Who here has experience running alt refrigerants like duracool, envirosafe, freeze 12, etc. ?

I’m in the process of switching over to a sanden compressor (stock condenser for now) and curious to try something new.

.

__________________
1981 240D 4sp manual. Ivory White.

What do you want to know?

R-12 in a fixed system is the best. It meets the design for lubricants, flow, hoses, etc. Not many shops service it anymore.

While the w123 I had retrofitted to r134a worked well enough, those that I’ve kept with r-12 have been better. They don’t all leak or fail, especially if you run the ac system when driving to keep seals and hoses coated with oil.

Ive used envirosafe refrigerants particularly for the purpose of finding and repairing systems. Legally you shouldn’t refill any refrigerant system, you shoukd find and repair the leak and then use the correct refrigerant. Even 134a isn’t great for the environment. Technically for leak checking you can vent a tiny bit of refrigerant to the atmosphere, by pressurizing a system with nitrogen and a trace amount of refrigerant. I much prefer to use es-12a or industrial 12a, both from envirosafe, and use a hydrocarbon sniffer. Works really well and works with r-12 and r-134a systems.

Some may not like the prospect of doing this, I get it. It’s another more flammable substance underhood. But that’s not an argument we need to make in this thread. Especially for testing, and having a system that you can drive and operate while troubleshooting and sniffing or looking for dye.

I wouldn’t mess with other CFC blends. If you’re going to do anything, either run the correct r-12, retrofit to r-134a, or run one of the hydrocarbon 12a refrigerants.

Refrigerators in most homes now have the same hydrocarbon refrigerants. I was shopping refrigerators and was surprised to see how many had it pressed into the metal panel on the rear of them. Granted those are really sealed systems, but still, that concerns me more than hydrocarbon in an auto accident system, unless you have some issue like a big leak in an evaporator or something.

You’ll be happy with envirosafe. I’d ignore the comments that it works with moisture and air… if you’ve had a leaky system that let air in, replace the r/d, pull a hard vacuum, and run industrial 12a. They recommend against a hard vac with the standard es-12a, but I don’t really understand why. Ive always pulled the hard vacuum then charged it properly. Even in leaky systems it runs well for much longer.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

Thanks for this.

From what you've written, I realize that I do not understand the differences between what I referred to in the initial post as "alt refrigerants." Is envirosafe considered 12a? Which are considered CFC blends to be avoided?

__________________
1981 240D 4sp manual. Ivory White.

As far as I'm aware, R12a can be kind of tricky to locate. There's folks out there who can help but it's not something you can find on the shelf at the store and it requires making some phone calls. It's properties are still much better than R134 though so it might be worth the hunt.

-Matt

Thanks for that Matt, much appreciated.
The search begins…

__________________
1981 240D 4sp manual. Ivory White.

You’ll have to go back and read the various discussions and interpretation of the law (clean air act) to get it all straight. But my 85% understanding is this:

- R-12 got phased out
- The EPA set regulations about allowable alternate refrigerants. A variety of things were considered, including blends that got to a reasonable pressure-temperature profile. Some were traditional refrigerants, but the obvious choice for a suitable retrofit was r-134a, which when done well, works ok in many applications. Our Mercedes cars are a tough one as it uses a fairly weak compressor on a low power engine, and had an underwhelming ac to begin with.
- hydrocarbons are a viable replacement for r-134a; officially not for r-12 based upon how the laws are written.
- the most common hydrocarbon blends that match an r12 type pressure temperature curve are called r-12a.
-some folks claim that these propane butane blends aren’t as miscible with oils as refrigerants. While this isn’t a big deal with industrial systems, it is for motor vehicle ac. They claim proof is in the fact that compressor manufacturers don’t warranty compressors used with hydrocarbons. But that isn’t necessarily really proof… there could be a wide range of reasons why they won’t.
- one thing that is known regarding blends, regardless of if they’re hydrocarbon, mixed refrigerant, etc. is that they will leak at different rates, so the blend will change in time. This can result in a mix
That has different pressure properties than originally used. Apparently this can be a concern with propane in the 12a mixtures, because the isobutane will leak faster and then the propane pressures can go too high (IIRC). My angle on this is that it really means one should run slightly undercharged and then replace the mix every so often if you have concerns about leakage. However I’m primarily a believer in using the stuff to identify leak points to fix, then getting real proper refrigerant into a leak free system.

Overall I’m not terribly opposed to the 12a HC blends. But I look at them as a means to have a useful ac in a driving diy repair. Not the actual long term solution. If I had an unfixable leaking vehicle my opinion might differ a bit.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

No phone calls necessary. It is readily available on eBay, or from the manufacturer or their distributor. I think I got some on Amazon once too.

