Total equivalent warming impact analysis of HFO blends and CO2 in refrigeration applications.

The search for replacements for HCFC and HFC based refrigerants such as R-22 and R-404A, being phased out globally due to stratospheric ozone depletion potential and global warming issues, has led to the development of low GWP HFOs and HFO blend alternatives. While refrigerant GWP is an important criteria in making system and refrigerant decisions, the total equivalent warming impact (TEWI) of a system provides a more accurate representation of the overall environmental impact. TEWI considers not only the direct emissions of a refrigerant thru leakage, but also factors in the indirect carbon emissions due to electricity generation. This paper will report system modeling TEWI data comparing new HFO blends in centralized direct expansion racks, distributed direct expansion racks, refrigeration cascades, and secondary loop systems to traditional refrigerants as well as CO2 transcritical booster systems. This study will also analyze the total cost of ownership as well as how different climate zones and energy emission factors impact refrigeration systems carbon emissions around the globe.