PFK are industrial duct fans dedicated to rectangular ducts. The PFK series fans have been designed for installations where high efficiency and quiet fan operation are required. PFK fans work well both as exhaust and supply fans for general ventilation, e.g. in warehouses, shops, public utility buildings. Thanks to the flat design, they are successfully used in low-rise rooms where it is not possible to use round ducts, in particular in underground garages and low-rise production halls.