Heat pumps (HPs) are attracting lately increasing attention due to their features to meet the sustainability criteria. Air-to-water heat pumps (AWHPs) have gained prominent success because they can be put in place of oil or gas boilers in heating systems. AWHPs energy consumption and their contribution to the reduction of heating systems gas emissions is strongly related to the seasonal coefficient of performance for heating (SCOP), which is affected by various factors with the most decisive to be the ambient temperature. The SCOP is crucial for the energy labelling of HPs and the estimation of operation costs in every location. The aim of this paper is to estimate and compare the SCOP of various AWHPs models installed in buildings at 16 different Greek locations, in the 4 climate zones of Greece, by using hourly temperature data of the last decade (2010-2019) which were recorded in a network of automatic weather stations across Greece. Numerical results show that the climate plays a key role in the calculation of the seasonal efficiency of AWHPs but also highlight the importance of using different temperature data for each location, even if they are in the same climate zone, in order to obtain accurate results.
Read full abstract