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PeterAC
15th November 2009, 01:30 PM
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
15th November 2009, 07:39 PM
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
16th November 2009, 06:29 AM
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
16th November 2009, 06:38 AM
Homegrown Power: What a week. (http://www.thebackshed.com/windmill/forum1/forum_posts.asp?TID=46)

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
16th November 2009, 02:41 PM
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
18th November 2009, 09:29 PM
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
19th November 2009, 07:28 PM
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 494C - 600C

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
25th November 2009, 09:23 PM
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 (http://www.hychill.com.au/tech/)

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
25th November 2009, 10:11 PM
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
26th November 2009, 10:07 AM
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 (http://www.hychill.com.au/tech/)

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
26th November 2009, 01:44 PM
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
26th November 2009, 09:12 PM
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
26th November 2009, 10:39 PM
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
27th November 2009, 01:36 AM
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
27th November 2009, 09:25 PM
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.

RODEONICK
27th November 2009, 10:09 PM
i have a filler that allows me to fill BBQ bottles with car gas (and save a small fortune) and in all honesty you cant tell the differance between the gases so i think your getting your leg pulled. I get why you guys want to do this but how are you going to get it into the ac system?
Cheeers Nick..

Westwinds
28th November 2009, 07:33 PM
Gday,In central west NSW the LPG gas at the servo is the same gas that is delivered to houses that have gas stoves and heating.The delivery guy told me that the reason for this is transport and storage logistics.I dont know if it is propane or butane but i think one of them has a extra molacule. regards Westwinds

PeterAC
28th November 2009, 09:28 PM
[QUOTE=RODEONICK;42297]i have a filler that allows me to fill BBQ bottles with car gas ]

Where can this filler be bought from.

Aircon regas in a 1991 car. [Archive] - Aussie Phorums (http://phorums.com.au/archive/index.php/t-149434.html)

Nick, read this on how to get it into the car.

Westwinds, house gas is propane, and even in Newcastle there are servo's that have big banners up advertising their auto gas as 100% propane. I don't know what benefit for a car propane has over a propane/butane mix. I assume then that you have charged up with straight propane. In Newcastle the domestic gas installers and repairers are only licenced to work with the home mix ie. propane. I spoke to a welding gas supplier and he said auto gas and home gas are the same and can also be lots of different blends of different gasses other than propane and butane, so I believe there is a lot of myth information out there. I know the auto gas is suppose to be different %'s of propane/butane depending on what is supplied to the servo at any given time and does not have to be a set ratio.

Peter<><

Qwarla
29th November 2009, 10:38 PM
Peter AC go back and read this site. (http://www.hychill.com.au/tech/)
In particular read the MSDS for the different gasses. Click on Safety Information on the Left side.

HR12 is stated as being C3H8 0-50% and CH(CH3)3 0-50%. So it is a veriable mix.

HR22/502 is C3H8 95% CH(CH3)3 5%.

HR290 is C3H8 100%

HR600a is CH(CH3)3 100%.

From this it is easy to see the mix of gas can be any proportion you like.

Now having said that think about how the gas is delivered to your part of the world. I know here a ship will come into the port and discharges it's load of gas all into the same tank. From there various companies get their supply. From there it is delivered to houses, servos and the like. All the same stuff. The only varing thing is the origions of the gas.

And low and behold, much the same thing happens with petrol. It all comes out of the same ship, but some ends up as BP, some Shell some Caltex and so on. And that ship filled up at only ONE refinery.

Makes me laugh when people go on about how much better one companies petrol is than the other. :D

Johnnojack
30th November 2009, 08:54 PM
[QUOTE=RODEONICK;42297]i have a filler that allows me to fill BBQ bottles with car gas ]

Where can this filler be bought from.

Peter<><

You can't buy one you have to make it. It is an "illegal device" so lets just keep quiet and deny such a thing exists.;)

Matt
4th December 2009, 07:44 PM
More info please on how to do this or pointers, I have two cars to get going again. Know a bit about refridgeration and am capable.

Qwarla
4th December 2009, 10:53 PM
More info please on how to do this or pointers, I have two cars to get going again. Know a bit about refridgeration and am capable.


Matt have you read this entire thread? If you have you will have found the answer. Now go back to post #5. Follow the link and have a read. All the answers you seek can be found there.
Good luck. ;)

Matt
5th December 2009, 07:52 AM
mmm, interesting I found the MSDS and PDF files very good information. One last question - It was mentioned that the prcedure was for a R12 system only not R134a, is this true or is there enough eveidence to suggest its equally possible. The hychill site tends to suggest it will.

Thanks.

Qwarla
6th December 2009, 02:00 AM
I assume you read the bit about the procedure for changing from R12 to R134a. The changing of 'O' rings and compressor oil.

To change from R134a to HR12 then it would be fairly safe to assume you should only need to change the oil to the compattable and flush the system. The 'O' rings may need changing but I could not say for sure.

PeterAC
6th December 2009, 08:08 AM
Hi Qwarla and Matt,

I've been ploughing through lots of googling forums re the regassing and I'm not supporting autogas or Hychill or anything just summarising the info I have found.

The Hychill fits both the R12 and the R134a systems. No need to modify either. Both use different oils but the Hychill is compatible with both oils so no need to change type of oil. Not sure if the seals for R134a are compatible for the R12 oil and visa versa.

Qwarla I found the info about the percentage of isobutane very interesting. I want to chase that up more just for info sake. I've read that there is a gas isobutane used as a refrigerant and that butane is not, don't know why. I've also read that propane can be purchased 100%.

