If you have searched for air purifiers, you may have come across the term "True HEPA Filter." In fact, the True HEPA filter is widely accepted as the most common air filter in both classic and modern air purifiers. This air filter is also the most important factor in determining the performance of a single air purifier.

But, in real-world usage, you may be fooled by several brands of air purifiers that claim to have a True HEPA filter.

The problem is, you don't know if all of the "True HEPA filters" are the same, or there are specifications to separate the class of these HEPA filters by value. Even so much research on the Internet don't satisfy you, and you also can't find a good True HEPA filter.

Don't worry about it!

In HealthyBreeze, we know all your problems with indoor air quality and air purifiers. We know you need the right air purifier to improve your quality of life. We're specialists in the field of air purifiers, but more than that, we 're just like you, people.

We also have significant issues with respiratory allergies and asthma, and we know that you're trying to master the air purifier and put an end to your suffering. Today, you'll know all about the True HEPA filter in our in-depth guide.

Ready to know more about the True HEPA Filter? Great! Keep reading below.

What's the True HEPA Filter?

True HEPA filter with HEPA stands for High Efficiency Particulate Arrest or High Efficiency Particulate Air is the highest standard for physical air filtration used by air purifiers.

In addition, HEPA filters are used in many applications, such as vacuum cleaners, cars and even aircraft. Furthermore, to be called a True HEPA filter, one HEPA air filter must be accredited to eliminate 99.97 per cent of all microscopic particles as small as 0.3 microns in size, which is the smallest particle size to get into your lungs.

Microns, which are one millionth of a meter, are how the particles are weighed. To help you know the size of a micron, we can't visually see anything less than 10 microns. 

The True HEPA filter is mostly made of high density paper, consisting of very thin fibers with distances between 0.3 and 2.0 microns. The fibers are randomly distributed and aligned in all directions.

There is a common belief that the air space between the fibers must be as small as 0.3 microns, so that the True HEPA filter will absorb something larger than this amount. This is, however, wrong and impractical. With a smart design, the True HEPA filter can target ultra-fine particles using a combination of three physical mechanisms:

Inertia effect: Unclean air flows through the filter media of the True HEPA filter, but the smaller particles (or larger pollutant particles) can not keep up with the gas flow. Consider, with their large-scale inertia, that these heavier particles move along a straight line and will soon be caught by one of these fibers in the True HEPA filter. That's why the fibers have to be uniformly distributed. The larger the objects, the more likely they are to be detected by the True HEPA Filter Inertial Impact Mechanism.

Interception: This method includes particles of a much smaller scale, so that they can conveniently obey the logic and do not collide directly to the True HEPA filter fibers. Nevertheless, the radius of these particles is much greater than the distance between the strip and the edge of the fiber (which is typically between 0.3 and 2 microns). Therefore, the edge of the fibers will be caught.

Broadcasting: This process is the most critical aspect of the True HEPA filter, and only the smallest particles can be eliminated. When the particles are as small as 0.3 microns, they do not strictly obey the logic and will pass randomly due to the interaction with the gas molecules (Brownian motion). The smaller the particles, the higher their freedom of movement, and therefore the higher the likelihood that they will encounter the fiber. When the particle size decreases, the diffusion mechanism becomes more significant.

So, in order to calculate the complete output of one True HEPA filter, you must count the effects of all three filtering mechanisms.

Are all HEPA filters the same?

No, not all HEPA filters are the same thing. There are significant differences in HEPA filters made by many brands of air purifiers. Depending on the quality of the materials as well as the density of HEPA fiber filters, one HEPA filter may be different from the other.

There are a lot of terms like "HEPA-type" or "HEPA-like" in the air purifier market and they are totally inferior to the "True HEPA Filter." These filters can only capture particles as small as 2-5 microns, which reduces the efficiency of one True HEPA filter by more than 600 per cent. Therefore, the safest approach is always to search for True HEPA filter air purifiers.

But how do you know that one air purifier has a True HEPA filter? Next, it must follow the strict requirements set by the United States.

The Energy Department. The True HEPA filter must eliminate 99.97 per cent of all particles larger than or equal to 0.3 microns as specified by the Department of Energy (DOE) of the United States.

You should search for the HEPA class in your air filter that follows either the European Standard or the MERV rating. 

Can you wash HEPA Filters?

If your HEPA filter is not clearly labeled as washable, then the answer is no, you can not wash your HEPA filters without damaging them.

Otherwise, you could wash it, but you need to know how to clean the air filter.

Pros and Cons of the True HEPA filters:

We've heard more about the True HEPA filter, but you really don't know whether this air filter is perfect or not.

Below are the pros / cons of the True HEPA filter:


  • Highly effective, most toxic pollutants are captured
  • Trapped particles should remain within the air filter.
  • Physical air filter will not emit ozone, which causes asthma and other breathing problems.


  • Needs daily filter replacement in order to preserve performance
  • Does not remove odors and smells

One of the best ways to save your health is to have an air purifier in your home. Don't hesitate to invest in one, by looking at the best air purifiers on the market. We, at HealthyBreeze, are going to help you in this mission. 

Our friendly and helpful customer service team is always just a phone call, email or quick chat away if you need assistance choosing the correct air purifier for your space and needs. 

At HealthyBreeze, we offer you the best air purifier you can find, from a low-cost alternative to medical-grade air purifiers. To help everyone improve their lives, we're going to offer the most reliable purifiers you can invest in without hesitation.