27140 County 6 Fountain, MN 55935: 27165 County 6 Fountain, MN 55935: 27223 County 6 Fountain, MN 55935: 27241 County 6 Fountain, MN 55935: 27276 County 6 Fountain, MN 55935: 27821 County 6 Fountain, MN 55935: 28823 County 6 Fountain, MN 55935: 29420 County 6 Fountain, MN 55935: 29559 County 6 Fountain, MN 55935: 29739 County 6 Fountain, MN 55935: 30270 County 6 Fountain, MN 55935
MERV ratings range from 1 â 16 and measurements are in microns. Some of the common particles related to MERV ratings are pet dander, insecticide dust, smog, dust, viruses, wood, tobacco smoke, spores, bacteria and pollen. Some of the most common filters found in residential use only have a merv rating of 1 to 4.
The particles are added upstream of the test filter and a laser particle counter samples. the air before it enters the filter and after it leaves the filter. The two particle counts are compared to. calculate the Particle Size Efficiency of the tested filter. Once this is determined, a MERV Parameters. chart is used to determine the MERV rating. See the MERV Rating Chart below for more information about the difference in performance between. filters with different MERV ratings.