What is Pre-Filter in an Air Purifier?

Air Purifiers are definitely a wonderful invention to help clean the air inside your home, car or offices.

No matter how advanced or basic the air purifier is, it contains the pre-filter above everything else.

But, what is a pre-filter and what does it do?

Well, in this article, let us have a look at the uses of a pre-filter in an air purifier and why it is an important device.

What is an Air Purifier Pre-Filter?

A pre-filter is a device that removes large waste particles like dust, hair, pollen, fibers, insects etc… present in the air.

Pre-Filter Functions

A lot of the air purifiers come with a dedicated pre-filter while some air purifier brands combine the pre-filter with an Activated carbon filter.

Washable Air Purifier Pre-Filter

Whichever way it is equipped in an air purifier, it’s main goal is to act as a first line of defense by attracting/catching as many large particles as possible.

A pre-filter is also responsible for the prolonged lifespan of other main filters in an air purifier such as the True HEPA filter as it saves their efforts of removing large particles in the air.

If the pre-filter was not present in your air purifier, it puts a lot of pressure on the True HEPA filter and as a result they wear out much quicker, resulting in spending a lot of money on filter replacements every year.

Since all the large particles like hair fur, dust, pollen etc.. are trapped by the pre-filter, the remaining filters can work at their full potential, thereby delivering you the cleanest air possible.

How Long Does a Pre-Filter Last?

Whether it comes as dedicated or combined with an Activated carbon filter, a pre-filter usually lasts for a very long time.

If it is a dedicated pre-filter, then it can be washed and reused as long as your purifiers lasts.

And, if it comes equipped with a carbon filter, then it has to be changed with your activated carbon filter.

How Do You Clean a Pre Filter of an Air Purifier?

Cleaning the dedicated pre-filter is very easy and most air purifiers display alerts when it is time to change/wash the filters.

  1. Turn the Device OFF

    First of all, switch off the air purifier.

  2. Extract the Pre-filter

    Remove the Stage 1 washable pre-filter, which is usually behind the front-grille of your air cleaner.

  3. Wash it thoroughly

    Take it outside and wash it using warm water with your hand.

  4. Let it Dry

    Next, shake any excess water and allow it to dry.

  5. Put it back in the device

    Once done, insert the pre-filter back into its spot and close the grille.


So, now that you’ve understood the importance of a pre-filter in the air purifier, it is high time you clean it regularly for best air filtration.

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