Energy concept of the main building

  Ducts in the main building Copyright: © E.ON ERC EBC

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 strongly. 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. Highly integrated and complex energy generation, storage, and distribution achieve this.



Energy Fluxes within main building Copyright: © EBC

The energy system of the new E.ON ERC main building is based on geothermal energy and heat displacement in combination 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 regenerates the sorption brine during summer for cooling purposes. Thus, we operate a combined heat-cold-and-power-plant.


Heat pump

Heat pump Copyright: © Cofely Deutschland GmbH]

The heat pump used is the Quantum by Cofely with its new radial turbo compressor technology. This heat pump is equipped with drive shaft bearings, that use state-of-the-art magnetic technology. Hence, there is no mechanical wear on the turning parts and minimal risk of failure. The heat pump can operate in both heating and cooling modes.

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 cooling 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

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 a combined heat and power plant (CHP). Hence, during summer the CHP`s waste heat is used within the process instead of being dissipated to the environment.


Decentralized façade ventilation units

Façade ventilation unit Copyright: © TROX

The controlling system of the E.ON ERC main building has to ensure that the different distribution systems for heating and cooling are working together in an efficient way. Thereby the concrete core activation is responsible for long term demands of the building, whereas the ventilation units take care of the occupants' short term demands.

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, air conditioning can be provided in a very efficient way.