Grasbrunn - vehicle registration office

Not only heating, but also air conditioning involves high energy consumption. Therefore, the district of Munich decided to replace the previously inefficient air cooling system of the vehicle registration office (which is housed inside a flat-roof building) in Grasbrunn with cooling through ground water as part of necessary modernisation measures.

ERDWERK conducted the conceptual design and supervised the project as the general planner. Because of the very favourable hydraulic conditions in the “Münchner Schotterebene” gravel plain, it was sufficient to install only one production and one reinjection well. The ground water, which has an almost constant temperature of 10-12°C, is developed with the help of a submersible pump and passed through a heat exchanger. A secondary circuit serves to cool down the air that flows into the premises. The thermally processed ground water is subsequently reinjected into the ground water through the reinjection well. A production rate of only about 3 l/s is adequate to air-condition the entire vehicle registration office..  The geothermal system has been operating smoothly since its completion in the spring of 2005, and fulfils the high expectations of the registration office staff, especially during the warm summer months.