© Photo | ebm-papst

Ice-Cold Savings

The specialist for refrigeration and air-conditioning devices, Roller, is consistently converting from AC to EC technology in its evaporators – the customers have also been convinced of this step now


If we picture the refrigeration and air-conditioning industry as a large parking lot, Roller would probably be a Mercedes or BMW. On the global market, this company based in Gerlingen is one of the top providers of evaporators, heat exchangers and air-conditioning devices for commercial use. This self-image is something that development manager Ingo Raisch deals with very consciously. “We don’t even try to use price to break into the market. Instead we put everything into always being a step ahead technologically.” A symbol for this innovation-driven thinking is surely the consistent change to modern, energy efficient technology. Since the beginning of this year, energy saving GreenTech EC fans have been replacing their AC counterparts in three evaporator series. This new variant is not an alternative as with other providers, but rather is mandatory. If you want Roller, you also have to want EC. “Surely a bold step”, Raisch admits. “But it has paid off for us.”

The pilot project

Roller development manager Ingo Raisch (left) and Martin Schulz from ebm-papst while inspecting a fan with a GreenTech EC motor

To understand how it came to this step, first we have to turn back the clock a little and jump to the year 2009. At that time the situation at Roller still looked a little different. AC and shaded-pole motors still operated in the appliances then. However, the energy efficiency trend was also becoming ever more important for the customers of the Gerlingen, Germany-based company. Large supermarket chains, for example, often explicitly demanded EC technology in their tender documents. Therefore Raisch risked the pilot project with an evaporator series that to date had been driven by shadedpole motors. The great requirement of technology partner ebmpapst was this: The changeover has to take place on a 1:1 scale. The motor replacement must be possible without any additional changes to the end product. Besides the dimensions, accordingly, the air performance had to remain identical – ideally, with a decreasing noise level.

“Naturally it was to our benefit that we have nurtured good contacts with Roller for many years,” explains Martin Schulz, Team leader project management in sales at ebm-papst Germany. The two companies have worked together since the mid 1990s. “Our engineers knew precisely the application and its specifications.” Accordingly, the mechanical changeover happened very quickly. The developers also masterfully overcame the challenge posed by low operating temperatures in the double-digit below-zero range, as Schulz reports: “We purposely selected materials and parts which have no problem functioning, even at minus 40 degrees.”

Higher investment with added value

The real challenge was for Roller: the company’s Sales team also had to communicate the paradigm shift to all those customers who had not insisted on it. “Of course, one or two were a bit upset upon seeing a price increase in the new price list,” says Raisch. “We contained that by taking the initiative in communicating the added value.” Roller started an information campaign with flyers, presentations and everything else that goes along with this.

The production at Roller

This strategy bore fruit: The sales figures remained stable and even rose in some cases. “Naturally this was due not only to our Marketing department, but also to the facts, which simply speak for themselves,” adds Raisch. The data is indeed impressive. With the energy-saving motor, the energy savings compared to the shaded-pole motor are as high as 70 percent. In other words, the extra cost for the supposedly more expensive technology is recovered right away within two months. After two to three years, the savings even cover the entire purchase price of the end device. The high efficiency of the energy-saving motor even goes one better. For when less energy is required, the waste heat also decreases, and with it the required cooling capacity. All of that went over well with the customers. The feedback was so unanimously positive that it was easy for Roller to decide to also risk the switch to EC technology in series with AC motors. Even if the jump in efficiency is not as high as with shaded-pole motors, with the newest EC generation it is nevertheless a respectable 30 percent.

Reducing four to two

In 2011 the starting gun for the next phase was fired. The new EC fans were integrated into three series at once. The project requirements were similar: Dimensions as well as output and noise data remained the same, while savings as a result of state-of-the-art technology stood in the foreground. “Of course another important point was added to this”, adds Martin Schulz of ebm-papst. “Roller was concerned with reducing the diversity of its components – instead of four different motors which drive the evaporator fans there should be only two.”

Roller is now installing energy-saving motors in half of their evaporator series – the rest are to follow suit shortly

The previous diversity can be explained rather simply: Vacuum or pressure evaporators commend themselves depending on room geometry and range of applications. Since not all customers require the same output, Roller offered two motors with different speeds for each of the two variants. “And that was precisely the starting point for reducing the diversity”, explains developer Raisch. “An AC motor has a fixed speed, while in the EC motor two different speeds are as easy as child’s play to program.” For Roller, cutting the diversity of its components is a humongous advantage: “Needing to have fewer different components in the warehouse enables us to have a substantially more flexible warehouse and spare part logistics.” Not only that. The service benefits from the mechanical interchangeability of shaded-pole, AC and EC motors from ebmpapst. If an end device ever fails, the technician can get it running again with whatever variant he or she happens to have in the boot. When the replacement EC arrives, they can be swapped without much effort.

Inspired by these many arguments and by customer feedback, Roller is consistently carrying out the changeover to GreenTech EC technology. For Roller the plan stands firm: “In two to three years we want to be using EC motors exclusively.” The next large series changeover will follow in the Spring of 2013. Currently the work for this is already in full swing at Roller as well as ebm-papst.

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