The heat source system is equipped with 1 borehole with a total length of 96 m. The heating circuit operates without buffer storage, however, a hydraulic shunt is installed. Therefore a second circulation pump is installed in the heating circuit. The DHW circuit contains a DHW storage. Besides underfloor heating, the system additionally uses a 200 m² concrete core activation for heating. The combination of both, underfloor heating and concrete core acitvation as well as low inlet temperatures set positive preconditions for the heat pump system.   

Efficiency in 2010 amounted to 4.5 which is above the average of 3.9 as far as ground source heat pumps are concerned. Good efficiency values result from low inlet temperatures in the heating circuit and average temperatures in the brine circuit in winter. The back-up heater's share of 1 % of the total electrical energy demand lies below the average of 2 % and thus contributes positively to good SPF values. The brine pump's share is not considered seperately. The DHW share in 2010 amounted to 2 % and is far below the average of 18 % which contributes to a good efficiency values because of the low temperature level needed for heating.

  * in accordance with EN 14511