R12 Conversion to R134A?

[kalbert]

Originally Posted by Keith Seymore

For educational purposes: what is the failure mode of having moisture in the desiccant/drier? Does it freeze under heavy duty use and cause problems?

K

When you suck a vaccum you get most/all of the air out but some moisture gets left behind. The dessicant is supposed to soak the rest up so it isn't circulating either. Since air and water don't boil the same as the refrigerant they are just in the way and taking up space that could be occupied by stuff that will. If the system is left open (or empty) chances are the dessicant is saturated and no matter what you do there will be moisture circulating. Then the pressures won't ever be quite right, and despite your best fine tuning efforts it will be cool bit not cold, because there's water in there that's not taking heat off the evaporator anywhere near as good as the refrigerant does.

Its another one of those 2° tricks that alone isn't much but you add that 2° with the 2° you get from straightening all the condenser fins and the 2° you get from this or that and you're seeing the difference between cool and cold.