MERV 6 is the lowest MERV rating. While more efficient than a simple fiberglass filter, filters with a MERV 6 rating will remove only larger scale particles like allergens, dirt, debris, lint and dust. MERV 6 rated filters are typically more affordable than higher MERV rated filters.
MERV 8 rated filters are higher quality filters. MERV 8 filters remove basically the same contaminants as a MERV 6, but are more efficient; with a dust spot efficiency of 30-35%, they are 20 times more efficient than regular fiberglass filters.
Filters with a MERV 11 rating have a dust spot efficiency of 60-65% and are 30 times more efficient than regular fiberglass filters. MERV 11 rated filters are typically recommended for households with customers or homeowners who suffer from breathing difficulties or issues. They provide exceptional residential filtration, as well as a healthier breathing environment.
MERV 13 rated filters have a dust spot efficiency of 80-90%, and they are highly efficient filters both for residential and commercial use. MERV 13 filters remove a higher range of pollutants, including larger amounts of bacteria and even some viruses, and they are top of line for customers suffering from breathing problems.