© ebm-papst

Ahead of time with the EC motor: More effi­cient, quieter, smarter

Fan tech­nology has devel­oped very rapidly over the past 50 years. This 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. ebm-papst has been a key part of this evolu­tion.

More than half a century ago, the success 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. Whereas then the VW Beetle 1200 with its 38 hp required nine whole liters of gas to drive 100 kilo­me­ters, a modern 90 hp Golf requires just 4 liters.

And fans have expe­ri­enced a similar increase in effi­ciency – by a factor of six – over the past 50 years. Further­more, the industry has moved further and further away from selling the fan as an isolated product. Today, manu­fac­turers offer complete func­tional and assembly modules that can be inte­grated into a wide range of customer appli­ca­tions without great effort using plug & play. Three phases describe the most impor­tant changes in fan tech­nology in the last half century.

Small external rotors as initial igni­tion

The “Behr fan” – the first external rotor motor that ebm-papst produced and marketed in 1963, still as ebm. (Photo | ebm-papst)

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 tight. 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! How brave this step was is illus­trated by the fact that the team had not yet even tested the new product exhaus­tively.

Workers producing centrifugal fans in Mulfingen in 1968. (Photo | ebm-papst)

But the coup was successful – and 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 and continued to develop it. At the same time, the company modern­ized and auto­mated its produc­tion step by step 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 company has taken up the cause: Every product must be ecolog­i­cally and econom­i­cally supe­rior to its prede­cessor.

The areas of appli­ca­tion have also expanded greatly since the early seven­ties: ebm-papst motors and fans are now turning in the computers, air condi­tioners, oil burners and belt machines of sound studios and they drive agita­tors in the beverage industry.

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, so-called 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 end of 1990s, the break­through for EC motors came in coop­er­a­tion with a German system manu­fac­turer. Many EC motors are used in its clean room facto­ries.

Produc­tion at the Nieder­stetten site began in 1981 with the company’s own winding facility. (Photo | ebm-papst)

At the turn of the 21st century, the EC motors made their final break­through. At that time, society and poli­tics were recog­nizing that the climate can be protected by signif­i­cantly reduced energy consump­tion, among other things. As a result, ebm-papst devel­oped EC vari­ants for other and larger prod­ucts – the largest output today is 12 kilo­watts. 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 easier on the envi­ron­ment.

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. This is how customers save not only a lot of energy but also a lot of money in their air condi­tioners, data centers and house­hold appli­ances.

More effi­cient and quieter

A cutaway model thanks to an external rotor motor featuring EC tech­nology: The rotor does not rotate in, but rather around the stator and works without rare-earth magnets. (Photo | ebm-papst)

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.

With the RadiCal centrifugal fan in scroll housing devel­oped in 2017, the company presented a super-quiet solu­tion for home use. Its aero­dy­nam­i­cally opti­mized 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, mini­mizes disturbing low-frequency sounds.

Getting better and better

In 2010 the “Green­Tech” philos­ophy became the outward mani­fes­ta­tion of opti­mizing prod­ucts, company processes and produc­tion with regard to envi­ron­mental compat­i­bility. Forward-looking devel­op­ment, envi­ron­men­tally friendly produc­tion and maximum energy effi­ciency are combined with the greatest possible customer benefit. In terms of energy effi­ciency, this is not yet the end of the story. Even with motor effi­ciency of 90%, further improve­ments can be made, for example in terms of aero­dy­namics.

ebm-papst makes prod­ucts that are ready for Industry 4.0 and inter­con­nects the produc­tion processes. (Photo | ebm-papst)

At the same time, ebm-papst is contin­uing to work to make the produc­tion of its prod­ucts ever more energy and resource-effi­cient. From a phys­ical and tech­nical point of view, there is still room for inno­va­tion here. One of the trends of which the fans are making use is increasing networking under the buzz­word “Industry 4.0.” For example, fans can already be inte­grated completely into system concepts via bus inter­faces. This not only trans­mits the desired speed to the fan, but allows the fan to commu­ni­cate inde­pen­dently. It there­fore reports faults, and also other detailed para­me­ters that can be used to control a building’s air condi­tioning system more effi­ciently, for example.

The AxiEco Protect axial fan is used 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. (Photo | ebm-papst)

ebm-papst was able to offer solu­tions for the networked world early on since the elec­tronics were already inte­grated into its EC fans. And 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 in addi­tion to focusing on needs. 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: new busi­ness models are also required. 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. Mean­while, ebm-papst has combined its sustain­ability concept with digi­tal­iza­tion: “Green­In­tel­li­gence.” This sign is the latest expres­sion of the company’s contin­uous striving for inno­va­tions. And for ebm-papst, this is still the best strategy for success­fully shaping fan tech­nology devel­op­ments in the future.

The most impor­tant mile­stones at a glance:


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.


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


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


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


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


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.


ebm-papst cele­brates its 50th anniver­sary.


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.


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


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.


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.

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