There is a “lower pressure” original version, and then the “industrial” version. The original version was modified to be shippable in thin wall cans, but it’s pressure characteristics prevent you from loading it into a hard vacuum. They want you to have a partial pressure of air in the system which seems like insanity to me. But again for investigating leaks to repair, not a huge deal as a tool.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

“Partial vacuum” is a point I can’t quite grasp.
So say I’ve pulled vacuum, I’m to let the drop-down a few HG before filling? Unclear…
And a point of practicality, what is the fitting style people typically use to connect those cans to the pressure ports?

__________________
1981 240D 4sp manual. Ivory White.

I’ve never understood it that well either. Apparently blends are either 60/40 or 70/30 propane/isobutane. The original 60/40 blend could be transported in thin wall containers, the 70/30 blend couldn’t.

The issue is that the isobutane keeps overall pressures lower, and more means that there isn’t as much working fluid. Remember that AC works on pressure changes, and more specifically, phase changes going from liquid to gas.

As I understand it, the higher amount of isobutane keeps pressures lower, but that affects the ability to compress and condense the propane working fluid. So you already had less. The result in automotive AC is that the compressor short cycles. To remedy this they want the original 12a to be charged into ambient atmosphere (system containing some amount of air). Of course air doesn’t condense and so isn’t a working fluid at all. So cooling is compromised. Charge to a vacuum and in order to get pressures high enough to operate and not short cycle the compressor then things are way out of whack on the high side.

The industrial 12a is packaged in thick wall containers that can be shipped and work better. It can be charged to a hard vacuum. I believe the industrial blend is the actual correct blend that is used in commercial (stationary) refrigeration systems.

The other issue is that this is a blend. MVAC systems are intrinsically leaky. So it will distill to a different ratio as the diffeeent components leak at different rates. So this means you need to somehow check or re-fill every so often if your system has a leak.

It also should be charged as a liquid in the high side. The issue is that it will draw oil away and the MVAC systems are intended to carry oil through the system. So you don’t want these blends which will carry oil to wash the internal surfaces clean.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

Wow I just checked and you are correct! I had no idea it was available online. It has always been such a nightmare to source locally.

Would be nice if Pelican started selling o ring kits optimized for the joints in common car series (123, 124, 126, 201, 210, etc), and perhaps the es-12a industrial. Especially if it could be lumped in for free shipping!

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

Be absolutely certain you know what you're getting involved with and the potential dangers. This quote is from another forum on the subject of alternative refrigerants.....

R12A is a hydrocarbon that is extremely flammable. You might recognize it by its more common name PROPANE. It will contaminate your entire system, and once contaminated, everything will need to be replaced, if you want to convert it back. The problem with R134A is that the smaller molecules of the gas, can penetrate the old rubber hoses, and that you also need to change the oil, flush the entire system of the old oil, and re-hose the entire system with barrier hose, if you want to do it correctly. With air conditioning, there are no short cuts, and using the wrong products devalues your car. It is your car, and you are free to do as you like, we can only advise you. I have seen how volatile an engine fire can be when the air conditioning hoses burn through, and the oil in the refrigerant lines starts to burn. It is like a flame thrower. I can image the same scenario with PROPANE in place of the R12 or R134A refrigerant. I can hear it now, when the flames hit the PROPANE, the flames will travel through the hoses, and all the a/c system will go BOOM, like a hand grenade. Don't want to be anywhere near when that happens.

Thanks for that 123boy, I appreciate your concern.

I have read that particular post, and unfortunately there’s not a lot of truth or science in it. The 12a horse has been beaten to death many times, mostly by a dogmatic member who doesn’t seem to post anymore. In the meantime, I just need to figure out this fuse issue…

__________________
1981 240D 4sp manual. Ivory White.

Not really sure one way or the other. Until yesterday, I was unaware of R12a. I'll stick with R134a, for now. I'm just trying to nudge people to have respect for compressed gasses and ac systems. I think a lot of people are under the impression they can fix anything on a car so why should the ac be any different? Overcharging is no joke. It might not explode like a hand grenade, but shrapnel is shrapnel no matter its origin. Healthy respect, know you limitations and dont guess.
As always: A little knowledge can be a dangerous thing.

If you're interested in learning more, there's lots of good material to read on the subject and the duracool sales reps are extremely helpful. Forum member BillGrissom has documented his usage fairly extensively.

__________________
1981 240D 4sp manual. Ivory White.