PC-programs and modelling for borehole heat exchanger design

Design of ground heat exchangers for heat pumps is increasingly done with the support of easy-to-use, fast computer programs. These programs vary widely in calculation approach and accuracy. This paper gives a short overview of the early development, and focuses mainly on programs based on the g-function-method. This method is a suitable compromise between rules of thumb and tables on one hand and time-consuming numerical simulation on the other hand. Other programs are also discussed briefly, and a study on the reliability of such programs is discussed.