Abstract: Heat transfer structure for transferring heat from products of combustion to air to be conditioned in a furnace. The heat transfer structure includes an inlet portion receiving hot products of combustion from a burner and extending generally transversely to the direction of the flow of air to be conditioned by heat transfer association therewith. The heat transfer structure further includes at least three successive legs extending generally parallel to the direction of air flow. In one form, the transverse leg is disposed at the inlet portion of the air flow passages, and in a modified form, the transverse leg is disposed remotely therefrom. In the illustrated embodiments, the air moving structure is disposed in a lowermost portion of the cabinet, with the transverse inlet leg of the heat exchanger being selectively disposed lowermost or uppermost to define the two selective arrangements.

Abstract: A method and apparatus for bending a heat exchanger coil, and particularly a fin-on-tube coil, is provided which reduce pressure on the coil at a bending location to prevent damage to the fins and coil by effecting relative movement between a support bed for the coil, defining a coil plane, and a rotating mandrel, in a direction perpendicular to the coil plane during approximately the first 10.degree. of rotation of the mandrel. Such relative movement can be accomplished by either moving the support bed or by moving the rotational axis of the mandrel.