The magazine of Friedhelm Loh Group

The magazine of Friedhelm Loh Group

Energy-efficient enclosure cooling
Experience – Engineering

This is how Voith saves Energy

Saving energy. Voith attaches great importance to sustainability and energy efficiency. For years, this global technology group has been committed to achieving long-lasting success under fair and environmentally friendly conditions. The results are outstanding, with the company’s environmental management receiving multiple awards. Now the Heidenheim-based company has discovered
yet more potential savings – this time in enclosure climate control.

Text Dr. Jörg Lantzsch and Hans-Robert Koch ––– Photography

While giving a tour of the manufacturing facilities, Markus Brunkal has a story to tell about every machine he passes. Now aged 54, he has been at Voith ever since he began his apprenticeship as a machine fitter. He feels at home here and knows this place like the back of his hand. Since 2011, Brunkal has been focused on sustainability. This friendly figure, born and raised in the Swabia region, is responsible for resource and energy management at Voith Turbo in Heidenheim – the drive technology division of the Voith Group. In Brunkal’s words: “My job requires you to look very closely because it covers every single consumer – from the floor lighting and heating in the manufacturing facilities through to the large production machinery.”

Ambitious goals

Everywhere you turn, there are units in operation whose energy and resource consumption influences the company’s overall usage. “The targets at Voith are highly ambitious, with 20 per cent of energy to be saved over the course of six years,” explains Brunkal. “And we have of course seen to the proverbial low-hanging fruit first.” In other words, the more successful projects that are completed, the harder it becomes to make further progress. Voith Turbo’s savings targets don’t just cover energy, but also water and waste.

When considering machine tools’ energy efficiency, staff focused mainly on the drives, hydraulic units and utilisation of the individual machines.

Wolfgang Steck, who as the Head of Assembly and Test Field is responsible for areas such as production, recalls: “In the beginning, our main priority was to harvest the necessary data. We hadn’t even taken detailed measurements of energy consumption values at that point.” Bit by bit, a consumer list emerged, which served as the basis for depicting how much energy was being used and where. “It goes without saying that we examined the highest consumption values first,” says Steck. Due to the high amount of energy they consume, the hardening shop, the machining centres for metalworking, the test benches and the paint shop are all high on the company’s consumer list.

Best practices from all sites

In Voith’s Turbo division alone, a total of seven employees from different departments work together to examine how resources and energy can be used efficiently. Over the years, this working group has already achieved great success in its quest for measures to boost efficiency. Primary energy consumption, for example, was lowered from 37 gigawatt hours in 2011 to 30 gigawatt hours in the last financial year. In the same period, fresh water consumption shrank from 127 to an impressive 77 cubic metres, and waste levels were reduced by around 1,000 metric tons.

Together with Markus Brunkal, a Rittal customer service employee checks a Rittal Blue e+ cooling unit’s current efficiency values.

At its sites across the globe, Voith is dedicated to increasing resource and energy efficiency. “Voith Turbo’s working groups in Germany meet up twice a year  to share ideas among themselves, and now and then we also invite external specialists,” says Steck. “During one particular working group meeting, there was an employee from Rittal who gave a presentation on the savings that could be achieved with climate control solutions for enclosures,” he recalls. Energy efficiency of machine tools in production had of course already been looked at in previous years. “But we were concentrating mainly on the drives, hydraulic units and utilisation of the individual machines. Until then, we hadn’t given any thought to enclosure climate control,” explains Steck.

“Straight after the event, we set to work,” recalls Brunkal, adding: “After all, we had just discovered a new consumer and we were keen to look at its energy efficiency in greater detail.” And this turned out to be much easier than first thought. The Rittal customer service team conducts service and efficiency checks to provide customers with a detailed outline of potential savings – one such customer being Voith Turbo. “Two employees from Rittal spent a week with us at the factory, closely examining each and every machine tool and its enclosure climate control,” says Brunkal.

Savings of over 70 per cent

In total, 50 different machines featured climate control technology in their enclosures. “The Rittal customer service team made our job very easy,” Brunkal points out. The result of the service check contains a variety of information pertaining to the condition of the enclosure’s climate control for each machine examined. The comprehensive documentation also gives a recommendation on whether it would make sense to replace a cooling unit, which unit would be best suited, and how much energy the customer could save if they opted for a replacement.

By conducting a service and efficiency check, a Rittal service engineer revealed new potential savings for the customer.

In the case of Voith’s Heidenheim site, Rittal recommended replacing 21 machine tools in total. Depending on the cooling output required, the cooling units from the Blue e or the Blue e+ range offer energy-­efficient alternatives. “We hadn’t expected the results of the efficiency check to really take us by surprise like they did,” said Brunkal, amazed by the considerable energy savings to be made. The documents Rittal drew up for Voith also calculated the payback periods and estimated that the energy cost savings would be over 70 per cent, i.e. 25,000 euros each year. This meant that retrofitting the more energy-efficient cooling units would pay off after just two years on average.  

Voith is a stickler for numbers. “We prioritise measures based on a new KPI,” explains Steck. Besides the impact on planned energy savings and the proportion of costs of the overall investments envisaged, the company also considers cost-­effectiveness – in other words, the payback period – when making its decisions. A short payback period is a key argument for Steck: “The management team usually doesn’t take long to approve measures that have a payback period of less than three years.”

The retrofit saw energy costs fall by more than 70 per cent, equating to an annual saving of 25,000 euros.

After the retrofit

The company retrofitted its machine tools with the new cooling units last summer. All in all, 28 cooling units from the Rittal Blue e+ range and seven cooling units from the Blue e range were installed in the 21 machine tools. A few adjustments aside, the retrofit went without a hitch. “The employees from Rittal made the job very easy for us,” says Brunkal, commending the Rittal customer service team for its support. As the working groups regularly move between the different sites, Voith Turbo’s other sites in Germany have also made use of the Rittal service and efficiency check – and the outcome has been just as impressive. “Owing to our positive experience here in Heidenheim, the other sites will also switch to using more energy-efficient cooling solutions in their machine tools over the new few months,” says Brunkal.

  • This is how energy saving works

    Sometimes it needs foreign help to optimise a process. Voith Turbo shows how it's done and discovers more potential savings with Rittal. 

    Discover what’s possible
    When adopting measures to boost energy efficiency, enclosure climate control is often forgotten about – despite it offering a very short payback period in many cases. This is where the service and efficiency check from Rittal can lend a helping hand, with its service experts checking all installed enclosure cooling units. Rittal generates in-depth documentation, recommending where retrofitting would be beneficial and highlighting where savings can be made. What’s more, calculating the payback period helps customers decide whether they want to make the investment.
    Want to know more about the efficiency check from Rittal? Contact us at:

    Surprising solutions
    Whenever it’s on the lookout for ways to increase efficiency, the energy and resource efficiency working group at Voith Turbo comes across surprising solutions time and again that have made significant improvements. Retrofitting test benches with generator brakes and removing the mechanical ones, for example, brought about several advantages at once. Because the wells on the company premises offered a cost-effective supply of water, test benches were previously cooled with fresh water at a low cost. Once warm, the water would be channelled into the nearby river. Electrical energy is now produced as a result of using generators as brakes in the test benches and is used within the company. Although the test piece is still cooled on test benches using water, water warmed in this way is now used for heating and supplying hot water, which cuts energy costs even further.


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