Merv Air Filter Scale

The ashrae, or american society of heating, refrigeration, and air conditioning engineers assign merv ratings to air filters from 1 to 16 with 1 being at the low end of air filtration and 16 at the high end.

Merv air filter scale. The merv rating scale defines the minimum percentage of particles that must be trapped by an air filter in order to obtain a particular rating. Merv 12 filter, for comparison, will filter out 90% of the same particles. They never need to be replaced.

The minimum efficiency reporting value, commonly known as merv, is a rating scale to measure the effectiveness of air filters. A basic merv 4 filter will likely be the cheapest but won’t catch certain small particles (like dust mites and pet dander) that could be in your home. The reason for using a low merv filter before a high merv filter is to manage cost.

A merv 6 filter may seem low on that scale, but it is more than effective at keeping out harmful pollutants and allergens and is quite affordable as well. They also remove smaller particles. Merv ratings go from 1 to 20 with the number’s increasing with the filter’s efficacy.

It is the standard that all air filters are rated through their process and effectiveness. That’s why hospitals tend to use merv 16 or higher, to capture the most pollutants possible. Filters with a merv 6 rating will remove large particles like allergens, dirt, debris, lint, dust, etc.

For a merv filter to get close to the efficiency of a hepa filter, it. The merv rating system is intended to be used to determine the filter’s ability to remove particulates from the air. The merv rating system has a scale of 1 to 20.

As air moves through a building’s hvac system, air filters trap and collect large and small particles such as dust, allergens and microorganisms. Here is a handy guide from wikipedia: Merv, otherwise known as minimum efficiency reporting value, is a system used to evaluate the efficiency of an air filter based on how effective it is at catching particles of varying sizes.