초록 ▼

A sheet metal colinear-to-coaxial duct transition assembly for a fuel-fired, direct vent heating appliance is fabricated by providing a one-piece rectangular sheet metal plenum box having a rear wall with first and second circular openings therein, and an open front side. A separate rectangular fron

A sheet metal colinear-to-coaxial duct transition assembly for a fuel-fired, direct vent heating appliance is fabricated by providing a one-piece rectangular sheet metal plenum box having a rear wall with first and second circular openings therein, and an open front side. A separate rectangular front wall of the plenum box is also formed and has a circular opening therein. Prior to assembling the plenum box, a rearwardly projecting combustion air stub duct is secured to the rear plenum box wall at the first opening therein, and a forwardly projecting combustion air intake duct is secured to the front plenum box wall at the opening therein. Cooperating side edge portions and flange pockets on the front wall and the open side of the plenum box and then interlocked and crimped to complete the plenum box. A flue gas discharge duct is then extended rearwardly through the front air intake duct to cause a rear end portion of the flue gas discharge duct to project outwardly through the second opening in the rear plenum box wall, and secured to the rear wall so that a front portion of the flue gas discharge duct extends coaxially through the interior of the forwardly projecting air intake duct. The coaxial front ducts may then be connected to a coaxial vent termination assembly, and the rear duct portions may be connected to the colinear flue gas discharge and combustion air intake ducts of a fuel-fired, direct vent heating appliance.

대표청구항 ▼

[ What is claimed is:] [1.] A method of fabricating a colinear-to-coaxial duct transition assembly for a fuel-fired, direct vent heating appliance, said method comprising the steps of:providing a plenum box having a rear wall with spaced apart first and second openings therein, and an open front sid

[ What is claimed is:] [1.] A method of fabricating a colinear-to-coaxial duct transition assembly for a fuel-fired, direct vent heating appliance, said method comprising the steps of:providing a plenum box having a rear wall with spaced apart first and second openings therein, and an open front side spaced apart from said rear wall in a first direction and having side edge portions;securing a rearwardly projecting first combustion air inlet duct to said rear wall at said first opening and in communication with the interior of said plenum box;providing a front wall member having an opening therein and side edge portions interlockable with said side edge portions of said plenum box;attaching a second combustion air inlet duct to a side portion of said front wall member at said opening therein;interlocking said side edge portions of said front wall member and said plenum box in a manner causing said front wall member to cover said open front side of said plenum box, with said second combustion inlet air duct projecting forwardly from said front wall member and communicating with the interior of said plenum box;deforming portions of the interlocked side edge portions in a manner anchoring said front wall member to said plenum box;providing a flue gas discharge duct;extending said flue gas discharge duct rearwardly through said second combustion air inlet duct, the interior of said plenum box, and said second opening in said rear wall so that a front longitudinal portion of said flue gas discharge duct is coaxially disposed within said second combustion air duct and a rear longitudinal portion of said flue gas discharge duct projects rearwardly beyond said rear wall; andanchoring said flue gas discharge duct to said rear wall.