Geothermal
In the Renewable Energy House, geothermal energy is used in the form of a geothermal heat pump with 4 vertical borehole heat exchangers (“vertical loops”) each 115 m deep. During winter the heat pump is used to heat the back building offices and conference rooms. The design of the radiators in the back building secure a typical maximum supply temperature in the order of 35-40 °C and in any case below 55 °C. The maximum heat load for the back building is 25 kW. The heat pump transforms energy from a low temperature level into heat at a high temperature level where it can be used for heating purposes. The heat pump used in the Renewable Energy House has a maximum heating output of 28.3 kW. The geothermal system is not only used for heating but acts also as a heat sink for the excess condensor heat of the solar absorption cooling system in summertime. Not only does the design of the borehole heat exchangers have to account for the heat load but also for the excess heat injection from solar cooling in summer. The 4 borehole heat exchangers have been installed by drilling inside the interior courtyard, with the drilling rig passing the narrow doorway with only a few centimeters of clearance.
Geothermal Heating & Cooling system equipment sponsors
- EWS Erdwärme Systemtechnik GmbH & Co. - design and support in pipe connections, pumps
- GEFGA - antifreeze (glycole)
- Haka.Gerodur AG - borehole heat exchangers
- Maroton Gmbh - borehole grouting material
- Ochsner Wärmepumpen GmbH - heat pump
- Stüwa Konrad Stükerjürgen GmbH - borehole heat exchanger, borehole design, system supervision
- UBeG - System design calculations, borehole design, system supervision
- Verheyden - drilling and installation of borehole heat exchangers and pipe connections
