Important Note: Almost ALL furnace filters have a different “actual size” than the nominal size printed on the air filter. With the 4″ and 5″ air filters there is a wider variance between the nominal and actual size depending on the manufacturer.
Important Note: Almost ALL furnace filters have a different “actual size” than the nominal size printed on the air filter. With the 4″ and 5″ air filters there is a wider variance between the nominal and actual size depending on the manufacturer.
Important Note: Almost ALL furnace filters have a different “actual size” than the nominal size printed on the air filter. With the 4″ and 5″ air filters there is a wider variance between the nominal and actual size depending on the manufacturer.