KÜNZELSAU, Germany, 14 October 2022: Ziehl-Abegg showcased its new generation of ZAplus axial fan unit at Chillventa, from October 11 to 13 in Nuremberg, which Dr Sascha Klett, its Chief Technical Officer, described as a technology where “sound emission levels and energy consumption are significantly reduced”.

Klett said, “In many cases, this eliminates the need for additional sound insulation whilst keeping within noise level limits.” This, he added, will please supermarket operators just as much as industrial operators of systems fitted with chillers.

Klett said the improvements had earned the technology the right to be called a “new development”, as the modifications are of a fundamental nature. The experts have once again put their faith in models drawn from the natural world and incorporated a number of biomimetic aspects into the technical design, he said.

Photo courtesy ZIEHL-ABEGG

Klett said, “We are reducing noise by up to four dB(A).” For comparison, six dB(A) represents a doubling of the noise, he emphasises. This reduction is achieved with the help of a further development of the familiar biomimetic fan blade with a serrated trailing edge, he explained.

This element was learnt from the extremely quiet flight of the owl and incorporated into the technical design, he said. What is new is that the leading edge now also has a slightly rippled design, he said. “We used marine creatures as a model for this,” Klett said, adding that the rippled leading edge alters the detachment of the airflow from the rotor blade – the air is moved for longer in a controlled manner.

According to Ziehl-Abegg, the previously standard guide vane for the more targeted handling of the airflow – with the keywords being throw distance – has been fine-tuned: The smaller guide vane now has 17 struts instead of the usual 11. And the spacer ring has been biomimetically enhanced – that is, it was also rippled at the trailing edge. “This is directly reflected in the decrease in the noise level,” Klett said.

The ZAplus Next Generation fan unit

According to Ziehl-Abegg, technicians will be amazed at the installation dimensions: The outside dimensions remain standard (1,070 millimetres), but the inner diameter is increased from 910 to 960 millimetres.

Also, the rotor and blades, which were manufactured out of solid aluminium, will now be replaced by an aluminium rotor and blades made of a high-strength composite material, the company said. Readings taken from a first customer device have shown energy savings of nine per cent, Ziehl-Abegg claimed.

According to the company, mass production of the unit will commence next summer. The supply of ZAplus 960 Next Generation samples to customers is scheduled to start at the beginning of 2023, the company said, adding that other sizes of ZAplus Next Generation will follow.