Understanding MERV Ratings on Air Filters

As air moves through your HVAC system, air filters trap and collect large and small particles such as dust, allergens and microorganisms. This filtration system helps provide healthier indoor air quality. An air filter’s minimum efficiency reporting value (MERV) rating measures how effectively the filter stops dust and other contaminants from passing through the filter and into the air stream. Filters with higher MERV ratings trap small particles more effectively than filters with lower MERV ratings.

It is important to note that a higher MERV rating might not work in your system. The smaller pores in more highly rated air filters create resistance to air flow, and if the filter is used in an HVAC system that is not designed to handle this resistance, it can lower the system's efficiency, decrease indoor air quality, and put strain on the system's fan.

An air filter with a MERV 11-13 rating filters down to 1.0 - 3.0 micron particle size. This filter captures particles such as pollen, dust mites, textile/carpet fibers, dust lint, Legionella, lead dust, humidifier dust and nebulizer dust.

An air filter with a MERV 16 rating filters down to .03 - 1.0 micron particle size. In addition to what a Merv 11 filter captures, a MERV 16 filter captures particles such as bacteria, tobacco smoke, auto fumes, sneeze nuclei, pet dander, insecticide dust and face powder.

If you need a medical grade air filter system, we recommend and can install the IQAir Perfect 16 air filter system. This whole house air purifier filters out “ultrafine” particles down to .003 microns and captures the smallest particles that exist, including viruses and bacteria.

For more about how you can improve your indoor air quality, contact us at 510-848-5010, or visit our website. We’ve been providing expert heating and air conditioning services for Berkley, Oakland, Piedmont, Montclair, Albany, El Cerrito and the greater East Bay area since 1929.