Hello, I am a chemical engineer trying to repair a broken laboratory chiller bath, and I am trying to understand how the refrigerant I use will affect the lowest temperature I can obtain with it (R12 vs R22)

I have a pretty good understanding of thermodynamics so that's not a problem. From what I have been able to find by researching refrigeration systems, R22 can provide more cooling capacity for a given compressor, which does not mean that it can cool something to a lower temperature. R12 is a no-brainer if the system was designed for R12 because of the damage that R22 causes to rubber seals, resulting in leaks.

Basically I am understanding that the minumum temperature possible is not as important as cooling capacity. If I may make an anology, it's like the difference between using a liquid coolant line that is -40° but flowing slowly, versus using a coolant line that is -10° with a higher flow rate. The amount of heat energy (enyhalpy) that can be removed from a system is the same for either one, if you ignore the boost in compressor capacity provided via R22.

Am I making any sense here?

Thanks in advance,
Craig