MERV Ratings

What is a MERV Rating?

Minimum Efficiency Reporting Value (MERV) is a scale designed to rate the effectiveness of air filters.


MERV Min. particle size Typical controlled contaminant Typical Application
17–20 < 0.3 μm Virus, carbon dust, sea salt, smoke Electronics & pharmaceutical manufacturing cleanroom
13–16 0.3–1.0 μm Bacteria, droplet nuclei (sneeze), cooking oil, most smoke and insecticide dust, most face powder, most paint pigments hospital & general surgery
9–12 1.0–3.0 μm Legionella, Humidifier dust, Lead dust, Milled flour, Auto emission particulates, Nebulizer droplets Superior residential, better commercial, hospital laboratories
5–8 3.0–10.0 μm Mold, spores, dust mite debris, cat and dog dander, hair spray, fabric protector, dusting aids, pudding mix Better residential, general commercial, industrial workspaces
1–4 > 10.0 μm Pollen, dust mites, cockroach debris, sanding dust, spray paint dust, textile fibers, carpet fibers Residential window AC unit