Two response tests of two « identical » boreholes drilled to a depth of 160 m near Luzern, Europäischer Workshop über Geothermische Response Tests

The analysis of two response tests performed on two borehole heat exchangers drilled close to each other and constructed with the same design shows that the estimated ground thermal conductivity differs by 10%. Possible sources of error are examined and quantified in order to explain the difference. This analysis also highlights the sensitivity of a response test to outside conditions and, when the line source approximation is used, to the stability of the heat injection rate.