EC radial tube fan with noise-insulated housing. Housing made of galvanized sheet steel with round connection pieces adapted to standard pipes. Sound-absorbing perforated sheet metal inner lining, backed with 50mm thick mineral fiber board. Removable cover. Fan compartment and housing spiral freely accessible. Motor and impeller can be pulled out. Impeller: Energy-saving radial impeller with backwards curved blades. Dynamically balanced for quiet operation. Driven by energy-saving, speed-controlled EC external rotor motor with protection class IP44 with maximum efficiency. Maintenance-free and free from radio interference, ball bearings. Integrated electronic temperature monitoring for EC motor and electronics. Stepless speed control with potentiometer or stepless speed control with universal control system EUR-EC. Connection via standard terminal box (IP54) mounted on an outgoing cable.