Why would the companies bother stating that one product contains contains more or less of one than another I have no idea. I don't really hear of it although I don't walk in the gas industry circles except for the gas stations that advertise 100% propane. Again I've read that propane/butane does not throw out as much heat as straight propane which would explain why propane is used for heating/cooking but 100% propane can still be used to power a car, ie country areas.

Matt
6th December 2009, 09:51 PM
Gents, what do you think of this/these ?

Manifold Gauges Air Conditioning Refrigeration Car Air - eBay Other Test Equipment, Test Equipment, Electrical, Business, Industrial. (end time 09-Dec-09 21:08:07 AEDST) (http://cgi.ebay.com.au/Manifold-Gauges-Air-Conditioning-Refrigeration-Car-Air_W0QQitemZ170414760438QQcmdZViewItemQQptZAU_B_I _Electrical_Test_Equipment?hash=item27ad82e1f6)

Looks like the right thing, I have a vacuum pump need a few adapters I think.

Qwarla
6th December 2009, 10:27 PM
Matt that gauge set would be the go. Would depend on the end price of the auction thou. You can also buy them from places like maybe BlackWoods, and some of the good tool suppliers. It would be worth checking the retail price before going to far with the auction.
Item number 350274423663 on ebay. Buyitnow $59. Vertually the same thing but without as many fittings.

PeterAC, yes propane is better for heating. Butane is better for autogas as it is said to give slightly higher power.
From information I have been given the problem can arise in cooler climates because butane requires more heat to evaporate it than propane, and that is one reason for it normally being in a mix and that mix can vary with time of year. It's a bit like petro diesel can vary in the cold country with time of year. The stuff they sell up here would certianly be different to the stuff used down South Pole. Artic diesel is probably very close to power kero.

johnnyhc
15th December 2009, 11:17 AM
Ladies and gents,

I thought I might chime in, and I hope the info provided is of assistance:

I'm one of HyChill's technical advisors.

I'll try to deal with all the main points made on this thread and then you can make up your own mind.

Re: HyChill Minus 30 (formerly known as HR12) compatibility with R12 and R134a system components:

HyChill Minus 30 is compatible with all components and lubricants used in R12 and R134a systems. The only known issue related to late model vehicles where cheap and nasty "reduced barrier" (sometimes known as 'thin walled') hoses are used on the low-pressure side. These hoses are very prone to leakage, but strangely seem to leak hydrocarbon refrigerants faster than R134a in many cases, resulting in regular re-gassing being necessary. Our policy is to recommend these poor hoses be replaced with proper "full-barrier" hoses and the issue is resolved and your car will hold charge (whether R12, R134a or hydrocarbon) much longer.

Re: Why all the different products with different mixes of propane/iso-butane/ethane?

It's all about energy efficiency and desired cooling temperatures.

This is a big subject. Background can be found here: Vapor-compression refrigeration - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Vapor-compression_refrigeration)

However, in summary:


Each major class or blend of refrigerant typically has it's own unique thermodynamic properties (boiling point, pressure/temperature curve, enthalpy etc).
The compressor and expansion valve in an AC circuit are designed to provide optimum cooling capacity for a particular type of refrigerant.
In the case of a car, the AC circuit components design is optimised for the thermodynamic properties of either R134a or R12
HyChill Minus 30 is a blend of hydrocarbons chosen to achieve the best performance and efficiency when used in an AC circuit designed for R12 or R134a
If you were to use HyChill Minus 10 (for example) in a car AC circuit, you would expect reduced performance because the thermodynamic properties of R600a (iso-butane) are not well matched to the design of the components in a car AC system.
The same argument goes for HyChill Minus 40 or Minus 50. In particular with HyChill Minus 40 (100% propane) or HyChill Minus 50 (propane with a small amount of ethane) you will be loading the compressor (and therefore the engine) to an unnecessary degree because the pressures generated on the high side by these gases is far from optimal for this type of system.

As a slightly different example, consider Electrolux which is now transitioning all its domestic fridge production to Hydrocarbons. They only use HyChill Minus 10 (isobutane) because that's what they've designed their refrigerator AC system for and to use anything else would be ridiculous because they would not achieve the rated energy efficiency.

Re: Why not just use autogas or bottle/cooking gas?

It's all about energy efficiency and the risk of damage to internal components.

For the record, autogas' primary hydrocarbon components can be anything from just propane right through to normal-butane (which is different thermodynamically from iso-butane). As far as hydrocarbons go, there may also be a significant proportion of ethane in the fuel.

Ethane is not at all well suited to R134a/R12 systems. But I won't go further into that now. This post is long enough as it is!

Similar to the thermodynamic differences with different types of hydrocarbons, bottle/cooking gas is predominantly propane because the burners that are fed by this gas will only burn efficiently on the gas for which they were designed. In other words, normal (or iso) butane thermodynamic properties are different from propane and so the orifice sizes on the burner holes will not be correct and the burn will be very inefficient (or may not work adequately enough at all) - this should further instill an awareness of the importance of choosing the correct hydrocarbon for a thermodynamic process.

Please refer again to my previous point about efficiency. Purity issues aside, using LPG autogas or cooking gas in your car AC will be giving you significantly sub-optimal results with a high degree of certainty.

It's hard to tell just by listening to the engine as the compressor cuts in and out, however, but the thermodynamics is clear. 100% propane has a boiling point of approx -50degC (way too low for this application - a waste of energy) and much higher pressures than iso-butane. Iso-butane on the other extreme has a boiling point of -10degC and a pressure/temp curve that is not suited to an R12 or R134a compressor and TX valve. In all this I haven't even mentioned the issues of temperature glide etc. And if there is any ethane in the batch of LPG or cooking gas you procured, then your performance will get even worse.

And the unfortunate part is that the system may 'appear' to work (it produces cold air) but you're none the wiser to the improvements in fuel economy and compressor life you could achieve over the long run if you chose the correct product.

