However, there are different grades of HEPA filters, ranging from H10 to H14.The higher the grade, the higher the performance. Filters H10 to H12 are sometimes referred to as True HEPA filters. H13-H14 HEPA filters are within the highest level of HEPA air filtration and are considered medical grade. There are different classes of HEPA filters, in accordance with the EN 779 standardization standard.
Classic HEPA filters are usually class H10, H11 or H12.The best HEPA air purifiers will use H12 HEPA filters. According to the Institute of Environmental Science and Technology, (EST) with respect to performance, there are 6 types: A, B, C, D, E %26 F. Each has its own distinctive characteristics, as shown in table 1 below. HEPA filters can come in many forms with differentiating factors, such as grade, class, or MERV rating.
There are standards set by the Department of Energy (DOE), but the type of HEPA filter may vary by manufacturer. That's right; the Levoit LV-H135 comes with the medical-grade HEPA filter that can capture more than 99% of the smallest air pollutants that are small, up to 0.1 microns in size. Specifically, the H13 filter captures particles that are more than 3 times smaller than classic HEPA filters. That's why modern air purifiers come with a detector that tells you when HEPA filters need to be changed.
When looking for air purifiers and air filters, it's important to note that HEPA filters are available with different levels of efficiency. According to Department of Energy standards, a HEPA filter must remove at least 99.97% of particles in the air that have a diameter of 0.3 microns, also known as microns. A HEPA H13 filter can trap 99.95% of particles of 0.1 micron in diameter, while a HEPA H14 filter can capture 99.995%. The uneven weave of the filter screen results in a large amount of air swirls, and small particles are adsorbed to HEPA under the action of the air cyclone.
All in all, you can see that improved HEPA H13 air purifiers are more difficult to incorporate into an air purifier. The highest MERV grade support is MERV 13-16, but HEPA filters are generally classified as MERV 17 because of their ability to capture particles as small as 0.3 microns, or up to 0.1 microns, for medical grade HEPA filters. All in all, a decent HEPA H13 air purifier at an affordable price, but it's quite far from the best medical grade air purifier. While HEPA filters began as a defense against nuclear particles, the shift to commercialization has made it possible for everyday consumers to use filters in a more diverse way.
Today, HEPA filters are the most widespread small particle filters, used in HVAC (air purifiers, air conditioners), biochemical applications, and overhead lines. Although the HEPA filter is often the greatest defense against particles in the air, when combined with additional filtration or sterilization, it can further improve air quality and extend the life of the HEPA filter. If you're looking to buy a HEPA air purifier, look for high-efficiency air purification. In theory, a HEPA filter is literally any filter that can capture at least 99.97% of very small particles of 0.3 microns in size.
In HEPA H13 filters, you'll see that True HEPA filters mainly target particles of 0.3 microns, while HEPA H13 filters target particles even smaller than 0.1 microns.