What Does MERV Stand For?

MERV is an abbreviation for Minimum Efficiency Reporting Value. What does it mean? Well in simple terms it is a measurement used for air filters on a scale of 1-16. The higher the MERV number the more ability a filter has to stop contaminants from getting through and circulating through your house. Therefore, a low MERV number means it can only filter out the largest particles.

The MERV system was established in 1987 by the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers). Basically, the rating tells the lowest level of performance of the particular filter.

Remember the old phrase “a picture is worth a thousand words?” Well, we feel that a MERV chart image might help you understand better how the higher MERV number compares with more filtration.

After looking at the chart you might be asking yourself “how much filtration is needed?”

Sometimes the answer may depend on your health considerations. In general, NanoAir Solutions recommends MERV 13 because it filters out even microscopic viruses from the air you breathe. And yet it doesn’t go to the extreme in expense.

And when it comes to your health, do you really want to risk it with a MERV 2 or 3 – a filter that doesn’t even really do that much filtering? Why would someone even consider that? Well, often as consumers we look at the choices and the range of prices. And psychologically we don’t like to go for the cheapest because we think “that has to be the worst” and we clearly don’t want that. But sometimes we don’t really understand and just go up a step or two from there.

What about allergies or other health concerns? In these cases, a filter capable of removing allergens is necessary! And when it comes to the air you breathe and your health it’s better to make an educated decision.

Now one filter may not be the solution for every situation, but NanoAir knows its stuff and is 100% behind their MERV 13 filters. NanoAir Solutions has been in this business a long time and they are the experts.

It makes sense to think about a higher MERV filter being denser and therefore possibly restricting airflow. But there are several other factors that come into play when measuring the airflow of your system (blower motor types, the size and surface area of the filters, etc.) which we will get to in our next blog post.

You can find contractors that disagree regarding the effects of a higher MERV rating on airflow. Some contractors are dead set against them claiming they can cause a large enough drop in air pressure in your duct system that it will significantly increase energy bills and damage your HVAC system. But generally, this is just a feeling they have, may only be partially correct, and not backed up by research.

You can find contractors that disagree regarding the effects of a higher MERV rating on airflow. Some contractors are dead set against them claiming they can cause a large enough drop in air pressure in your duct system that it will significantly increase energy bills and damage your HVAC system. But generally, this is just a feeling they have, may only be partially correct, and not backed up by research.

This leads us to understand that it is generally safe and cost efficient for you to choose higher MERV ratings. The question then becomes, how high should you go and to what cost?

The cost of very high MERV filters can get pretty expensive. And while they may last longer, they still will need to be changed regularly. So, you will find yourself weighing the cost benefit, especially on the highest MERV ratings available.

We find it helpful to use the chart above and as such recommend MERV 13. It helps homeowners and businesses to filter more possible harming contaminants without going overboard on the cost.

The actual size of your filter may be determined by how the intake housing was constructed and installed. So, if you want a MERV 13 filter but a little bigger, more surface area, i.e. 4” thick, your system may need a slight modification. It depends on how it was installed. A little tape measure work where the filter goes should clue you in. If you need a slight modification, we believe it is worth it in the long run resulting in better filtration and better health, and a cleaner air handling system.