50 Years of Fan Technology: The EC Motor

50 Years of Fan Technology: Ahead of the Curve with the EC motor

June 11, 2020

Fan technology has developed very rapidly over the past 50 years. Leading technologies, pioneering application solutions, innovative products – all of these would not be possible if you didn’t look at the big development picture: ventilation connections and therefore the perfect interaction of motor technology, electronics and aerodynamics. Proudly, ebm-papst has been a key part of this evolution.

More than half a century ago, the story of the fan and motor manufacturer ebm-papst began in Mulfingen in Baden-Württemberg. Since then, fan technology has experienced a transformation similar to that of the automotive industry when the VW Beetle 1200 with its 38 horsepower (hp) required nine whole liters of gas to drive 100 kilometers whereas a modern 90 hp Golf requires just 4 liters.

Fans have experienced a similar increase in efficiency – by a factor of six – over the past 50 years. Today, the industry has moved further and further away from selling the fan as an isolated product. Manufacturers offer complete functional and assembly modules that can be integrated into a wide range of customer applications using plug & play. The game-changing transitions of fan technology had been through three significant phases in the last half-century.

Small external rotors as initial ignition

With its establishment in October 1963, ebm-papst played a leading role in the development of fan technology. Gerhard Sturm founded ebm at that time to produce small size 60 motors. This was a new product, as motors of this kind were only available in much larger versions. Thanks to their design, external rotor motors can be completely lowered in the impeller hub, creating a compact functional unit. The market had been waiting for these small motors: They were soon used in a wide range of applications where space is limited. Applications ranged from range hoods and other household appliances to Schwarzkopf hair dryers.

But the start did not go smoothly: Only three years after it was founded, this motor’s initial problems threatened the company’s very existence. Customers complained about fans that were rattling after just a short time. ebm-papst put all its eggs in one basket and, at the height of the crisis, offered a newly developed motor as a solution to these problems – including a four-year guarantee.

The unbelievably brave move made its first step to success – the new product became an absolute bestseller: the size 68 external rotor asynchronous motor. In the years that followed, ebm-papst derived various other products from this basic motor. At the same time, the company modernized and automated its production to meet the constantly increasing demand from home and abroad. The courage to keep developing the company was driven by company founder Gerhard Sturm. And his very initial company philosophy of producing “green products” has taken off – the insistence of having every product to be ecologically and economically superior to its predecessor

Fig. 1: The “Behr fan” – the first external rotor motor that ebm-papst (still as ebm back then) produced and marketed in 1963.

Fig. 2: Workers producing centrifugal fans in 1968. Mulfingen, Germany

Ahead of the curve with the EC motor

However, since asynchronous motor technology had some shortcomings, especially when it came to small motors, in the mid-1970s, ebm-papst started working increasingly on the development of electronically commutated permanent-magnet synchronous motors – EC motors. A rotating magnetic field is generated in these products, which the external rotor fitted with permanent magnets follows. The entire system is significantly more efficient and can be more precisely controlled.

Following its guiding principle, ebm-papst was committed to its new development, even though the prices for the required semiconductors remained high for a long time and electricity costs were relatively low – and so the interest in this energy-saving solution was limited.
But the conviction that economic and ecological progress were mutually dependent proved to be correct: at the turn of the 21st century, the EC motors made their final breakthrough. ebm-papst developed EC variants for other and larger products – the largest output today is 12 kilowatts. At that time, society and politics were recognizing climate change and the importance of reducing energy consumption, among other global issues.

Gradually, it was possible to increase the efficiency of the EC motors to over 90% in some cases, to significantly increase the power density and thus be more eco-friendly. Two pioneering projects in air conditioning technology at the start of the new century exemplified this trend: A company used the new energy-saving motor in its new generation of air conditioners and a discount chain with locations across Germany used the so-called “EC giants” – EC axial fans with integrated electronics and diameters of 800 to 990 millimeters. In the end, customers saved energy and money beyond their expectations, in their air conditioners, data centers and household appliances.