To put it in greater perspective, you can be quite confident that your AC system will be LESS efficient running autogas or bottle gas than if it were properly charged with even R12 or R134a. To achieve superior performance that R12 or R134a, you will need to use the correct propane/isobutane blend hydrocarbon (in HyChill's case, that is "Minus 30").

Now, onto purity issues. My background is in the oil and gas industry, and my other employer (LPG Measurement Technology Pty. Ltd.) are experts in LPG and cooking gas for over 35 years. We run the measurement lab which almost all LPG calibration equipment in the country (and also for many other countries) is tested and calibrated.

What you need to understand is that LPG and cooking gas are manufactured for the purpose of being used as a fuel, and the quality controls are optimised accordingly. In short, LPG can contain a whole bunch of components which are to be regarded as contaminants in an air-conditioning system.

Such contaminants include:


Water. This is very bad for the internals of an AC system, particularly R134a systems. The oil (such as PAG oil) and any residual R134a in the system will chemically react with water to form strong acids (such as hydrofluoric acid), which will eat your system out from the inside. Aside: However, if you thoroughly flush and clean your AC circuit and replace with mineral oil and Minus 30, your system will have virtually zero risk of internal corrosion as both fluids do not react with water - this is a worthwhile consideration if you want to maximise the life of your system well beyond what R134a would provide.
Suflur-based compounds. These also form strong acids, particular if there is residual moisture in the system.
Solid matter/particles. The expansion (TX) valve in an AC circuit is a tiny orifice. If it gets blocked by a particle, you're AC system is stuffed.

I hope I have given solid reasons for choosing the correct type of refrigerant and to avoid non-refrigerant grade hydrocarbons.

In short, the mixture and class of refrigerant DOES matter. So you're thinking to yourself "sure, sure, he's just telling you what his boss wants you to hear"... and my response is, 'fine' if you insist, but the entire Refrigeration Engineering profession disagrees with you. At any rate, if you choose to charge your car with LPG or bottle gas anyway, at least you're now reasonably well aware of the drawbacks and risks and you can make your own judgement call.


Response to the comment by Captaincademan: "If your gas has leaked out that means you have a leak in the system somewhere? Leak + LPG + Hot engine and spark = hospital. "

Although probably well intentioned, this statement is misleading.

It takes a spark of a certain amount of energy to ignite Minus 30, and only if there is exactly the right mixture of gas and air present around the spark at the time. That ratio is between 2% and 10% gas vs. air, for your reference. Hot surfaces in the engine bay are not sufficient to cause ignition. I can't remember the autoignition temp off the top of my head, sorry. We know of numerous cases of catastrophic failures of the AC lines causing a large proportion of the gas to be dumped straight onto a hot exhaust manifold but failing to ignite. Such 'dumps' of gas refrigerate the surfaces they hit, making it yet harder to achieve an autoignition temp, and even if that temp is reached the surrounding area is usually too rich in hydrocarbon to ignite.

Not even a lit cigarette, even when exposed to a flammable HC mixture, is sufficient to cause ignition.

But it is a flammable gas and so it always pays to be extra careful. Make sure the area you are working in is well ventilated (a closed room is not a good idea) and there are no ignition sources nearby.

For reference, the behaviour of hydrocarbon refrigerants, from the point of view of safety, is the same as bottle LPG or auto LPG. Treat it with the same care and precautions that you would those gases.

Also, to put things in context, remember that light hydrocarbon gases are safety class 2, whereas petrol is class 3 - a higher hazard than LPG or HC refrigerant.

Previous posters have made some very astute remarks about the safety issues so I won't go into them here. It is extremely difficult to make a solid case for any statistically significant risk no matter what the leakage scenario, when in normal use. After all, there is only about 300g in the system. The majority of leaks are very small and there is ZERO chance of them ever igniting due to the fact that it is impossible for a significant flammable mixture to develop in a large enough size and in an ignition-prone location. That is evidenced by the fact (as remarked by Dave Jones) that HC in AC is 'old hat'. To be more specific, it's been around as an alternative for approx 15 YEARS now. There have been millions of vehicle charges performed, and no safety defect trend except for the occasional act of stupidity by an installer.
Finally, readers of this post should understand that R12 and R134a are super-potent environmentally harmful gases - so much so that there are Federal laws in place which make it a crime to knowingly release R12 or R134a into the atmosphere. In other words, regassing your system with hydrocarbons should only be performed AFTER you have had a qualified AC technician evacuate and collect the R12 and R134a from your system. If they are not a hydrocarbon-friendly shop, they might try and give you a hard time if you volunteer that you're going to charge it yourself with HyChill (there's big efforts by the fluorochemical companies via numerous 'front' groups such as VASA to lie, mislead and deceive the auto AC industry about hydrocarbons). To save hassles, you can just tell them you are decomissioning the AC system and want to do the right thing first by having a qualified person remove the gas first. Then do what you like with it.

Our tech support people are pretty good so you if need more info just look us up in the phone book or on the web. I won't post numbers or addresses here because that may be impolite.

Cheers

John Clark
Technical Advisor
HyChill

Johnnojack
16th December 2009, 02:54 PM
Thank you John for your time and effort in giving us such good info on this topic.:)

PeterAC
16th December 2009, 05:16 PM
I will be regassing up with Minus 30 on Friday and let people know how cool I am. :D I decided I preferred someone to chase up leaks and clean/dry the system rather than me learn a new skill that takes three times as long as an A/C pro.

Thankyou John for your information.

Peter<><

johnnyhc
16th December 2009, 07:34 PM
Glad you found the info helpful.

Oh, and I also meant to comment on the cost of HC refrigerant vs. automotive LPG.

