All HEPA filters are rated MERV 17 or higher, providing protection to the HVAC system and improving indoor air quality. Kevin Albers, developer of ISO-Aire, explains the difference between a MERV filter and a HEPA filter in this short video. It is recommended to use air filters with at least a MERV 13 rating, or a higher HEPA rating when possible. The HEPA test on a 95% ASHRAE air filter is approximately 50% efficient on 0.3 micron particles once they are loaded with dust.
The MERV rating system measures the size of particles that can pass through air filters. Before installing an air cleaner with a high MERV rating or a HEPA filter, make sure that your heating and cooling systems are capable of handling it. It is best to consult an HVAC engineer before attempting to upgrade any air filter. MERV 13 filters are beneficial for people with asthma and allergies, as well as households with pets.
They capture 90% or more of particles from 3-10 microns at their worst. MERV stands for “Minimum Efficiency Reporting Value” and is determined by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE). When particles from the working environment enter the RESPA air intake port, they impact and intercept the filter fibers. It is important to have the best air filtration and disinfection systems on the market, even if they are mislabeled as HEPA or HEPA-like filters to make them more affordable.
Each rating scale measures the effectiveness of the air filter from lowest to highest. For smaller particles, the filter fibers act as branches that trap harmful engine contaminants passing through the filter. A HEPA filter with a MERV 17 rating will trap 99.97% of air particles with a size of 0.3 microns, but will capture an even greater percentage of particles smaller or larger than that size.