Solar heating and cooling technologies can have a vital role to play in understanding the targets in energy
security, economic development, and mitigating climate change. This study aimed to investigate the performance
of the combined solar cooling/heating system using a Photovoltaic Thermal collector (PVT) for residential
applications. The main advantage of using PVT is the conversion of the maximum amount of solar
energy into electricity and thermal energy. In this work, water is used to cool the panel and, consequently,
increase the efficiency. The cooling cycle comprises a hybrid ejector-compression refrigeration cycle with two
evaporator temperatures. To reduce the effect of the global warming phenomenon, two different refrigerants
with lower Global Warming Potential (GWP), such as R600a and R290, are used instead of R134a. The inlet
water does not only gain heat from the PVT but also the collector output water is heated in a condenser and
heater. The results indicate that increasing the water mass flow rate from 0.011 kg/s to 0.03 kg/s (39–108 Lit/h)
at solar intensity (G) of 945 W/m2 results in enhancing the overall efficiency of the PVT system from 66.7% to
75.8%. In terms of the highest Coefficient of performance (COP) and the lowest exergy destruction, R290 shows
better performance comparing to the other refrigerants. In more details, using R290, instead of R134a, results in
up to 7.5% enhancement in the COP of the cycle. The water mass flow rate is optimized at m? w=0.013 kg/s to
achieve the highest COP and the lowest exergy destruction. Also, it is reported that the temperature of the outlet
water from the system varies between 31.72 °C to 46.73 °C during the day. Finally, it is revealed that using R290
for the refrigeration cycle and cooling the panel result in enhancing the COP of the cycle by 11.1%, increasing
the temperature of the outlet water from the system by 9.17 °C and decreasing the refrigerant flow rate by
60.17%, in comparison with a system