Everything You Need to Know About HEPA Filters and Why You Need One

If you’ve been thinking about purchasing an air purifier you’ve probably noticed manufacturers throw the term HEPA around a lot. A HEPA filter is a filter used inside many air purifiers. 

HEPA is an acronym for High-Efficiency Particulate Air. Essentially, it traps smaller particles than your typical filter – as small as 3 microns.

You’re told that a purifier is better because it has one of these filters. Is that true? And just what is a HEPA filter? You’ll find all of the answers you’re looking for below.

Our Top 3 HEPA Filter Air Purifiers Picks:

How does a HEPA Filter Work?

A HEPA filter has tiny twisted glass fibers packed together tightly, making it hard for small particles to get through. As the air flows over the filter, a HEPA filter catches up to 99.97 percent of particles in the air mixture on its fibrous surface. 

A HEPA filter’s purpose is to clean the air we breathe. We take in a ton of potentially harmful microscopic particles every time we breathe in. The HEPA filter captures 99.97 percent of them before they get into our lungs.

The HEPA filter captures particles in three different ways:

In the first method, when particles catch the side of the filter and stick to it this is called interception.

The second process is impaction – this is when particles make a direct impact with the filter, stopping their forward progress.

The third and final way these filters can capture small particles is by diffusion. This is when the particles interact with gases flowing through the filter. It slows them down, causing them to entangle in the filter.

What Problems can HEPA Filters Help Solve?

HEPA filters can help solve a range of health problems. They do a great job of capturing pet dander, pollen and, dust. That makes them the perfect tool for making your home less allergenic. 

For anyone that suffers from daily allergies, these filters can feel like a “life saver” – at least when we’re in our own homes. 

A HEPA filter can’t cure lung disease, but it can help to prevent further health problems that can make things worse.

Manufacturers use HEPA filters in a range of industrial applications – including the nuclear industry, where they help to prevent the spread of radioactive particles.

While they aren’t designed to specifically capture odors, some of the particles they remove from the air, such as mold, have a distinctly unpleasant smell. Removing them from the air removes their odor as well.

Types of HEPA Filters

Things get tricky when we start looking at the different types of HEPA filters. Intuitively we would think one HEPA filter is no different from another.

Not so fast. It turns out that Americans and Europeans have different standards when it comes to defining a HEPA filter – American standards are much more rigid. In Europe, a filter only has to capture 99.95 percent of particles 3 microns or larger to be labeled a HEPA filter, compared to American standards which call for 99.97 percent.

The other problem is many companies are advertising “HEPA-Type” filters that aren’t HEPA at all. It can be hard to make sense of it all. Read on and things will become a lot clearer.

What’s the Difference between HEPA Filters and True HEPA Filters?

Is there a difference between a HEPA and a True HEPA filter? The short answer is no. Some manufacturers have started to use the term True HEPA to indicate that their product complies with the actual HEPA standard. 

A HEPA filter and a True HEPA filter both meet the standard set by the United States Department of Energy. Unfortunately, some products use HEPA in their marketing campaigns, that aren’t HEPA at all. True HEPA, is the new term used to confirm that a product has a filter that meets the official definition.

What’s the Difference between True HEPA Filters and HEPA-Type Filters?

What about HEPA Type filters? They’re the reason that manufacturers have created the term True HEPA to indicate a HEPA compliant product. HEPA Type filters aren’t actually HEPA at all. 

Just to recap, a HEPA filter captures 99.97 percent of particles that are 3 microns or larger. That means that out of every 10,000 particles of this size that contact the filter, only 3 get through. A HEPA Type filter may capture somewhere between 85 and 99 percent of particles that are 2 microns or larger. There’s no set standard for these products.

How do HEPA Filters compare to Other Types of filters?

Microfiltration vs HEPA Filtering – Microfiltration systems offer comparable results to HEPA filters, but the process is quite different. Microfiltration uses multiple layers of filters. The first layer is a 1 ply cellulose filter media that captures large particles of dirt and the second layer is a polypropylene melt-blown filter that captures the smaller particles the first layer missed.

Microfiltration will capture between 90 and 98 percent of particles, depending on the quality of the filter.

Ion Filters vs HEPA Filters – Ion air purifiers are quite different from HEPA based products. They work by releasing electrically charged ions into the air around them. These charged ions bond with unwanted particles making them heavier than the air. The particles then drop to the ground, or on nearby surfaces so that we don’t breathe them in. 

The problem is that these particles aren’t captured, so they can be kicked back up into the air when someone walks through the room.

Particles may also accumulate on walls and furniture creating black spots. These aren’t just unpleasant to look at, they may also be harmful to your health.

Electrostatic Filters vs HEPA Filters – Air purifiers with Electrostatic filters charge the particles in the air, similar to an ozone filter. The difference is these purifiers then filter the particles and collect them on a plate which needs to be removed and washed periodically.

EPA Filters vs HEPA Filters  – EPA filters can vary a lot in their effectiveness. They capture between 85 percent and 99.5 percent of small particles. Even on the upper end of the scale, they are not as effective as HEPA filters.

Carbon Filters vs HEPA Filters – HEPA filters and carbon filters do different things. As we’ve already covered, HEPA filters remove particles as small as 3 microns with 99.97 percent efficiency.

Carbon filters capture odors, smoke, and chemicals from the air in highly absorbent carbon pores which open up when in contact with oxygen, trapping these particles inside. They’re common in industrial settings, but they are often used in coffee makers as well as a purifier to remove any impurities and improve the taste.

HEPA Filters FAQs

A Good Investment?

Air purifiers with HEPA filters (or true HEPA filters) are a little more costly than similar products and are also more expensive to replace. There’s a simple reason for this and that’s because they work. You can save money by choosing an air purifier that uses a “HEPA Type” product, but you’ll also be leaving a lot of the contaminants in the air you’re trying to remove. A True HEPA air purifier is a good investment.

🥇 Best HEPA Filter Air Purifiers Buying Guide

The section below includes the top 3 HEPA air purifiers that we’ve carefully selected based on a range of features. One of the most important deciding factors is how effective the air purifiers are at removing pollutant particles from the air. 

We’ve included a range of HEPA air purifiers that are great for different types of rooms and situations. Therefore, you can find something for a bedroom as well as an air purifier made for larger spaces like living rooms.

Some of the other factors we thought about while ranking these air purifiers include whether they have sensors, auto-modes, night-time settings, and how easy they are to use. We’ve also paid attention to the customer reviews to gauge their overall experience with the air purifiers to help with the ranking process.

View RabbitAir HEPA Air Purifier on Amazon