Assessment of the utilization of equivalent warming impact metrics in refrigeration, air conditioning and heat pump systems

The refrigeration, air conditioning and heat pump (RACHP) industry is a significant contributor to the climate change through its associated direct and indirect greenhouse gas (GHG) emissions. Several policies and regulations are being approved to control the working fluids used in existing and future installations, but the equivalent environmental benefit is not clear. In works that analyze the operation of environmentally friendly refrigerants in different configurations, various metrics based on different assumptions have been used to calculate the CO2 equivalent reduction. This work reviews and analyses the environmental metrics used in RACHP systems and the assumptions proposed for their calculation, depending on the application, to promote their inclusion in future works. The peculiarities of each work are discussed together with an interpretation of their main considerations and simplifications. From the literature review and analysis, it is seen that despite the existence of guidelines for the environmental metrics calculation, considerations with notable differences for the same applications are still assumed, even in the case of the Life Cycle Climate Performance (LCCP) metric. Recommendations for the Total Equivalent Warming Impact (TEWI) metric application are provided.