Problems and solutions of an underground water source heat pump system for a historical valuable building: an energy analysis

During 2007-2012 period a very important historical valuable building in the centre of Vicenza was retrofitted by both structural and energy/mechanical plants points of view. Particular attention was paid to the heating, ventilation and air conditioning plant; it was retrofitted installing an underground water source electrical compression heat pump. A monitoring and data logging system was provided in order to log many data concerning energy flows and the main operating parameters. In this paper the analysis of the performance data of the 2014 and 2015 cooling seasons and the 2014/2015 heating seasons is developed. Such monitoring activity is also requested by the local Authority in order to verify both the utilization of underground water and the energy performances of the HVAC plant. The analysis reveals that, even if appreciable energy savings with respect to more traditional plants were expected, some critical aspects determined poor energy performances of the plant in the first operation period. This work presents such issues and the technical solutions suggested by the Authors, recently implemented to improve the energy performances of the plant. Data of the first period after the technical optimization are also reported and analyzed.