It's all about volume and the distribution system. Consider for a moment:


Automotive LPG is used in such large volumes compared to HCs. The difference in orders of magnitude is monstrous, and that has a huge effect on the retail cost per kg.
The size of each "sale unit" (60 litres of LPG, say, vs 300-400g of HC).

Not to mention the extra processing, testing and container cleaning steps involved for a refrigerant grade product vs. automotive grade.

I can assure you that HyChill is not making a fortune on selling HC's by any stretch of the imagination. It was only in the last few years that we began to break even.

The potential for cost reductions in future is also very large, as the usage of HC's becomes more widespread. Similar economies of scale would come into play. If it became the defacto-standard refrigerant then I think the retail costs could come down to $1 - $2 per kg! But we're not there yet.

And while ever the lobbyists and front groups for the big foreign chemical companies like DuPont and Honeywell keep spinning their lies and showing scary videos to motor vehicle company execs who don't know any better, we may never get those economies of scale. If you find the product beneficial and are satisfied it's a good solution, I would humbly ask you pass the word on. It would be greatly appreciated. We're just a small Australian family company up against multi-billion dollar foreign corporate monopolies. It aint easy!

Take care,

John W Clark
Technical Advisor
HyChill

Westwinds
16th December 2009, 09:27 PM
Gday johnnyhc,Thank you for your informative posts.Welcome to the forum. Regards Westwinds

Matt
22nd December 2009, 07:00 PM
And the result is?.....



I will be regassing up with Minus 30 on Friday and let people know how cool I am. :D I decided I preferred someone to chase up leaks and clean/dry the system rather than me learn a new skill that takes three times as long as an A/C pro.

Thankyou John for your information.

Peter<><

Qwarla
23rd December 2009, 09:18 PM
And the result is?.....


The A/C works that good he is now a solid block of ice. :D :D :D

69roadster
20th July 2010, 01:57 PM
You guys are absolutely crazy!!
I can't believe that some company rep is selling you all on it too.

I would never run a flammable gas in an automotive a/c system.

If the system were in the middle of a car somewhere and protected like a gas tank or LPG powered vehicle is, then I would do it. But it's NOT! It's out there pretty much in front of everything and will take the impact first. The fronts of cars are where the majority of damage occurs even in a minor accident. I don't care what anyone says. This is dangerous. It's like putting your fuel tank out there in front. It's crazy. Accident = BOOM! and fire.

If it were a good idea, the car manufactures would do it. It is not a good idea. You all are taking chances and justifying it to yourselves that it's OK. Again, it's NOT!!

So you think the car manufactures are protecting the producers of R-134? Think again. If it were cheaper and safe, they would do it. No company cares about anything but the bottom line.

83Patrol
20th July 2010, 09:24 PM
I agree. Just like if biodiesel or WVO really were good ideas, manufacturers would ship cars with 2 tanks, pollack valves and a 30 plate HE.

Tony From West Oz
20th July 2010, 10:16 PM
You guys are absolutely crazy!!
I can't believe that some company rep is selling you all on it too.

I would never run a flammable gas in an automotive a/c system.

If the system were in the middle of a car somewhere and protected like a gas tank or LPG powered vehicle is, then I would do it. But it's NOT! It's out there pretty much in front of everything and will take the impact first. The fronts of cars are where the majority of damage occurs even in a minor accident. I don't care what anyone says. This is dangerous. It's like putting your fuel tank out there in front. It's crazy. Accident = BOOM! and fire.

If it were a good idea, the car manufactures would do it. It is not a good idea. You all are taking chances and justifying it to yourselves that it's OK. Again, it's NOT!!

So you think the car manufactures are protecting the producers of R-134? Think again. If it were cheaper and safe, they would do it. No company cares about anything but the bottom line.
The only reason the car makers are using R134 is that it was legislated that R12 was not permitted, yet you can still buy it in USA, and recharge your system with it. We can't in Australia. R134 does not cut it with older systems designed for R12.
Yet you drive around in a vehicle with many hundreds of times the explosive power (of the 200-400g of propane in the air conditioner), in the petrol in your carburetor or fuel injection system.
And these cars NEVER catch fire in a vehicle crash do they?

Have fun,

Tony

69roadster
21st July 2010, 06:59 AM
Yet you drive around in a vehicle with many hundreds of times the explosive power (of the 200-400g of propane in the air conditioner), in the petrol in your carburetor or fuel injection system.
And these cars NEVER catch fire in a vehicle crash do they?


Sometimes they do, but most often not. Why? Because, the fuel injection system or carburetor is protected by that big hunk of metal called the ENGINE.

What protects the A/C condenser? A plastic grill.

Keep on fooling yourselves with these justifications and analogies.

Matt
21st July 2010, 07:39 AM
A tet was done with a leak in the car and real people in it, they had singed eyebrows, there simply is not enough in there to really cause to big an issue, especially when it vents to the outside. BTW R12 and R134 will both burn, except they give off toxic compunds, give me R600 anyday ie Greenfreeze.

69roadster
21st July 2010, 08:03 AM
A tet was done with a leak in the car and real people in it, they had singed eyebrows, there simply is not enough in there to really cause to big an issue, especially when it vents to the outside. BTW R12 and R134 will both burn, except they give off toxic compunds, give me R600 anyday ie Greenfreeze.

That's not what I am talking about.

What I am talking about is front-end collision and fire likelihood (big issue). Propane is highly flammable and just because it's in a small quantity doesn't mean it's not likely to ignite in an explosive nature in a front-end collision. It's highly likely to ignite due to the unprotected A/C condenser right there in front.

Just give this logical thought everyone. Why would anyone want to take this risk?

