The ground lends itself particularly well to be the thermal source from which to subtract or to which to yield the heat necessary to operate a machine in reverse cycle operating respectively as a heat pump or as a chiller. This action can be carried out by removing or releasing heat directly to the land mass itself. This technique is widely used in many European and non-European countries. The research work consists in the experimental characterization of geothermal probes already installed within the university campus.
Geothermal heat pumps have significant advantages in terms of low environmental impact and reduction of energy consumption related to heating and cooling of civil and industrial buildings. The main difference with respect to a classic heat pump for air conditioning is in the fluid exchanging that is not the outside air, but another fluid, usually water and glycol, which in turn exchanges thermal energy with the subsoil. The great advantages related to the thermal properties of the subsoil and a reduction of daily and seasonal thermal fluctuations, are contrasted by the additional costs for the implementation of the probes that require a drilling of the ground in the case of vertical probes, or the excavation of trenches for horizontal probes.