MERV Rating

The acronym MERV stands for "Minimum Efficiency Reporting Value." MERV ratings are used to rate the ability of an air cleaner filter to remove dust from the air as it passes through the filter. MERV is a standard used to measure the overall efficiency of a filter. The MERV scale ranges from 1 to 16, and measures a filter's ability to remove particles from .30 to 10 microns in size. To give you an idea of the scale of a micron, 100 microns is about the thickness of a piece of paper or a human hair. Filters with higher ratings not only remove more particles from the air, they also remove smaller particles.

Filter Selection

How often should you change your filter.

MERV Filter Efficiency Guide

Arrestance Efficiency MERV Rating Tested Contaminant
60-80% Less then 20% 1 - 4 >10.0 micron Particle Size.
Pollen, Dust Mites, Sanding Dust, Spray Paint Dust, Textile Fibers, Carpet Fibers
80-90% Less then 20% 5 3.0-10.0 micron Particle Size.  
Mold Spores, Hair Spray, Fabric Protector, Dusting Aids, Cement Dust, Pudding Mix 
90-95% 20-30% 6
90-95% 25-30% 6-7
95-98% 40-50% 8
98% 50-60% 9-10 1.0-3.0 micron Particle Size.  
Legionella, Humidifier Dust, Lead Dust, Milled Flour, Auto Emissions, Welding Fumes 
99% 60-70% 10-11
99% 70-80% 12-13
99% 80-90% 13-14 .30-1.0 micron Particle Size.
All Bacteria, Most Tobacco Smoke, Proplet Nuceli (Sneeze)
99% 90-95% 14-15
NA 95% 16