RadiCal: Low-pressure centrifugal fans with backward-curved blades

Centrifugal fans with backward-curved blades

Backward-curved fan blades with a rigid, hybrid design

RadiCal centrifugal fans with backward-curved blades are the new standard in ventilation and air-conditioning. RadiCal features include both noise minimisation and a further decrease in energy consumption. The RadiCal impeller with backward-curved blades is made of fibreglass-reinforced plastic, enabling an aerodynamically optimised shape that cuts the noise level in half and reduces power requirements significantly.

Optimised RadiCal impeller with backward-curved blades

Optimised RadiCal impeller with backward-curved blades

The designs for the impeller and the backward-curved blades were optimised with complex simulation models adjusted using measurements on prototypes. The result is an optimal, low-loss flow of air through the impeller without the drastic cross-sectional jumps that cause losses in the impeller. A uniform flow profile without laminar separation results in fewer noise sources and better acoustics. The plastic's good damping characteristics also help reduce noise emissions.

The impellers are produced from a special composite material, in a single piece without joints. This makes a high circumferential speed possible, so the fan has a high power density.

Even without special varnish, the impellers are highly corrosion-resistant, for example if exposed to salt water or salty air. Direct solar radiation has no damaging effects on the UV-resistant material.

Compact low-pressure series with miniaturised motor-electronics combinations

RadiCal motor-electronics combinations

GreenTech EC motors are used in the RadiCal low-pressure centrifugal fans. In terms of efficiency, they exceed legally mandated ErP limits. With these, up to 50% less energy consumption can be achieved in comparison with AC solutions.

The motors in RadiCal low-pressure centrifugal fans have been miniaturised and are much more compact than their predecessors. With the current dimensions, easy and trouble-free replacement of existing AC solutions is possible at any time.

The motor's heat management system also has an optimised design. The stator is completely encapsulated in high-performance plastic. Air inlets in the rotor guarantee perfect heat dissipation for the motor, resulting in a further considerable increase in efficiency. The high level of IP protection permits the use of these fans even in critical applications.

The RadiCal with GreenTech EC motor features continuous control with a 0-10 V or PWM input signal. Versions with two fixed speed levels are available up to size 250 mm, with the higher speed providing a power reserve in comparison with the AC version. From size 250 mm, control via an RS-485 interface using the MODBUS RTU protocol is also possible.

RadiCal – the new standard in ventilation and air-conditioning technology

Precision cooling systems (Stulz)
Precision cooling systems (Stulz)

RadiCal centrifugal fans with backward-curved blades are used in many ventilation and air-conditioning applications such as control cabinet cooling, in-line duct fans, home ventilation units or heat pumps. In all of these applications, it pays to switch to the high-efficiency RadiCal low-pressure centrifugal fans with GreenTech EC motors or to opt for them from the outset.

RadiCal low-pressure centrifugal fans from ebm-papst – facts at a glance:

  • Perfectly matched components (controller/motor/impeller)
  • High efficiency with improved ventilation technology and new EC motors
  • Extremely quiet running with optimised impeller air flow
  • Significantly reduced rotation noise
  • Unmatched compactness
  • Mechanical compatibility of AC and EC fans
  • EC fans with 2 speed levels or continuously adjustable
  • High power density
  • Rugged design and maintenance-free operation
  • Very easy commissioning
  • Fulfils ErP specifications

Product search for centrifugal fans RadiCal


Search criteria:

Nominal voltage in V
Type of voltage  
Frequency in Hz
Air flow in m³/h
Dimensions in mm

27 centrifugal fans RadiCal found.

Type  n ~ D/Y qV UN p f AC/DC
in min-1  in m³/hin Vin Pain Hz 
37701~ 150200 .. 240 50/60AC
37701~ 150200 .. 240 50/60AC
27101~ 350200 .. 240 50/60AC
41201~ 510200 .. 240 50/60AC
41201~ 510200 .. 240 50/60AC
25801~ 625200 .. 240 50/60AC
25801~ 625200 .. 240 50/60AC
32301~ 800200 .. 240 50/60AC
22001~ 640200 .. 240 50/60AC
22001~ 640200 .. 240 50/60AC
28601~ 960200 .. 240 50/60AC
28601~ 960200 .. 240 50/60AC
19551~ 640230 50/60AC
25101~ 870200 .. 240 50/60AC
25101~ 900200 .. 240 50/60AC
37701~ 150200 .. 240 50/60AC
37701~ 150200 .. 240 50/60AC
27101~ 350200 .. 240 50/60AC
32001~ 520200 .. 240 50/60AC
41201~ 510200 .. 240 50/60AC
41201~ 510200 .. 240 50/60AC
25801~ 625200 .. 240 50/60AC
25801~ 625200 .. 240 50/60AC
22001~ 640200 .. 240 50/60AC
22001~ 640200 .. 240 50/60AC
28601~ 960200 .. 240 50/60AC
28601~ 960200 .. 240 50/60AC
n = Speed
~ = Phase
D/Y = Connection
qV = Air flow
UN = Nominal voltage
p = Max. back pressure
f = Frequency
AC/DC = Type of voltage

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