Low Temperature

There are different low-temperature Geotherm sources, which can be used differently: Terrestrial heat probes, terrestrial heat probe fields, energy from the groundwater, energy stakes and geo structures, etc.

Terrestrial heat probes (vertically heat exchanger), are frequently-used, in order to supply heat pumps with the necessary terrestrial heat. In the U-tubes circulates a heat-transfer liquid. For combined heating and cooling maximally 150 meters deep probes are used and exclusively for heating purposes up to 400 meters of length. The principle of the heat exchange with near-surface earth layers is also the same for geo structures. In this case fundamental parts of the buildings are used by integration of pipings for the liquid circulation. These pipings are suitable for the desired energy-exchange, both, for heatings and coolings.

Also the groundwater with temperatures of approx. 8 - 12 °C can be used energetically. Compared to surface waters, groundwater has only a minimal seasonal temporal variation. Large occurances are predominantly found along rivers, in valleys of the pre-alpes but also inside alpine locations, where permeable water-prominent gravel layers are. They can be as big as 30 to 6 meters. With appropriate drillings, existing groundwater-flows can be opened.

Restrictions by building and operation of geotherm plants by using plants of the near the surface heat (terrestrial heat pumps, ground-water heat pumps, energy stakes, etc.) are particularly given for reasons of the ground-water protection. For the build and operation of low depth drillings (<400m i.e. terrestrial heat probes) usually a water protection-legal grant and/or concession of the responsible grant authority is necessary. Earth registers and heat baskets outside of ground-water protection zones do not require water protection-legal grant.

Examples of low-temperature sources