Fig 3: A cutaway model featuring EC technology

Evolution Continues with Innovation and Digitalisation

The most important developments in the past 15 years have been in the fields of aerodynamics and aeroacoustics. Ten years ago, medium-sized impellers demonstrated efficiency levels between 25% and 45%. These are now in the 60 % range. At the same time, ebm-papst is working constantly to significantly reduce the fans’ noise level, as they are often used in noise-sensitive environments such as hotel rooms or residential ventilation systems. With the RadiCal centrifugal fan in scroll housing developed in 2017, the company presented a super-quiet solution for home use. Its aerodynamically optimised housing reduces the noise level by 3.5 dB(A) as compared to a centrifugal blower. If needed, the RadiCal can be combined with the FlowGrid air inlet grille mounted on the intake side. This reduces the turbulence caused by fittings in the unit and, in particular, minimises disturbing low-frequency sounds.

In 2010 ebm-papst came out the “GreenTech” philosophy which is the outward manifestation of optimising products, company processes and production with regard to environmental compatibility. Forward-looking development, environmentally friendly production and maximum energy efficiency are combined to generate the greatest possible benefit for customers and society.

In terms of energy efficiency, this is not yet the end of the story. Even with motor efficiency of 90%, ebm-papst has never stopped innovating to make the production of its products ever more energy and resource-efficient. From a physical and technical point of view, there is still lots of room for great ideas. One of the trends of which the fans are making use is increasing interconnectivity under the buzzword “Industry 4.0.” For instance, fans can already be integrated completely into system concepts via bus interfaces. This not only transmits the desired speed to the fan, but also allows the fan to communicate independently. It, therefore, reports faults and other parameters that can be used to control air conditioning systems more efficiently.

Now the company is continuing to advance the development of digital solutions: Network-capable air and drive solutions that enable easy remote monitoring and predictive maintenance. Underlying such devices are intelligent solutions that can collect and transfer data, as well as software that evaluates this data.

But that’s not all. To continue to inspire the future of fan technology, the company founded the ebm-papst neo start-up in Dortmund in 2017. It is working on the next generation of digital solutions. The sustainability concept is now combined with digitalization. The company philosophy, therefore, evolved from “GreenTech” to “GreenIntelligence” – the latest expression of the company’s continuous striving for innovations. And for ebm-papst, this is still the best strategy for shaping fan technology developments in the future.

Fig. 4: ebm-papst makes products that are ready for Industry 4.0 and interconnects the production processes.

ebm-papst Milestones

1963: Establishment of Elektrobau Mulfingen (ebm). In the beginning, the company produced mainly small external rotor asynchronous motors. After their introduction, these compact motors were soon found in various applications where installation space was limited.

1965: Development of the first tubeaxial fan with EC/DC technology. At the time, these were referred to as “brushless DC motors.”

1992: Acquisition of PAPST Motoren GmbH in St. Georgen, Black Forest.

1997: Acquisition of the Landshut site from ALCATEL. The company was renamed Motoren Ventilatoren Landshut GmbH (mvl)

2003: The three companies were renamed ebm-papst Mulfingen, ebm-papst St. Georgen and ebm-papst Landshut.

2010: With GreenTech, ebm-papst implemented a corporate philosophy based on resource efficiency and sustainability. GreenTech encompasses proactive development, environmentally-friendly production, maximum energy efficiency and the greatest possible customer benefits.

2013: ebm-papst celebrates its 50th anniversary.

2016: Presentation of the “AxiBlade” axial fan. It was used in evaporators, condensers and heat exchangers for ventilation, air conditioning and refrigeration technology. ebm-papst achieved revenue of nearly EUR 1.7 billion and employed more than 13,000 people worldwide.

2017: ebm-papst introduced a ready-to-install centrifugal fan for use in residential ventilation units: The RadiCal in a scroll housing.

2018: ebm-papst exceeded the revenue threshold of EUR 2 billion for the first time. This means that growth of EUR 143 million was achieved in this financial year and GreenIntelligence was launched.

2020: The AxiEco Protect axial fan is presented for use in evaporators, heat pumps and other ventilation and air conditioning devices. Thanks to their very high efficiency, even the AC designs can meet the requirements of the future ErP Directive.