Patent ID: 7530889

Claim:
An HVAC system, comprising: a. an HVAC unit; b. at least one air inlet and one air outlet duct to the HVAC unit; and c. at least two air diversion, direction, distribution or air mixing doors, each door including an outer sealing surface and opposed ends, the opposed ends each of which are tapered or canted and each having an axis boss disposed thereon wherein the outer sealing surface of a first door can pass within the two axis bosses of a second door; wherein the at least two doors are barrel doors, each barrel door including a barrel part and two opposite ends, the opposite ends being shaped like circular segments, each door rotatable about a rotational axis parallel to and spaced apart from the rotational axis of the other door; and wherein the at least two barrel doors are nested so that the barrel part of a first barrel door is placed substantially completely within a space defined by the barrel part, two opposite ends and axis of rotation of a second barrel door such that the barrel part of the first barrel door selectively swings or passes on the first barrel door's axis of rotation out of, into and through the space defined by the barrel part, two opposite ends and axis of rotation of the second barrel door.