What does MERV mean?

What is MERV? What's the difference? Why can't I just use the filters from my hardware store? These are questions that our customers often ask us. And why you certainly can use thin filters from your local hardware store, they won't be as effective. (See our post "More than just a rock-catcher) 

So, hopefully, this post will help you understand exactly what makes a MERV filter a MERV filter.


MERV stands for Minimum Efficiency Reporting Value. 

Well, what does that mean? 

This is basically a standard developed by the American Society of Heating, Refrigeration and Air Conditioner Engineers (ASHRAE) to measure the degree of filtration, and the values vary from 1 to 16. i.e. MERV 10 or MERV 16. The higher the number or rating, the more efficient the filter will be in trapping airborne particles, and particles are measured in microns. (To put it in perspective, 1 inch equals over 25,000 microns)

The following chart should help you get an idea of the types of particles a MERV filter can trap.

Most home air systems can adequately remove airborne contaminants with a filter rated between MERV 8-13, while MERV 14 and higher are typically found in hospital and general surgery settings. Every Simmons Installation in Chesapeake, VA comes standard with a MERV 11, and some of our customers use higher ratings.

What's important, is to have the right filter for your HVAC system and air quality needs. While a higher rated filter will trap more particles, the pores are smaller which can lead to poor air flow and put stress on your heating and cooling equipment.  

Do you have questions on the effectiveness of your filter? Give us a call at 757-424-2911.