Furnace Filter

Some of the most common Furnace Filters found in residential use only have a MERV rating of 1 to 4. Often times these furnace filters are not assigned a MERV rating. These are typically disposable panel type filters and do not do a good job of filtering the air because they will not stop particles smaller than 10 microns. MERV 5 to 8 rated furnace filters are a better choice and are more commonly found in commercial applications. These furnace filters will collect particles as small as 3 microns and are a good choice for homeowners.