This specialty filter is designed for use in return grille applications.?Many homes?have filter grilles, located at? the return air openings, that accommodate a one-inch filter.? Because of the one-inch limitation homeowners are limited as to their choice of filters, without retrofitting their systems.? A one-inch filter by nature has low surface area and needs to be replaced often.? Higher efficiency one-inch filters load with dirt quickly and can restrict airflow.

This 3″?return grille filter replaces the 1″?filter without any retrofitting.? A self-sealing foam gasket surrounds the filter on the upstream size and makes a tight seal with the grille surface, eliminating air bypass.