Water-to-water heat pumps
Ground water as a heat source
Does your region have an ample supply of ground water? If so, it could be an ideal heat source that you can tap into by using a water-to-water heat pump. Read on to find out all about this type of heating system.
The ideal installation site for a ground water heat pump is a cellar or utility room as this keeps the distance to the two wells to a minimum. It also makes it easier to protect the lines from freezing. In unfavourable locations, you can alternatively install a water-to-water heat pump with an intermediate brine circuit, although this will impair the system’s efficiency.
The same applies to every type of heat pump: heat pump heating systems can only achieve optimum efficiency when combined with radiant panel heating systems. So it is strongly recommended to plan new buildings with underfloor heating or wall-mounted heating elements. For existing buildings, it is ideal if underfloor heating has already been installed. If not, it can be worth thinking about retrofitting a heating system of this kind or using alternatives, such as wall heating systems, ceiling panels or large radiators.
The following checklist shows you how to get the best out of a heating system that uses ground water as an energy source:
The higher the seasonal performance factor (SPF) of a heat pump, the less electricity it consumes. The efficiency of the various models can be compared on the basis of the SPF.
The European Union issues energy efficiency labels for heat pumps. When choosing a water-to-water heat pump, make sure your appliance has an A+++ label.
Using solar power from a photovoltaic system on your home’s roof makes running your water source heat pump particularly economical and self-sufficient with regard to energy. Heat pumps with the SG Ready label specifically utilise excess power from photovoltaic systems.
Every heat pump heating system needs a hot water tank for DHW heating. In most cases, it is also worthwhile installing an additional buffer cylinder for storing heat for the central heating system.
Energy suppliers offer special electricity rates for heat pumps that include shut-off times. Providing sufficient storage volume will allow you to bridge these periods easily.
Combination tanks allow you to store DHW and heating water in one container.
The insulation standards of existing buildings must be fairly good to use systems of this kind. If not, a hybrid solution consisting of a gas condensing boiler and heat pump may be the better choice.
Answers to your questions about water-to-water heat pumps
A ground water heat pump needs about 2000 litres of ground water per hour to achieve a ten-kilowatt heating output. A hydrological survey must be conducted in advance to determine whether the substrate can provide enough water.
The ground water must contain low levels of dissolved oxygen and have low conductivity. Otherwise, the well will be prone to corrosion and clogging due to the formation of deposits.
Local water authorities of cities and municipalities are responsible for monitoring the water and for water management processes, such as approving ground water heat pumps (in Germany).
Our recommendation: Heat pump BWW-1
The BWW-1 water-to-water heat pump extracts free energy from the ground. Thanks to their high efficiency all year round, they thus ensure a reliable heat supply.