If former industrial and commercial areas are overbuilt, entire districts are often created in a very short time with a distinctive atmosphere and modern flair. This is also the case in the Düsseldorf district of Derendorf, where the discarded freight yard makes way for the "Neues Düsseldorfer Stadtquartier", which heavily relies on heat pumps.
For the future-oriented heating / cooling concept, the soil conditions proved to be ideal for using the heat source “groundwater”. In any case, the area in the old branches of the Lower Rhine is, in this regard, extremely productive.
Two wells, each 18 meters deep, were drilled. The sump well was placed downstream of the sampling well, at a distance of 70 meters, in order to avoid mixing. 365 days a year – even on very cold winter days – constant groundwater temperatures between 8 and 12 ° C prevail at this depth. The delivery rate of the extraction well is a maximum of 60 cubic meters per hour. 18 hours a day, the groundwater may be deprived of energy.
Key facts
Building
Heat pump and source
Location
Düsseldorf, Germany
Number of HP
4
Construction
2009
Installed power
352W
Heat distribution
panel heating
Operation mode
cascade
Heated area
10.200 m² living
Heat source
groundwater
Heating system
Domestic hot water
Heat demand
345 kW
Type of system
unknown
Heating temperature
unknown
Max. temperature
unknown
Circulation system
unknown
Other information
Efficiency of the heat pump (SPF)
4,5
Investments costs
unknown
PV installation
no
Description of the technical concept
The water is fed into the house via large, well-insulated pipelines and passes through four heat. Two brine-water heat pumps each are placed in a space-saving manner in the technical room of the basement, the entire system is cascaded. A control unit ensures that the operating hours of all four large appliances are almost identical. This is important to ensure a long service life of the system. The heat source is groundwater, which is made available to the four heat pumps via a large-scale DC link heat exchanger. Two storage tanks, each with a capacity of 1,000 liters, separate the heat generator from the heat distribution system and ensure efficient and trouble-free operation of the system.