Deploying low-GWP refrigerants in vapor compression refrigeration systems: performance trade-offs, adoption barriers, and socio-technical pathways

The global phase-down of high-global-warming-potential (GWP) hydrofluorocarbons (HFCs) is accelerating the transition toward low-GWP refrigerants. However, the deployment of low-GWP refrigerants remains constrained by trade-offs among energy efficiency, volumetric cooling capacity (VCC), flammability, cost, and serviceability. A comprehensive evaluation of these interrelated factors is therefore necessary to ensure that refrigerant selection considers not only GWP and thermodynamic performance but also broader practical and environmental considerations. The objective of this review is to provide a unified socio-technical approach to vapor-compression refrigeration cycles (VCRCs) that connects the intrinsic limitations of R744, hydrocarbons (HCs), hydrofluoroolefins (HFOs), and refrigerant mixtures with suitable performance enhancement strategies and deployment requirements. The published experimental, numerical, thermodynamic, environmental, economic, and deployment studies are comparatively synthesized based on coefficient of performance (COP), VCC, compressor power, exergy efficiency, safety, cost, regulation, component availability, supply-chain readiness, and workforce capability. Enhancement techniques, such as subcooling, internal heat exchangers (IHXs), ejectors, vortex tubes, nano-lubricants, and multistage compression, are evaluated based on the refrigerant-specific limitations addressed. The representative results show that increasing the ambient temperature from 25 to 35 °C reduced the COP of the transcritical R744 system by 34.8 %, whereas the optimized vortex tube improved the COP by 20.3–21.1 %, cooling capacity by 7.8–11.3 %, and exergy efficiency by 7.9–11.3 %. Life-cycle assessment results also indicated that R744 reduced total emissions by 31.9 % compared with R134a. Overall, the review highlights that no low-GWP refrigerant is universally optimal; rather, refrigerant selection and deployment should be tailored to the refrigerant properties, enhancement technologies, application requirements, climatic conditions, and available infrastructure. The framework provides guidance on refrigerant selection and system design for domestic, supermarket, transport, and industrial refrigeration applications.