## 1 Introduction  
In recent decades, the growing focus on renewable energy has led to an increasing interest in low-temperature geothermal energy (i.e., geo-exchange resource) as a sustainable source of energy for air-climatization of buildings. The coupling of ground heat exchangers (such as borehole heat exchangers (BHEs) or pumping/injection wells) with Ground-Source Heat Pump (GSHP) systems, used for heating and cooling of buildings, represents a valid and modern technology that exploits the constant heat source of the subsoil [1]. By exploiting the temperature of the ground surrounding the ground exchanger at shallow depths (usually 100-150 m), the installation of geo-exchange systems can cause significant thermal disturbances in the subsurface, affecting not only the efficiency of the system itself but also local ecosystems and groundwater resources [2, 3, 4]. Thermal perturbations generated by ground exchangers can result in long-term effects on subsoil temperature, altering natural thermal gradients and potentially affecting biodiversity and habitat stability [5, 6, 7, 8]. Understanding the dynamics of these perturbations is essential to assess the environmental impact of geothermal installations and optimize energy management practices [9; 10; 11]. The most common geo-exchange systems include Groundwater Heat Pump (GWHP) and Ground-Source Heat Pump (GSHP) systems, each with its unique operational mechanisms, benefits, and challenges. Both systems exploit the yearly constant temperature of the subsurface to provide energy-efficient heating and cooling systems for buildings, but they differ significantly in terms of heat transfer mechanisms, system configuration, and environmental conditions. GWHP systems are open-loop systems, which directly use groundwater as a heat source or sink and consist of one or more wells (for extraction and injection). Water is pumped from an aquifer, passed through a heat exchanger, and then returned to the aquifer through the injection well or to a surface water body [12; 13]; they can effectively operate in areas with abundant groundwater resources, offering high efficiency due to the thermal properties of groundwater [14], which typically maintains a more consistent temperature throughout the year compared to soil or rock [15; 16]. GSHP systems are closed-loop systems, which operate by circulating heat transfer fluid (usually water or an antifreeze solution) through a network of single, double U-shape, or coaxial plastic pipes (i.e., BHE) buried in the subsurface. In general, BHE systems can be installed in various configurations (vertical, horizontal, or coaxial), making them suitable for a wide range of site conditions, including those with limited access to groundwater or where space for groundwater wells is restricted [4; 17; 18; 19; 20]. These systems are generally more durable and require less maintenance than open-loop ones, as they operate in a closed environment, reducing the risks of contamination of the heat exchange fluid. They can be optimized in terms of number and layout by means of analytical or numerical tools [21; 22; 23]. Closed-loop systems can also be installed in decommissioned wells and sometimes coupled with existing air conditioning systems [24]. Geo-exchange systems have high thermal interaction with the surrounding environment, in terms of thermal perturbation and groundwater thermal effects. If in some regions of Italy, GWHP systems are subject to specific regulation on thermal perturbation [25], for GSHP systems, no specific issue has been defined so far [26]. Indeed, continuous extraction of groundwater can lead to issues such as groundwater depletion and localized thermal pollution, which can affect aquatic ecosystems or neighboring users [27; 28; 29]. In densely populated urban areas, where the demand for energy-efficient solutions is high, the deployment of GSHP systems offers an opportunity to lower both carbon emissions and the environmental footprint of buildings [30; 31].