MERV rating: what does it mean?

When searching for the right filter, you’ll usually encounter the term “MERV”, or Minimum Efficiency Reporting Value. It’s important to understand what that exactly means so that you can choose the air filter that’s right for your air quality needs.

The higher the MERV rating is from 1 to 20, the better the filter is at trapping certain particles. Filters with a higher MERV rating are better at trapping small particles. Filters with MERV ratings from 1 to 16 are typically used in residential or commercial areas, while ratings of 17 to 20 are used in surgical operation rooms or other areas that require total cleanliness. According to the EPA, this is the standard chart that filter manufacturers use to rate their filters:


MERV Rating

Average Particle Size Efficiency in Microns

1-4

3.0 - 10.0 less than 20%

6

3.0 - 10.0 49.9%

8

3.0 - 10.0 84.9%

10

1.0 - 3.0 50% - 64.9%, 3.0 - 10.0 85% or greater

12

1.0 - 3.0 80% - 89.9%, 3.0 - 10.0 90% or greater

14

0.3 - 1.0 75% - 84%, 1.0 - 3.0 90% or greater

16

0.3 - 1.0 75% or greater


While you may assume that the higher a MERV rating is, the more it will help you, this is actually incorrect. Many HVAC systems are designed for filters with certain ratings. If a higher MERV rating is used than what is necessary, the HVAC unit may have to work harder, thus lowering its efficiency.

So, what is the best air filter MERV rating to use?

Typically, residential buildings should have a filter with a MERV rating anywhere from 8 to 13.

While higher rated air filters haven’t directly proven to stop the spread of Covid-19, it is recommended that residential and commercial areas use a filter with a rating of 13 or above to significantly reduce the spread of viruses.

But whichever air filter you choose to use in your home, the most important factor is how often you replace it with a new one. Check out our air filter subscription services with MERV filter ratings of 8, 10 and 12.