HEPA filters are the top of the line when it comes to air filtration, with a rating equivalent to a MERV 17 or higher. These filters are capable of trapping 99.97% of air particles that are 0.3 microns in size, and even more of particles smaller or larger than that size. They are commonly used in operating rooms, clean rooms, and other indoor spaces that require high-level air filtration. The MERV, or Minimum Efficiency Reporting Value, is a form of measurement rather than a specific type of filter. A filter with a MERV rating of twelve is around 95% effective at removing particulate matter from the air, and those with a MERV rating of thirteen are around 98% effective.
Most residential air filters have a MERV rating of eight or more, making them suitable for people with moderate allergies or asthma. Filters with a MERV rating of one to seven are considered to be of medium efficiency and remove fewer air particles from the environment. Technically, filters that meet HEPA requirements have a MERV rating of 12 or higher, meaning they are effective at trapping 99.97% of particulate matter from the air. Developed by the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE), MERV is an acronym that stands for Minimum Efficiency Reporting Value. In other words, if HEPA filters received a MERV rating, they would have approximately a MERV rating of 17 or higher. In light of the threat posed by the spread of COVID-19 and other germs, replacing a building's air filter with a HEPA one is much more effective than using one with a MERV 13 rating.
This is because the virus is very small (from 0.06 to 0.12 microns), so the more efficient the filter, the better. The MERV classification determines the efficiency of an air filter when it comes to trapping larger or smaller particles. A MERV rating of eight to eleven is still considered to be highly efficient and can remove up to 85% of particulate matter from the air. A HEPA filter is basically the ultimate solution in the world of air filters and far exceeds what a MERV 13 can do. In the world of home and office air filters, some confusion may persist between the MERV and the Registered Minimum Efficiency Value (MERV), which is a number between one and sixteen that represents the efficiency of an air filter in removing particulates from indoor air.
