What Is a MERV Rating?

MERV Rating Infographic
MERV Rating Infographic

What does MERV mean?

MERV stands for Minimum Efficiency Reporting Value.

What is a MERV Rating?

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.

Why is there a MERV Rating?

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.

What MERV rating should I use?

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.

What is the benefit of a higher air filter MERV rating?

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.

Why Replace My Air Filter?

Here are a few reasons to replace your air filter regularly, regardless of the MERV rating:

  • Removes unwanted dust, dirt, and other indoor particles
  • Lowers the cost of energy in your home or business
  • Prevents triggers of indoor allergies and asthma
  • Lessens mold and mildew growth

When to Replace Your Air Filter by MERV Rating

  • MERV 6 - Change every 30 Days
  • MERV 8 - Change every 60-90 Days
  • MERV 11 - Change every 60-90 Days
  • MERV 13 - Change every 60-90 Days

Read more about the differences between MERV rating, MPR and FPR.