Air duct and Chimney

Air duct noun - A duct that provides ventilation (as in mines).

Chimney and air duct are semantically related in flue pipe topic. In some cases you can use "Chimney" instead a noun phrase "Air duct".

Chimney noun - A vertical flue that provides a path through which smoke from a fire is carried away through the wall or roof of a building.

Air duct and chimney are semantically related in flue pipe topic. Sometimes you can use "Air duct" instead a noun "Chimney".