Original sentence: While CO2 has no ozone depletion potential and essentially no direct' global warming potential, it is very difficult to achieve a reasonable cycle efficiency using CO2 as compared to other conventional refrigerants, without having substantial expenditures on enhancing the system with large heat exchangers, vapor injection options, expanders, etc
Edited sentence: While CO2 has no ozone depletion potential and essentially no direct global warming potential, it is very difficult to achieve a reasonable cycle efficiency using CO2 as compared to other conventional refrigerants, without having substantial expenditures on enhancing the system with large heat exchangers, vapor injection options, expanders, etc