A numerical and experimental investigation of ground heat transfer including edge insulation effects

This paper presents the results of an investigation of the thermal performance of a purpose built, full-scale, test house. The work utilises experimental results that explore heat losses from two similar rooms to the ground. One of the rooms benefits from expanded polystyrene edge insulation placed 300 mm below ground surface. Thermocouples were used to measure temperature changes at 20 min intervals, over a five year period, beneath and adjacent to the test house. A two-dimensional numerical simulation of the experiment is performed. The results show that a relatively simple heat conduction analysis of the problem can yield acceptable accuracy. Good agreement was obtained between simulated and measured transient temperature variations. Phase lag of ground temperature variations was also accurately simulated. The results also show the impact of edge insulation on the heat flow paths around the building. The method adopted can be readily applied to estimate the thermal response of new designs, thus assisting with the overall aims of producing energy efficient buildings for the future.