Energon

Energon office building from the north

The Energon is a passive house standard office building on Eselsberg in Ulm . It has a net floor area of 6911 m² and approx. 420 workplaces. The symmetrical structure of the Energon has 5 floors with a spatially outwardly curved facade. The building is a reinforced concrete skeleton construction with a facade made of wooden elements. Most of the offices are rented to companies in the IT and software industry. Large training rooms and a casino are also available. In the center of the building, a large, glass-roofed atrium , in which all stairs and connecting walkways are located, forms the communicative focal point of the building. A shadowless south-facing slope was chosen as the location for the building in order to be able to use the optimal solar radiation. The client is the Software AG Foundation , the architect is the oehler faigle archkom solar architektur office , and the energy concept, the building services and building physics were planned by ebök . The requirements and components were coordinated with one another from the outset through joint planning by the architect, building technician and structural engineer.

technology

Geothermal probes and the use of geothermal energy

The EnerGon has 40 earth bores, each 100 meters deep, into which plastic pipes with a U shape are embedded. These pipes have water flowing through them as a heat transfer fluid and release heat to the ground in summer or absorb heat from the constant soil temperature of 10 ° Celsius in winter. The water of the concrete core temperature control is now preheated or pre-cooled via heat exchangers between the geothermal probes and the concrete core temperature control (CCT). The supply air for the fresh air supply to the energon is also preheated or pre-cooled via heat exchangers.

Temperature control

The CCT consists of water pipes that are concreted into the concrete ceiling. Every room can be comfortably and imperceptibly heated or cooled via the large radiant surface of the ceiling sub-layer. Due to the passive house standard insulation, only minimal temperature differences are required for heating and cooling. Cooling takes place with a minimum of 18 ° C water temperature, and heating takes place with a maximum of 22 ° C water temperature.

Schematic representation of the supply air heating and concrete core temperature control

ventilation

The ventilation system in the Energon guarantees with a circulation rate of a maximum of 29,000 m ³ / h, a year-round pleasant and well-tempered fresh air distribution throughout the building. For pre-heating in winter and pre-cooling in summer, a concrete pipe with a length of 28 m and a diameter of 1.8 m was laid in the ground. The supply air enters this duct via 3 suction towers, flows through it and absorbs or releases heat. The previously pre-cooled supply air can also be cooled down via the temperature exchange through the geothermal probes. In the winter months, on the other hand, the already preheated supply air can be further heated to approx. 5 ° Celsius with the help of geothermal probes. There is also the option of extracting around 65% of its original heat from the exhaust air and returning it to the supply air. If this is not enough, the thermal energy from the district heating connection is used to additionally heat the supply air.

Thermal insulation

The house has a 35 cm thick thermal insulation in the facade, 20 cm under the building base plate and 50 cm on the roof. The facade was prefabricated and assembled using a wooden element construction method developed by the architects oehler faigle archkom . According to the passive house planning package PHPP, the passive house consumes 12 kWh of heating energy per m² of usable area and year.

lighting

With regard to the lighting, an artificial light source in daylight is only necessary in a few cases. The blinds on the facade of the building have reflectors on top that guide light directly into the offices, even if the lower area of the blinds is completely closed to protect against glare. The interior corridors in the building are adequately supplied with daylight via glass elements next to the office doors. The more centrally located offices benefit from the incidence of light through the roof of the inner courtyard. This incidence of light can of course also be regulated via blinds. All artificial lighting is equipped with energy-saving lamps and additional ballasts to optimize efficiency. In addition, sensors for presence detection and daylight-dependent regulation of the illuminance ensure further energy efficiency

Energy concept

The Energon Ulm is one of the first office buildings that was planned and built according to the criteria of the passive house standard. On October 28, 2002, the Passive House Services GmbH in Darmstadt awarded the Energon office building the certificate of quality- tested passive house . The certificate was presented to the client during the official inauguration on October 30, 2002. In addition to the passive building components, the building has two solar technology systems. A photovoltaic system is located directly on the roof of the office building and another is on the neighboring parking garage, which is part of the overall project. Together they achieve 136 kWp and an annual yield of around 137,000 kWh. With the output of the two systems alone, around 70% of the primary energy requirement of the building is covered. The additional use of district heating generates so much energy that almost the entire energy consumption of the building is covered. Thus, the operation of the energon is almost CO ₂ -neutral, which saves 175 tons of CO ₂ annually.

The building was certified as a passive house by the Passive House Institute Darmstadt in 2002 with the following values:

Primary energy parameter heating energy = 35 kWh / (m² a),
Primary energy parameter air conditioning = 17 kWh / (m² a),
Primary energy value hot water = 7 kWh / (m² a),
Primary energy value other = 9 kWh / (m² a),
Primary energy value PV electricity = −72 kWh / (m² a)

Chronology of Energon Ulm

1999 October / November Preliminary talks with invited teams of architects / December Invitation to tender for an architecture competition with the specification: Buildings in passive house standard

2000 February Submission of the drafts / March Technical evaluation / April Decision on the winning draft, start of planning

2001 May laying of the foundation stone

2002 Funding by the Federal Ministry of Economics & Technology / October 31st inauguration / November move in of the first tenants

2003 July German Solar Prize in the "Solar Building" category

2004 January 1st Start of the official 2-year measurement phase

2005 February Innovation Prize for Architecture and Technology / December 31, end of the official measurement phase

2006 June Award for best cooling concept in German office buildings

2007 EU publishes Energon as a model office building

Web link / sources

48.41925 9.9345555555556Coordinates: 48 ° 25 '9.3 " N , 9 ° 56' 4.4" E