MERV classification 13-16 filters are capable of trapping 90% or more of particles in the range of 1.0-10.0 microns. The MERV 13 will prevent less than 75% of particles of 0, 3-1 and 0 microns from passing through, the MERV 14 will reach 84%, the MERV 15 up to 94%, and the MERV 16 can trap 95% or more of the smaller particles. Both have excellent capabilities to trap larger contaminants. Although the MERV-13 may be slightly better at trapping the smallest contaminants, the MERV-12 is not far behind either. The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) developed a test method called Minimum Efficiency Reporting Values (MERV) to evaluate the efficiency of an air filter based on its effectiveness in trapping particles of different sizes.
ASHRAE recommends a MERV 6 or higher, while the U. S. Department of Energy recommends MERV 13 and LEED recommends MERV 8 as a minimum. Pleated filters that are MERV 8 to 13, unlike fiberglass, can effectively filter small particles and reduce the pressure drop. A filter with a higher MERV rating can block microscopic particles, such as smoke molecules, due to its tighter mesh fabric.
Therefore, filters that have more than 13 in their MERV rating can filter particles closer to the size of 0.3 microns. This means that a filter with a MERV-12 rating has a balance between keeping indoor air quality pure without interfering with the ventilation function of an air conditioning system. Air filters with different sizes and MERV classifications will have different prices. In conclusion, a filter with a MERV-13 rating will provide the cleanest air quality in your home purchased through the use of an air filter.