At MERV 13, the highest rating you'll find for most popular residential HVAC filter sizes is the maximum you can trust for bacteria, smoke and other microscopic particles. Filters with a MERV rating of 14 to 20, such as commercial, HEPA and ULPA filters, offer the highest level of filtration and are generally not needed in most homes and businesses. The MERV rating scale ranges from 1 to 20, with 1 being the lowest and 20 being the highest. Sometimes, particles such as pollen, pet dander, and fine dust can slip through a filter with a lower MERV rating.
To prevent this, you may want to choose a MERV 11 air filter instead of a MERV 8 air filter. This is especially important if you're concerned about the effects of breathing fine air particles. Filters with a MERV rating of 16 to 20 are generally only found in hospitals, clean rooms, and nuclear power plants. However, contrary to these warnings, there are plenty of testimonials from owners that MERV 11, 12 and even 13 filters have worked well in their systems for years.
The main difference between the MPR and MERV classification systems is that the MPR classification system focuses on the filter's effectiveness in removing E1 microparticles from the air. A high MERV rating on an air filter generally means that the filter is thicker and that the HVAC system will have to work harder to circulate air throughout the house. In 1987, the American Society of Heating, Refrigeration and Air Conditioning Engineers designed the MERV rating scale to provide a more accurate picture of an air filter's capabilities. The air is charged with particles, sent through the filter only once and the results are measured.
Choosing the right MERV rating is an important decision in terms of total cost, air quality and product durability. The MERV, also known as the Minimum Efficiency Report Value, is a system used to evaluate the efficiency of an air filter based on its effectiveness in trapping particles of different sizes. Using an air filter with a MERV rating that is too high is just as bad as using one that is too low. When removing the old dirty filter, it may be necessary to have a plastic bag handy to put the dirty filter inside.
The MERV rating is there to tell you how efficient the air filter is at filtering particles of certain sizes.