What types and sizes of ductwork are there?
The system requires only two types of duct – the main plenum and the supply tubing. The supply tubing is a 2-inch (51-mm) inside diameter flexible duct, wrapped with fiberglass insulation and an outer reinforced aluminized mylar vapor-seal jacket. The main plenum is either a 7-inch (178 mm) or 9-inch (229 mm) inside diameter duct, depending on the design and capacity of the system. In special cases, you can use a rectangular duct of equivalent size.
