Heat source groundwater
Groundwater heat pumps
Water/water heat pumps
The year-round constant temperatures between 8 and 12 °C make groundwater a heat source that can be used with high efficiency via water/water heat pumps. With annual performance factors (APF) of up to 6 in operational practice and APF of 4 – even in combination with radiators – OCHSNER groundwater heat pumps work very profitably and economically.
Product overview Groundwater heat pumps
The Smart Grid-enabled high-end water/water heat pump OCHSNER AQUA FOX stands for maximum efficiency (SCOP up to 7.8, A+++) and quality. It operates whisper-quietly (32–36 dB), adapts flexibly to your needs thanks to inverter technology, and is equipped with an intuitive touch display and Modbus interface. Whether as a compact Tower S200 or space-saving indoor unit S1, it is ideal for heating, passive cooling, and domestic hot water preparation in single and multi-family homes.
Function of a groundwater heat pump
In the extraction well, the groundwater is extracted and directed to the heat pump. A heat exchanger transfers the energy to the refrigerant, while the groundwater cools down slightly. OCHSNER systems ensure that the water is subsequently returned completely and cleanly via the injection well in accordance with legal requirements.
Supply & injection wells for the groundwater heat pump
To develop the heat source groundwater, preparatory work and drilling are required. Two wells are drilled: supply or extraction well and infiltration or injection well.
Distance between the wells
The two boreholes must be placed with sufficient distance so that the warmer supply and the cooled return cannot mix. In any case, the return line must be located downstream of the extraction point in the flow direction of the groundwater.
Detailed consultation
What is technically feasible and whether your property is suitable for the environmentally friendly and economical heat source groundwater can be answered by your OCHSNER system partner in a detailed consultation.
For whom is a groundwater heat pump suitable?
Particularly suitable for the use of groundwater heat pumps are building sites where groundwater is available at a depth of 8 to 20 meters. Deeper drilling is often not economical, near-surface water is subject to greater temperature fluctuations and is often contaminated by environmental pollution. In any case, an OCHSNER system partner will recommend a multi-hour pumping test during planning. This allows determining whether water can be extracted in sufficient quantities. A sample is taken and subsequently a water analysis is created. The water analysis can exclude corrosion risks from problematic ingredients.
Plate or tube bundle heat exchanger?
OCHSNER groundwater heat pumps use two different types of heat exchangers. Plate heat exchangers: Plate heat exchangers (PHE) are suitable for very good water qualities and effectively transfer heat to the refrigerant. Tube bundle heat exchangers: The slightly smaller transfer performance of tube bundle heat exchangers (TBHE) is offset by the fact that they can also cope with poorer water qualities. Various factors contribute to this. The wall thickness of OCHSNER TBHE is twice as thick as that of plate heat exchangers. Stainless steel 304 is used on the outside and 1.4404 for the tubes inside. This ensures very good corrosion resistance and reduces the risk of mechanical damage. OCHSNER TBHE have a 250 times larger inner diameter in the channels for conducting groundwater than PHE. They are therefore insensitive to blockages caused by suspended matter in the water such as sand and other contamination. At the same time, the risk of freezing is reduced. A special filter is always connected upstream for permanently good operational safety.
The most frequently asked questions about groundwater heat pumps
For an initial assessment of the possibilities, it is helpful to inquire whether there are already groundwater heat pumps in the neighborhood or if there have been test drillings. Any lower water authority or the water management office can provide information on whether groundwater occurs and if it can be used with a heat pump.
OCHSNER groundwater heat pumps are among the most durable and reliable systems. Only in cases of poorer water quality must the filter at the suction well be cleaned at intervals or the heat exchangers be flushed to protect against sludge.
Groundwater at the recommended depths cannot freeze. With proper design, there is no risk of frost.
Groundwater heat pumps operate very efficiently. The result is low heating costs, which make the heat pump very popular. However, installation is only possible where the groundwater quality is suitable.
Advantages of a groundwater heat pump:
- high efficiency
- low heating costs
- combination with solar thermal for hot water preparation possible
Disadvantages of a groundwater heat pump:
- dependence on the quality of the groundwater
- more complex permits & reporting obligations
The electricity consumption for operating a groundwater heat pump primarily depends on the size and quality of the building as well as your heating habits. How high the electricity consumption will actually be can be determined in the individual consultation with your OCHSNER expert. Inquire now without obligation!
The price of a groundwater heat pump consists of operating costs, development costs, and investment costs for purchasing the heat pump itself.
The costs are usually very individual and vary depending on performance, installation situation, and region. The soil conditions and the depth of the groundwater table also determine the price.
Exact information on the costs for operating a groundwater heat pump can be found in our OCHSNER heating cost calculator.
Groundwater is public property, is subject to special protection, and ensures our drinking water supply. Therefore, groundwater use is always subject to approval.
Yes, there are attractive funding programs through the Federal Office for Economic Affairs and Export Control (BAFA) or through the KfW Development Bank. Here is the link to the funding information.
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