Well-dimensioned probe fields are in equilibrium with the heat flow from the earth. This means that, where correctly dimensioned and installed, the geothermal energy system draws out the quantity of energy released from the rock. This avoids any rapid cooling of the substratum, and the system functions with a high degree of efficiency for many decades.

Project Siegburg - geothermal energy exploitation:

• Single-family house with 150 m² living space (existing property, constructed 1984)
• Heating (radiators) and domestic hot water heating (approx. 1,700 full-load hours per annum)
• Heat pump with 10.6 kW heating capacity
• Annual coefficient of performance achieved in the first 18 months: 4.6
• Probe field consisting of 3 IVD coaxial probes, each 18 m, in a sandy substratum

Crucial factors when calculating the probe fields required (e.g. using Earth Energy Designer software) are the rock involved, the groundwater and the heating, cooling and domestic hot water heating requirements of the house. The space available and possible distances between probes are also important when calculating the number of probes and their configuration on the property. Appropriate geological research and calculations of probe fields can be realised by Geothermie RheinMainNeckar GmbH. Data from existing systems are also evaluated here.