What is a Pre-Filter in an Air Purifier?

Updated: Jul 7, 2022 6:14 PM
What is a Pre-Filter in an Air Purifier?

If you are shopping around for a top-performing air purifier, you may be getting overwhelmed by all of the advertising jargon and technical terms. One such term that is thrown out a lot is a pre-filter. What is a pre-filter in an air purifier and what does it do? Keep reading to find out.

KEY TAKEAWAYS:

  • An air purifier’s pre-filter will trap larger-than-average particles, such as pet hair before they have a chance to gum up the actual air filter.
  • Using a pre-filter can increase the overall effectiveness and lifespan of a standard true HEPA filter.
  • Make sure to clean your pre-filter according to the manufacturer’s instructions to maintain efficacy.

How do Filters Work in the First Place?

To understand pre-filters, you must first understand actual air filters. An air purifier’s standard filter works when the purifier’s fans force air through it. The filter will “filter out” impurities by capturing and trapping these pollutants as the air blows through. Another set of fans will then blow this purified air back into your living space. To understand better how filters work and how quickly a given air purifier will clean the atmosphere of a room, you should know what a good cadr rating is for an air purifier. Additionally, you might want to know the CFM in an air filter and the energy usage of an air purifier, so you get the most benefit from your device.

Insider Tip

The filter will “filter out” impurities by capturing and trapping these pollutants as the air blows through. Another set of fans will then blow this purified air back into your living space.

So How Does a Pre-Filter Work?

As the name suggests, a pre-filter is the filter before the filter. Simply put, the pre-filter will stop anything potentially obstructive from being allowed into the main filtration compartment. The fans of an air purifier are pretty strong and can accidentally pull in larger-than-average particles, such as specks of dirt, hair follicles, and more. The pre-filter holds on to these large particles so they can’t clog up the actual filter. This is a good thing, because you don’t want to know what happens if you don’t change the air filter in an air purifier. It starts to stink!

Benefits of a Pre-Filter

If you have never experienced an air purifier then you may wonder what an air purifier is good for. There are several benefits to using an air purifier that comes equipped with a well-made pre-filter. Here are just a few.

Insider Tip

The pre-filter will stop anything potentially obstructive from being allowed into the main filtration compartment.

Reduced Pet Dander

As pet owners are well aware, animals can shed a whole lot of fur and hair throughout the year. This dander can easily get sucked into an air purifier and gum up the works. Using an air purifier with a good pre-filter will hold on to that pet hair before it gets to the integrated air filter. This will help protect the filter from becoming clogged but will also help reduce pet-related allergens from your living space.

Increased Lifespan of HEPA Filters

Experts agree that you should replace a HEPA filter every six months to a year. There is one problem with that, however, as HEPA filter replacements can be costly. If you want to save a few bucks, try an air purifier with an integrated pre-filter. The research here is scarce, but using a pre-filter should help you slightly extend the overall life of your HEPA filter. Hey, every bit counts.

Warning

The fans of an air purifier are pretty strong and can accidentally pull in larger-than-average particles, such as specks of dirt, hair follicles, and more.

F.A.Q.S

How often do you need to change an air purifier pre-filter?

This will depend on the design of the pre-filter itself, though many pre-filters should be changed out or cleaned once every month.


How to clean an air purifier pre-filter?

This will depend on the design of your pre-filter. Read the instructions to be sure it can be cleaned and then follow the details to the letter. For instance, some pre-filters may need to be cleaned with water, while others should avoid becoming wet.


Can air purifiers take care of cat hair?

Air purifiers can certainly take care of cat-related allergens that are floating in the air. As for the cat hair itself, you may need a capable pre-filter that has been purpose-built to capture animal dander.



STAT: True HEPA filtration is medical-grade filtration and captures up to 99.97% of particles as small as 0.3 microns from the air. (source)

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