Captaincademan
21st July 2010, 09:24 AM
Playing devils advocate here, given the small volume, the fact that the pipes are aluminium and not liable to spark when broken, or get very hot due to aluminium's exceptional performance as a heat conducter, I reckon you would have to try pretty hard to get a burn. personally the only way I can see a burn happening, is to have the venting gas discharge directly onto a naked flame or a very hot spark. even if the conditions were perfectly organised, i think you would get a flame at the break, and that would only last a few seconds at the most as the gas would vent pretty quickly.

I also think you can rule out ignition through impact pressure, as there would be so many ways for the pressure of impact of a collision to dissipate that I dont think pressure induced ignition would occur.

I think the biggest danger would be gassing yourself through a leak in the evaporator under your dash, but this would be true regardless of the type of refridgerant.

As far as lpg systems being protected by the engine, this is not always the case as the lpg pump that regulates the pressure to the manifold is usually bolted to the wheel arch or similar in a convenient location as it needs to be connected to the coolant system to stop it from freezing.

It is so very rare for cars to catch fire when you compare it to the accident rate.

The good thing is if you do get a leak and are running it on propane / lpg whatever, everyone knows what the smell is and would recognise it immediately. It sets of this little DANGER bell in everyones mind, and anyone with half a brain will bug out.:eek:

Having said all that, the cost of having your gas system recharged is not that prohibitive when you compare it to say a set of tyres, and I will probably continue to use the proper refridgerant should my bloody expensive aircon system require regassing in the near future... :D:D

johnnyhc
21st July 2010, 06:23 PM
I would never run a flammable gas in an automotive a/c system.


We'll you're plum out of luck then, 69roadster, because the whole world is soon going crazy (by your definition). If you read the air con press you would know that DuPont et al, the people that currently make and supply R134a will cease production of it over the coming years due to the environmental harm it is understood to cause.

And guess what they are replacing it with??? Drumroll please... HFO1234yf - a FLAMMABLE refrigerant gas that is highly toxic when combusted.

Uh oh... are you ready to sweat in your next air-conditionerless new car, 69roadster?

Excuse me for having a little fun with you just then, but seriously now, although you are entitled to believe whatever you like your beliefs on the blanket non-feasibility of flammable refrigerants are just plain ridiculous and obviously founded on a complete misunderstanding of the real behaviour and risks of this class of fluid and a complete denial of 20 years of commercial use in the aftermarket with not a single cabin fire EVER.



If it were a good idea, the car manufactures would do it. It is not a good idea. You all are taking chances and justifying it to yourselves that it's OK. Again, it's NOT!!


Unfortunately it's not that simple, sir. If you've ever tried to break a new technology into a market that, up to that point, had been totally monopolised for over 50 years by a cartel of extremely cash-rich multinationals, you'd know that your notion that a superior technology should just get accepted purely on it's merits is uber-idealistic non-sense. Add into that mix a massive black, grey and white propaganda campaign full of "bomb" scare tactics and other specious arguments, and the innovator finds himself facing battle on a very steep and uneven field.



So you think the car manufactures are protecting the producers of R-134? Think again. If it were cheaper and safe, they would do it. No company cares about anything but the bottom line.

I suggest you think more deeply. Do you know how much car manufacturers pay for R134a? Do you for one minute think it is the same price as it costs in the service market?

Secondly, there are a number of car manufacturers that are ready to go with vehicles running flammable HFO1234yf.

Thirdly, there is at least one vehicle manufacturer who is using hydrocarbons at point of manufacture. I'm not at liberty to divulge their name at this time, but the details are expected to be released in the next 4-8 weeks. They are not a major manufacturer though. It's a specialist vehicle manufacturer.
...I'll await your reply something along the lines of "oh, but it's not a major manufacturer so it doesn't count"...

Finally, you have a golden opportunity right here to prove your point once and for all in a manner that I can never compete with - it's on the public record that hydrocarbons have been around in the auto aftermarket for over 20 years. It's also in peer-reviewed publications that in excess of 20 million car-user-years of hydrocarbon use has gone by up to 2004 (much more since then). All you have to do is show this forum the string of cabin fires (or whatever you think is the massive danger) that have occurred since then and you have won and I am silenced once and for all.

So, you gonna step up or just keep swinging your emotion-charged non-theories?

It takes all kinds to make a world, of that there is no doubt.

69roadster
22nd July 2010, 05:10 AM
We'll you're plum out of luck then, 69roadster, because the whole world is soon going crazy (by your definition).


You are misguided. If you think the info in your post justifies the use of Propane in an auto A/C system you are mistaken.

H1234yf has not been totally approved yet and there are many hurdles for it go through as far a additional safety measures in the design of the a/c system itself to accommodate the fact that is acknowledged that it is what they call "minimally flammable". I'm talking EPA here. They are the ones ultimately control things. Plus, there are some states in the US that have their own laws that completely prohibit the use of any flammable refrigerant in an automobile. EPA will have to convince those states that H1234yf can be used safely before those states will change their laws.
We'll see.

What is being talked about in this thread is the usage of propane (that is HIGHLY flammable) in an existing a/c system with no additional safety features. This is way, different.

Also, btw, R134 will be manufactured for a long time to come for servicing existing systems as there will be no conversion process from R134 to H1234yf like there is for R12 to R134. There has been no date even talked about from EPA for R134a as far as the cease of production.

Edit:
I didn't mean to come of as an arrogant American by saying that EPA controls things. It's just that we buy so many cars of all makes here. And certainly all manufacturers have to take that into account if they want to ship here. And, I believe most do.

