Measured by the ILK in Dresden!

Size 400 centrifugal fans measured in an air handling unit

Comparison of fi rst and second generation size 400 RadiPac. The results were taken from the expert report 1) ILK-B- 31-15-3981a (dated 09.03.2015) produced by the Institute of Air Handling and Refrigeration (ILK) in Dresden and 2) our own laboratory measurements.

All-in-all, modification of the flow machine and the motor brought about a more than 8 percentage points increase in the efficiency of the RadiPac fans. This can be seen from the difference between the green and black curves.

The full expert report of the ILK in Dresden can be viewed here:

Technical Report ILK Dresden
Energy efficiency measurement of ventilation units

Our impressive test results

RadiPac production

The characteristic curves show the "old" vs. "new" comparison for size 400 measured on the certifi ed test stand with free air and in installed condition.

The results of the optimisation process are impressive, as shown by the "old" versus "new" comparison in Figs. 1 and 2.

All-in-all, modification of the flow machine brought about a more than 13% increase in the efficiency of the RadiPac fans At the same time the noise level dropped by over 3 dB (A). The extra efficiency is converted into higher air flows, in other words the new fans attain higher operating points.

The corresponding measurements were taken on an officially certified (TÜV) aeroacoustic fan test stand (c.f. text: Certified test stand) which permits the simultaneous recording of air performance data and noise values. This chamber or combination test rig consists of two low-reflection half chambers with high-impedance floor conforming to accuracy class 1 for acoustic measurements. Air performance measurements can be conducted at an air flow of up to 100,000 m³/h with a static pressure increase of up to 3,000 Pa.

More: Old vs. new comparison for size 560 

Direct comparison of size 400 fans with competing products in installed condition. The installation situation is shown above.

ebm-papst does not shy away from comparison with commercially available, highly efficient fan concepts and comes out well on top. The two sizes 400 and 560 were used for comparison and the measurements were taken in the same installation situation closely resembling real usage conditions.

The ebm-papst RadiPac (green curve) was challenged by:

  • A manufacturer who also develops EC external rotor motors (blue) and
  • A company which uses corresponding control electronics (red) with PM internal rotor motors (permanent magnet).

The diagram shows air performance, overall efficiency and noise generation. The characteristic curves speak for themselves.

More: Direct comparison of size 560 fans with competing 

Certified test stand

Certain test specifi cations must be observed for category A measurements with free inlet and free outlet.

As a certified manufacturer, ebm-papst fully conforms to the following criteria as specified for test stands by the guidelines of the AHU manufacturers’ association: "An expert report/test report for fans will be accepted if testing was performed in accordance with the latest standard DIN EN ISO 5801:12-2010 (ISO 5801:2007 incl. corr. 1:2008) by a named test body on a suction-side chamber test rig and the component is manufactured without any modifications."

Authentic operating conditions

Authentic operating conditions
The illustration shows the installation situation in the AHU on the test stand.

The fans in an air handling unit operate in more or less confined spaces. This leads to a reduction in air performance which has to be taken into consideration when selecting the right fan. At ebm-papst allowance is made for the installation situation. For comparison measurements, the test fans are fitted in an AHU housing. Use was made of the dimensions 900×900×760 mm for size 400 fans. For size 560, the dimensions of the AHU housing were 1230×1230×760 mm. All the fans were centrally mounted in the AHU box.

More disclosures:

EC motors 


Attainable IE classes 

Frequency converter operation 

Typical applications 

Worth noting 

System optimisation: An overall concept with potential