Seasonal performance comparison of R-410A and R-454B in a variable-speed air-cooled scroll chiller

In recent years, there has been increasing concern about the impact of air conditioning and refrigeration on global warming. This is particularly related to the emissions of refrigerants with high global warming potentials (GWP), such as R-410A, which is used in air conditioning and chiller systems. There has been a concerted effort within the HVAC industry to find lower GWP refrigerants to replace R-410A in HVAC systems. In this paper, a 10.5 kW (3 TR) air-cooled variable-speed scroll chiller has been utilized to conduct an experimental comparison of R-410A (GWP of 2088) and its low GWP A2L alternative R-454B (GWP of 466) according to AHRI 551/591 testing condition at rating and part load condition with optimized charge. The compressor speed and suction superheat were matched for both refrigerants at all the test conditions. R-454B shows 98 % capacity and 102 % efficiency compared to R-410A at rating conditions of 35 °C outdoors and water return temperature of 12 °C. The IPLV of the R-454B chiller was just 1 % higher than R-410A. The discharge temperature of R-454B and compressor isentropic efficiency is 8 % higher and almost like R-410A, respectively. The optimized charge of R-454B was 5 % lower refrigerant charge compared to R-410A. The LCCP analysis for major Indian cities over a 15-year operational span demonstrates a notable reduction, ranging from 6.6 % to 7.3 %, in overall R-454B emissions compared to R-410A. The study demonstrates that R-454B is a drop-in replacement to R-410A designs and reduces the direct GHG emission from the chiller by 76 %.