Reference "Algae": Comparison separatus - DU-32
Geothermal project in Fussach (AT): Two 90 m deep boreholes with different probe types allow a comparison of the efficiency between a classic double-U probe and the innovative separatus probe.
Property description:
The single-family house in Fussach AT, built in 2021, with a living space of 220 m², is heated by a modulating heat pump with a maximum heating output of 13 kW.
The soil consists of water-saturated clay and has a temperature of ~ 5° C at a depth of one meter. The heat source is accessed through two boreholes, each 90 meters long and 152 mm in diameter.
The first well, in operation since 2021, is equipped with a 32 mm diameter double-U probe. The backfill has a thermal conductivity of 1.0 W/mK. The second well, in operation since 2024, uses a 50 mm diameter Separatus probe and a thermally enhanced backfill with a thermal conductivity of 2.0 W/mK.
This version allows a direct comparison of these two probe types and impressively demonstrates the performance of the separatus probe.
Data:
| Borehole and heat exchanger parameters | ||
| separatus | Double-U 32 | |
| Borehole diameter | 152 mm | |
| Drilling method | Wash drilling | |
| depth | 90 m | 90 m |
| Dimensions (diameter x wall) | 50 x 3.1 mm | 32 x 3.0 mm |
| Solar flux | turbulent | turbulent |
| Length of connection cable (forward & backward) | 10 Meter | 36 Meter |
| Conductivity backfill | 2.0 W/(m*K) | 1.0 W/(m*K) |
| Soil conductivity | ~1,5 W/(m*K) | |
| Ground temperature -1.0 meter (February 15, 2024) | 4,8 °C | |
| Designed volume flow | 1.1 m³ / h | |
Performance & Temperatures:
