Patent ID: 8540792

Claim:
A magnetic sealing cover for a furnace filter slot in a ferro-magnetic return duct of a heating, ventilation, and air conditioning (HVAC) system, said return duct having a generally rectangular configuration with opposite faces and opposite sides, one of said return duct faces including said furnace filter slot, which sealing cover comprises: inner and outer sheets of flexible, impermeable material; said sheets being sealed together along their respective side edges and ends, forming a sheet assembly with first and second side edges and first and second opposite ends; first and second side sets of magnet segments, each side set being sealed between said sheets adjacent to a respective first and second side edge; each said set of magnets comprising multiple, individual, magnet segments longitudinally aligned and extending between said sheet ends in proximity to a respective sheet side edge; first and second end magnet segments sealed between said sheets in proximity to said first and second sheet assembly ends respectively; first and second transverse fold lines each extending between said first and second side edges in proximity to a respective sheet assembly end; and said sheet assembly having an installed, sealing position with said sheet assembly overlying said furnace filter slot and said first and second side sets of magnets releasably, magnetically attached to said return duct face, said sheet assembly ends being folded over respective return duct side faces along respective fold lines, and said duct assembly ends being releasably, magnetically attached to said return duct side faces by said end magnet sets.