When it comes to air filtration, the MERV rating system is the primary way to measure a filter's efficiency. MERV stands for Minimum Efficiency Reporting Value, and it's a scale that ranges from 1 to 20. The higher the MERV rating, the more particles a filter can capture from the air. MERV 9-12 filters are the most common for residential use.
A MERV 9 filter will trap less than 50% of particles of size 1.0-3.0 microns, while a MERV 10 filter can stop up to 64%. A MERV 11 filter can get up to 79%, and a MERV 12 filter is capable of trapping up to 89%. So what's the difference between a MERV 10 and a MERV 11 filter? A MERV 10 air filter can trap 65-79% of average-sized contaminants, while a MERV 11 air filter can trap between 80% and 89%. This means that a MERV 11 filter is more efficient than a MERV 10. How does MPR compare to MERV ratings? MPR stands for Microparticle Performance Rating, and it measures how well a filter captures particles between 0.3 and 1 micron in size.
This is different from MERV ratings, which measure how well a filter captures particles between 0.3 and 10 microns in size. A MERV 5-8 filter provides good filtration and removes most pollen, mold spores, and dust mites. A MERV 11 filter traps all of that, plus pet dander, smoke, smog, and air from coughs and sneezes. Filters with higher MERV ratings trap small particles more effectively than filters with lower MERV ratings.
For example, if an air filter can capture at least 20% of E1 particles, 65% of E2 particles, and 85% of E3 particles, it will obtain a MERV 11 rating. MERV 17-20 filters are commonly used in operating rooms, cleanrooms, and other settings that require absolute cleanliness. However, if the MERV rating is too high (above MERV 1), it can increase system backpressure and block airflow through the central air system, which worsens the efficiency of the HVAC system. Once you understand how the MERV rating table works, you can choose air filters with the right ratings for your needs. If your MERV 11 oven filter has a pleated surface, its air filtration capacity increases dramatically.