The heat pump plays an essential role for the containment of the consumption for air conditioning, thanks to the ability to regenerate the heat captured from a low temperature source, making it suitable to heat at high temperature.
However, the efficiency of the heat pump is extremely dependent to many elements, as thedistribution system, the temperature of the source, the supply temperature, as well as the frequent passages from one state of operation to another or the part load ratio.
For these reasons on field monitoring tests are extremely important, because they allow to obtain information on heat pumps behavior in real conditions. Results coming from two on field monitoring campaigns are presented in this paper, both regarding geothermal heat pumps.
The first one is an historical building located in Camogli, in the province of Genova, used as a retirement home for elderly seamen. This building was built in 1931 and renovated in 2008, when the entire distribution system was replaced and three geothermal heat pumps were installed for heating, cooling and domestic hot water production. The plant was monitored for three years and results are presented here. The second plant consists in a geothermal heat pump coupled with thermo-photovoltaic solar panels. During the winter, when the solar panels have reduced performances due to lower insolation and outdoor air temperatures, it is possible to exploit the low-temperature heat supplied by the solar collectors as auxiliary source for the heat pump. During the summer solar panels can produce domestic hot water, in substitution to the heat pump. Results of the monitoring campaigns, for the cooling mode, can assess the actual performances improvement of the heat pump and the best logic for using thetwo sources.