The invention is directed to replacement media advancing air filter in air handling units with a flow channel. The filter having a housing and an exposure slot with filter media storage area that has an unexposed pleated, folded filter media portion stored therein. The filter media portion being folded and stacked in and compactly held at least in part within the storage area. A motor is coupled to a power supply and in communication with a controller. The motor moves a movement member that moves a portion of the filter media from a stored state in the storage area into the exposure slot and is exposed to the air in the air flow channel creating an exposed portion of the filter media. The exposed portion is collected within a containment area as a further portion of media is moved into the exposure slot to replace the exposed portion therein.