Ventilation shafts are an important part of any building's air circulation system. They are typically constructed of metal or plastic and are used to transport air from one area to another. The term 'ventilation shaft' can also refer to a vertical shaft that is used to provide ventilation to a specific area. In this crossword, the solutions for the term 'ventilation shaft' are 'AIRWAY' (6 letters) and 'DUCT' (4 letters). An AIRWAY is a passage through which air flows, while a DUCT is a tube or conduit that carries air from one place to another. Together, these two solutions accurately describe the purpose of a ventilation shaft.