Experimental Analysis of Horizontal Ground Heat Exchanger for Northern Tunisia

The aim of this study is first to evaluate the Tunisian geothermal energy and second to test the performance of horizontal ground heat exchanger. An experimental set-up has been constructed for climatic condition of Borj Cedria located in the north of Tunisia for space cooling. Results obtained during experiment were presented and discussed. The ground temperature at several depths was measured, the overall heat transfer coefficient (U) was determined. To evaluate the system efficiency, the energy analysis was applied; the energy efficiency was found to range from 14% to 28%. The heat exchange rate was quantified, the pressure losses were calculated. The total heat rejected by using the ground heat exchanger (GHE) system was compared to the total cool requirements of a tested room with 12 m 2 surface. The results showed that the GHE, with 25 m of length buried at 1 m depth, covers 38% of the total cool requirement of the tested room. This study showed that the ground heat exchanger provide a new way of cooling buildings, it also showed that Tunisia have an important thermal potential. This favorable circumstance allows Tunisia to be a pioneer in the exploitation of geothermal energy for the installation of ground source heat pump systems.