Special GRT

Geothermal measuring penetrometer - the Response Test for energy piles

The geothermal measuring penetrometer has been specially developed with focus on an easy installation and a relatively inexpensive measurement of the effective thermal conductivity and the undisturbed ground temperature to a depth of about 20 m (see photo - preparation of a GRT). Therefore it is an ideal tool for an early parameter collection in the planning / design phase for energy pile systems.

Otherwise costly and time-consuming installations of either a test borehole heat exchanger or a test energy pile can be eliminated by using the geothermal measuring penetrometer. After the conduction of the GRT, the probe is removed again.

The geotechnical method for installing the 45-mm probe corresponds to the "heavy dynamic probing / DPH" and thus is not subject to legal approval. Hence, an additional time advantage over conventional testing methods can be realized.

Thermal Needle System - the Response Test for ground heat collectors

The "Thermal Needle System" allows the on-site measurement of the thermal conductivity in the near-surface soil layers up to a typical burial depth of horizontal ground heat collectors of approximately 1.2 to 1.5 m (see picture below for the system in use, with data logger).

The working principle of the thermal needle system basically corresponds to a geothermal response test for borehole heat exchangers. It provides reliable values of thermal conductivity for individual soil layers and undisturbed surface temperature for the design / planning of medium to large ground heat collectors.

For small geothermal ground heat collectors, thermophysical literature values are still used fairly often, while it is easily possible to gain safety for planning and probably save investment costs by utilizing a thermal needle system.

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