Merv Air Filter Rating

The merv filter rating is the domestic and international industry standard rating system established by the american society of heating refrigerating and air conditioning engineers.

Merv air filter rating.

An air filter s merv rating is a scale from 1 16 that describes the minimum efficiency of the air filter. Merv 8 filters remove basically the same particulates as a merv 6 but they are more efficient. Below is a chart from john semmelhack showing the percentage of particles removed by size range of particle and the merv rating of the filter. This method tests air cleaning devices for dust removal efficiency.

On 10 20 pm particles 19 n a n a virus unattached radioactive materials 99 999. The test is based on particle size. Filters with higher merv ratings trap small particles more effectively than filters with lower merv ratings. Many homes use filters with a merv rating of 1 4 which mostly filter out dust lint and pollen among other larger common particles they do very little to trap small microparticles.

With a dust spot efficiency of 30 35 they are 20 times more efficient than regular fiberglass filters. The merv rating system is intended to be used to determine the filter s ability to remove particulates from the air. The rating system is called ashrae standard 52 2 2007. The higher the merv rating the better the filter is at trapping specific types of particles.

Ashrae stands for the american society of heating refrigerating and air conditioning engineers. Merv air filter ratings range from 1 least efficient captureability to 16 very efficient. This can create more resistance in airflow than a system is designed to manage thus making it. Merv 8 rated filters are high quality filters.

Ashrae developed the merv air filter efficiency rating system. A low merv rating means that the filter does not remove as many particulates from the air. Merv rating chart standard 52 5 minimum efficiency reporting value dust spot efficiency arrestance typical controlled contaminant typical applications and limitations typical air filter cleaner type 20 n a n a 0 30 pm particle size cleanrooms 99 999 eff. The higher the merv rating the smaller the pores are for air to flow through an hvac filter.

The other two systems were created by 3m mpr and the home depot fpr to differentiate their offerings. For a filter to get the merv 13 rating for example it must filter out a minimum of 90 of the pm10 a minimum of 85 of the pm2 5 and a minimum of 50 of the pm1 0.