Old Manitowoc ice machine refrigerant.
First let me start by saying I'm a long time reader first time poster and have always valued the useful information over the last few years. This is the first fourm I've come across that has real information instead of hacks telling me just mix refrigerants, "fuc* da rules".
Anyway.. I got a complete 1994 Manitowoc 600lb ice machine (water cooled) for free. The machine has been sitting in a shut down restaurant for 10 years. Brought it home, wired and plumbed it, ran it, and saw the bottom line on the evaporator frosting up but the evaporator seemed to stay pretty warm and failed to produce ice. So I checked the pressures and my suction was -15"HG while my head pressure was 55~60PSI during the freeze cycle. The service manual calls for 19-6PSI suction and 125-130PSI head with the ambient air temp of 70o F. With that being said it has just about no refrigerant left in it. It was originally charged with 32oz of R12. So I think I'm going to evacuate the system and recharge it. Now for my question.. Can I use R290 (propane) as an R12 alternative being that it carries the mineral oil from the compressor? BEFORE you all nail me to the cross and crucify me for mentioning propane I personally feel it is a terrible idea to use it in automotive or any other kind of Air conditioning. It is widely used in Europe and various other parts of the world. Now I have seen people use it in refrigerators and heard of possible ignition problems with evaporator or condenser fan motors and the defrost timer too. But this is a water cooled unit that is going to sit in my pool house screen porch and maybe be used 10 times a year. I would LOVE to just use R414B (Hot Shot) and be done with it but I cant justify buying a 25lb keg for $250 and using only like $30 of it. Any thoughts, insights, help and insults would be great. Thanks. By the way I've been researching this topic for about 3 weeks now and get mixed schools on this. Some people swear by it others not so much. I just would use it in any air conditioner especially automotive systems.