Is Merv 11 the Best Air Filter for Your Home?

Learn about Merv ratings and how they affect your home's air quality and HVAC system efficiency. Find out why Merv 11 is likely your best bet.

Is Merv 11 the Best Air Filter for Your Home?

In most cases, a Merv 11 air filter is not too tall for residential use. Generally speaking, anything under a Merv 13 air filter should provide very efficient air purification in a house without affecting airflow. Merv 13 filters are effective at trapping 98% of the airborne particulates found in an average household. But how often do Merv 13 filters need to be replaced? Experts recommend changing MERV 8 filters every 2 to 3 months to keep them running at full capacity.

Although the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) suggests MERV 13, it may not be the most efficient option for some residential HVAC systems. According to the U. S. Environmental Protection Agency, filters in the 7-13 range often have little difference from higher MERV ratings, but they will allow your system to operate much more efficiently.

If you or any family members suffer from allergies, asthma or other respiratory conditions, you may want to use a filter with a Merv rating of approximately 10 to 12. Anything higher than a MERV 11 is designed for commercial households or households with family members suffering from respiratory problems. The main difference between the MPR and MERV rating systems is that the MPR rating system focuses on the effectiveness of a filter in removing E1 microparticles from the air. Basically, the higher the MERV rating, the greater the air filtration capabilities of a particular filter. MERV 13 will prevent less than 75% of 0.3-1.0 micron particles from passing, MERV 14 will reach up to 84%, MERV 15 up to 94%, and MERV 16 can trap 95% or more of smaller particles. Unfortunately, one of the best-selling filter products, Filtrete from 3M, does NOT use MERV, preferring its “Microparticle Performance Rating” (MPR).If your furnace's MERV rating is too high, it can force it to work too hard and leave it vulnerable to damage.

The higher the MERV rating of a filter, the less dust particles and other contaminants can pass through it. It should also be noted that filters at the lower end of the MERV scale are not even tested for efficiency in capturing E1 and E2 particulate matter. Using an oven filter with a higher MERV rating than your use case requires may have adverse effects. When you balance all these problems, you will in fact find the sweet spot in the MERV 8 vs MERV 11 vs MERV 13 spectrum. However, a high MERV rating on an air filter usually means that the filter is thicker and that the HVAC system will have to work harder to circulate air throughout the house.

In addition to everything that MERV 8 and MERV 11 filters trap, MERV 13 filters also trap tobacco smoke, fire smoke, contaminants in body fluids released by sneezing, and coughs and bacteria. Choosing an air filter with an appropriate Merv rating is essential for keeping your home's air clean and healthy while avoiding any potential damage to your HVAC system. If you're looking for an efficient air filter for your home, then Merv 11 is likely your best bet.