Furnace Filter Merv Rating

Every furnace filter has a minimum efficiency reporting value merv rating which measures how efficiently the filter captures particles of specific sizes that pass through it as your furnace operates.

Furnace filter merv rating.

Merv filter ratings and efficiency. Below is a table grouping merv ratings by particle size. Merv ratings range from 1 to 16. Particles are measured in microns and range from carpet and textile fibers greater than 10 microns to microscopic bacteria less than 0 3 microns.

Merv ratings range from 1 least efficient to 16 extremely efficient. Merv 17 through merv 20 filters are typically used in surgical operating rooms clean rooms and other contexts that require absolute cleanliness. The rating indicates the size of particles the air filter is designed to capture. Ranging from 1 to 20 the larger the number the better the filter is at catching small particles.

You might have been using furnace filters with one that is too low or too high for your furnace without knowing it. In general filters with a rating of merv 16 or below are considered to be hvac system grade filters for residential commercial and general hospital use. Read our blog for more information on how to choose the right filter for your furnace. At the very lowest merv rating 1 4 your filter will still capture pollen dust mites cockroach debris sanding dust spray paint dust textile fibers and carpet fibers.

If the rating is too low potentially dangerous or damage causing particles can easily slip by. Filters within a merv rating of 17 20 are almost never necessary in a residential home.