This thesis could be useful to underline advantages and disadvantages of a geothermal system designed to the building conditioning. The aim of this work is to define a methodology to analyse a geothermal system considering: hydrogeological, energetic, environmental and economic-financial aspects. This methodology will be tested through the application of a case study located in Turin. Furthermore, the methodology could be replicated for the other geothermal system of Turin. In particular, an open loop geothermal heat pump system is treated. It was designed to provide both heating and cooling for a health assistance residence of Turin. This specific system is particularly interesting because it is a new realization and it works from some years at full capacity.