Can any of the AC experts discuss R12a refrigerant, which is claimed to be
OK for ozone layer (and legal) but superior performing compared to R134.

TIA

R12 (never heard of 12a) is no longer sold in the US except in a recycled
form. It is a CFC and death to Ozone. Very expensive as well.

You can't just change gases. Your system must be spec'd to use R 12 or one
of the drop in replacements. The drop ins are blends of several gases as
are most of the newer products so you can't just add them to a system with
12 in it. You have to recover, evacuate and then charge to specific
weighted charges or with pressure gages depending on the system.

R-134 is NOT a substitute. It runs at different pressures.

Different oils, compressors, valves and seals.

If you do not know what you are doing, don't, it will end up costing you a
fortune to get it unscrewed..

You also need to have the EPA cert before you touch anything which could
cause an accidental release of refrigerant to the atmosphere.





"Private" <please (AT) dont (DOT) bother> wrote

I had my old plymouth voyager recharged with 'FR-12' which was an R-12
substitute. Worked pretty well.
See the article at
http://www.autobodypro.com/safety/articles/0031.htm

I had heard of some folks, before substitutes became available, using
propane to charge an older system. Pretty scary when you have a collision
and the sealed system leaks and ignites several pounds of propane....

"Jay R" <jrgiuliani (AT) verizon (DOT) net> wrote

The substitutes typically work ok and are the only alternative in auto ac.

In many cases it is cheaper to tarade the car. I had an 86 Voyager that the
clutch came apart on. It had 248,000 miles on it. Price for the new
compressor and the flush and recharge, yu were looking at a $1,200 bill.

I run a scientific equipment repair company and have about 60 certified
refrigeration techs and none of them wanted to touch it.

In commercial ac, you can replace the system components with parts designed
for the newer refrigerants and the advanatge is they are generally more
efficient.

Problem is you usually have to change everything but the pipe, sometimes
even that.





"Oppie" <oppie (AT) saynotospam (DOT) com> wrote

Scientific equipment repair company, eh? Do I know you?
I'm a design engineer for LUDL Electronic Products - a scientific equipment
manufacturer.

Aside from that, My old voyager had the AC clutch die at about 100K. I got a
new clutch and installed it without having to touch the sealed system. At
about 200K the hoses started to get an oily coating which meant that the
refrigerant was leaking out along with the oil. I got a new set of hoses,
receiver/dryer and H valve (expansion valve). Did a crude pump-down myself
to test for leaks and then brought to a shop to add oil, complete the pump
down and recharge with FR12. I probably should have replaced the compressor
at that point but I was already $400 into the job. Worked acceptably for
another year until the motor blew.
Oppie

"Jay R" <jrgiuliani (AT) verizon (DOT) net> wrote

On Jul 19, 8:42*pm, "oppie" <fi... (AT) verizon (DOT) net> wrote:
I had a 93 bonniville that I had converted from r12 to r134, cost me
about $200. They replaced the reciever/dryer and all the o-rings,
flushed the system then recharged it. It worked great, but I sold the
car after 4years so I don't know if it is still fine.. they also
replaced the access valves to the larger size that 134 requires.

Probably not,

We made freeze dryers, tightly controlled environmental chambers and other
ultra low application equipment.

Other stuff as well but those were the biggies.

Did a lot of PLC control work but that is the extent of the electronics.

I ran the technical support group. I had servcie, parts, tech support,
remanufacture and also a very profitable rebuild and upgrade group.

Upgrading refrigeration equipment to green refrigerant systems and lower
energy components is a big business. Nealy all businesses and schools are
falling over themselves trying to out green each other.

We had a parting of the ways recently whem they moved my operation to
upstate NY from the Philly area.

Since all but my last kid are through with college, I took a dial back jib
with a local electrical construction company.

I am doing some new business development, some of the controller work and
help out with project management.

I get to spend more time on hobbies and my grandson.





<p_vouers (AT) goochs (DOT) com> wrote

On Jul 19, 8:42 pm, "oppie" <fi... (AT) verizon (DOT) net> wrote:
I had a 93 bonniville that I had converted from r12 to r134, cost me
about $200. They replaced the reciever/dryer and all the o-rings,
flushed the system then recharged it. It worked great, but I sold the
car after 4years so I don't know if it is still fine.. they also
replaced the access valves to the larger size that 134 requires.