Captaincademan
22nd July 2010, 09:27 AM
I think you will find the biggest controlling body is not the EPA, not the Government or even automobile unions, but in this particular field it will the largest refridgerant manufacturer - Dupont. it will all come down to which patent they secure next. I firmly beleive the gas the automotive industry adopts will completely depend on dupont's choice of gas system, and any arguements (environmental, safety, toxicity etc just like the old CFC debate) for removal of the old will probably be suited to the selection of the new gas system (if it occurs at all).

johnnyhc
25th July 2010, 03:16 PM
69roadster,

Since first commercial use as a drop-in replacement for R134a and R12 around 20 years ago, hydrocarbons (the best performance coming from a mix of propane and butane) there have been many theoretical assessments of risk of applying hydrocarbons to motor vehicle air conditioning, both in systems designed for HC's and as a replacement for R12 and R134a.

Your comments and assertions about the flammability are on the same basis as these risk assessments - they are theoretical in nature.

Not surprisingly, the various risk assessments came to very different conclusions, with an almost perfect correlation between the conclusion of the risk assessment and the source of it's funding. One has to wonder why DuPont et al would even fund a risk assessment on a competitors product to begin with.

However, over those 20 years HC's have been used in motor vehicle AC on a scale that is highly significant and to prove with finality whether the product is fit for purpose. The most current (as of 2004) peer reviewed data quantifies that approximately 20 MILLION car-user-years of use of HC's in auto AC had been accumulated up to that point.

As for our company, HyChill hydrocarbon refrigerants are running as I write this in 10% - 15% of ALL cars on the road in Australia.

I think I made a mistake in my last post of making too many points, so here's the million dollar question all on it's own:

Where is the trail of exploded vehicle cabins, injuries and/or dead bodies?

If your theorizing is accurate, it must be evident by now in actual road statistics.

Or is 20+ million car-user-years and 20 years of commercial use not enough for you? Or are HyChill and other HC manufacturers receivers of some supernatural protection from On High for all this time? Or do you still think we need more time? 50 years, 100 perhaps?

John W Clark
Technical Advisor
HyChill

69roadster
27th July 2010, 05:55 AM
If your theorizing is accurate, it must be evident by now in actual road statistics.


You are right. That is the question. You posted it but didn't provide any answers.
Please provide study results and the details of those studies. Just because you say there are a lot of cars running around out there with it means nothing.

I see. You work for a company that manufactures this stuff. Of course you will defend it and always make it appear that you have won the debate. But, you haven't posted anything in your posts that's any less than a theory than I have.

It's just common sense. Putting a flammable gas in an automotive a/c system where the condenser of that system is at the very front of an automobile, in a very vulnerable place in an impact, is not a good idea.
You can twist this any way you want (and you have done a good job of that) and it doesn't change that fact (sorry, theory).

Captain Echidna
28th July 2010, 04:11 PM
What are the statistics on car fires caused by flamable refrigerants?
If there are statistics, 69 Roadster, you should be able to provide them that demonstrate cars with flamable refrigerants are a higher risk. If you cant because there are no statistics, its because there is no noteworthy risk.
Knowing the dificulty of getting gas to ignite. (having a few LPG powered cars in my life) getting the stuff to ignite on a regular basis can be difficult, even with a spark plug and high voltage coils.
To get the gas to leak (easy), in the right ratio to ignite (it has about a 4% range of air:gas ratio to be flamable, very hard), followed by a spark at the right time.... If you can find ONE instance of a fire starting from refrigerant I would be surprised. I think the only time it would catch fire is if a fire is already established.

Matt
29th July 2010, 08:54 PM
In terms of flamability R134 burns too just at a higher temp and the byproduct is very nasty, I would prefer propane any day. I fully agree with the issue regarding big business, they have far too much sway and any system will be designed around the one they want, since they have the patent and the science and the money to put into it why shouldn't it? Well R12, R134 are very good reasons, one not as bad as the other to not belive any big company.

Just like biodiesel and the specifications here in Oz, the bar is set higher than that of the mineral fuel. Its all lopsided and truth suffers always.

I have not heard of issues with car fires and statistics lie just as well as any spin doctor makes them.

It is outside the cabin too so risk of frontal accident far outways the risk of 250 grams of gas.

I appreciate your position, I just believe that some big organisations cannot be trusted, sure there is risk, manage it and live with it, you do every day getting out of bed.

You are misguided. If you think the info in your post justifies the use of Propane in an auto A/C system you are mistaken.

H1234yf has not been totally approved yet and there are many hurdles for it go through as far a additional safety measures in the design of the a/c system itself to accommodate the fact that is acknowledged that it is what they call "minimally flammable". I'm talking EPA here. They are the ones ultimately control things. Plus, there are some states in the US that have their own laws that completely prohibit the use of any flammable refrigerant in an automobile. EPA will have to convince those states that H1234yf can be used safely before those states will change their laws.
We'll see.

What is being talked about in this thread is the usage of propane (that is HIGHLY flammable) in an existing a/c system with no additional safety features. This is way, different.

Also, btw, R134 will be manufactured for a long time to come for servicing existing systems as there will be no conversion process from R134 to H1234yf like there is for R12 to R134. There has been no date even talked about from EPA for R134a as far as the cease of production.

Edit:
I didn't mean to come of as an arrogant American by saying that EPA controls things. It's just that we buy so many cars of all makes here. And certainly all manufacturers have to take that into account if they want to ship here. And, I believe most do.

johnnyhc
30th July 2010, 04:33 PM
You are right. That is the question. You posted it but didn't provide any answers.
Please provide study results and the details of those studies. Just because you say there are a lot of cars running around out there with it means nothing.
.

Unless I have mistaken your challenge to me, you are asking me to provide studies showing that something (in this case, HC incidents) doesn't exist.

Such a request is a logical nonsense. No one can conclusively prove that something DOESNT exist. Please think your request through and reconsider.

