would you recharge an AC cruise-air unit with propane-butane refrigerant?

[sdowney717]

additionally, would you use any propane in a boat?

I have a marine AC cruise air that the copper line some time ago must have broken by way of metal fatique where it meets the cruise-air unit. this is a simple copper flare with a heavy duty flare nut type of attachment.
Anyhow, I can recharge it with a flammable refrigerant that substitutes for R-22 since I have some here in the garage. But I know there would be a risk of a leak and then a possible boom.

http://www.hydrocoolonline.com/

I also think a flexible refrigerant line running to the evaporator would be a good idea.

[Candyfloss]

My knowledge of refrigeration is limited to what I learned by osmosis from my Dad who was a Refrigeration Engineer, but I can tell you he earned most of his money repairing & replacing broken copper pipes. Of course his refrigerant of choice was Freon, which is now banned, but he searched for breaks & leaks with a propane torch inside a gauze cage. The flame would turn green in the presence of Freon. This obviously is not going to work with a propane refrigerant.

If you feel the need of a cautionary tale regarding propane on boats, you could do worse than read Jack Dillon's Thread "11 Years on a 27ft Boat".

[mj_lover]

if the unit has been broken / leaked a while, the seals and receiver dryer should also be replaced, system placed under a vacuum to remove all moisture. at which point the is no valid reason to not convert to 134A, as it is the only manufacturer approved refrigerant. not saying the other stuff is bad, could be great, but you don't know what is in it for additives and such, and the company will not tell you, as they want your money. and if your gonna spend money might as well put the proven stuff in. Also, make sure you use PAG oil in the unit, regardless of what route you take, or you compressor will not live long.

my 2 cents

personally I'm not a fan of propane on boats (diesel all the way!), but just be careful if you do use it, it does go boom ventilation, etc

[sdowney717]

this detector got very good reviews
http://www.amazon.com/Combustible-De...pr_product_top

here is an interesting story of propane which caused CO poisoning
http://www.multihullsmag.com/magazin...%20article.htm


I will look into the r134a idea. Dont know if something designed for r22 can use that.

With PAG oils, moisture in a system causes bad corrosion and breakdown of the oil which is sort of like a soap. Mineral oil systems were better but can still be an issue.
Water in the system can freeze and block expansion valves orfice tubes capillary tubes etc...

[Stan D]

I've been researching the conversion from 22 to 134 for an old car, and from what I've found, the only other differences are the fittings and the oil. It is important to back flush the crud out.

[ssor]

Before freon there was ammonia (very toxic) and butane (very flammable). terrible accidents with both.

[oznabrag]

My knowledge of refrigeration is limited to what I learned by osmosis from my Dad who was a Refrigeration Engineer, but I can tell you he earned most of his money repairing & replacing broken copper pipes. Of course his refrigerant of choice was Freon, which is now banned, but he searched for breaks & leaks with a propane torch inside a gauze cage. The flame would turn green in the presence of Freon. This obviously is not going to work with a propane refrigerant.

If you feel the need of a cautionary tale regarding propane on boats, you could do worse than read Jack Dillon's Thread "11 Years on a 27ft Boat".

Yes. The flame would turn green, and the heat would convert the Freon into Phosgene gas, a particularly nasty chemical weapon from the WWI era.

It's a miracle that anybody lives past childhood, eh?

[rickinnocal]

R134a is specifically formulated to be a direct replacement for R22. The boiling and condensation specs are close to identical. The specs for a Butane/Propane mix are unknown as you don't know what the ratio is, so no way of knowing how well it will work.

Thousands of older cars are succesfully converted from R22 to R134a every year. It doesn't get as cold as R22, and it seems to leak more, but it works fine. I'd just pick up a conversion kit from your local AutoZone and do it. That will contain the new refrigerant, new fittings, and the correct oil for the retrofit.

As said above, if the systems been open for a while than you need to replace the dryer, and you 'should' place the system under a vacuum to draw out any moisture. People who don't have access to a vacuum pump often just vent a can or so worth of 134a through the system through an open joint before putting the compressor oil in instead.... that actually dries the system better, but it's bad for the environment.

Richard

[mj_lover]

heads up to the venting refrigerant to the atmosphere, here in Canada anyway, there is a hefty fine for stuff like that, up to $20,000 day, not sure what the laws are south of the border.. just a heads up, correct on the fittings being different, its an easy conversion

[Bob Adams]

Wrong refigerant guys. The Cruisair uses R 22 which is still available, albeit somewhat expensive. Autos use R134a, before that R12. In my opinion, putting a flammable, heavier than air gas(propane) on a boat is best avoided.

Here ya go, not so expensive:

http://cgi.ebay.com/ebaymotors/R22-R...Q5fAccessories

+1 on the new dryer, good idea to pull a vacuum also.

[sdowney717]

http://hvac-talk.com/vbb/showthread.php?t=162338

looking into r22 charging and leak testing I found this forum. Apparently is is totally legal to vent r22 to air if it is mixed with nitrogen as it is then not considered refrigerant.
I think they allow this exception because that is how they test for leaks. Seems somewhat hypocritical to me. Some people working on large systems use a lot of r22-nitrogen mixtures.
This is how it is done though. apparently the detectors they use need to snif some refrigerant to point to a leak.

Also it seems that a few of the posters on this thread had no idea that a tech can use R-22 to leak check. How and where did you guys get your EPA cards? I've used entire 30lb jugs of R-22 to leak check larger chillers. How can you leak check an entire chiller using soap bubbles and looking for oil?