Furnace Filter Merv Rating

Merv ratings range from 1 to 16.

Furnace filter merv rating.

If the rating is too low potentially dangerous or damage causing particles can easily slip by. The higher the merv rating on a filter the fewer dust particles and contaminants can pass through it. 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.

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

Filters within a merv rating of 17 20 are almost never necessary in a residential home. The rating indicates the size of particles the air filter is designed to capture. 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. 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.

Merv stands for minimum efficiency reporting value which is a rating system designed by the american society of heating refrigerating and air conditioning engineers. Read our blog for more information on how to choose the right filter for your furnace.