An R454C air-to-water (ATW) monoblock heat pump was experimentally evaluated by an independent laboratory, benchmarked against a high-efficiency R290 ATW monoblock system. Test results show that the R454C system achieved COP values within 2% of the R290 baseline, despite using an outdoor heat exchanger with approximately 30% lower effective heat transfer area. 

Split ATW heat pumps remain relevant due to installation constraints and the need to avoid water–glycol secondary loops, which may be needed in monoblock systems to mitigate freezing. The present work aims to investigate the performance potential of an R454C-based split ATW system. A detailed system model is developed and validated using experimental data obtained from the R ...