Fans for Ventilation and Air Conditioning


Scroll casing with backward curved hollow profile blades – double inlet

Economic, quiet and compact

Through the combination of two high technologies - the aerodynamics of the rotavent impeller combined with energy efficient IEC motors - Nicotra Gebhardt has developed a series of coupled direct driven centrifugal fans setting new standards for economy and quiet operation.

Your benefits:

  • Powerful fan range direct driven with coupling
  • Maintenance and wear free drive (no V-belts)
  • Short payback time due to high energy saving, especially with long operating periods
  • Higher comfort levels through particularly low noise fans and motors
  • Problem free speed control from with frequency inverter

Optimal aerodynamics

Low turbulance velocity for both inlet and discharge due to the large free cross section and minimal flow restraint of the impeller, an example of aerodynamics and performance of the rotavent.


Reduction of high frequency noise levels is just one of the advantages of the rotavent, together with optimised motors and frequency inverters. Minimal sound levels due to low blade passing frequencies from the optimised impeller geometry of the rotavent. The impeller has obliquely inclined blades with trailing edges, and the throat plate is inclined opposingly.

High efficiencies

Nicotra Gebhardt fans of the RZA rotavent range are operating at high efficiency in wide area of the fan curve

Wear-free drive by direct coupling

The use of direct coupling drive avoids wear of the drive as this is the case with belt driven fans.

  • Double inlet fan with direct drive by coupling
  • Lockformed scroll casing made of galvanised steel sheet, with side frames, connecting flange at discharge
  • Fan with directly coupled motor (incl. PTC-Thermistors) fitted on pedestal and base frame. max. Medium temperature +40 °C
  • High performance impeller with 12 hollow section true aerofoil blades inclined obliquely to the shaft axis, welded in postion and painted
  • Throat plate inclined obliquely in opposition to blade incination
  • Inlet cones matched to the impeller reduce entry losses to a minimum
  • Impeller and shaft balanced as an assembly in according to DIN ISO 1940
  • Shaft accurately trued, connection to motor (B3) realised with elastic rubber coupling
  • Self aligning double row ball bearings within standard plummer blocks, mounted on robust support frame. Can be relubricated when not in service
  • Performance data (w/o drive) according to tolerance class 1 to DIN 24166