The Minimum Efficiency Reporting Value (MERV) classification system is the industry standard when it comes to air filter ratings. Developed by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE), it is the only nationally regulated classification system for air filters in the USA. The MERV system specifies the ability of a filter to capture particles and air pollutants. It is used to compare different air filters, making it easier for homeowners to decide which one to choose.
The higher the rating (for MERV, FPR and MPR), the smaller the air and dust particles your home air conditioning filter can capture. In standard cases, a MERV 8 air filter is considered a more than adequate option. However, if an air filter has a stated MERV rating of between 1 and 4, it can remove pollen, dust mites, textile fibers, carpet fibers, and sanding dust up to a particle size of 10 microns. In these cases, a MERV 11 air filter can provide additional benefits and capture a wider range of particles that would pass through a MERV 8 filter.
Newer units should not have airflow problems with higher MERV ratings, although older models may work more with a MERV 13 filter installed when they originally had a MERV 6 filter in the air intake. A higher MERV rating may mean slightly more restricted airflow; however, most current HVAC systems are capable of handling a MERV 11 air filter without increasing system voltage. Whether you choose the MERV classification system, the MPR system, or the FPR system, make sure you choose an air filter with an appropriate rating based on your home conditions. While it can be difficult to decide which systems to follow, the MERV is considered the industry standard when it comes to air filter ratings and is generally the most commonly used system.
