MERV ratings are used to determine the capabilities of an air filter and its level of filtration efficiency. The MERV rating system ranges from 1 to 16, with higher ratings indicating a higher level of filtration. MERV 13-16 filters are capable of trapping 90% or more of particles in the 1.0-10.0 micron range, while MERV 12 filters can trap up to 75% of 0.3-1.0 micron particles. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommends MERV 13 and 14, while the U.
S. Department of Energy recommends MERV 13 and LEED recommends MERV 8 as a minimum. In addition, most low-capacity air handlers are unable to mount the static pressure required for high-MERV filters, so CFI configurations with these often require in-line boost fans. When it comes to efficiency, the Health Shield filter has been tested and proven to remove at least 90% of E3 particles, 85% of E2 particles and 50% of E1 particles - exceeding the requirements for a MERV 13 rating. In addition, it has a total particle arrest rate of 98.1%.
The goal of using a MERV 12 filter or higher is better indoor air quality (IAQ): cleaner and more breathable air for everyone, especially those with allergies, asthma, COPD, etc. Filters with a MERV rating between 9 and 12 capture much smaller particles, including pet dander and car emissions. Overall, a filter with a MERV-12 rating has that balance between keeping IAQ pure without interfering with the blower function of an HVAC system. A MERV 11 filter only needs to stop 20% of particles at 0.3 to 1.0 microns (three to ten times larger than a COVID-19 particle), a MERV 12 only needs to stop 35% of particles below 0.3 microns, and a MERV 13 only needs to stop half. When it comes to face masks, it is recommended to use a high-MERV activated carbon filter between two layers of cloth for maximum protection against airborne particles. It is also important to replace your filter periodically to keep your oven in perfect condition for years to come. In conclusion, while both MERV 12 and 13 filters have excellent capabilities when it comes to trapping larger contaminants, the Health Shield filter has been tested and proven to exceed the requirements for a MERV 13 rating - making it the clear winner when it comes to efficiency.