MERV is another acronym commonly found in the HVAC sector and stands for Minimum Energy Report Value. That in itself will likely mean nothing to you, so here at A&E Air Conditioning and Heating, we’d like to explain in greater detail not just what a MERV is, but why it is important for HVAC systems.

The MERV relates specifically to air filters within HVAC systems. It is used to help provide a clear indication of the effectiveness and overall quality of an HVAC air filter, and was originally developed by ASHRAE, the American Society of Heating, Refrigeration and Air-Conditioning Engineers. In short, the MERV enables a quick and easy comparison between air filters of varying brands and models.

The MERV scale runs from number 1 up to number 20, with a rating of number 1 being the lowest quality possible and 20 being the very best. The actual quality is measured by how well a filter stops polluting particles from passing through the filter, and also the size of the particles.

What is the minimum MERV rating I should look for in a filter?

It might be tempting to think that a rating of between 17 and 20 would be the best for an HVAC filter, but actually, you would be wrong. A MERV rating of between 17 and 20 is usually reserved for HEPA filters, which have the capability of removing even the smallest particle pollutants. Problem is, they are such effective filters, air also struggles to pass freely through them, which can compromise the efficiency of your HVAC unit, putting undue pressure on the motor and reducing air flow.