What does a HEPA filter do? (What is a HEPA Air Purifier?)

In this article we’ll answer three questions:

By the end you’ll discover why HEPA filters and air purifiers are so important to the air quality inside your home.


What does a HEPA filter do?

If you shopped for vacuum cleaners and air purifiers you’ve definitely come across the acronym HEPA.

This is used to differentiate quality between devices on the market.

HEPA stands for High Efficiency Particulate Air. In air purifiers, HEPA means that the filters 99.97% of contaminants including dust, dander, pollen, mold and other common allergens.

What is a HEPA Air Purifier?

A HEPA air purifier is a device that is equipped with a HEPA filter.

This HEPA filter captures airborne particles and prevents them from irritating your lungs and lowering the air quality in your homes.

We have a free guide on the best air purifiers ensuring you find the best ones.

Our top 2 air purifiers with the True HEPA filter are Honeywell HPA300 and Levoit Core 300.

How many types of HEPA filters are there?

Unfortunately, many companies use the term HEPA on their products but this can be misleading to consumers.

There are many different terms “True HEPA” “HEPA-type” and “HEPA-like” labelled on air purifiers. What you want to look out for is True HEPA.

In order for products to be labelled “True HEPA” they must meet the strict standards set by the US Department of Energy.

These standards set that the HEPA filter must capture 99.97% of particles as small as 0.3 microns. To better visualize this size, a human hair is 0.5 microns, while the smallest allergen are 7 times smaller than that.

Unlike True HEPA, there are no standards for HEPA-like or HEPA-type filters. The lack of standards means that these air filters can’t guarantee the same effectiveness.

Why are True HEPA filters the best?

A True HEPA device costs more because the filter is the best in the industry.

Cheaper air purifiers will have an inferior filter inside.

It’s important to buy an air purifier with the “TRUE HEPA” label.

It’s also important to note that filters come in two types:

  1. A highly dense paper filter that must be replaced every few months
  2. A mesh HEPA filter that’s washable (and permanent)

Pros of True HEPA filters

Because a True HEPA air purifier is excellent at trapping almost all airborne contaminants, it’s the best choice for someone who has asthma or suffers from allergies.

This dense filter is amazing at trapping allergens such as dust, pollen, mold pet hair and dander.

Cons of True HEPA filters

One of the biggest cons of HEPA filters is that it can’t remove odors, viruses or bacteria.

A HEPA filter works by trapping particles but it does nothing for odors.

Most air purifiers will also have an activated carbon filter that is designed to neutralize odors and smells.

Viruses and bacteria can only be removed by Ultraviolet Light filters.

The lights sends out radiation that zaps the the harmful viruses and bacteria by destroying their DNA structure.

Finally, HEPA air purifiers are the most expensive device because the filter is the most advanced technology that removes 99.97% of all contaminants.

Read more articles about air purifiers:

Frequently Asked Questions About Air Purifiers
The Benefits of Air Purifiers
ACH and CADR Ratings Explained
How Do I Choose an Air Purifier
How to Choose the Right Size for an Air Purifier