H10 to H12 filters are sometimes referred to as True HEPA filters, and they are able to trap fewer particles than higher-grade filters. H13 and H14 filters, on the other hand, are known as medical grade HEPA filters and are able to capture 99.95% and 99.995% of all particles down to 0.3 microns, respectively. H13 HEPA filters are considered the highest level when it comes to this technology, making them perfect for use in hospitals, clinics and other medical environments. They can also be referred to as H11 or H12 filters.
In terms of efficiency, HEPA H13 filters are able to trap up to 99.95% of particles with a minimum size of 0.1 micron in diameter. This makes them just as efficient as other types of air purifiers, such as electrostatic vs. HEPA air purifiers, HEPA filters versus air purifiers, diffusers versus air purifiers, and water-based versus filter-based air cleaners. H13-H14 HEPA filters are within the highest level of HEPA air filtration and are considered medical grade. The main difference between the HEPA filter and the True HEPA filter is their filtration efficiency.
Generally speaking, the HEPA-type filter has an efficiency rate of 99% for capturing particles as small as 2 microns, while True HEPA filters boast a better efficiency rate of 99.97% on particles as small as 0.3 microns. HEPA-type filters are often combined with the most economical and compact air purifiers, while true HEPA filters are labeled with the largest premium air purifiers. Unless a filter meets the DOE standards for HEPA filtration, it cannot be considered true HEPA - even if it is able to capture 0.3 micron particles and capture a high percentage of them. HEPA filters capture and remove particles through direct effort and impact, but also through more complex mechanisms known as interception and diffusion which are designed to capture a higher percentage of particles. This is why medical grade HEPA filters are used in hospitals, operating rooms, and in the manufacture of pharmaceuticals. In order to reduce COVID-19 viral load, Nagl recommends installing an air recirculation unit with an H13 or H14 HEPA filter. A HEPA filter is an air filter typically made of plastic fibers (polypropylene), fiberglass, or borosilicate glass fibers. When purchasing a True HEPA filter, you should be able to obtain third-party testing that shows that the brand took the right steps to meet the DOE HEPA standards and test its efficiency.
It is important to note that not all HEPA-type filters can be sold under the guise of being true HEPA - even if they have an efficiency rate of 99%.Choosing a medical-grade H13 HEPA filter over less efficient variants can offer some notable benefits compared to an air conditioner since air purifiers work to clean the air more effectively by removing dust, pet dander, pollen, bacteria, viruses and other airborne contaminants with a durable, waterproof True HEPA filter. These considerations with respect to HEPA filters are essential when their goal is to reduce viral transmission from aerosols.