Hydrocarbon Refrigerants???
 

Hello Gentlemen, I need your knowledge, oponion, +/- testimonials and other infos about the use of Hydrocarbon R12 alternative refrigerants like ES-12a, Duracool, ...etc... on an '84 300CD Turbo with GM R4 compressor and R12 system. I heard it is supposed to perform better than any other R12 alternatives with low system pressure then less stress on the compressor except that there is a risk of an explosion or fire due to the flammability of the hydrocarbon properties of this refrigerants.

It's already getting too hot now and the price of the real R12 is ridiculously high and sometimes too unreasonable, around $30+ for a 12 oz can and $700+ for a 30 lb. jug, and all I need is 2.9 lbs., I believe. I just wanted my 4 month old 300CD turbo to blow some real cold air out of the vent when it is above 90 deg outside. It blows cold when raining or during night time or early morning driving but not when it's hot (around 90+ deg.) and especially when I'm on a bumper to bumper traffic or whenever the car is on idle. Everything is functioning, fan clutch is good, elect. aux. fan is good, the heater monovalve is good, CCU is good and the whole 9 yards. So, that being said, I am convinced and decided to rebuild the AC system, new compresssor, new exp. valve and drier.

My plan of attack this weekend since I already have all the parts in hand, is to have the system identified what kind of freon does it have right now and have it recovered and evacuated and flushed by a local AC indie shop.(they can do it for $45 something) Then I'm goin' to replace the compressor, exp. valve as well as the drier and pressure switch myself. The only thing that I don't have right now is the freon. But I just wanted to have the system replaced and sealed this weekend just so all I have to do next week is to vacuum and charge. But I still can't decide whether to go hydrocarbon or not. I am aware that it is supposed to properly function on the real R12 but..... you know what I mean.... $$$$$

Any comments and suggestions will be greatly appreciated. Thanks!

Prepare yourself for many folks telling you to stick with the R-12. And to be honest, that is the best idea. However, these systems really aren't that great even WITH R-12.
I think the exploding characteristics of "Dura-cool" type products in an accident is overblown.
Listen to folks and their reasoning, then the decision is yours. Good luck.:)

Well, first off, hydrocarbon refrigerants are supposedly illegal to use in on-road vehicles.

Straight propane is a common automotive refrigerant in Mexico.

Straight propane has pressures that are WAY too high for MVAC use. The P/T curve for propane is almost exactly that of R22, not R12. It's use in Mexico would add more excitement to an already exciting driving experience there ;).

The addition of ~30-40% isobutane to propane puts the thermodynamics more in the R12 range.

I AM NOT ADVOCATING THIS. I have used a "test" refrigerant when I had a particularly difficult leak to find (it was leaking thru the WIRES of the aux fan switch as it turned out!!) and found it performed nicely; very much like R12; not better, but like R12 IMHO.

Your symptoms (would REALLY help to have pressures, ambient, RPM, but.....) are classic for lack of heat exchange at the CONDENSOR. I know you say the fans are perfect, but the rain scenario says otherwise. Low charge will do the same.

Why are you replacing those parts on an operating system? Leak? compressor noise?

R12
 

If you want to get an argument ...Just bring up religion, politics or now (refrigerants)....Always Fun topics...

I think the legal side of it is that HC12 can be used in (Some States) as long as the vehicle has been retrofitted to 134 before switching to the HC12.....
Lots of debate on the flamability issues..... but from what I understand is that safety is not an issue as much as the EPA regs and the retrofit and the patent on 134A.....Its all about money in the end...
Europe & Canada uses the isobutane mix in millions of vehicles with no problems....and we know how safe those folks like to be.....I worry more about the 18 wheel tanker trucks going over 80 mph pulling a load of propane or worse.... than I do about a few ounces of refrigerant....not to mention the ~90 psi gasoline fuel injection systems on a lot of modern vehicles hauling 20 gallons of gas in the tank....Read and look up some of the DOT codes on the trailers that pass you going 80mph+ and you will soon put into perspective your highway safety concerns...

