Comparison of the environmental impact of HFC and natural refrigerant transport refrigeration units from a life-cycle perspective

In recent years, the temperature-controlled transport sector hasexperienced a significant growth, which is expected to proceed with aneven higher rate over the next few years. However, with such anexpansion of the sector, the carbon footprint of transport refrigerationsystems must be considered and mitigated. The overall carbon footprintof a refrigeration system can be divided into direct emissionsrefrigerant leakage in each process, and indirect emissions, caused bythe energy consumption in each process and evaluated as the CO2equivalent emissions.In this study, a simplified life cycle comparative approach is used toevaluate and compare the carbon footprint of a traditional HFC (R134a)transport refrigeration unit and of a newly developed naturalrefrigerant (R744) one through some selected blocks along the supplychain of the refrigerating system, including refrigerant production andrecycling and unit manufacturing, operation and disposal.During on-road operations, the environmental impact of naturalrefrigerant cooling units vs traditional ones will be highlighted interms of both direct (natural refrigerant vs synthetic) and indirect(higher COP) contributions. The carbon footprint results will then beused to discuss then importance of the emissions associated with on-roadoperation in perspective of the system overall emissions for both thecooling units, in order to compare the systems sustainability on alarger context.