| 摘要 |
The operating components of a forced air furnace are disposed within a double-walled cabinet structure having inner and outer metal walls which define therebetween an insulating air space that replaces the fibrous insulation normally adhered to the interior surface of furnace cabinetry. The illustrated cabinet structure representatively comprises a coil housing positioned atop a return housing. Each housing is formed from initially flat inner and outer sheet metal panels having rectangular configurations and various transverse projections thereon which permit the panels to be nested in a spaced apart, laterally facing relationship. Opposite end portions of the nested panels are then transversely bent in the same direction to form from the nested panels three interconnected sides of the housing, and the outer ends of the bent panel structure are secured together by elongated metal joining members extended across the resulting open fourth side of the housing. The transverse projections on the bent panel members automatically cooperate to hold them together and to maintain the insulating air space therebetween. To complete each housing a hollow, double-walled metal access panel is removably secured to the outer ends of the bent panels and extends across the open fourth side of the housing. |
