New gener­a­tion of fans, econom­ical and quiet

For many appli­ca­tions, air is the ideal cooling medium to dissi­pate waste heat. For large amounts of heat in small spaces, a high-volume air flow is needed. Until now, high-perfor­mance fans that could deliver this air perfor­mance were loud, not espe­cially econom­ical to operate, and often could only be controlled in a limited fashion. A new gener­a­tion of high-perfor­mance fans is now improving cooling effi­ciency and saving expen­sive energy. And for later disposal, the envi­ron­ment was already taken into consid­er­a­tion during the design phase, making it easier for users to fulfil both current and future stan­dards.

Figure 1: fan of the S-Panther series, size 172 mm.

As elec­tronic compo­nents continue to get smaller and more powerful, they can be fitted into smaller devices with the same or even higher perfor­mance. This applies for many sectors such as IT, telecom­mu­ni­ca­tions and automa­tion and also for frequency converters, welding machines and the contin­u­ally improving solar inverters. The experts at ebm-papst have devel­oped a new gener­a­tion of high-perfor­mance fans, the S-Panther series (Figure 1), to give users of the latest tech­nology a suit­able fan solu­tion. This gener­a­tion was devel­oped specif­i­cally with the aim of reducing noise emis­sion, but without having to make compro­mises in air perfor­mance or effi­ciency.

New fan, proven tech­nology

To achieve that aim, it was neces­sary to completely rethink the aero­dy­namics and develop the fan from scratch. A compar­ison of the perfor­mance data for the current 172 mm S-Force fan at 6000 rpm with that of the new fan from the S-Panther series with the same dimen­sions at 4500 rpm shows that the maximum air perfor­mance has increased and the pres­sure saddle curve has been lowered (Figure 2). This design is suit­able for moving maximum amounts of cooling air for almost all appli­ca­tions. Thanks to a further design refine­ment based on blades with winglets and trailing edges, it was possible to reduce the sound power level across the entire frequency range. An addi­tional contri­bu­tion comes from a new strut design specially config­ured to the blade geom­etry. The improved air conduc­tion allows reduced speed for the same air perfor­mance, resulting in reduced noise emis­sions.

When the speed of the new fan from the S-Panther series is varied so that the same curve as that of the previous model is reached, a consid­er­able reduc­tion in the sound power level can be observed (Figure 3). Even at medium power levels, the oper­ating noise at the same oper­ating point has been reduced by up to 9 dB(A). The oper­ating range to the left of the indi­cated line is char­ac­terised by strong aero­dy­namic detach­ment mech­a­nisms. The sound power levels of both fans are the same there. Never­the­less, here too the new fans feature crucial improve­ments as regards noise percep­tion (Figure 4). So-called tonal noise in partic­ular, which results from the number of blades and the speed and is always regarded as a nuisance, has been reduced consid­er­ably

Figure 2: Compar­ison sound power and fan perfor­mance S-Force and S-Panther, size 172 mm.

Figure 3: Compar­ison sound power S-Force and S-Panther, size 172 mm at same perfor­mance.

The mechan­ical stresses on all fan compo­nents have been reduced by the new design and its accom­pa­nying speed reduc­tion, allowing the use of new tech­nolo­gies such as the mechan­ical design of the plastic impeller, the shaft-hub assembly or the rotor dynamics.
The bearing systems can be kept simpler, and together with reduced effort for balancing, they facil­i­tate produc­tion at the same quality level. Drive is provided by proven 3-phase multi­pole motors with 6-, 8-, 10- or 12-pole magne­tised rotor units which together with the 9-slot stator packs effi­ciently convert elec­trical to mechan­ical energy.

Perfor­mance in figures

The sizes range from 80×80 mm up to 172 mm and cover all speed vari­ants. Depending on the appli­ca­tion, both low- and high-speed versions are avail­able. Produc­tion of the new S-Panther fans will begin with the 63 and 32 series and will later be expanded to the 80 and 120 mm classes. All members of the new product family were designed from the begin­ning for envi­ron­men­tally friendly produc­tion and future disposal.