The high efficiency radial fans have been developed especially for modern ventilation and air conditioning applications and are ideal for the movement of air and light aggressive gas and vapours. The size comply with standard R20 and are in accordance to DIN 323. The designation of size corresponds to the outside diameter of the impeller.

The casing is manufactured from galvanized sheet steel. Side plate and scroll plate are joined together by a rolled seam. Mounting brackets can be fitted to the fan side plate in steps of 90°. The centrifugal impeller is made of galvanized sheet metal, and is mounted directly to the rotor of the external rotor motor and is balanced at two levels together with the rotor according to G 2,5 to DIN ISO 1940.

Direction of rotation for fan types ERS is clockwise viewed from the inlet side, but for fan types DRS it is counter-clockwise viewed from the cable outlet side.