Ducts are conduits or passages used in heating, ventilation, and air conditioning (HVAC) systems to deliver and remove air. The necessary airflows include supply air, return air, and exhaust air. Ducts commonly also deliver ventilation air as part of the supply air. Thus, air ducts are one method of ensuring acceptable indoor air quality as well as thermal comfort. A duct system is also referred to as ductwork.

The ductwork BAS-CVS offers can be made from galvanized steel, stainless steel, black/mild steel (carbon steel) and Aluminum.