Hindawi Publishing Corporation International Journal of Geophysics Volume 2013, Article ID 916541, 14 pages http://dx.doi.org/10.1155/2013/916541 Research Article Measurements and Design Calculations for a Deep Coaxial Borehole Heat Exchanger in Aachen, Germany Lydia Dijkshoorn,1 Simon Speer,2 and Renate Pechnig3 1 Institute for Applied Geophysics and Geothermal Energy, E.On Energy Research Center, RWTH Aachen University, Mathieustraße 10, 52074 Aachen, Germany 2 Institute for Mining Engineering I, RWTH-Aachen University, Wullnerstraße¨ 2, 52056 Aachen, Germany 3 Geophysica Beratungsgesellschaft mbH, Lutticherstraße¨ 32, 52064 Aachen, Germany Correspondence should be addressed to Lydia Dijkshoorn;
[email protected] Received 21 December 2012; Accepted 24 February 2013 Academic Editor: Jean-Pierre Burg Copyright © 2013 Lydia Dijkshoorn et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This study aims at evaluating the feasibility of an installation for space heating and cooling the building of the university inthe center of the city Aachen, Germany, with a 2500 m deep coaxial borehole heat exchanger (BHE). Direct heating the building in ∘ winter requires temperatures of 40 C. In summer, cooling the university building uses a climatic control adsorption unit, which ∘ requires a temperature of minimum 55 C. The drilled rocks of the 2500 m deep borehole have extremely low permeabilities and porosities less than 1%. Their thermal conductivity varies between 2.2 W/(m⋅K) and 8.9 W/(m⋅K). The high values are related to the ∘ quartzite sandstones.