MERV: Friend or Foe?


Simply put, the answer is both.

Between the impact of LEED and a more informed consumer base, healthy indoor environments are top of mind — and rightfully so. The average person spends 90 percent of their time indoors. And, according to the U.S. Environmental Protection Agency, indoor air pollutant levels can be 2 to 5 times higher than those outdoor — all the more reason to have clean, pollutant-free air at work and at home.

One of the solutions used to tackle pollutants indoors are Minimum Efficiency Reporting Value, or MERV-rated air filters. With ratings from 1 to 20, these filters are installed in heating and cooling equipment. The higher the rating; the greater percentage of particles are captured on each pass. For example, MERV 1-4 is designed to filter cockroaches and debris, while MERV 17-20 is designed to capture extremely minute particles, including smoke and viruses.

Given the incredible filtering capacity of a MERV 17-20, why not make this the standard? Unfortunately, it’s not that simple. Your MERV-rated filter needs to be compatible with your HVAC system. If not, particles will clog the filer and airflow will slow down, requiring your HVAC systems fans and motor to work harder. The end result is that these fans and motor will burn out more quickly, putting a strain on maintenance budgets.

The lesson here is that before you jump on the bandwagon for high-rated MERV filters, be certain to consult an HVAC professional. Also, consider other complementary products and solutions that contribute to healthier indoor air quality, such as formaldehyde-scavenging drywall or low-VOC carpet and paint. Of course, you are always encouraged to chat with the CertainTeed team of building scientists as well — just drop us a note below.

Comments are closed.