Ductwork is a system of pipes or channels used to distribute heating and cooling air throughout a building in a forced air system.

An energy modeler must be able to identify ductwork in a mechanical drawing and note that there are often two paths of ductwork, supply and return.

Sometimes, a third ductwork path is included when there is dedicated outside air

Finally, additional ductwork may exist for the purpose of local exhaust in the case of fumehoods or bathroom exhaust.

Duct Design requires a separate expertise but is often completed based on the load calculation produced by an energy model.