Evaluation of Alternative Refrigerants for Mini-Split Air Conditioners (LV-17-014)

The phase-out of hydrochlorofluorocarbon (HCFC) refrigerants in developing countries is currently under way according to the Montreal Protocol. R-22 is one of the most commonly used HCFCs in the developing nations. It is extremely well suited for air conditioning and refrigeration (AC&R) in high ambient temperature environments. Non-Article 5 countries have already gone through the phase-out of HCFCs and settled on using R-410A as the refrigerant of choice for AC applications. Previous studies have shown that R-410A results in significant capacity and performance degradation at higher ambient temperature conditions. There is a growing concern about finding alternative refrigerants to R-22 that would have zero ozone depletion potential (ODP), lower global warming potential (GWP), and at the same time maintain acceptable performance at higher ambient temperatures. Furthermore, the developed world’s transition through higher GWP refrigerants such as hydrofluorocarbons (HFCs) and HFC blends resulted in significant direct CO2 equivalent emissions. It is imperative to develop a bridge for developing nations to avoid the transition from HCFC to HFC and then from HFC to alternative lower GWP refrigerants. This paper summarizes data from an experimental campaign on alternative refrigerant evaluation for R-22 and R-410A substitutes for mini-split air conditioners designed for high ambient temperature environments. The experimental evaluation was performed according to ANSI/ASHRAE Standard 37, and the performance was rated at test conditions specified by ANSI/AHRI 210-240 and ISO 5151.