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MERV Ratings Explained

Air filter quality is measured based on the MERV (which stands for “Minimum Efficiency Reporting Value) system. The MERV rating rates filters based on how effective they are in catching particles of varying sizes. The higher the MERV rating, the higher the air filtration capabilities of a particular filter.

MERV ratings range from 1 to 20 (1 is the lowest level of filtration, 20 is the highest). Filters that are MERV 16 through 20 are usually only found in hospitals, cleanrooms, and nuclear power plants. Most home or residential air filters are rated anywhere between MERV 5 and 13. FST only recommends using filters with a rating about MERV 8 in residences.