Experimental study of residential air-to-air heat pump performances in the field.

Air-to-air heat pump (AAHP) is regarded as one of the energy saving technologies in the building sector. However, experimental studies on AAHP performances in the field are still insufficient. In order to investigate practical performances, in situ experiments are carried out on a split residential AAHP. The measurements are mainly realized on the indoor unit side, including air velocity (via hot wire sensors), dry and wet bulb temperatures and atmospheric pressure. The performances are analyzed in different operational modes, especially the unsteady-state operation and the defrosting phase. The paper proposes a measurement procedure for the AAHP seasonal coefficient of performance and discusses the optimum recorded data rate. Finally, the results of this study could provide useful guidelines to check in situ performances, since performance checking will be more and more required to ensure the energy gains and the economic benefits that the end-user expects when purchasing an AAHP.