Critical assessment of R410A alternatives for mini-split air conditioners in the Egyptian market

Abstract

In this study, the potential implementation of three different low-GWP refrigerants (R32, R452B, and R454B) as replacements for R410A was investigated. The study was performed using a simulation tool developed by the authors called RACHP-Lab, which is a vapor compression system simulation tool developed based on physics-based simulation for typical mini-split air conditioners. The simulation study was carried out and validated using experimental performance data of 10 different air conditioning units available in the Egyptian market. The units included fixed-speed or variable-speed compressors and operated in cooling or heating modes. Drop-in replacement with the new refrigerants was carried out. For R32, the capacity increased between 4.9% and 13% for cooling cases, and 6.3% and 12.4% for heating cases. However, COP did not improve in all cases. For R452B and R454B with direct replacement, the capacity nearly remained the same, with an increase of COP between 1.6% and 8.0%. Soft optimization was also conducted on cooling cases where compressor suction superheat, condenser subcooling, and compressor volumetric speed were optimized to maximize COP while maintaining the original capacity of R410A. R32 showed an improvement of COP over R410A between 4.6% and 15.5%, while for R452B and R454B between 2.2% and 13.2%.