For Germany’s elite speed skaters, the Sport­forum in Berlin is an impor­tant training facility, as its speed skating rink is the local Olympic training center, the venue for inter­na­tional compe­ti­tions, and a large number of Berlin clubs also train there.

Athletes can count on perfect condi­tions – including immac­u­lately smooth ice. But this can only be achieved if the climate in the arena is also constantly cool and dry.

This is no easy task, as activ­i­ties in the rink vary greatly: from concen­trated training by a few Olympians on the 262- and 440-meter lanes and public hustle and bustle on the 1,800-square-meter ice surface to compe­ti­tions with 3,500 spec­ta­tors in the stands. Temper­a­ture fluc­tu­a­tions also go hand in hand with changing capacity utiliza­tion.

The ice rink was built in 1962 and expanded in 1986.
It was the first indoor speed skating rink in the world at that time.

The total ice surface is 4,400 square meters.
The long track is 440 meters long, the short one 262 meters.

Mirror-smooth instead of a drip­stone cave

This creates conden­sa­tion that can collect on the ceiling and struts and drip onto the ice surface. However, it’s not so good to skate on the begin­nings of a drip­stone cave. “We need the arena temper­a­ture to be eight degrees Celsius so that the differ­ence between the ice and the ambient temper­a­ture doesn’t lead to conden­sa­tion or mist forma­tion,” explains Sven Kuwatsch, tech­nical manager of the Sport­forum.

That’s why the venti­lation systems in the belly of the arena are working at full speed. “One runs contin­u­ously, a second is switched on when there is a lot of activity, and the third is the redun­dancy in case one of the other two fails,” explains Daniel Bürgel, Customer Service at Munters GmbH, which manu­fac­tures and main­tains the systems.

Exchanging and drying air

Just circu­lating the air from the arena would not be enough to prevent conden­sa­tion, so the systems also dehu­midify. To do this, the air from the arena is drawn over a constantly rotating rotor, on which the mois­ture settles.

To enable the rotor to release the absorbed mois­ture, a small part of the rotor runs through a regen­er­a­tion unit in which fresh air heated to around 130 degrees Celsius absorbs the mois­ture and carries it away to the outside. Because this also heats the process air, it is cooled down again before being blown back into the arena.

Since the systems were installed in 1998, each process air unit has had a large belt-driven centrifugal fan for the supply and exhaust air. The fans were noisy, inef­fi­cient and had already suffered a great deal from 25 years of use in humid air. It was high time to bring the systems up to date. Daniel Bürgel suggested that Sport­forum Berlin carry out a retrofit.

“With savings of 30 percent calcu­lated in advance, the Sport­forum was also quick to make the deci­sion.”

Daniel Bürgel, Customer Service Advisor North in Service / After Sales at Munters GmbH

Energy savings thanks to retrofit

Shortly before, Bürgel had had a posi­tive expe­ri­ence with a retrofit in a smaller ice rink in Berlin. He works closely with Hamburg-based venti­lation special­ists Breuell und Hilgen­feldt GmbH, which, as an ebm-papst service center, uses highly effi­cient EC fans. “It works really well and we can achieve substan­tial energy savings,” says Bürgel enthu­si­as­ti­cally. “With savings of 30 percent calcu­lated in advance, the Sport­forum was also quick to make the deci­sion.”

The indi­vidual fans were each replaced by a FanGrid with three state-of-the-art centrifugal fans from the RadiPac range. Thanks to the EC motor and opti­mized blade made of glass-fiber-rein­forced composite mate­rial, they are extremely effi­cient. Thanks to their excel­lent control char­ac­ter­is­tics, they can be oper­ated as required, which saves addi­tional energy. They are also up to 7dB(A) quieter than their prede­ces­sors. “Because three fans operate in one FanGrid, we can also increase reli­a­bility,” explains Dieter Hilde­brandt, Sales Manager Retrofit Germany at Breuell and Hilgen­feldt.

Effec­tive step for greater energy effi­ciency

Hildebrandt’s initial measure­ments after replacing the supply and exhaust fans showed total energy savings of 52 percent for the system. However, when the retrofit was performed in the spring, the large outer track had already defrosted, and only the smaller and inner surfaces were still in oper­a­tion. But major devi­a­tions are not expected when the arena returns to full oper­a­tion in October.

Either way, this retrofit is an impor­tant step for the Sport­forum on its path to a smaller energy foot­print: “We’re looking every­where right now to see where we can save energy. The retrofit in the speed skating arena is one of these measures – and an effec­tive one at that.”