Project: Residential Group of 8 Single-Family Houses with Underground Garages, Swimming Pools, Retaining Walls, and Fencing Location: Sofia, Lozenets District, Krastova Vada locality, Regulated Land Plot I-1260, quarter 65a

Execution Period: September 2024 – on going

Number of Boreholes: 24 boreholes at a depth of 100m. There are 8 boreholes designated for each single-family house with an outdoor pool and a total built-up area of 820 m². Horizontal piping has been laid to geothermal collectors, which will power two 24 kW water-to-water heat pump units, with an option for free cooling during the summer.

Drilling for geothermal energy at a depth of 100 meters is a key stage in the construction of geothermal heating and cooling systems. At this depth, the ground temperature remains relatively constant (between 13 and 15 degrees Celsius) and is sufficient for efficient heat extraction, making this method extremely suitable for heating and cooling buildings.

“ЖИЛИЩНА ГРУПА ОТ 8 ЕДНОФАМИЛНИ КЪЩИ с подземни гаражи, басейни, подпорни стени и ограда“, гр. София, р-н "Лозенец", м. "Кръстова вада" УПИ I-1260, кв. 65а
“ЖИЛИЩНА ГРУПА ОТ 8 ЕДНОФАМИЛНИ КЪЩИ с подземни гаражи, басейни, подпорни стени и ограда“, гр. София, р-н "Лозенец", м. "Кръстова вада" УПИ I-1260, кв. 65а

Drilling Process

  • Drilling: The drilling was performed using a Klemm KR806 160kW drilling rig,
    owned by Geothron Engineering OOD.
  • Probe Installation: Once the borehole is completed, U-shaped geothermal polyethylene pipe kits (PE RC 100SDR 11 Ø 32 – 40mm) are installed in the opening. Drilling to a depth of 100 meters allows the system to extract the necessary heat even in colder climatic conditions.
  • Connection to the Heating System: After the probes are installed and the borehole is cemented with geothermal sulphate-resistant thermal cement   (ROЕFIX CreteoInject CC 854HS), they are connected to the geothermal pump, which circulates fluid (usually antifreeze) through the borehole. This fluid extracts heat from the ground and transfers it to the building's heating or cooling system.