Not all HEPA filters are alike. You might have come across expressions like ‘True HEPA,’ ‘HEPA-like,’ ‘H13 HEPA’, and ‘Medical-Grade HEPA.’ Are all these the same kind of filter, or are there differences between them?

Before we check out a list of the best H13 HEPA filters, we need to clear up what HEPA actually means. 

Here’s a quick insight: H13 HEPA filters are the most thorough small-particle filters used eve in medical-grade air purifiers.

Testing HEPA filters with smoke and a small particle generator. H13 HEPA filters perform better than True HEPA filters.

The HEPA filter is the most basic filtration system for all the best HEPA air purifiers use. HEPA stands for High-Efficiency Particulate Air. Here is how the DOE defines HEPA filter:

“(HEPA filters) remove at least 99.97% of airborne particles 0.3 micrometers (μm) in diameter. The filter’s minimal resistance to airflow, or pressure drop, is usually specified around 300 pascals (0.044 psi) at its nominal volumetric flow rate.” (DOE)

In short, HEPA filters capture small particles like dust, pollen, mold, smoke, pet dander, and so on very well.

Now we know what HEPA is. Let’s answer this:

What Is The Difference Between HEPA, True HEPA, H13 HEPA, And Medical-Grade HEPA Filters?

“True HEPA is better than HEPA filter.”

 True HEPA vs. HEPA

That’s not true at all. ‘True HEPA’ is just a marketing term companies producing HEPA filters have come up with. There is absolutely no difference between an air purifier with True HEPA vs. HEPA filters; it’s just that True HEPA was tested to sound better in consumers’ ears.

What you really need to care about when buying HEPA air purifiers are terms like ‘HEPA-like’ and ‘HEPA-style.’ Those are basically wannabe HEPA filters. They don’t satisfy HEPA standards; they do not capture more than 99.97% particles that are 0.3 microns in diameter.

What Is H13 HEPA And Medical-Grade HEPA?

There are different classes of HEPA filters, according to EN 779 normalization standard. Classic HEPA filters are usually H10, H11, or H12 class. The best HEPA air purifiers will use H12 HEPA filters.

However, H13 is even better than normal HEPA filters. Specifically, the H13 filter captures particles that are more than 3x smaller than classic HEPA filters. Here’s the H13 HEPA standard:

“H13 HEPA filters remove at least 99.9% of airborne particles 0.1 micrometers (μm) in diameter.”

H13 HEPA, compared to HEPA or True HEPA, removes even the smallest particles True HEPA is unable to capture. Here include asbestos particles, paint pigments, insecticides, and so on, as seen on the True HEPA vs. H13 HEPA comparison here: