I have been working on detailing the engine and of course discovered a broken a/c compressor mount. I since welded it. My question is whether this type of compressor still used the R12. No one seems to know when I brought it in for service. Compressor is large square unit and is hard to see in the pic. Ports are labeled Suction and Discharge at the top. Dash air does not work. Previous owner had declined to service it and in their paperwork their servicer stated they had no idea what type of refrigerant was in the system.
My understanding is that AC compressors that handle R12 can handle R134a because these two refrigerants work in similar pressure ranges (vs R410 which operates at a much higher pressure range). However, the required lubricant oil can be different for different compressors.
As R12 refrigerant has been gradually phased out since 1992 and onwards, the cost to buy R12 is becoming more and more expensive over the years. To the point now R12 is so rare and expensive, its no longer economical to continue using R12. So more and more people choose to use the 134a to replace R12.
I believe most older R12 systems, if not all, can be retrofitted to use r134a. The conversion process seems just to replace the port adapters.
I had a trailer that was built in the '80s and it has an old air condition system that uses R12. When I called for a mobile service for repair, they said the refrigerant was empty, so they just refilled it with R135a. It seems just works fine.
Before I would do anything, I need to determine if this thing has anything left in the system and if not, where it leaked. Not sure if it is economically feasible on something that has long refrigerant hoses going from front to rear. I guess this is a task I would farm out if I were to continue. Would be nice if it worked. I think dash air are the first to go on coaches.
(01-21-2023, 09:53 PM)BusNit Wrote: Before I would do anything, I need to determine if this thing has anything left in the system and if not, where it leaked. Not sure if it is economically feasible on something that has long refrigerant hoses going from front to rear. I guess this is a task I would farm out if I were to continue. Would be nice if it worked. I think dash air are the first to go on coaches.
IMHO, if you want to repair the dash air, the only salvageable parts may be the condenser and evaporator. It's best to replace the compressor, hoses and receiver/dryer. The price of refrigerant has skyrocketed. R134a is on the way out and the new R1234 is very expensive. Stock up on refrigerant if you plan to repair and maintain the system. The green new deal will make refrigerant extremely expensive in the future.
At the end of the day you could probably run the generator and roof air for years and be ahead financially.
Jim
2014 Newell Coach 1482 Mid Entry 45'8" Valid Slides and Valid Levelling
You should be able to retrofit the compressor and other component's pretty cheap, the lines and the fittings would be my concern from the age of them. Vintage Air sells kits to retrofit many applications, the other option is to put a small mini split up front like this.
Another option would be to convert to a hydrocarbon based refrigerant (propane/butane). Do a bit of research and you may find it a less expensive option.
(01-22-2023, 06:53 AM)folivier Wrote: Another option would be to convert to a hydrocarbon based refrigerant (propane/butane). Do a bit of research and you may find it a less expensive option.
Haha, I know it is a popular option. A friend was driving his pickup over to visit me when his propane filled dash air leaked and caused an explosion under the hood. That damage is not what I would want to see in a coach.
Jim
2014 Newell Coach 1482 Mid Entry 45'8" Valid Slides and Valid Levelling
I do have a small stock of R22 and 410 but no 12. I would not use any isobutane refrigerants due to the risk. I hated the fact the new Fisher & Paykel refrigerator uses R600 and is inside the coach. Seems everything is using that stuff. I bought a couple of Toshiba dual hose inverter portable A/C units for keeping the bus cool in the summer when not in use to preserve the basement a/c's. Those two run on R32 which is a lesser flammability refrigerant. I do dabble in A/C and have every tool for servicing them aside from a recovery pump and recycle tank. I should add that I need to pick up a torch to handle silver soldering of which I do not have. That said, as I get older, it seems my time is more limited. Weather in AZ is fickle despite what many people think. These last couple of weeks, the temps have been in the low 50's by day along with a breeze just takes everything out of you and the result is no desire to work outside. When the weather breaks a bit, we get temps in the 80's for a short period of time (The only time my motorcycle sees any use) and then temps hit the high 90's to low 100's which is our hibernating weather much like the east coasters do in the winter. Reverse cycles. That's my story and I am sticking to it!
My 2 cents on propane as a refrigerant - The propane tank on my coach holds LOTS more propane than the dash A/C . . . .
Lets not forget what lead acid batteries are capable of when out gassing . . .
Propane is heavier than air & won't burn unless mixed in the right ratio with air - with so much excess air blowing over the engine. . . .
-- I sure would like more details on the propane a/c that exploded under the hood.
All that said,
Your choice on how to repair your dash a/c depends on who you plan to have service it. Using current standard materials usually leaves more options available in the future.
