R12 replacement air con

[PeterAC Senior Member Find all posts View Profile Close PeterAC]

Going to regass the air con in the merc. I've read of a number of alternatrives to R134a such as HR12, R290, LPG, BBQ bottlegas, the last three being essentially the same. Who has used alternatives and how do have they gone? I've read R134a puts extra load on the compressor in the 300D.

Peter<><

[Westwinds Donating Member Find all posts View Profile Close Westwinds]

Re: R12 replacement air con

Gday,Regased my Bravo last July with LPG.Going great.A friend of mine use to operate a rabbit chiller near Broken Hill and his refrigeration unit was completely gased on LPG.regards Westwinds

[PeterAC Senior Member Find all posts View Profile Close PeterAC]

Re: R12 replacement air con

Westwinds when you say LPG specifically what are you referring to. Is it from a bowser at a servo type gas or bbq bottle gas?

[PeterAC Senior Member Find all posts View Profile Close PeterAC]

Re: R12 replacement air con

Homegrown Power: What a week.

Have a look at this Dave for a how to put it in. Don't know enough yet to know if this is easy or not and what gizmoes are needed to do it.

[Captaincademan Senior Member Find all posts View Profile Close Captaincademan]

Re: R12 replacement air con

Well my Dad ran his 1985 Fairlane aircon on LPG for years. Ran colder than you could imagine! It might be worth finding out about the lubricant properties of LPG though as the modern compressor requires a certian oil in the gas stream to lubricate the cylinders in the compressor. Its not just any old oil as the oil needs to be able to be carried in the gas stream itself i.e. "aerosol" type and not just a fluid running around the system in the bottom of the tubes. The compressor in my cruiser's aircon failed / seized due to a slow leak in the system and loss of lubricant.

Bottom line check out if you need to add a lubricant or not.

If your gas has leaked out that means you have a leak in the system somewhere? Leak + LPG + Hot engine and spark = hospital.

[Johnnojack Senior Member Find all posts View Profile Close Johnnojack]

Re: R12 replacement air con

This is nothing new, running LPG or Propane which is LPG without the Butane. I believe it is a more efficient gas than R134a and even better than the old R12 which beats R134a
As for the safety aspect the amount is fairly small depending on the system but is about 180 to 220ml. A lot less than the 60 or so litres of LPG in the fuel tank. You still need oil with every gas to lubricate the compressor. Any weeping oil leaks are a sign of a gas leak and should be fixed asap. I spoke to the a/c guy about using propane and he said yep can do, but need to completely flush old gas and oil, replace reciever dryer then replace with different oil then regas. More expensive than regas with R134a due to all the extra time I guess.
That said if you have an system Dave that is not working anyway having a go with LPG can't hurt. As for the reciever/dryer every a/c guy will put on a new one (you pay) yet all you need to do is put it in the oven on low for a while, dry out any moisture it has collected then whack it back on.
An a/c system with any water in it will not work for long.

[Qwarla Senior Member Find all posts View Profile Close Qwarla]

Re: R12 replacement air con

One thing to remember is that LPG is a fairly safe gas, when compared to say acetylene.
The explosive range of LPG is fairly narrow.

Autoignition Temperature

494ºC - 600ºC

Flammable Limits LEL

2.2% (in air v/v)

Flammable Limits UEL 9.6% (in air v/v)

So in a confined space it doesn't take a lot before the mixture is too righ to burn. Only 9.6%

[83Patrol Donating Member Find all posts View Profile Close 83Patrol]

Re: R12 replacement air con

There's a commercial product available that's about 50% propane and 50% butane if anyone's looking to get it done by a 'professional', called HR12:

HyChill Refrigerants - Manufacturers of Hydrocarbon Refrigeration Gases, HC's, HR12, ER12 - CFCs, HFCs, HCFCs, hydroflurocarbons, R12, R22/502, R290, R600a, and R134a Replacements

I know a place in Melb who gives the option of using it if anyone was looking to pay to get it done.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: R12 replacement air con

I suggested using HR12 several years ago when my Aircond man recharged my R12 Air conditioning on the Second FATMOBILE (1980 MB 300D) with this product.

There was mixed reception.

Perhaps it was on the OzBbenz forum, Memory is going again. . . .


Tony

[Johnnojack Senior Member Find all posts View Profile Close Johnnojack]

Re: R12 replacement air con

There's a commercial product available that's about 50% propane and 50% butane if anyone's looking to get it done by a 'professional', called HR12:

HyChill Refrigerants - Manufacturers of Hydrocarbon Refrigeration Gases, HC's, HR12, ER12 - CFCs, HFCs, HCFCs, hydroflurocarbons, R12, R22/502, R290, R600a, and R134a Replacements

I know a place in Melb who gives the option of using it if anyone was looking to pay to get it done.

Funny that, but LPG from the servo pump is I think specified at 40-60%butane and 40-60% propane. I bet tho that HR12 costs 10X as much as LPG

[83Patrol Donating Member Find all posts View Profile Close 83Patrol]

Re: R12 replacement air con

Yep, it's definitely more expensive, but I put that there for people who don't like, or cant, do it themselves or know anyone in the game.

Honest, it wasn't a plug for a friend's business. Really.

[PeterAC Senior Member Find all posts View Profile Close PeterAC]

Re: R12 replacement air con

Where can someone buy small amounts of LPG autogas as opposed to LPG home gas. Autogas is a mixture of propane and butane and homegas is straight propane. This is according to the LPG Australia website.

I've read that the butane in the mix is important for the compressor.

I've tried to find somewhere to buy small amounts of autogas to be put in a small gas cylinder but no luck. Can only get home gas. Any ideas? As a last resort I'll get the HR12.

Peter<><

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: R12 replacement air con

When I get my car regassed (had to to Mrs' W124 last year) the fridgie charged me $100 for the job. This is the same as when I had the Fatmobile regassed years ago.
It took around 3/4 hour, including checking the system held vacuum and looking for evidence of leaks, using ultraviolet light.

I felt this was a reasonable price.

Others may have been charged more, or feel that I paid too much.

Regards,
Tony

[83Patrol Donating Member Find all posts View Profile Close 83Patrol]

Re: R12 replacement air con

I felt this was a reasonable price.

The going retail rate around here seems to be around $150 these days, so it sounds reasonable to me.

[PeterAC Senior Member Find all posts View Profile Close PeterAC]

Re: R12 replacement air con

The air con system runs at a higher pressure on straight propane than R12 ( but lower than R134a )but on autogas with butane it lowers the pressure the system runs at. This allows the compressor to work easier on autogas and more effectively. It supposedly works better than R12. Hychill use isobutane rather than butane.