I know its still a bit early in the year to talk aobut air conditioning, but i've found some stats on the various "replacement" refigerants being sold out there. Turns out a good portion of them use 134a as their main ingrediant

Freeze-12 (the most popular I've seen)
80% HFC-134a, 20% HCFC-142b. Not a drop in replacement for CFC-12 or HFC-134a.

Free Zone/RB-276
79% HFC-134a, 19% HCFC-142b, 2% lubricant. Not flammable as blended. Not a drop in replacement for CFC-12 or HFC-134a.

Hot Shot/ Kar Kool
50% HCFC-22, 39% HCFC-124, 9.5% HCFC-142b, 1.5% R-600a (isobutane). Not flammable as blended. Not a drop in replacement.

GXG-X4/ Autofrost/ Chillit
51% HCFC-22, 28.5% HCFC-124, 16.5% HCFC-142b, 4% R-600a. Not flammabale as belnded, not a drop in replacement.

GXG-X5
41% HCFC-22, 15% HCFC-142b, 40% HFC-227ea, 4% R-600a. Not flammable as blended. Not a drop in replacement.

R-406a/ GHG
55% HCFC-22, 41% HCFC-142b, 4% R-600a. Not flammable as blended. Not a drop in replacement.

Ikon-12
Aprroved for automotive use in 1996, but Ikon corporation claims that the refigerant blend is confidential business information.

Frigc FR-12
39%HCFC-124, 59% HFC-134a, 2% R-600 (butane). Not flammable as blended. Not a Drop in replacement.

OZ-12, R-176, HC-12a, Duracool 12a, R-405A, MT-31
All SNAP unapproved by the EPA.

hope this can add some useful info into the forum.

 

actually Freeze 12 is a drop in replacement for R12 and R134. It can be added/mixed to either and be completely compatible if the oil charge is also done at the same time. Nice thing about it is that it can be used to supercharge the cooling on R134 systems that just don't seem to get cold.

and I didn't see R12A, my second choice, but probably simular to Duacool 12A

 

I just threw in the el cheapo Meijer/Wal-mart $40 kit and it has worked just fine for the last two summers. We'll see if I can make it three.

Always remember to properly vacuum down the system and check if it is holding before re-charging the system. This also gets any old refrigerant out of the system....especially useful for the first re-charge you are doing personally. Who knows what a previous owner put in there before?

 

I done AC and refrigeration for 10 years.
My favorite was HOT SHOT. But it is
expensive. For cars I just use r134a and
do a SLIGHT overcharge and it works like a
champ. Notice SLIGHT overcharge


P.S. That really sucks about Dimebag Darrell
He will be missed

 

i wouldn't mix r-12 with r-134. Actaully, to quote my source "It cannot be overemphasized that CFC-12, a chlorofluorocarbon refrigerant, and HFC-134a, a hydrofluorocarbon rifrigerant, are not compatible. They must, under no circumstances be mixed..." so on and so forth. And considering freeze 12 is 4/5ths r-134a, i'd make damn sure there was no R-12 left in the system before using it.

Normally people recommend that 134a can be used insted of r12 for older systems. And provided that the system was vacuumed our properly and the proper lubricant used, then it wouldnt be a problem. But a guy i know who's been doing A/C for years says that the majority of r12 compressors that mazda uses has had problems handling 134a for whatever reason.

Kinda puts us people with old old AC systems in a pickle. With the cost of r12 at aobut $1200 for a 30 pound tank, its not feasible to recharge it with that, and there are risks of damage when replacing with a different refigerant. I just wanted to post that information to let people know that the majority of the replacement refirgerants are either HFC-134a or HFC-22 based.

 

Actually been running Freeze 12 mixed with R12 in my vert for the last 2 years and a year in my old SC400 without any problems at all.

What problems would there be anyway??? When retrofitting a R12 with R134, you just evac the system, replace the seals (because of oil contamination, not R12 contamination; R12=Mineral based oil, R134=Synthetic based oil), and replace the fittings. With the Oil charge with Freeze 12 being a simular synthetic to the old mineral based R12 esther oil, you don't even have to change the fittings or seals.

From the manufactures website:

 

Steel is right. Leaving the free chlorine in the system is what is corrosive. The chlorofluorocarbon never breaksdown which is why it is bad for the ozone. The R-12 needs to be purged from the system first. Those of you with a leaky system will have no problem here. Just keep adding a can of R134A each month, insta purge. But in all seriousness, just purge your system and then refill with R134A.
I can get my cryogenics engineer to explain it further if you must.

 

Change the filter drier is a must. Dump out all the oil out of
your compressor and pull a good vacumme. You will
be ok

 

I'm sorry AC sucks so bad even when its 110 out side and a 100% humidity I rather be hot than slow.

 

When you get older, you'll prefer being cool amd comfortable, to being fast!

 

Our cars run hot as it is. I almost had a heat stroke sitting in L.A. traffic with no A/C. I fixed mine the next weekend and life has been very good since.

Nothing better than having a frigid A/C on hot humid day.......sitting inside music blasting FROST blowing out of the middle vents. The guy in the '72 ford pickup next to you is looking at the frost and druel drips out of his mouth as he tries desperatly to vent his oven. You give a little shiver as you realize your getting chilled......I could go on.

 

My A/C does not make me slow.