Environmental assessment of natural and fourth-generation synthetic refrigerant blends for sustainable cooling in India

Abstract

Climate change is a critical global concern, driven in part by the continuous increase in greenhouse gas (GHG) emissions. The refrigeration and air conditioning industries significantly contribute to these emissions through the use of hydrofluorocarbons (HFCs), which are potent GHGs. This study evaluates the environmental impacts of natural and fourth-generation synthetic refrigerants to support the development of a sustainable cooling action plan for India. Focusing on low global warming potential (GWP) refrigerant blends, the study investigates the atmospheric oxidation pathways of HFOs—R1234yf, R1234ze(Z), R1234ze(E), and R1243yf—alongside propane, identifying a 90 : 10 propane–R1234yf blend as a promising alternative to R32 in residential split air conditioners up to 7 kW. Thermodynamic analysis reveals that this blend achieves a 15% improvement in both volumetric cooling capacity and coefficient of performance compared with R32 while significantly lowering GWP to the level of R1234yf. Environmental and economic assessments show that the blend emits approximately 5.1 tCO₂e annually, which is 22 times lesser than R32, and offers cost benefits due to its reduced capital and environmental expenditures. The total environmental impact metric for the simulated blend indicates that CO₂-equivalent emissions can be reduced up to 96% when R32 is replaced with the R1234yf + propane blend. Based on these findings, this study proposes key policy imperatives for accelerating the adoption of natural refrigerants in India, in alignment with the Kigali Amendment's HFC phasedown schedule.