On the contrary, the burden of proof with such questions must always run the other way - those that contend there is a safety defect trend must demonstrate that trend.

By all means have another go at suggesting by what means I should be required to prove the product is safe. I'm all ears.

The fluorocarbon industry keeps an eagle eye out for each and every hydrocarbon related incident. Every single incident even remotely related to hydrocarbons have been printed up in fluorocarbon industry propaganda outlets, without exception, across the entire history of debate. They even went nuts about one incident in New Zealand until the authorities announced it was an R134a fire.

For what it's worth, please consider this advice: Most assertions made by everyone carry some degree of vested interest or inherent bias. The way you carry on about my (clearly declared) vested interest and your implication that everything I say should be discounted would require that you must discount basically everything that is said and discussed on a daily basis (if you're going to be consistent). On the contrary, one of the best ways to separate truth from error is to seek information from both sides of the fence and identify what statements are commonly agreed upon, either implicitly or explicitly. That common ground has a much higher likelihood of being accurate. In this particular case you will find that both sides agree (my side explicitly, their side implicitly) that there are only a handful of HC-related incidents over 20 years, and the incident reports for those incidents make it quite clear that gross negligence is to blame rather than the product being unfit for purpose. This is a reasonably reliable process for truth discovery and the conclusions should be obvious.

I don't have any problem at all listing here on this forum every single HC-related incident that we are aware of. It is a very short list. Just say the word and I'll do it.

But I suspect that won't be enough for you because you will naturally reject my list out-of-hand because I have a vested interest. If that's the case, just say the word and I'll send you the contact details of any of a number of fluorocarbon propaganda organisations and you can ask them. Be my guest. They'll give you the same list complete with a whole lot of spin to misdirect that facts of each case. But most of the spin is pretty easy to see through. But wait a minute - you'll have to reject everything they say too, otherwise you'll be guilty of inconsistency, won't you?

Your final comment amounts to a suggestion that the 'precautionary principal' should be applied in this case. That line may have worked back in the early days before use was widespread and there was no real-world safety history to refer to. But those days are long gone. Any reasonable person should be willing to accept that 20 years of usage is a long enough period to reveal trends.

At root, your conclusion (in my analysis) is based upon on an incomplete and inexperienced understanding of the product compounded by an insufficiently detailed analysis of risks. You fail to even recognise that there are considerably more hazardous fluids located in prominent locations in the front half of the engine bay, instead you talk like having a flammable substance in the engine bay like it is something new to motor cars. That's all OK though. You're entitled to your opinion. It's your jumping on this forum and throwing around black-and-white simplistic analysis that I take issue with.

Of course I have a vested interest in the argument. However, the record shows I've fully identified myself and thereby declared my interest from the beginning. By the substance of your posts it seems plausible that you have more than just a passing awareness of AC systems and the AC industry, and yet you haven't even provided one jot of identifying information. Some readers of this thread might legitimately wonder what your connections to this subject are.

With respect, produce the evidence supporting your theories. If you still insist there is some way (other than proving the non-existence of something) that I can assist with demonstrating this then spell it out to me.

John Clark
Technical Advisor
HyChill

smithw
31st July 2010, 09:37 AM
I have worked at a number of repair shops, and car fires are very rare, But I would say the number one non dileabrate cause would be parking in dry grass, the catalytic converter is very hot and can set stuff on fire very quickly, wiring faults and lose battery would be next, kids sticking coins or foil in the cigarette lighter, Plastic air filter also go up in older cars it they not fitted correctly or the car backfires, which can happen on lpg cars. I have also seen fuel lines drop off or leak, and a bic lighter which found its way into the heater core. the owner said it was like a shot gun going off but it didn't ignite. It maybe possible for the air con pump to run out of oil and get very hot and leak (which Ive seen) and maybe ignite the lpg, but its pretty unlikely and it such small amount of gas anyway. I would be more worried about the misses pulling of to the side of the road and parking in the grass to answer her phone, or the can of lawn mower petrol in the boot.

69roadster
10th August 2010, 04:03 AM
Unless I have mistaken your challenge to me, you are asking me to provide studies showing that something (in this case, HC incidents) doesn't exist.

Well, that was pretty much the response from you I was expecting. Twisting and more twisting. Of course they don't exist, that was my point. Without statistics, you pretty much have to rely on common sense which you are not doing.

The point you have failed to acknowledge is the proximity of the flammable gas in an automotive A/C system. Of course there are other flammable gases and liquids in the engine compartment. However, they are near the middle of the engine. This is way different that putting it up front in the vulnerable area where the condenser is.

Qwarla
10th August 2010, 07:43 PM
Roadster it amazes me the way you are intent on flogging a dead horse.

You need to go find some facts first and stop basing your argument on hysteria.

On an episode of Myth Busters they explored the scene from a James Bond movie where he shoots a gas cylinder, which explodes and takes out the bad guys and he escapes.

Well the fact is LPG/propane is not like that and no matter what weapon the used to shoot the cylinder all that happened was the cylinder was punctured and the gas escaped.


NO FIRE!!!!!, NO EXPLOSION!!!!!!!

