What does a filter’s MERV rating mean?

MERV stands for Minimum Efficiency Reporting Value, which is a rating system that measures the effectiveness of an air filter at capturing and removing airborne particles. The MERV rating ranges from 1 to 20, with a higher number indicating a more efficient filter.

The MERV rating is determined by testing a filter's ability to capture particles of different sizes, ranging from 0.3 to 10 microns in diameter. The higher the MERV rating, the more particles the filter can capture, including dust, pollen, pet dander, and other airborne contaminants.

Here is a general breakdown of MERV ratings and the types of particles they can capture:
  • MERV 1-4: Captures large particles such as dust, pollen, and fibers.
  • MERV 5-8: Captures smaller particles such as mold spores and pet dander.
  • MERV 9-12: Captures even smaller particles such as fine dust, smoke, and bacteria.
  • MERV 13-16: Captures very small particles such as viruses and exhaust fumes.
  • MERV 17-20: Captures the smallest particles such as bacteria and tobacco smoke.