Energy and exergy analysis of horizontal ground heat exchanger for hot climatic condition of northern Tunisia

• Horizontal ground source heat exchanger has been installed and tested.
• The energy and exergy analysis were applied, increasing mass flow rate decrease energy and exergy efficiency.
• The heat exchange rate is about 26 W m−1 which reflects the importance of surface geothermal energy in Tunisia.
• The GHE system covers 65% of the total cool requirement of a tested room with 12 m2 of surface.

This paper deals with the energy and exergy analysis of horizontal ground heat exchanger (HGHE) for hot climatic condition of northern Tunisia. The HGHE consists of 50 m of length buried at 1 m of depth. The ground temperatures at several depths were measured, the overall heat transfer coefficient (overall HTC) was determined, the heat exchange rate was quantified. In addition, the effects of various parameters such as the HGHE length and diameter and the mass flow rate of circulating water were inspected analytically. The results showed that the energy and exergy efficiencies are found to range between 52 and 18% and 36 and 12%, respectively. For a tested room with 12 m2 of surface area, the GHE system allowed to cover 65% of its total cool requirement.