Improving the efficiency of the numerical modelling of built environment earth-contact heat transfers

This paper reports on a method which has been developed to improve the efficiency of the numerical simulation of built environment earth-contact heat transfers. This method modifies a numerical method by incorporating elements of the response factor method. Additionally, this paper reports on the use of extrapolation techniques to further speed up one stage of the simulation. Essentially, the method requires that a numerical technique be initially used to generate a certain number of simulated hours for use as a time-series by the response factor element of the method. This first ([`]pre-processing') part of the procedure takes a certain time and this time can be significantly reduced by means of the extrapolation techniques described in the paper. However, assuming that the earth-contact domain remains unchanged from then on, this [`]pre-processing' does not need to repeated, and every subsequent simulation that is performed to calculate the effect on the earth-contact heat transfer of changing another parameter (i.e. during a parametric analysis) takes only a few seconds. Reductions in run-time for these successive simulations are of the order of 1000 times faster than the full finite volume technique whilst still retaining the flexibility and accuracy of this method.