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Mondofromredondo
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Discussion Starter #1
Hi all,
I have a 20 year old Adler-Barbour refrigeration system.
I have to replace the condenser / compressor unit so when I disconnect the cold plate it will leave the old style refrigerant in the cold plate. So when I connect the new condenser / compressor unit loaded with the new stuff will that be a problem?

Thanks,
Keith
 

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ancient mariner
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search google ----- mixing refrigerants----you will find a lot of information about it there
 

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You will probably need a refrig mechanic to help....you will need to pull a vacumn in the system to get all the old gas and any air out before the new gas goes in. There's also the issue of gas-compressor oil compatability. You may have a R-12 freon system and the oil in it will not work with the newer gases.
 

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From what I've heard, the compressor oil in a R-12 system will turn to goo if you put R-134a in. I would think all of the advice given is correct.

With that said, when my 12volt AB didn't work, instead of spending $900 on a new compressor unit, I cut off the old compressor and brazed one on that I cut off an old R-134a 110vac mini fridge, added a filler plug and filled it with R-134a. It's been running for the last year on shorepower/inverter for the last year without any problems.
 

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DON'T MIX REFRIGERANTS!!! Remove the old refrigerant (probably R-12) from the cold plate. Technically it should be "recovered" by an EPA certified technician as R-12 is controlled substance which destroys the ozone layer and cannot legally be vented to the atmosphere. The new compressor unit will probably come pre-charged with R-134a and will have the proper oil as well. The small amount of "old" oil in the cold plate shouldn't be a problem.
 

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If by chance you can remove all the R-12 you can recharge with the 134A you will also have to change up the oil to one which will be compatible with the old parts. One more thing the R-12 mixed with any tpye of flame is nerve gas the reason for the mention is people have been known to use a propane torch to heat up fittings so they can get them free. Best to have a licensed person do the work.
 

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ancient mariner
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freeze12

johnsen's freeze 12 is supposed to be compatible with R12 & the oil in an R12 system. check it out on google. this looks like an easer way to go.
 

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ancient mariner
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you would have to get the 134A out of the new parts first & pull a vacuum on the system.
 

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It's not so much a refrigerant problem as a oil problem. The R-12 system used a mineral oil, probably 3Gs oil, the new system uses a man made oil, probably polyoester oil. If the two oils are mixed you get tar and the system is destroyed, the evaporator needs to be cleaned out with the proper cleaner first, then you can install the new condensing unit.

PS, I'm in the commercial and industrial refrigeration business.
 

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It's not so much a refrigerant problem as a oil problem. The R-12 system used a mineral oil, probably 3Gs oil, the new system uses a man made oil, probably polyoester oil. If the two oils are mixed you get tar and the system is destroyed, the evaporator needs to be cleaned out with the proper cleaner first, then you can install the new condensing unit.

PS, I'm in the commercial and industrial refrigeration business.
Question for you Denby (with apologies for hijacking the thread, but the question is related to the topic of the OP):

How difficult is it to convert an R12 system to an R134 system?

I have two independent refrig systems on BR: one for the frig, the other for the freezer. The only difference between the systems is the size of the box. Five years ago in the Caribbean I had a new system installed -- call that system #2. I asked the refer mechanic to install system #2 with R-12 because I had another R12 system (call that one #1) aboard and the mechanic advised R12 was more efficient and I'm all for minimizing genset operating hours. (Before the greenies get on my case, I know, R12 kills ozone, but gensets burn diesel and that causes global warming ---- so what's a tree hugger to do????)

The refer guy said he could drain the oil that came with the compressor and install R12 compatible oil. He did and it's worked well ever since. Now the old R12 system (#1) has failed and I will need to replace it. Because we're in the US we can't / won't get an R12 replacement. So system #1 will probably be R 134 and as I would like both systems on the same gas, system #2 needs to be converted from R12 back to R134.

Question: how hard is it to get all the R12 oil out of the compressor so that it can be replaced with an R134 compatible oil? What are the economically reasonable options for dealing with this situation?
 

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Billy,

It's not to hard to get the oil out of the compressor, drain oil out then flush with a cleaner, the entire system has to be flushed with a cleaner as the oil travels through the system with the refrigerant. It will be expensive.
R-12 is a much better refrigerant and more efficient then R-134A.
One more thing, all this hype about freon being so bad for the environment why is it not banned world wide? Only over here is it banned. I work on equipment brought in from Europe, Asia and South American that have compressors that originally had mineral oil in them.
 

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One of None
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Hi all,
I have a 20 year old Adler-Barbour refrigeration system.
I have to replace the condenser / compressor unit so when I disconnect the cold plate it will leave the old style refrigerant in the cold plate. So when I connect the new condenser / compressor unit loaded with the new stuff will that be a problem?

