geoKOAX - Geothermal Probes

The core of the of geoKOAX heat exchanger technology is passive turbulence. The continuous change from laminar flows to turbulent flows increases the heat transfer coefficient by 20 % in the case of a 9 ft 10in/ 3 m probe and by up to 100 % in the case of a 32 ft 9in/10 m probe (Source: RWTH (Rheinisch Westphalian Technical University) Aachen)

The geoKOAX probe features about 6 times as much carrier fluid volume as conventional double-U probe systems. The coaxial tube is filled with a heat carrier liquid with particularly low viscosity and serves to store heat. This permits a precise release of the required energy at a constant temperature and also longer down-times of the heat pump, which are relevant for annual performance figures.

The geometric concept of the geoKOAX system means that the contact surface area for geothermal heat is twice as large as that for conventional geothermal probes. As result of the homogenous, smooth coating, the space between the probe and the soil is even. This ensures a homogeneous filling of the annular space without any air pockets.

The arrangement of multiple pipes, which is common with conventional probes, has proven to be suboptimal for transmission of energy, because the space between the pipes and the soil is uneven. The concentric orientation of the geoKOAX coaxial tube ensures that the space between the coaxial probe and the soil is even, thus leading to significantly lower borehole resistance. This makes for much better absorption of energy, which is relevant for annual performance figures.