R-134a vs R12 Temp Pressure Chart

[ACProf]

Here's a comparison of R-134a to R-12 refrigerant vapor pressures at specific temperatures.
R-134A has a slightly lower pressure at evaporator temperatures (30-40 degrees), but R-134a also has a much higher pressure at condenser temperatures (120-150 degrees).

NOTE: For best heat transfer, condenser temperatures should be 30-40 degrees hotter than the ambient air temperature entering the condenser.