Duct work, ducts or ducting, are conduits or tubes that typically form part of a ventilation system, used to convey air / dust & removing from plant through chimney. Hard pipes used to transfer water or gas not classed as duct work.

Duct design involves planning (layout design), sizing, optimizing and detailing. Duct work should be among the first items to be considered when designing a new system / building because of its importance in the overall utility of the building and the need to integrate complex duct routes with other elements of the overall design. This can be particularly difficult where structural elements pass through building services spaces, such as the down stands of beams, or where ducts have to pass through other elements of the building.

Ducts can be fabricated from a range of materials