The Chief Technical Officer at the German fan manufacturer Ziehl-Abegg, explains the benefits for building planners and developers: “In many cases, this eliminates the need for additional sound insulation whilst keeping within noise level limits. Sound emission levels and energy consumption are significantly reduced,” says Dr. Sascha Klett commenting on the further development of ZAplus, the top seller amongst axial fans. This will please supermarket operators just as much as industrial operators of systems fitted with chillers.
Klett emphasizes that the improvements had really earned 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.
“We are reducing noise by up to four dB(A),” emphasizes CEO Klett. For comparison: six dB(A) represents a doubling of the noise. This is achieved with the help of a further development of the familiar biomimetic fan blade with a serrated trailing edge. This element was learned from the extremely quiet flight of the owl and incorporated into the technical design. What is new is that the leading edge now also has a slightly rippled design. “We used marine creatures as a model for this”, explains Klett. This rippled leading edge alters the detachment of the airflow from the rotor blade: the air is moved for longer in a controlled manner.
The previously standard guide vane for the more targeted handling of the airflow (keyword 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, i.e. it was also rippled at the trailing edge. “This is directly reflected in the decrease in the noise level,” emphasizes Klett.
Technicians will be amazed at the installation dimensions: the outside dimensions remain standard (1070 millimetres) but the inner diameter is increased from 910 to 960 millimetres. One more modification: The rotor and blades, which were previously manufactured out of solid aluminium, will now be replaced by an aluminium rotor and blades made of a high-strength composite material. Readings taken from a first customer device have shown energy savings of nine percent, according to Ziehl-Abegg.
Mass production will commence next summer. The supply of ZAplus 960 Next Generation samples to customers is scheduled to start at the beginning of 2023. Other sizes of ZAplus Next Generation will follow.
