Pre-Filters in Air Purifiers

Air purifiers typically have a number of different filters.  The room air is passed through these different filters step by step, which ensures the outgoing air to be efficiently cleaned.  Generally, the first filter placed in an air purifier is the pre-filter.  Pre-filters are generally affordable, washable, robust filters.

In the below guide, we will share with you what a pre-filter is, what it does, how it does it, and why they are essential.  Many air cleaner models come with a pre-filter, simply because of how useful this feature is.

 What is the Function of a Pre-Filter?

Extend the life of your main filter.  In other words, to save you time and money.

The pre-filter is the front line in an air cleaner.  It captures the largest particles before the air moves on to the rest of the primary filters.  Pre-filters are very useful as they strengthen the air filtering process and prevent debris from clogging the primary filters.  This way the lifetime of the more expensive primary filters is also extended.

TIPS!

Pre-filters are effective in capturing hair, dust, insects, sand, dirt, and other larger particles.

How Does a Pre-Filter Work?

A pre-filter is, quite literally, a filter that is placed before your main filter or main filters.  So the air that enters your air purifier first interacts with the pre-filter before it reaches any of the other filters in the device.

Pre-filters work in a similar fashion to a sieve.  They consist of cheap and disposable materials, making up a tight grid or fleece. They have pores, where larger dirt particles are trapped before the air is passed on to the main filter/s.  These mats are generally durable and washable.

Unlike expensive and elaborate filters like the HEPA filters and activated carbon filters, pre-filters typically have a long lifespan.  They are made to be cleaned and reused.

Do I Need a Pre-Filter?

If all of the larger and coarser particles were sucked directly into your HEPA filter or any other main filter rather than the pre-filter, then your HEPA filter’s lifespan and effectiveness would be significantly reduced.

Instead, these cheap and durable pre-filters save you money and time by protecting your elaborate and expensive main filters.  Unlike these main filters, pre-filters can be cleaned and reused for long periods.  They serve quire an essential purpose.

How Do I Clean a Pre-Filter in an Air Purifier?

Pre-filters are often suitable for permanent use. Unlike the main filter, they do not have to be replaced.  Nevertheless, dust builds up in the filter over time, so regular maintenance is still important.  Otherwise, pollutants such as dust, pollen, hair, fur, and dirt get stuck in the pre-filter and will dramatically decrease the overall performance of your device.  

  • Turn the air cleaner off and remove the washable pre-filter.
  • Take the pre-filter out and shake it well.
  • Vacuum the pre-filter.
  • Wash the pre-filter under warm water by your hand.
  • Allow the pre-filter to dry and insert it back.

If your air purifier operates continuously, it is recommended to clean your pre-filter at least once a month.  You can briefly vacuum the pre-filter, followed by a thorough wash under running water.  Generally, you will visibly see the difference between the uncleaned and cleaned filter.

Be aware of the specifications of your pre-filter.  Not all pre-filter types are suitable for vacuuming or for washing.  Some may need to be rinsed or cleaned in a different method.  Follow the instructions laid out by the manufacturer of your device.

What Types of Air Pre-Filters Are Available?

The most common type of a pre-filter looks very similar to your standard sieve filter.  It is typically made out of a basic fabric or paper product.  This type of pre-filter can be cleaned through vacuuming.

Another common type of a pre-filter is made up of a screen or a grid.  This is used to capture large particles from the air.  A similar and effective pre-filter type is made up of a sponge-like material.

TIPS!

If the pre-filter is made using a static-charged collection grid, the lifetime of the filter significantly extends.  However, this type comes at a price, making them less sought after.

There are pre-filters that include activated carbon.  While it makes them much more effective, these pre-filters need to be replaced more often.  Mind you, this type of pre-filters should not be washed.  So it is better to find an air purifier that has a simple pre-filter, but an activated carbon filter as one of the main filters instead.

How Long do Pre-Filters Last Before Replacement?

Pre-filters usually have a long life as they can be washed, vacuumed, and reused many times. 

Though no matter how well you look after and maintain your pre-filter, it has a certain half-life.  They are durable, but they do not last forever.

Depending on the level of use, some last many decades, while some only last under a decade.  Nevertheless, they are generally quite affordable to replace.

How Long do Pre-Filters Last Before Replacement?

Pre-filters usually have a long life as they can be washed, vacuumed, and reused many times. 

Though no matter how well you look after and maintain your pre-filter, it has a certain half-life.  They are durable, but they do not last forever.

Depending on the level of use, some last many decades, while some only last under a decade.  Nevertheless, they are generally quite affordable to replace.

Why Are Pre-Filters Cheaper to Replace Than Main Filters?

Some of the most popular primary filters in air purifiers are HEPA filters and activated carbon filters.  Both types of filters have to meet rigorous standards in order to be manufactured with the corresponding certifications.

In HEPA filters, these standards ensure that they capture 99.97% of all particles larger than 0,3 µm in diameter size.  The elaborate structure of the filter thus justifies the high cost associated with the end product.

A pre-filter on the other hand does not follow any particular set of standards or guidelines.  It basically needs to be a coarse and durable filter that is placed before the main filter.  Its simple job is to prevent large particles from clogging up the rock star filters following it.

TIPS!

Accordingly, there is a variety of different pre-filters available in the market.  Although they have different structures and they work in different ways, they pretty much perform the same task overall.

Often, manufacturers will use the most affordable fabric or paper, or grid provided that the pre-filter serves its purpose.  Most of these pre-filters, regardless of their affordable composition, last long years of use.  Thanks to their cost point, their replacement price also does not break the bank. 

Are Pre-Filters Effective Against Dust?

Yes.  Pre-filters help cleaning part of the dust in the air.  However, do not rely on them completely.  As the name suggests, pre-filters only roughly clear out the air before the primary filter steps up and acts its role.  Pre-filters remove some of the hair, dust, insects, sand, dirt, and other large particles from your indoor air.  Then, your main filter performs the actual cleaning.

If dust is your main problem, an air purifier is the right solution.  Perhaps every air purifier can reduce the amount of dust in your air.  However, there are different types of air purifiers.  Furthermore, each type has numerous models available in the market.  Each has its advantages and disadvantages.  There are many variables including, but not limited to, types of filters, technical abilities, coverage area, size, and price.  It is important to choose the right air cleaner for you, depending on the specifics of your case.

Conclusion 

You clearly know a thing or two about air purifiers if you are here reading this article.  So, no need to tell you about the countless benefits.  Pre-filtration essentially extends the life of your main filter, which means your air will be cleaner for longer.  It also means you will save money and time.  So, we highly recommend you to choose an air purifier with a pre-filter.