Dortmund. A football coach had the “right touch” if he can visibly increase the efficiency of its team by substituting a player. A clever substitution strategy does not only bring about good results on the pitch, but also in the building services of a football stadium. Stefan Kopetzky, manager of technical operation in the Signal Iduna Park, the stadium of the German Bundesliga team Borussia Dortmund, is currently proving this. Together with the Dortmund pump expert WILO SE he started to introduce high efficiency into the pump equipment of the biggest German football stadium with its 80,552 seats. The sub-centrals of the heating installation located in the north stand are currently being equipped with “Wilo-Stratos” high-efficiency pumps.

 

The positive results of this measure can surely not be read from the goal account of the sixfold German championship winner and the Champions League winner of 1997 – but it becomes obvious on the electricity meter and the results are considerable. One uncontrolled double pump alone has a power consumption of about 8,000 kWh per year. According to first estimates, an early replacement by a “Wilo-Stratos D 80/1-12” high-efficiency pump will result in a reduction of consumption to under 3,500 kWh/a. Even higher saving potentials were calculated for a sub-distribution for the first aid station, the office of the security service and the spectators’ toilets of the north stand. The recent replacement of the old pumps by more high-efficiency pumps of the “Wilo-Stratos” series is estimated to bring about savings between 70 and 85 %. Together with another pump of this series, which is applied in a second sub-distribution, in heat distribution for the north stand, there will be energy-cost savings of about 1,700 Euros per year. The investment costs for the new “Wilo-Stratos” high-efficiency pump will pay off after approx. five years.

 

The stadium has been extended several times and was once more modernised for the World Championship 2006. The investment into highly efficient pump technology will pay off almost as quickly as in other commercial properties. The pump expert Wilo explains this with the intensive utilisation which goes far beyond the home matches of Borussia Dortmund: “The offices, the conference and event rooms as well as the catering areas in the stands are regularly used, so that the heating installation is in permanent operation”, says Wilo salesman Volker Brehm. In total, each of the almost 50 heating pumps in the sub-centrals and sub-distributions of the stadium make up about 5,100 to 5,500 operating hours. “By replacing all uncontrolled old pumps, of which many still exist, by Wilo high-efficiency pumps, power savings of more than 36,000 kilowatt hours can be realised per year. This corresponds to a reduction of electricity costs of about 7,000 Euros”, says Volker Brehm.

 

The heat generation for the stand areas and the heating of the football pitch of the Signal Iduna Park takes place in a generously dimensioned heat station under the south stand. The heart of the installation is the three natural gas boilers, which are dimensioned in a way that a home match can run smoothly even in the event of freezing wintery cold. The boiler room is operated by the city’s energy provider ‘Dortmunder Stadtwerke’, a supply contract with the operator of the stadium guarantees the heat supply. Every boiler unit provides 1,600 kilowatt, with two boilers operating and one serving as a backup. For hydraulic reasons, the heat is supplied at fixed speed; and four glanded “Wilo-CronoLine-IL” pumps are used. To heat the football pitch, a separate substation with heating circuit and heating exchanger was established so that the system’s hydraulics of the remaining heating installation will not be put at a risk in the event of water losses from the largely dimensioned panel heating. The plate heat exchanger has an output of 1,300 kW; in wintery weather conditions, the heating of the pitch is activated 24 hours before a match.

 

Beyond the heating pumps, Wilo also supplied the pressure boosting systems. As it is important to avoid disturbing noise from the building services during events other than football matches, installations on the basis of glandless pumps were chosen. The “Wilo-Multivert MVIS” high-pressure centrifugal pumps operate in a more quite and vibration-free way than glanded pumps of comparable hydraulic performance. A pump of this series causes at full power a noise level of 40 dB(A)– a little more than the soft rustling of the leaves of a tree. So it is up to 20 dB(A) more quiet than comparable pumps in glanded construction. In Dortmund’s stadium several pressure boosting systems are applied, each of them equipped with four “Wilo-Multivert MVIS” pumps. In order to meet the extremely fluctuating power requirements during sold out matches, with peak loads before and after the matches as well as during the half-time breaks, one pump is always operated as the base-load pump, whereas three other pumps are switched on depending on the load (cascade control). The maximum flow is e. g. in the north stand 20 m3/h.

 

The building services in the “football temple”, which was built for the World Championship 1974, has – just as the stadium itself – a long history. So the pump equipment has continuously been adjusted to the increased requirements over the past 35 years. Currently, the focus lies on the optimisation of the energy efficiency. High-efficiency pumps in heat distribution allow the operators to realise considerable savings of energy costs in the current modernisation steps.