Ahoy! Refrigeration Techs

[chaco]

I am installing a used Adler Barbour DCM-12 Condensing Unit from the mid 80's
and want to change the Refrigerant from BANNED R-12 to R-134a.
Techs have offered to SNEAK me some R-12, but I want to have a System
that can be worked on and charged worldwide in the Future :nerd:
Please help me with the procedure and amount of Refrigerant to charge the
System
Cold Beer has always helped Boat Owners have the Courage to attempt and finish Impossible Projects

Good Bye Ice Bag !

 

[Guy Stevens]

No you can't....

That is the short answer. There are two options open for you:
1> Get some R-12 from where ever you can.
2> You could use a product called Hotshot.

Now I don't recommend option #2 because one of the mail ingriedients of hotshot is propane, and if the reefer leaks, it is going to leak down into the bilge, and could be an explosion hazzard.

The reason that you can't reliably change a hermetic compressor from r12 to r 134a is that there is a significant difference in the oils available. There is no way to completely clean the mineral oil from used with r-12 out of the system. We can do this with non hermetic compressors, but not really with hermetically sealed ones. You can't clean them out, because the motor actually rides in a bath of the refrigerant and the oil, touline is the standard cleaner for systems, and it would not get all the mineral oil out of the old windings, and would attack the winding insulation.

The oils and trace r-12 left in the oil if mixed produce a product that closely resembles chewed bubble gum.

You could use one of the exotics like 410? (I'd have to look up which one you could use). However you would have to buy it in 30 lb containers, and it would not be worth doing, as the would be like $300.00 wholesale at with a license.

You would in any case be better off building a new system. Or at least using a new compressor.

Guy

 

[jkm]

Dan

If you decide to stick with the R-12 and have a problem finding cans let me know.

John

 

[chaco]

Thank you Guy and John !
Sounds like I will stick with the R-12 and change out the compressor as it
fails. Are we looking at an automotive aerosol can to charge the system ?

And...thank you for your response on the Vandalism Question

 

[rwthomas1]

Last time I checked R12 was no longer manufactured in the US however it is still made in Mexico. The result is that it is actually one of the most commonly imported illegal substances to the US.

That said, it is fairly easy to get and the prices have come down considerably now that most refrigeration systems are 134a or other refrigerants. IIRC, anyone can complete a test online and get a license to buy refrigerants. That way you could buy your own and give it to your tech.

I have two vehicles with R12 and so I have fought this battle before. Recommendations have been to keep R12 systems with R12 in them. Conversions usually don't work well as the components, etc. have been designed with R12 in mind. That and the problems with lubricant incompatibility that Guy alluded to.

I would find a good tech, a reliable source for R12, service the system and move on.

RT

 

[Guy Stevens]

Ironies

The law on R-12 is a little strange. You could purchase some in Mexico and bring it back into the states on YOUR OWN BOAT, provided that YOUR OWN BOAT had an r-12 system.

However you can't bring it back in say your car, for your boat use.....


This and other mysteries of a legal system.....

For the unit that you are looking at you should be less than 8 oz. Normaly something like 4.5. The UNIT MUST be filled using a scale, and it not overfilled, or disastrous results can happen. This is required by law to be on a tag that is on the sled (baseplate) of the unit. It might still be there. Do not overfill the system.

Also the system should be completely vacuumed down and all the moisture out of it before charging....


Guy

 

[newgringo]

R12 Drop Ins

I have used a couple different R12 "Drop In Replacements". The first was a mixture of Propane and camping fuel called Isobutane and the other was some stuff called Freeze 12. Both worked well but the Freeze 12 is preferred. Easily avalable in US but foreign? There is other substitutes available too. I recommend you stock up on R12 from wherever you can get it.

 

[Guy Stevens]

Freeze 12, Hot shot and the like are all propane based

They are not recommended for boat use because of the explosion potential if there is a leak.

Guy

 

[jkm]

I know that Dan has worked out his issue and is well on his way to getting his R 12 system up and running.

FWIW any front line automotive air conditioning company is usually licensed to work on R 12 systems and could help if so inclined.

Also most vintage car clubs (domestic cars) have guys that do that sort of thing-so if you need held try those sources and you should be OK.

John

 

[Greg Ross]

R-12/ 134a/ 460

I have a 20 year old Buick whos' AC has never been the same since conversion to R-134a. Obviously the gas density is nominally different. The system works fine when A/C is needed, problem arises on cool mornings. When the systm is cold the BCM thinks the coolant is low and disables the climate control?
I damaged a serviceable 20 year old Frigibar system on our boat year before last. Installed a new (built approx. 1982 and never installed) Adler Barbour Cold machine last Summer.
Initially thought it was low on refrigerant (R-12) With much help and many eMail exchanges with "Thermal Dynamics" we focused on the excess tubing orientation. The hoop of excess tubing had to be laid horizontal to allow the oil/ gas to flow thru the tiny oriface tube. Once that was sorted out voltage became an issue.
Wired direct to the batteries initially improved voltage drop condition but it was still very fussy about low voltage. (Had experienced no such problem with the Old Reliable "Frigibar"
I ended up electing to update, installed a current style fan/ coreless CPU style blower and a new controller module. At the end of the day I ended up with a good (old) system for much less then new.
I think R-12 will be around for a while yet.