H10 to H12 filters are sometimes referred to as True HEPA filters. They trap less particles than higher quality filters, such as H13 and H14, which are known as medical grade HEPA filters. These filters can capture up to 99.995% of all particles down to 0.3 microns. The main difference between the HEPA filter and the True HEPA filter is their filtration efficiency.
Generally, the HEPA-type filter has an efficiency rate of 99% for particles as small as 2 microns, while True HEPA filters have an improved efficiency rate of 99.97% for particles as small as 0.3 microns. The HEPA-type filter is often combined with a compact and inexpensive air purifier, while the True HEPA filter is labeled with the largest and most premium air purifier models.Many air purifiers claim that they can remove contaminants, but they may be hybrid purifiers with an additional carbon filter or the HEPA filter may be impregnated with activated carbon.
HEPAor HEPA-type filters are classified as MERV 9-12, meaning they can only filter particles in the air that are one to three microns in diameter. To get the best odor reduction in your home or office, you should look for an air purifier equipped with a medical-grade HEPA H13 filter.The highest MERV grade range is MERV 13-16, but HEPA filters are generally classified as MERV 17 due to their ability to capture particles as small as 0.3 microns, or up to 0.1 microns in the case of medical grade HEPA filters.
A manufacturer that makes air purifiers for use in their home cannot go to the DOE and obtain a HEPA seal of approval for use in their packaging.
HEPAfilters continue to work at this level for quite some time until they are shipped automatically or a replacement is purchased, depending on the configuration. When air is drawn into the HEPA filter, the fibers of the high-density filter trap contaminants that pass through it by direct impact, diffusion, sieving and interception. A HEPA filter can suck in air containing virus particles and trap these particles in the filter until it is finally discarded.
Absolute HEPA, sometimes used to mean the same thing as True HEPA, indicates an affirmation of even better filtration performance, up to 99.999 percent at 0.3 microns according to Terra Universal, a company that manufactures filters for vacuum cleaners. Government contractors must comply with strict regulations when installing HEPA filters in nuclear facility ventilation systems.To meet the HEPA specification, an air filter must trap 99.97 percent of all particles with a diameter of 0.3 microns.
The best way to find out what type of HEPA filter is used in an air purifier is to review the specifications in its manual or website.