Under the supervision of the Belgian Building Research Institute (BBRI) and with support from teams at the Geological Survey of Belgium and Environment Brussels, two ‘enhanced’ thermal response tests were recently conducted in the ‘Bois de la Cambre’ park, in two deep holes bored as a part of the Brugeo project.
These ‘enhanced’ thermal response tests are essential for an accurate mapping of the geothermal potential of closed systems (shallow geothermics). Using fibre optics, the researchers first read the initial temperature (at rest) of the ground as a function of depth; then, they measured how this temperature changed over time when an amount of heat similar to that of a geothermal loop is injected in the borehole. By analysing the results of these field tests, the researchers are able to determine the thermal conductivity of the various geological layers encountered. This is a major factor used in sizing vertical geothermal loop fields (closed systems).