MERV stands for Minimum Efficiency Reporting Value.
The MERV rating is a filter comparison system designed by an industry group called the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE). Simply put, it's a rating scale designed to allow consumers to easily compare the performance of one filter to another. Higher ratings mean the filters remove a larger percentage and broader range of debris from the air.
It is designed to measure a filter's ability to capture and hold particles and pollutants. The higher the MERV rating, the more particles – dust mites, pet dander, air allergens, etc. – your filter will remove from the air.
Matching the right MERV rating to your needs will improve your home's air quality and will extend the life of your furnace or air conditioner. An air filter with a rating of MERV 6 removes lint, household dust, and pollen. A MERV 8 air filter will remove those plus dust mites and mold spores. MERV 11 filters add pet dander, smoke, and smog to the list. MERV 13 filters will also remove bacteria and virus carriers. This means the MERV rating you should use depends on the air quality of your home or business and the needs of the people in it.
A higher MERV rating means that your air filter can remove more particles – dust mites, pet dander, air allergens, etc – from your home's air. Cleaner air creates a healthier environment. One thing to consider – screening out more particles from your air makes your air handler work a bit harder, so you may see a modest increase in power consumption by your air conditioning or furnace unit when choosing a higher MERV rating.
Here are a few reasons to replace your air filter regularly, regardless of the MERV rating:
Read more about the differences between MERV rating, MPR and FPR.