Furnace Filter Merv Rating

Ranging from 1 to 20 the larger the number the better the filter is at catching small particles.

Furnace filter merv rating.

Merv stands for minimum efficiency reporting value which is a rating system designed by the american society of heating refrigerating and air conditioning engineers. You might have been using furnace filters with one that is too low or too high for your furnace without knowing it. Merv ratings range from 1 to 16. Filters within a merv rating of 17 20 are almost never necessary in a residential home.

The higher the merv rating on a filter the fewer dust particles and contaminants can pass through it. Below is a table grouping merv ratings by particle size. Merv ratings range from 1 least efficient to 16 extremely efficient. If the rating is too low potentially dangerous or damage causing particles can easily slip by.

Read our blog for more information on how to choose the right filter for your furnace. Merv filter ratings and efficiency. Merv ratings indicate how effective a filter is at keeping different particles out. 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 17 through merv 20 filters are typically used in surgical operating rooms clean rooms and other contexts that require absolute cleanliness. 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.