When it comes to air filters, the MERV rating system is a standardized way of measuring the efficiency of a filter. The acronym stands for Minimum Efficiency Reporting Value, and it is used to measure how well a filter can capture particles of different sizes. A MERV 8 filter is considered superior filtration compared to air filters with a lower MERV rating, but it may not be enough to combat outdoor air pollution, pet fur and dander, or asthma and allergy triggers. A MERV 11 filter offers greater protection against airborne bacteria and viruses that spread through airborne droplets, as well as pet dander, smoke, smog and air pollution from coughs and sneezes.
A MERV 13 filter is the highest rating available and can trap tobacco smoke, fire smoke, contaminants in body fluids released by sneezing, and coughs and bacteria. When deciding which MERV rating is right for your home, consider the type of air pollutants you want to filter out. If you are concerned about outdoor air pollution, family members with respiratory problems or pets in the house, then choosing a higher MERV rating might be a good idea. For standard cases, a MERV 8 air filter is considered more than adequate.
It traps pollen and dust, as well as dust mites and mold spores. A MERV 11 filter catches all those things plus pet dander, smoke, smog and air pollution from coughs and sneezes. A MERV 13 filter is the highest rating available and can trap tobacco smoke, fire smoke, contaminants in body fluids released by sneezing, and coughs and bacteria. It's important to note that filters with higher MERV ratings should be changed more frequently (at least every three months) to avoid restricted airflow that can deplete efficiency or even damage the system. Generally speaking, anything that is under a MERV 13 air filter should provide very efficient air purification in a home without affecting airflow.