The ground as heat source.
Tapping the heat of mother earth.

In terms of the amount of energy supplied, the ground is the second best heat source after ground water.  Depending on the amount of space available and the composition of the ground, either ground heat collectors (horizontal brine pipes) or borehole heat exchangers (vertical brine pipes) are used to collect the heat from the ground. The ground heat of the upper soil layers down to a depth of approx. 100 m consists partly of stored solar energy and partly of energy from the interior of the earth.

A ground heat collector system requires a sufficiently large garden area. If this space is not available, or if the heat pump is also to be used for cooling, borehole heat exchangers are sunk vertically into the ground as an alternative to horizontally laid out ground heat collectors. Pressure-resistant pipes in which the brine circulates are placed in drilled holes extending down to a depth of up to 100 metres. Borehole heat exchangers are subject to authorisation by local water authorities.

• Minor temperature fluctuations of the ground throughout the year
• Therefore almost constant heat output throughout the year
• Almost constant COP, independent of external temperatures
• No defrosting of the evaporator necessary
• High annual performance factor
• Excavation work required for installation
• Ground heat collectors require ground space not covered by any type of construction, up to twice the size of the footprint of the building itself
• Borehole heat exchangers are subject to authorisation by local water authorities