Abstract The main purpose of this study is to evaluate, based on experimental data, the potential of pre-cooling the ventilation air based on ground-to-water heat exchanger, coupled with an intermediate water-to-air exchanger, during the summer period. The case study for this investigation is an existing nearly zero energy building located in Benevento, a middle-size city of South Italy with typical Mediterranean climate. Measurements of several performance parameters with four different HVAC possible configurations are shown as well as monitoring of energy uses and indoor microclimatic conditions in order to verify if comfort conditions inside the building are guaranteed together with the achievement of ‘nearly zero energy target’. Indeed, the study intends to assess the interaction between building and power grid and evaluate the temporal correspondence between building load and PV generation with hourly time step. The discussion about the hourly energy balance serves as reference to export or improve management and design strategies in regions with comparable climate conditions.