Rectangular Ductwork: A more traditional type that is easy to fabricate into flat surfaces for a trunk, branch lines, or tap-ins. Height limitations can be accommodated by using rectangular ductwork within the structure and can be shipped loose or knocked down for convenience.
Spiral Ductwork: Depending on certain performance requirements, these ducts can be connected using flange-to-flange connections or with slip joints and cut to any length (standard 10’.) Spiral duct is faster to install because it is light-weight and requires less material to hang. It also offers smoother air flow, with less noise and more leak resistance, and is aesthetically pleasing when used in exposed applications.