Spiral ductwork, also known as spiral pipe, is a type of ventilation duct that's made from a rigid, spirally wound tube of metal. It's used in residential, commercial, and industrial settings to transport air and remove stale air. As the name implies, the duct is formed by spiraling and locking strips of metal together to form a continuous piece. This forming method enables the manufacturer to produce various lengths of duct in less time, creating a duct that is typically less expensive than duct formed by rolling sheets.