Spiral duct’s debut in the HVAC industry revolves around the creation of the Bösingen, Switzerland-based company, Spiro International S.A. Founders Erling Jensen and Leif Andresen invented the first Spiro Tubeformer machine for making spiral duct in 1956 with hopes of designing an easier to seal and maintain ventilation system. Initially, the duct style was a novelty. Then contractors quickly began to realize its benefits.
Before Spiro Tubeformer machines were made available in the U.S., contractors ordered spiral duct directly from overseas. They factored in shipping and a 7- hour time difference when bidding jobs. And when the duct arrived, they could only hope that it was the right fit and not damaged.