An in-depth analysis of an air heat pump unit in a northern Italian single-family home reveals significant energy savings from integrating an air-geothermal heat exchanger. 

The study evaluates the HVAC system's real performance versus design expectations, emphasising factors like air-inlet conditions and ventilation flow rate. 

Results show that reducing indoor ventilation during low outdoor temperatures maintains unit efficiency and cuts indoor heat demand. 

Notably, the integration into the system of an air-geothermal heat exchanger reduces electricity consumption by around 30%, confirming its effectiveness in enhancing overall energy efficiency.