Abstract The shift to low-global-warming-potential (GWP) refrigerants is critical to mitigating climate change and improving energy efficiency. This study evaluates the performance of low-GWP refrigerants R513A and R516A as alternatives to R134a in water-to-water heat pump systems designed for simultaneous heating and cooling. Using experimental data and a validated mathematical model, the study evaluates coefficients of performance (COP), heat transfer rates, and refrigerant mass flow rates under medium- and high-temperature scenarios. Medium-temperature conditions consisted of evaporator inlet temperatures ranging from 0–5°C and condenser inlet temperatures of 35–40°C, while high-temperature conditions had evaporator inlet temperatures of 10–15°C and condenser inlet temperatures of 50–55°C. The results demonstrate that while R134a exhibits marginally higher COP in heating mode, R513A and R516A show competitive performance, with R516A excelling in high-temperature scenarios. This study highlights the potential of R513A and R516A for sustainable HVAC applications, contributing to global efforts in reducing greenhouse gas emissions.
Okafor et al. (Mon,) studied this question.