MERV ratings range from 1 to 20, with 1 being the lowest level of filtration and 20 being the highest. Filters with a MERV rating of 14-20 are typically found in hospitals, cleanrooms, and nuclear power plants. For residential use, a MERV 11 air filter is usually the best option. This type of filter offers efficient air purification without affecting airflow.
The table below shows the minimum threshold at which a filter must operate to obtain a specific MERV rating. For example, if an air filter can capture at least 20% of E1 particles, 65% of E2 and 85% of E3 particles, it will obtain a MERV 11 rating. MERV 11 air filters are more expensive than standard filters, but they provide better filtration and improved indoor air quality. When selecting an air filter, you should consider the MERV rating as well as the thickness of the filter.
A MERV 12 filter that is only 1 inch thick is likely to be more restrictive than a 4 inch thick MERV 12 filter. This comparison table helps highlight the differences between the MERV 8 and MERV 11 filters to make it easier to decide which one works best. Choosing the right MERV rating is an important decision in terms of total cost, air quality, and product durability. In general, filters with a MERV 16 rating or lower are considered HVAC system grade filters for residential, commercial, and general hospital use.
The goal of using a MERV 12 filter or higher is better IAQ: cleaner, more breathable air for everyone, especially those with allergies, asthma, COPD, etc.