Before long any vehicle still using R12 will probably be required to have a DOT skull & Crossbones 24" square black and red sticker on each side of the car.....and can only be driven in daylight hours under 35 mph on restricted county roads...after you pay the $5000.00 annual Earth punishment fee.....If...the EPA GPS monitor is fully functional....with regular site check in....If your dreaded R12 was to ever leak....Federal law would force you to compost yourself as compensation to mother nature.....

But if it were mine ...I would stay with the R12....get it on ebay when you get your 309 cert for 20 bucks...just a lot less trouble after you find the leak........For now.....

The reason I'm rebuilding the system with new comp., exp. valve, and drier is;
1. I am not certain whether or nor it is charged with R12 right now, therefore, I don't know what the gauge pressure should be.

2. Assuming that it has R12 in it, low side is bet. 15-20 psi and high side is bet. 200-220 psi @ 1500 RPM and it gets cold, but not when at idle around 700 RPM, as if the CCU control is set to ECONO.

3. Assuming it has 134a in it, manifold pressure is still off specs.


and by the way, here's another twist:

4. There is an R-134a retrofit sticker under the hood but there is neither high nor low side retrofit quich connect fittings, just the standard R12 fittings.

....hence the reason I wanted to overhaul the system by changing the compressor, expansion valve, and drier so I can start from scratch myself and won't have to chase the PO's previous AC work.

I would love to stiick with R12, because this is what's supposed to go in the system. My daily driver 300D is perfect with R12 in it. I have the 609 certificate but $$$$$. You know what I mean, R12 is priced ridiculously and unreasonably high. I hate to put 134a on the 300CD but I'm thinking about HydroCarbon alternatives, hence my inquiry for opinions and testimonials about this product.

Where did this information come from??.

Using R12 or duracool, etc. etc. ( hydrocarbon refrigerants ) is legal as long as you comply with the EPA laws on its use, storage and recovery.
I have a 30# tank. My 609 license and 3 cars operating R12.

Dave

I didnt have much luck with duracool in my benz but it works great in the explorer. I think the reason it didnt work well in the benz is because of the small condensor they have. I bought some r-12 and it works great. The benz only took 2 cans. I think it was cheap for the prformance.

There are also a handful of states where hydrocarbon refrigerants are banned for automotive use. The EPA site lists these. All I remember is that neither Missouri nor Illinois are on the list.

I've seen a video of the windows exploding out of a car, purporting to show just how dangerous hydrocarbons are to use in this application. I'm not sure that I believe the doom-and-gloom scenario; they probably had to be careful to be able to get the proper mix of hydrocarbons and air in the interior to make the effect (dramatic as it was).

R420a
 

Has anybody tried R420A? It is touted as a replacement for R12 ---- see www.rmsgas.com. I called these guys, but never got to speak to anybody but a very bored - sounding young lady, and no one called me back as promised.

R420a is just R134a with some (~12-20%) R142b(?) to carry the mineral oil in order for them to claim (incorrectly) that it is an R12 "drop-in" replacement.

It's the same essential formulation as Freeze-12.

80-88% R134a should work worse than 100% R134a. Thermodynamics and all, eh? ;)

MattL.
Here's the states. I'm not on it either.

420a
 

Thanks, 007

there is however a drop in replacement for R12... R409... it's not much cheaper than 12 however, and it's a blend forcing you to completely evacuate and totally recharge for the slightest leak. always fun.
check craigslist for R 12 tanks. ebay is more difficult to get, and the bidding lately for the tanks are crazy prices. 50Lb tanks around 700 30lb tanks around 450.00 whatever you buy, be sure to weigh it yourself, the tank weighs around 7 lbs, so subtract that weight from the total, and that is what you have in freon... look for a sealed tank with company logo on the seal, and if not sealed, look for a GREEN handle on the tank. any other color handle, and there is nothing stopping a crook from putting 134, or 22, or whatever in the bottle.
I got my 27lb tank...(20LBS R12) on craigslist, and the guy was a MB SL restorer! so he will be doing business with me in the future!
I suggest the 12 route, and agree with your desire to start from scratch.

5 hours left on this R12 auction... almost a full jug, 350ish dollars Plus 35 shipping... fair from Missouri...
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=007&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=170123429598&rd=1,1