Witt & Sohn AG designs and builds axial, centrifugal and jet fans for marine, tunnel, industrial and building applications from its Pinneberg works. Its smoke extraction range is declared to EN 12101-3 for powered smoke and heat exhaust ventilators, and its Strahlventilatoren are used for impulse ventilation of tunnels and enclosed car parks. The firm has manufactured fans for more than eighty years, originally as a supplier to German shipbuilding.