Abstract: A spacer clip for maintaining the coaxial spacing of the walls in a multiple wall chimney. A plurality of spacer clips are circumferentially positioned within the annulus between the walls. The clip attaches to the outer wall and includes a biasing arm which engages the inner wall to maintain the spacing between the walls. The biasing arm of the clips may be retracted to facilitate insertion or removal of the inner wall from within the outer wall.

Abstract: A furnace mounted humidifier for increasing the moisture content of the air flowing through the humidifier and subsequently the air flowing from the furnace. The simple construction of the scoop humidifier ensures convenient installation and operation while adding moisture to the air flow. The humidifier includes a housing adapted to be mounted to the furnace wall and inlet and outlet passageways positioned within the duct for directing air flow into and out of the housing. A moisture media within the housing retains water sprayed across it through which the air flow is directed. The configuration of the air passageways and the housing facilitate the continuous flow of air across the moisture media.

Abstract: A multiple walled metal chimney formed of a plurality of axially joined chimney sections each of which utilizes positionally captured spacer rings. Joint clamps are used to connect the chimney sections for formation of the complete chimney conduit. The spacer rings are positionally captured between annular shoulders formed in the inner and outer walls of the chimney sections to eliminate welding of the rings. The rings may include an expansion joint to allow circumferential expansion and contraction of the ring with the walls.