The present heating, ventilation and air conditioning (HVAC) air conveyance apparatus is plurality of panels adapted to be field-assembled to form the conveyance apparatus. These panels include a pair of first quadrilateral panels, each defining a right-angle flange extending from each of a pair of opposite edges and a pair of second quadrilateral panels, each defining a hemmed cleat along each of a pair of opposite edges. Each hemmed cleat is shaped and dimensioned to receive one of the first quadrilateral panel right-angle flanges to form the HVAC air conveyance apparatus. Also, HVAC unit mating flanges extending from each other edge of each of the first quadrilateral panels and/or from each other edge of each of the second quadrilateral panels, such that at least a pair of opposed peripheral HVAC unit mating flanges extend from each end of the HVAC air conveyance apparatus.