What is a temporary replacement for CFC-12 in reciprocating compressors?

In the context of replacing CFC-12 in reciprocating compressors, HCFC-22 is often considered a suitable temporary replacement. This refrigerant is a hydrochlorofluorocarbon that has been used in many applications and can operate in systems designed for CFC-12 with some modifications. HCFC-22 retains favorable thermodynamic properties that are similar to those of CFC-12, making it effective in refrigeration and air conditioning systems.

Moreover, HCFC-22 has a lower ozone depletion potential compared to CFC-12, which aligns with regulatory efforts to phase out substances that harm the ozone layer. While it is important to note that HCFC-22 is also targeted for phase-out under various environmental regulations due to its own impacts, it serves as a transitional refrigerant to help bridge the gap until more environmentally friendly alternatives are adopted widely.

In contrast, the other options like HFC-134a, HFC-123a, and HFC-125 are different classes of refrigerants that typically require more significant changes in system design or operation parameters, making them less suitable as direct replacements for CFC-12 in existing compressors without extensive modifications.