Energy Concept of the Main Building



Johannes Fütterer



+49 241 80 49790


  Cooling and Heating System Copyright: © E.ON ERC

Constructing energy efficient buildings and ensuring the thermal comfort of the occupants is a hard task to be fulfilled by architects and engineers. A common solution for this task is to insulate the surrounding walls and windows very strong. For office buildings this strong insulation shifts the annual energy consumption from heating and cooling energy. Therefore the energy concept of the E.ON ERC Main Building reduces the energy demand for heating and cooling with a responsible insulation. This is achieved by highly integrated and complex energy generation, conservation, distribution and benefit transfer.



Energy System of E.ON ERC Copyright: © E.ON ERC

The total energy system of the new E.ON ERC Main Building is based on geothermal energy and heat displacement in connection with a heat pump process. The geothermal field consists of 40 boreholes, each 100 m deep. Heating and cooling base loads are distributed by concrete core activation. A sorption-supported air conditioning unit provides fresh air to conference rooms and CIP-pools. Offices are equipped with façade ventilation units, covering peak loads with the supply of cold air during summer and warm air during winter. A gas-fired combined heat and power engine provides high temperature heat, which is used to regenerate sorption brine during summer.


Heat Pump

Heating pump Copyright: © Cofely Deutschland GmbH]

As Heat Pump the Quantum by Cofely with its new radial turbo compressor technology is used. This heat pump is equipped with drive shaft bearings which work by way of magnetic technology. Hence, there is no mechanical wear on the turning parts and minimal risk of failure. The heat pump is used in a bivalent mode and provides heating and cooling energy. The heat pump can actively shift heating and cooling demands inside the building and it is able to use external heat sources and heat skins like geothermal probes and a recooling plant. The heating power is up to 180 kW whereas the cooling power is up to 258 kW. The electricity consumed is partly generated in a combined heat and power plant.


Sorption-supported Air Conditioning

Schematic structure of Sorption-supported Air Conditioning Copyright: © Menerga GmbH

The central areas of the building like conference and meeting rooms as well as laboratories are supplied with conditioned air from central ventilation units. These units use a sorption process for air conditioning. In this process, the outdoor air is dried by a concentrated LiCl-brine. Meanwhile the return air is cooled down by evaporation and used to cool down the supply air via a cross-flow heat exchanger. The regeneration of diluted brine needs heating energy at a high temperature. This high temperature heating energy is generated by combined heat and power plant (CHP). Hence, during summer, CHP’s waste heat is used within the process instead of being dissipated to the environment.


Decentralized Façade Ventilation Units

Facade Ventilation Unit Copyright: © TROX

The controlling system of E.ON ERC main building has to make sure that the different distribution systems for heating and cooling are working together in an efficient way. Thereby, the core activation is responsible for long term demands of the building whereas the ventilation units take care of term demands of the user. All office rooms are equipped with decentralized façade ventilation units. These units are responsible for fresh air supply as well as active temperature control of the rooms. Speed controlled fans and an adaptive heat recovery system are integrated in every unit. Thereby, the air condition can be provided in a most efficient way.