Direct replacement for R-12?

[luvrbus]

I accidentally burned a hole in hose on a 134 system and the hose started a small fire when it popped the oil and the freon mixed under pressure made the flame look like a torch for about 30 seconds hot enough to melt aluminum,you can make almost anything dangerous with the right ingredients my oldest son a ex seal can build you a bomb with sugar or about anything else they sell at 7/11 lol   

good luck

[JohnEd]

Well, there are degrees of "purfect" and I think Art's points about propane being "purfector" are well made.  Not that you are wrong again, Sean.

John

[Sean]

I accidentally burned a hole in hose on a 134 system and the hose started a small fire when it popped the oil and the freon mixed under pressure made the flame look like a torch for about 30 seconds ...

This is a good point, Clifford.  While R-134a itself is not inflammable, the Polyol Ester Oil that is used as a lubricant in refrigeration systems is, with a flash point of 518°F.  Atomized and under pressure it can, indeed, become a torch.

Polyol Ester Oil (sometimes written Polyolester Oil or just POE) is used now in all automotive systems because it is compatible with a wide range of refrigerants including both R-12 and R-134a.

-Sean
http://OurOdyssey.BlogSpot.com

[robertglines1]

r-134 added Toter home cool again/Steam Engine in 100 degree weather 90% humidity another subject.   Don't you love summer in the midwest.    Bob

[artvonne]

Better check your facts, there, Paul.  1,1,1,2-Tetrafluoroethane is neither explosive nor inflammable.

  Read down the page to fire fighting measures, unusual fire and explosion hazards.

  While I would never argue 134a is flamable like propane, we can all agree that the industry, with the sale of 134a directly to the public, as well as a complete lack of media interest, have convinced far to many people that 134a in completely benign, when in fact is is quite dangerous and deadly. And while 134a in more ozone friendly, it is very bad from a greenhouse gas standpoint and has been building up in the atmosphere the last 10 years.

  While I dont buy into the whole GW and Ozone depletion myths, after all the screaming the last 25 years over the Oone hole and how R-12 was the cause of it all, it is completely hypocritical to see R-12 available anywhere, at any cost. It is equally hypocritical to see 134a being freely sold on the open market, when there are real, true, refrigerants we could all be using that are 100% green. Propane is totally green once you get past that lil flamability issue, and CO2 is only bad from an asphixiation standpoint. Other than that CO2 is completely benign to the environment.

  My only fear of Propane in the AC system in the Bus would be a massive leak or rupture in the evaporator area leading to ignition. And I do not believe a leak of that magnitude is likely.

  Which does beg the question; has anyone ever witnessed a major evaporator leak in a Bus?

[JohnEd]

Art,

Thanks.

John

[Sean]

...  Read down the page to fire fighting measures, unusual fire and explosion hazards. ...

"Unusual" means just that.  This material is not explosive or inflammable under normal conditions, including anything found in a refrigeration system or on a bus.  Under the right conditions, even your breakfast cereal is explosive; that's not what we were discussing in this thread.

Debating the merits, or lack thereof, of U.S. environmental policy, even as it impacts price and availability of common refrigerants, belongs OT -- I could write tomes about it here but I won't.  Let's stick here to the facts that actually have relevance to bus conversions.  Writing in this forum that R-134a is "explosive" is disingenuous, because it is NOT explosive as that term is understood in safety and firefighting circles.  This is just not a risk that someone converting a bus needs to be concerned with.  By contrast, using propane presents a very real fire and explosion risk, subjects the coach to additional marking requirements, and restricts it from traveling certain routes.  Beyond that, charging a compressor that runs on electricity, yet has not been ignition-protected, with propane would be sheer idiocy.

Additionally, writing that propane is less toxic than refrigerant gas is similarly disingenuous.  It's true in a certain sense, but it is like writing that hydrochloric acid is less toxic than cyanide -- true but not relevant, in that consuming either one is likely fatal.

I am not the arbiter of what gets discussed here (clearly).  But it is more than a little annoying when what started out as an informative technical thread degenerates into a political rant.  It dilutes the value of the technical information because lots of people just stop reading.  And it's really a shame if they walk away with incorrect information, such as "R-134a is explosive."

JMO and FWIW.

-Sean
http://OurOdyssey/BlogSpot.com

[JohnEd]

Boy Howdy...That almost sounds harsh and intolerant.  Must be the Flat Medium.  Or should I say "mostly level"?  I'm so confused....and intimidated, even.

Your Admiring Friend,

John

[rv_safetyman]

I started a thread in the OT asking why R12 and Halon (sister chemicals) are still available for sale.  I did this hoping to learn why I can sell Halon with no restriction.

Any bets on how many posts it will take before it goes into a political discussion

Jim

[Len Silva]

Just one more.

[rdbishop]

I would like to know more about how to use propane in a AC system. Art , you say the biggest problem is the expansion valve, Why? I have a rooftop unit I'm going to play with and it has the capillary tubes. Will that make a difference? What kind of oil is necessary?

Richard

[artvonne]

  The expansion valve pressures have to match the system pressures. R-12 oil is compatible with R-290. Search online for propane as refigerant, theres a lot to read.

 

[kevink1955]

If your roof top unit is R22 (most likely) propane will not work as a drop in replacment with out a large loss in cooling capacity. R12 and propane require a compressor with larger displacment (pumping capacity) than R22.

[AndyG]

I have a rooftop unit charged with r12.  It frosts up/freezes on occasion.  Most people agree that this is because the unit is low on refrigerant.  Is there a product available that I can use to top off my AC unit?

[daddysgirl]

The use and efficiency of propane as refrigerant is very useful information, IMHO.

But gasoline itself (the fluid) is not what explodes...it the vapor. Same for propane as well??.(If you notice the smell, leave wherever you are. Don't even pick up the phone, etc. But I believe the additive that provides the "stink" in propane is heavier than the propane itself. (It's how I know my house tank is low...the water heater will start to burn the additive near the tank bottom and smell). But we use propane in bus conversions for a multitude of things. Why can't a bus AC system be retrofitted and made safe for propane? What would it take to do so? If the industry is indeed going to begin phasing out 134A and replacing it with something insanely expensive in the future, why not start the "Bus Conversion Discussion Design" now?
Heck, how do they make dry ice? It's cold, right?
In a perfect world, we could come up with something that didn't rely on a finite resource, or require more battery capacity than is practical. Until then, creativity, engineers, and willingness are all that's necessary for use as a direct replacement for what we use now as a refrigerant. Why not?