134A sight glasses

[Jon Wehrenberg]

Jack,

That's a trick question. The 134 system should be different than a 12 system such as a larger condensing coil.

But a rule of thumb thrown around by folks when converting from 12 to 134 (not changing the system) is that there is a 15% loss of efficiency. I don't know if that is factual or lore.

[jack14r]

Jon,I think that 15% is real close,I remember that a good r12 car system would have 22 degree differential.I am pleased with the OTR in my Liberty thanks to everyone's help.By the way I had a friend who was at a cruise air service center in Virginia pick up a cruise air service manual for me a few weeks ago.When I took delivery of my Liberty I commented that the AC did not seem comfortable and the guys checked them out and reported 15 to 18 degrees of differential.Since I have the service manual with the pressure charts I decided to check the 2 front AC units,they were both overcharged,both of them now have over 20 degrees of differential.After that success,I decided to take out the outside TV,grill,refrig,and cabinet to gain access to another one,the fourth one is behind a panel in the first bay.My results are the same,both were overcharged,the one that does the bedroom has 18 degrees of differential and the other one has over 20 degrees.I guess the bedroom might be less because the compressor is about 25 feet from the bedroom unit.The service tech.in VA told my friend that cruise airs are very sensitive to the level of charge.It is amazing how much water condenses now that the freon charges are correct.The humidity inside seems quite a bit lower now and the comfort level is much better.Thanks again for the help.