Bry in Virginia wrote:

> > Is there a refrigerant replacement for R12 that DOESN'T require hardware changes?
> > I was told that there is one available, after R12 is totally purged from system- truth?
> Not legally, because EPA requires unique fittings for each different type of refrigerant.
> Bry

At 05:57 PM 5/23/01, Alex W Marks wrote:
>Is there a refrigerant replacement for R12 that DOESN'T require hardware changes?
>I was told that there is one available, after R12 is totally purged from system- truth?

Back to basics here: (USA only)

There are two approved refrigerants for automotive use: R-12 and R-134a.

There are many, many refrigerants that will more or less work in an automotive system.

R-413a appears to be a blend (which is not approved for automotive use) containing 88% R-134a plus other refrigerants, possibly R-22.

The air conditioning service industry operates under very strict regulations, with very high penalties for noncompliance.

If you carry a car that contains anything other than R-12 or R-134a to an air conditioning technician, he can't touch it. If he hooks his recycling system to a "contaminated" system (one that contains ANYTHING other than R-12 or R-134a), he must then treat the refrigerant that he pulled out of your car, and all refrigerant that it touched, as toxic waste. He must also have his recycling equipment decontaminated.

Bottom line:
As a practical matter, you can run anything that you want to in your own car, but you can't get it serviced professionally.



Hi Troops!
Got the following info from Graham in response to AC Question-

If there is I think I've got it because when I had mine recharged last year I just dropped it off and picked it up 2 hrs later and they didn't change anything. I've only just noticed the R413a sticker. Here's a copy of what I just received off another lister.

"Isceon 49" or "RX2" aka R-413A is a "drop-in" substitute for "CFC-12".  It is a mixture of 9% C3F8 (PFC-218), 88% of HFC-134a (HFC-134a), and 3% isobutane (HC-600a).

ISCEON 49 is a drop-in replacement for R-12 in refrigeration systems based on mineral oil. Its performance is similar to R-12, and requires no oil change.  R-413A is Zero ODP and lower GWP.

ISCEON 49, which is manufactured by Rhône Poulenc, is a mixture of HFC-134a, FC 218 (C3H8) and HC 600a (isobutane). ASHRAE has designated the refrigerant as R-413a.
Contact: Rhône-Poulenc, fax: (33) 1 47 68 23 18

Alex W Marks


At 12:57 PM 5/24/01, Bernard Embden wrote:

>>There is a product called Freeze 12 made by Johnsen's Sercon at 3327 Pipiline Road, Cleburne Texas. (1800-645-6088) Its a direct drop in replacement for R12. They claim that they are 100% legal. I spoke to someone who used this product and they say it does not cool as well as R12 (what does?)

You can use it - it will probably work. And you can't get your A/C serviced anywhere else.

Again - there are only two refrigerants that are fully approved and that you can get serviced anywhere in the USA - R-12 and R-134a.

Legal? Probably.

Drop-in? Perhaps.

Again, you can put anything that you want to in your A/C - but there are serious problems with anything except for the two standard refrigerants.


No, but we have the Eurocrats that stuff all kinds of sh.. ehh, crap down our throats. R12 as such has been outlawed here. The only practical choices are a conversion to R134 ($$$$ or DM DM DM) or, it seems, to use R413.

Unfortunately, this is something I am facing right now, as there is some oil leaking from the front of my compressor. I was told that it is basically not possible to fix this and that I'd have to spring for a new (or exchange) compressor. Comments to this are welcome.

If the compressor is replaced the system will, of course, have to be recharged, and, since it likely that some R12 was lost along with the oil, I can go for R413 or the whole nine yards....

Since our club is planning a four day trip to Italy in three weeks, I need to get this fixed ASAP.

Oh, if I can't get the fix scheduled in time, should I remove the belt to the compressor so that it doesn't freeze (no pun intended) somewhere along the way, taking god knows what with it?

Best regards,


If you convert to either refrigerant be sure to have it done by someone who knows the product.  There are nozzles to replace and you will likely want to change other components out for the best performance.  It's always going to require some minor mods at the very least otherwise it will not perform as well as it could.


At 06:26 PM 5/25/01, Rich wrote:
>  Within a few miles with the fan setting at "2" and normal mode (not recirculate), the center vent output temperature was down to 28F / -  2C.  A major part of the COLD output temp is the very low RH that makes these desert temps survivable.

An output temp of less than 32F indicates a malfunctioning freeze switch.
If the evaporator temp is lower than 32F, moisture from the incoming air will freeze on the evaporator, shutting off the air flow. Design temp is usually about 34 F.


At 06:48 PM 5/25/01, tom falkenberg wrote:
>i have this problem as well and my airflow gradually diminishes (i think as it freezes up) regardless of fan speed setting.  so where exactly is this freeze switch and how hard is it to replace?

You can try adjusting it first.

Raise hood.
Remove weatherstrip at back of hood.
Remove black plastic panel - be careful, as it is thin and will break easily.
In the center of the car you will see a small box with a couple of electrical connections and a capillary tube. There is a lock nut and an adjusting screw on top. I don't remember which way is warmer - just try it one way and see.

When the evaporator gets too cold, the freeze switch cuts off the compressor until the evaporator goes above freezing.

Wally Plumley
928 Specialists

I thought I read that it was approved pending publishing of the approval, but that is not really an issue outside of the United States.  I'm not sure exactly what that meant anyway.

If you have or are considering using R-413A you should read this.  This is the manufacturer's page on their R-413A product called isceon 49.

It seems that some modifications of the system should be made.  You should change the fittings so it won't be confused with another refrigerant.  But the oil doesn't need to be changed.