New “Cpro” fan from Ziehl-Abegg
Inspired by bionics and space technology
Following on from the “Owlet” axial fan, whose impeller blade design is based upon the shape of an owl’s wing to boost efficiency and reduce air-flow noise, developers at Ziehl-Abegg AG have now come up with the next sensation. Once again the innovative research team at the globally-operating fan manufacturer based in Künzelsau, looked to Nature and bionics for inspiration, linking the ideal aerodynamic shape of a water droplet with insights gained from the aerospace sector. This resulted in the plastic, high-performance centrifugal fan “Cpro”, which sets new standards in the fan and air conditioning sector in terms of acoustics, efficiency, low weight and simple installation. The technology pioneer Ziehl-Abegg, will present its new “Cpro” fan for the first time at the ISH/Aircontec trade fair, which will be held from March 6th to 10th in Frankfurt, at its exhibition stand 370 in Hall 5.0.
With its new top-quality product “Cpro”, the successor model to the “C”- impeller series known affectionately as the “blue marvel”, Ziehl-Abegg will be providing – from spring 2007 onwards – an even more powerful, quieter and more efficient product. “Cpro” stands for well-proven and innovative technology: The “C” represents the further development made in the successful “C”- impeller series, while “pro” stands for the brand new profile development for the impeller blades on the high-performance centrifugal fan. To achieve ideal aerodynamics and minimum air resistance, the profile of the Cpro impeller blades is based on the shape of a water droplet, and the wings of the space shuttle. In conjunction with the fan’s sloping trailing edge this results in a significant reduction in noise emissions, both for the fan’s total acoustic power level and it’s rotating sound.
The fan’s previous leading edge has been rounded off on the Cpro, and it now protrudes into the eye of the impeller. Various optimizations serve to cut impact losses, while increasing static pressure, boosting efficiency and providing a more stable characteristic. Developers at Ziel-Abegg have also, once again, refined the rotating diffuser concept, with which the “C”- impellers are equipped. The outlet cross-section has been expanded, resulting in a better conversion of dynamic pressure into static pressure. Because the Cpro is made purely of plastic, structure-borne sound is absorbed to a greater extent than is the case with conventional metallic impellers. The free-running Cpro impeller is available in diameters ranging from 250 to 630 mm to supply air flow volumes of up to roughly 28,000 m³/h at pressures of up to 2500 Pa.
“When one takes all the positive properties into consideration, the new Cpro fan concept exhibits some major advantages, both when compared with our previous “C”-impeller and with the conventional products from our rivals”, explained Peter Fenkl, CEO at Ziehl-Abegg AG, prior to the world premiere of the new high-performance fan at the Aircontec trade fair. “We are certain that the Cpro will become tomorrow’s benchmark in the area of centrifugal fans, in all matters concerning noise reduction, efficiency and energy saving.”
The “Cpro” belongs to the so-called “direct-driven, free-running impeller” design, which for years now has been gaining increased significance for fans in ventilation and central air-conditioning units. In comparison to traditional, belt-driven fans, the thing that most impresses production engineers, ventilation and air-conditioning device manufacturers, plant manufacturers and operators of the free-running impellers, is the simple and optimum option available for regulating the air flow volume and pressure to the required operating point by using a frequency inverter. The removal of the need for regular maintenance, normally associated with belt drive fans, brings with it additional benefits, as, with the adoption of free-running impellers, ventilation and air-conditioning units no longer need to have a second filter stage fitted in accordance with the ventilation and air-conditioning unit hygiene guideline VDI 6022. In addition to this, the extremely small dimensions of the Cpro free-running impeller have resulted in a major reduction in noise emissions, which in turn means that, in many instances, there is no need to fit a muffler or, if it can’t be dispensed with completely, a smaller one can be used.
When all these properties are taken together, the ventilation and air-conditioning unit fitted with a Cpro fan can now be made less expensively and more compactly, thus requiring less installation space in the technology room. The high static impeller efficiencies and unrestricted air inlet conditions for free-running impellers such as the Cpro, enable the achievement of high system efficiencies thereby generating major energy savings. And, don’t forget the easy accessibility to the free-running impeller, which makes it easier to clean, and which, in turn, improves the level of air hygiene.
