Dad's cylinder is marked Technical Chemical Company Dallas, Texas. DuPont was making refrigerant in a Mexican plant as well as some others, as we have some DuPont R134 marked Made in Mexico.

I have seen 'no label' cylinders too, which I avoid....FWIW

I think you can buy any refrigerant from any neighbor anywhere. not legally of course, but it's doubtfull the epa is following up on residents selling stuff...

does your dad live in mexico? or did the neighbor get it from there?

The neighbor brought back a varied assortment of refrigerants, 502, 410, R22, R12, R134, etc.

I do a lot of A/C work on the side. The shop where I used to work has a 2000 F150 and they asked me to come out and do the A/C on it. With a new condensor and a few modifications, vent temps at 100°F ambient are 35°F at idle and 30°F at 70 mph.

The thing I like about Ford is the larger condensor/evaporator (compared to GM) and the orifice tube system which is completely tuneable....

In contrast, my W116 with an expansion valve/ETR system (on R12) will only pull down to 33°F-35°F at 70 mph and about 40° at idle...

Daimler says France blocking some new registrations
 

I saw a video where a guy was trying to keep a canister of 1234 lit. He had to keep the ignition source in the stream of refrigerant just to keep it lit.

Stuff doesn't seem to burn very well.

... so instead of a chemical that can burn, they are installing one that's very high pressure (over 2500psi at condenser head pressures...) and a leak can suffocate you in an enclosed space... like a small car.
I mean, CO2 in liquid form is stable, but heated, up to 120 which is COMMON for R12 and 134... and the pressure goes off the chart...
the heat transfer is going to SUCK... they'll have to make the condensers out of cast iron or Stainless steel to handle the pressures, and I guess copper plate them to get heat out of them...
http://i33.photobucket.com/albums/d9...kers/co2pv.gif


note, this is a chart for pressures possible in an overfilled bottle... I couldn't find a working PT chart to compare with R12...

ok,
THIS article appears to state that R744 refrigeration does not use standard Phase Change cooling like all other refrigerants, due to the tremendous pressure possibilities... they use a gas cooling system instead of a typical condensing refrigeration system...
the math is waaaaaay above my head though, so perhaps I am misunderstanding the article...

I'll bet the torque needed to turn such a compressor would make a C02 based system unfeasible. EPIC FAIL

Says who? Have you run EOSs to determine shaft work requirements to get the applicable PV change?

Im not a fan of this new stuff, but speculation without basis doesnt help anyone.

Well, I guess I made some assumptions.

I assumed that higher pressure would require additional power but it appears that overall efficiency of C02 more than makes up for any differences in power requirements with R134a.

I found a study that concluded that CO2 actually performed 20% better than R134a with a properly built and tuned system that utilized a two stage compressor.

The benefits of CO2 are even better realized in a heat pump system that can even heat your water in a home installation.

Very interesting.

Let's just be honest, shall we????

R12 became 'dangerous' only after DuPont's patent lapsed. Think R134a is safe??? Look at its chemical composition....FWIW

France Declares War On Germany By Halting Mercedes Sales
 

Exactly. Funny how those two correlate in such a close amount of time. I remember seeing the propaganda ads on TV about how dangerous CFCs and Freon are. I think it was the early 90's. Even the teachers in school gave lectures and held classes on the subject.