R134a in most situations.
R134a
R134a
R134a.
r134a
Depends on what you are retrofiting from- to? R-22 to R-410a or r-12 to r134a?
In 1995 most switched from R12 to R134a.
R134a
Density of R-134a changes with respect to temperature and pressure.
Same thing, R stands for Refrigerant.
The EPA
An R12 system must be retrofitted to be made compatible with R-134a.