The heat source system is equipped with 1 borehole with a total length of 96 m. The brine pump is designed as a high efficiency pump and thus positiviely influences efficiency. The heating circuit contains a buffer storage which is located inside the heat pump. This part of the system also uses a high efficiency pump. The DHW circuit contains a DHW storage. Due to the installation of underfloor heating and low inlet temperatures, there are good preconditions for the heat pump system.   

As the data for this system is only available from July 2010 onwards, one can only estimate efficiency so far. The monthly SPFs during the heating period (2010 and 2011) lie constantly over the average of 3.9 of ground source heat pumps. During the summer months efficiency decreases as the system focuses primarily on DHW supply. The system's overall efficiency for the whole year, however, will presumably be above 3.9. The positive values can be traced back to low inlet temperatures of the heating circuit and brine circuit in winter. The brine pump's share of the total energy demand will be around 6 % and thus reflect the average. The rarely used back-up heater positively influences the heat pump's efficiency. The share of DHW is slightly higher and thus influences efficiency negatively as higher temperatures for DHW are needed.





  *area according to EnEV
  **measured from: 07/10 to 06/11
 ***heating and DHW according to energy performance certificate
  **** in accordance with EN 14511