Main content:
Campus Energy 21 as a new company headquarters
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Entrance to Dürr AG’s new Campus Energy 21 in Bietigheim-Bissingen, Germany
© Dürr AG
Dürr AG’s new company headquarters is called “Campus Energy 21”. The name refers to the company’s aim of achieving open communication and efficient working processes with a future-oriented energy concept that preserves resources. By using energy-saving construction systems, concrete core activation, geothermal heating, heat recovery, daylight-controlled illumination and additional energy efficiency measures, the intention is to reduce the energy consumption relative to standard buildings by 50% and the CO2 emissions by 60%. With around 1,500 employees, the new campus is the largest site owned by the Dürr company. The globally active machine and plant constructor has been bundling its Germany activities relating to painting, assembly and environmental technology in Bietigheim-Bissingen since 2009. These were previously distributed across several sites. Dürr’s registered office remains, however, in Stuttgart.
Building summary
| Project status |  In Operation |
|---|---|
| Location | 74321 Bietigheim-Bissingen, Baden-Württemberg |
| Completion | 30. Juni 2009 |
| Inauguration | 02. Juli 2009 |
| Building owner | Dürr Systems AG |
| Gross floor area | 39,266 m2 |
| Heated net floor area | 27,181 m2 |
| Gross volume | 110,797 m3 |
| Work places | 1,180 |
| A/V ratio | 0.31 m2/m3 |
| Key aspects |
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Project description
Campus Energy 21 is around 70,000 m² in size. The main aim was to achieve short routes to improve the internal working processes. The site features a new office complex consisting of three interlinked pavilions that, with their spatial proximity and short routes, embody the campus concept. Particular emphasis was placed on achieving a communicative and productive working environment. In addition, the site also includes a new customer centre, a logistics hall and a large hall for the technology centre where the company develops products and processes and carries out customer tests.
Research focus
The accompanying research has focussed on the operational management for the energy supply system, since the multivalent power, heating and cooling system, combined with geothermal heating, concrete core activation and heat recovery, is quite complex. This will be explained in more detail under “Energy concept”. The results of the scientific monitoring and the operational experiences will be assessed and made available for similar building energy concepts.
Building concept
The distinctive office building with a gross floor area of 39,000 m² consists of three interlinked pavilions that have been constructed using a reinforced concrete skeleton structure. The three pavilions consist of differently high blocks, each of which has an atrium in its centre. The overall building is divided into different functional units or basic zones, which enables use-specific control and regulation. On the ground floor these include the canteen area, kitchen, the entrance foyer and exhibition space, conference rooms and a section that is used for offices. The other floors are mainly used for offices, whereby these are mostly open-plan offices. There are special rooms for meetings and a few individual offices. There are also lounge-like breakout spaces on every floor for relaxing and communicating.
The three atria supply the building with sufficient daylight. Solar shading is provided by louvres divided into two sections that also provide sufficient daylight when there is shading in the lower area. Users can also control the louvres individually. The daylight use is supplemented with a floor lamp concept with position switching. This ensures direct illumination of the workspaces in accordance with daily needs as well as indirect illumination of the rooms.
The facade insulation consists of a conventional thermal insulation composite system with a thickness of 22 cm. The mean U-value of the facade amounts to 0.21 W/m²K. A further feature is the planned use of vacuum glazing in the ground floor windows. It is planned to install it in the foyer and entrance area as part of a pilot project as soon as the innovative glazing is available.
Energy concept
The central element of the energy provision is provided by the combined power, heating and cooling system, which consists of two gas-fired CHP plants and an absorption cooling system. The heat is used directly in winter and is converted into cooling energy in summer. With the CHP plants, the low-temperature heat is also used from the charge air cooler. Surplus heat can be released to the existing buildings at the site. The two CHP plants are operated with natural gas.
In addition, renewable heating and cooling energy is also utilised from a ground water well, from borehole heat exchangers that are more than 99 metres deep and via free cooling. A vapour-compression chiller, which also acts as a heat pump when used in reverse, enables the heat and cooling to be brought to the desired temperature level.
Heating and cooling are released to the rooms via cooling and heating ceilings on the ground floor and via concrete core temperature control on the upper floors. Static heating surfaces are installed in some areas such as the stairwells and the restaurant. In addition, the room ventilation systems also supply heating and cooling to the rooms. The supply air is pre-conditioned in a 240-metre-long, ground-air heat exchanger. On the upper floors, the air can be additionally heated as required using reheaters. Most of the air-conditioning systems are equipped with a heat recovery system. Heated exhaust air from the technology centre can also be used for heating the office spaces.
The energy provision is rounded off with a large photovoltaic system on the building’s roof.
Performance
Information on this subject will become available as the project continues.
Optimisation measures and possibilities
Information on this subject will become available as the project continues.
Construction costs and economic viability
From three different scenarios for supplying the building complex with energy, the most complex was chosen: a boiler, borehole heat exchangers and ground-air heat exchanger, incorporation of two CHP plants, use of an absorption chiller as well as a vapour-compression chiller or heat pump, heat recovery in the ventilation system and solar power generation. The concept therefore requires comparatively high investment costs. The economic assessment was made during the planning phase, taking into consideration the increasing costs for fossil fuels and electricity.
Further information will be provided on this during the course of the project.
Key energy data
| Energy indices according to German regulation EnEV (in kWh/m2a) | |
| Heating energy demand | 18.90 |
|---|---|
Implementation costs
| Costs of implementation in €/m2 | |
| Construction (KG 300) | 704 |
|---|---|
| Technical system (KG 400) | 382 |
Net construction costs (according to German DIN 276) relating to gross floor area (BGF, according to German DIN 277)