Thanks,
Keith
Ahem, may I share a lifetime's experiance in this area?
First.. the systems in most of these are very small.. at most I'd say they hold only a few ounces of Refrigerant. Keith said he was disconnecting the plate from the condenser. if his is like most there are "service valves" on the condenser. Most of the oil is in the comp. any oil in the plate would only be residual. really small compressors don't have drain ports. the only way to get old oil out is hardly worth the trouble but you would have cut the "process" tube off. turn the comp over to drain, then flush it with new compatable oil, shake it drain, a couple of times. pinch and braze closed the process tube. It's a mess and only worth doing on larger units.

Keith, is the new condenser R-134? the operating pressures should work on the old plate but I'd suggest you change it also. you may find that the old plate will only cool about 80% then it did with R-12 now if you do hook up the old plate you can use Liquid 134 (can upside down,) in the larger tube to reverse the flow back to the other service valve, then through the smaller. that should help get the residual out. but there will still be traces. service valves are designed isolate the condenser not the plate. (they can be confusing too)

Assuming you did all this the right. The thing to do after it's been running a day or two is to; yup! Isolate the comp cut the tube and drain and flush again.. also install a new filter dryer.

if you got lost halfway through the above.. better get a refrigeration tech. you do have a vacume pump, gauges and electronic scale to weigh in the right amount of 134? One problem that is very common with people that don't know they put way way too much refrigerant in the systems. Again,, if you stay with old plate, try to find the namplate on the system hopfully it will tell you how many ounces (not likely anywhere near pounds) the 134 should be about the same amount +- 10%

the new comp should have 134 already in it. it charges the lines when the service valves are opened, some have "quck connect self piercing" couplings. and no service valves.
134 is nasty too. caustic even..I think it eats fiberglass too..



good luck!
 

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ancient mariner
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denby------- have you ever used johnsen's freeze 12 ? their site says it is compatible with R12 & the oil in the system. it has been many years since i installed R12 systems. i have never worked with 134A
 

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██▓▓▒▒░&
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Bill, freeze12 is a mixture of two gasses and mixed gas refrigerants pretty much all suffer from the same problem: If there is any leakage, you need to totally evacuate the system and start over again in order to get the blend correct again. Can't "top it up", can't fix a leak and refill, must start over from scratch.

You'll find a lot of shops using miracle gasses and offering a 30-day warranty on their work. Would you buy a toaster with only a 30-day warranty?

Sorry to say, there are no miracles or shortcuts in AC systems. There are kludges, outright wastes, and compromises, but rarely more than one way to really "do it right". Which is, to fix and fix the leak (sounds simple, like removing an appendix, right?) and then refill with the right gas.

None of the gasses, including R12, are really THAT expensive compared to the rest of the work. Finding someone who knows what they are doing, and will stand behind their work? Ah, that's a bit harder.
 

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Cal 9.2 SilverSwan
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Check out the R22-A refrigerants to see if they are oil compatible. I know that 22 and 134a are not!.....
 

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Mondofromredondo
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Discussion Starter #16
Thanks to all!
Gulp.... I think I'll buy a complete new system. After all its a boat. It just wouldn't seem right to get away with doing it cheaply. It has to hurt a little right?

Keith
 

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If you can find it

Freeze 12 will go right into your system, with no changes. I haven't seen any of it in a while, but if it's still available, would solve your problem.
 

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██▓▓▒▒░&
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Keith, that pain comes with the "need" for cold.

Conversions are a roll of the dice, they work for some folks, some times. IF you can find a good AC mechanic--the cost of gas, any gas, at any price, if still an insignificant part of the bill. It only becomes a problem when the "repair" is done wrong, and redone three or four times, and then the consumables start adding up because oddly enough, they're never part of the warranty.

If you're in clean water, often the thermocline is fairly shallow, and if you drop your drinks in a mesh bag over the side for fifteen minutes, they come up reasonably cold. Bit of a problem keeping steaks that way, of course. :)
 

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Im a low temp refrigeration man myself and agree with Denby. First unless there is a solinoid or valve of some sort, when you remove the condenser all the freon should come out if you want it to or not. Also R134a sucks if the equipment was not 100% made for it. You can get lucky sometimes but there are 1/2 dozen other 12 replacements out there and Freeze 12 works ok but R401a(mp-39), R409, and many more IMHO are much better suited for these applications. Other appliance techs my have a little more perspective as I mostly work on larger equipment. Unless you have access to a lot of expenssive equipment you will never get the job done properly. I would hire it out or befriend a HVACR service tech at a bar or something.
 

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One of None
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Again, the systems in most of the boats here are very small. equal in size to a domestic refrigerator. just the pricing is whacked! Like who is going to do a conversion on a old r-12 domestic?
 
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