Testing HEPA filters with smoke and a small particle generator reveals that H13 HEPA filters are more effective than True (H10-H1) HEPA filters. In a nutshell, HEPA filters are great at capturing small particles such as dust, pollen, mold, smoke, pet dander, etc. If the filter does not meet the DOE standards for HEPA filtration, then it is not considered true HEPA. Generally speaking, the HEPA-type filter has an efficiency rate of 99% for capturing particles as small as 2 microns.
On the other hand, True HEPA filters boast a better efficiency rate of 99.97% on particles as small as 0.3 microns. The HEPA-type filter is often combined with the most economical and compact air purifier while the true HEPA filter is labeled with the largest premium air purifier. Medical-grade HEPA filters are the most effective method of air filtration and are classified as H13 filters. These can remove up to 99.995% of particles down to 0.1 micron.
A consumer air filter labeled True HEPA must meet the DOE standard closest to the DOE standard for a HEPA air filter and can capture up to 99.97% of particles measuring just 0.3 microns from the air. UltraHEPA is a marketing term used by AirDoctor which states that its air purifier is “100 times more effective than HEPA air filters, capable of removing particles down to 0.003 microns in size. Calling a filter a HEPA-type filter is essentially meaningless since it doesn't conform to any standard. Sanalife True HEPA portable air purifiers have multi-stage air cleaning power to provide the cleanest air possible and normal HEPA filter air purifiers are the least recommended since particles of 1.99 microns or smaller are not removed.
Choosing a medical-grade H13 HEPA filter over less efficient variants can offer some notable benefits, especially compared to an air conditioner, since air purifiers work to clean the air.