Why Choose the Right MERV Rating for a 3M Filtrete Filter

One of the most important considerations when choosing a filter is its MERV, or Minimum Efficiency Reporting Value, or its MPR, or Microparticle Performance Rating. In-stock 3M Filtrete filters are available in MERV ratings of 1, 2, 5, 7, 11, 12, and 13. These ratings determine average particle-size efficiency, measured in microns; the EPA, or Environmental Protection Agency, provides information about these values. Now consider what to look for when selecting a filter for a household furnace. The higher the MERV value, the more micron-size particles the filter captures and the tighter the airflow through the filter, meaning that the filter-media mesh is denser. This tighter construction also means less airflow to the furnace, so it is important to select a suitable filter. A furnace needs to breathe so that its heat exchanger does not overheat and crack, which is extremely dangerous and may even be life-threatening. This is another reason to replace filters regularly: a dirty filter reduces airflow through the furnace. Failure to replace the filter regularly can lead to poor temperature control, requiring thermostat adjustments and different settings to maintain the desired temperature, as well as higher energy costs, health problems, furnace failure, and a cracked heat exchanger.