Merv Air Filter Rating

The test is based on particle size.

Merv air filter rating.

The higher the merv rating the better the filter is at trapping specific types of particles. On 10 20 pm particles 19 n a n a virus unattached radioactive materials 99 999. Filters with a merv 11 rating have a dust spot efficiency of 60 65 and are 30 times more. The other two systems were created by 3m mpr and the home depot fpr to differentiate their offerings.

Ashrae stands for the american society of heating refrigerating and air conditioning engineers. The merv rating system is intended to be used to determine the filter s ability to remove particulates from the air. In general filters with a rating of merv. 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.

Ashrae developed the merv air filter efficiency rating system. Merv 8 filters remove basically the same particulates as a merv 6 but they are more efficient. This method tests air cleaning devices for dust removal efficiency. The higher the merv rating the smaller the pores are for air to flow through an hvac filter.

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. Merv air filter ratings range from 1 least efficient captureability to 16 very efficient. An air filter s minimum efficiency reporting value merv rating measures how effectively the filter stops dust and other contaminants from passing through the filter and into the air stream. The rating system is called ashrae standard 52 2 2007.

Filters with higher merv ratings trap small particles more effectively than filters with lower merv ratings. An air filter s merv rating is a scale from 1 16 that describes the minimum efficiency of the air filter. With a dust spot efficiency of 30 35 they are 20 times more efficient than regular fiberglass filters. Merv 8 rated filters are high quality filters.

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. 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.