Sorry - my language is probably too extreme for a friendly forum, but I'm in the business. Trane's lobby is so strong with the EPA that it got "CO2 Equivalence" on the same level of polictically-correct-speak Ozone Depleting Factors or health TEL's. Ridiculous.

CO2 equivalence is what I explained in the post above - simply a convoluted estimate intended to represent how much effect the lower efficiency has on increasing the "greenhouse effect." In other words, R-134a is supposedly less efficent, so it takes more energy to run a refrigeration cycle. More energy can be traced back to the power generating plant as more CO2 produced - because more power has to be produced.

CO2 Equivalence is nothing more than a contrived efficiency factor. However, that efficiency factor (CO2 Equivalence) is all based on the prevailing equipment design - which is optimized for the older refrigerants. That efficiency is improving as mfrs. are optimizing their equipment. But it's all a game to give Trane time to transition to another refrigerant instead of R-123, which will phase out eventually - the same as R-12. Trane has based their low-pressure refrigerant equipment (big stuff) on R-123, which is an R-11 replacement. However, R-134a is used by other companies (Carrier, York) in all equipment - even the big stuff, hence the competitve "blurring of the facts" about certain refrigerants. R-123 has demonstrated health issues in addition to still depleting ozone.

As far as our hobby, the CO2 Equivalence of R-134a means absolutely nothing in the context of using it as a pneumatic actuating fluid (retracts). Since it does not adversely affect personal health, and carries 0% ozone depleting potential, it's perfectly safe.