What does MERV Rating Stand For ?

The filtering materials used in a furnace air filter make a difference in efficiency. When we refer to efficiency, we mean how good a furnace filter is at removing particles from the air flow. The more efficient, the smaller the particles the filter will trap. A higher efficiency filter means cleaner air in your home, and fewer repairs of your air conditioning system.

A national organization, ASHRAE, developed the standard for testing filters. With this test, the results are express in MERV (minimum efficiency reporting value). Simply stated, the higher the MERV number, the more efficient the filter will be in removing contaminants and pollutants from the airflow.

Years ago the highest efficiency filter was a MERV 6 for deep pleated air filters, but as people became concerned with air quality, better filtering material and filter design were developed.

Our company offers a MERV 8, MERV 11, MERV 13, and ODOR DEFENSE® (a carbon filter). the highest efficiency furnace filter you can get for these types of systems is a MERV 13 but there could be a trade-off. This is because MERV 13 has higher resistance to airflow than a MERV 8 or MERV 11. If you have normal to good airflow, then the MERV 13 will not be a problem. We have sold millions without problems.

The MERV 13 air filter is more than twice as efficient as a MERV 8 in removing contaminants 1 micron in size. To understand how small 1 micron is, a human hair measures 100 microns. The drawback again, the higher the MERV rating, the higher airflow resistance.

Our own recommendation is the ODOR DEFENSE® air filter. This filter captures microscopic particles, and in addition it also captures foul odors and invisible toxic gases from the air in your home, while keeping air resistance low.

Finally, keep in mind that the MERV rating has nothing to do with size. MERV 8 and MERV 11 and MERV 13, and ODOR DEFENSE are all the same size filters for any given model number.