Energetic and financial evaluation of a solar assisted heat pump heating system with other usual heating systems in Athens

This study is a manifold energetic and financial comparison of various heating systems. The examined building is a well-insulated building of 100 m2 area located in Athens (Greece) and three different heating systems are investigated in order to determine the most suitable technology. The basic idea of this study is to compare a solar driven heat pump space heating system with an air source heat pump heating system and a fan coil heating system driven by solar collectors with an auxiliary electrical heater. Feeding a heat pump with hot water increases the Coefficient of Performance (C.O.P.) because the heat source temperature is higher compared to the case of air source heat pump. The energetic simulation tool of the analysis is the commercial software TRNSYS which simulates the behavior of complex transient systems. Many combinations of collecting area and storage tank volumes are presented because these are the main parameters which influence on a solar heating system performance. A simple sensitivity analysis proved that 25 m2 flat plate collectors (FPC) coupled with a storage tank of 1 m3 are able to feed the heat pump while 40 m2 of solar collectors coupled with a 1.25 m3 storage tank lead to solar coverage over 70%. Every system is designed carefully in order to maintain the thermal comfort conditions in high standards. The last part of this analysis is the financial evaluation of the examined technologies in terms of total cost which combines the investment and the operation cost.