And exactly the same thing will happen to my condensor if I had a head on. :D

69roadster
11th August 2010, 11:40 AM
Directly from EPA:

"It is illegal to use hydrocarbon refrigerants like HC-12a and DURACOOL 12a as substitutes for CFC-12 in automobile or truck air conditioning under any circumstances. How did EPA make this determination? The Clean Air Act, as amended in 1990, (http://www.epa.gov/air/caa/) required EPA to establish a program to review substitutes for ozone-depleting substances, including refrigerants. EPA's Significant New Alternatives Policy (SNAP) program carries out this mandate. Manufacturers of substitutes must submit information to EPA about the products, including ozone depletion potential, global warming potential, and toxicity and flammability data. EPA then compares these characteristics to both the refrigerant being replaced and the other available substitutes. Flammable refrigerants pose a special challenge, because air conditioning and refrigeration systems in the US have been designed to use nonflammable refrigerants. They are not designed to protect users, service technicians, and disposal personnel from the possibility of fire. Therefore, the use of flammable refrigerants in existing systems may pose a risk not found with nonflammable fluids. Although new systems may be designed to provide that protection, they are not specifically designed so today. Demonstrating that a flammable refrigerant can be used safely in current systems, whether existing or new, requires a comprehensive, detailed, scientifically valid risk assessment. EPA has required a risk assessment for flammable refrigerants since the inception of the SNAP program in 1994. An assessment must address potential leak scenarios such as collisions, servicing errors, and disposal procedures. In addition, it must consider ignition sources ranging from cigarette lighters or matches to sparks caused during a collision.
OZ Technology has submitted reports that it states demonstrate the safety of using OZ-12 and HC-12a in systems not designed to use such flammable refrigerants. However, after careful review of each document, EPA determined that none of the reports represented valid a risk assessment. Until such assessments are performed, EPA believes that flammable refrigerants like HC-12a, OZ-12 and DURACOOL 12a may pose potential risks not present when using nonflammable refrigerants. For these reasons, EPA does not allow the use of HC-12a, OZ-12 or DURACOOL 12a as substitutes for CFC-12 outside of industrial process refrigeration."

Oh, you better see this too:
YouTube - &#x202a;A video of a hydrocarbon refrigerant demonstration which wen&#x202c;&lrm; (http://www.youtube.com/watch?v=DjtowzVzl_4)

Tony From West Oz
13th August 2010, 01:47 AM
I disagree that mixing propane and air inside a confined space, and when it is greater concentration than the LEL and less than the UEL, igniting it is a valid test to simulate a leak from an air conditioning evaporator.

Even more stupid to ignite it with a match while in that gas combination. What would have happened if he was inhaling at the moment of ignition - yup, burned lungs. This is not good science and could have caused the death of the "Volunteer"

To my knowledge, the only propane explosions in vehicles that have occurred in Australia in the last 20 years were due to propane cylinders being transported in the vehicle where they had faulty valves, leaking gas into the cabin. These explosions occurred when the drivers door was opened.

All vehicles which are manufactured or imported into Australia must have "flow through ventilation" which, if the vehicle was moving, would dilute any leaking refrigerant gas with excess air, preventing the concentration reaching the LEL. If the air conditioner was running, the evaporator is under little or no pressure, which would limit gas leakage under those circumstances.
I believe that if the leak occurred while the vehicle was not running and unattended, the only time that an explosion might occur would be when the door was opened, and the switch was exposed to an explosive gas mixture. The person opening the door may have limited flash burns, but would be more likely to injure themselves in recoiling from the explosion.

While the information you have supplied may be law in Your country, please do not try to impose your laws on the rest of the world. Apart from that, many people in your country are promoting the use of propane based refrigerants in vehicles.

Regards,
Tony

johnnyhc
13th August 2010, 04:23 PM
I've been asking nicely, but I think it's time to get more forceful.

It's time to come clean, 69roadster.

I'm asking you to come clean for two reasons now. My original reason was that I was suspicious at the depth and breadth of the typical alarmist straw-man arguments that you were throwing around... they sounded all too familiar to the f-gas lobbyists I've continually butted heads with over this past decade. The more you talk the more likely it seems. Either that or you're just some arm-chair amateur, armed with google and cut-n-paste skills, with too much time on your hands.

Now I have a second reason - your continual avoidance of my request to back up your theories with real-life examples (let alone trends) supporting your claim might reasonably be leading other readers of this thread to suspect that I might have planted YOU here to make an ass out of yourself, thereby creating a positive impression for hydrocarbons.

So fess up, dude. Who are you? Have you ever worked for a fluorocarbon manufacturer or any organisation funded by them? Have you ever worked for any refrigeration or air conditioning industry body?

Put a name to your claims or risk alienating yourself even further from your readers.

As regards this gem from you:


Oh, you better see this too:
YouTube - &#x202a;A video of a hydrocarbon refrigerant demonstration which wen&#x202c;&lrm; (http://www.youtube.com/watch?v=DjtowzVzl_4)

69roadster, how about enlightening us with a detailed description of:
(a) The precise circumstances of this experiment
(b) The clearly stated aims of the experiment
(c) The relationship of this experiment to any real-world scenario
(d) The results and conclusions of the experiment.
Go on, enlighten us, and dig yourself in a deeper hole in the process. I'm waiting with baited breath....

For the sake of providing confidence to the readers of this forum, I will try to take time here and there to address the other matters raised by 69roadster in his previous posts, but I have real work to do at my day job and so as much as I'd like to rebut all of 69roadsters nonsense in as complete a manner as possible, my time has to be shared with other tasks.

Regards,

John W Clark
Technical Advisor
HyChill Australia Pty. Ltd.
85a Canterbury Rd, Kilsyth, Victoria, Australia
Freecall (aus): 1300 492 445 Ph: +61 3 97285055 Fax: +61 3 97618799
HyChill Refrigerants - Manufacturers of Hydrocarbon Refrigeration Gases, HC's, HR12, ER12 - CFCs, HFCs, HCFCs, hydroflurocarbons, R12, R22/502, R290, R600a, and R134a Replacements (http://www.hychill.com.au)

johnnyhc
13th August 2010, 05:38 PM
69roadster, some of the stuff you come out with really makes me wonder... As I've already stated, sometimes some of the stuff you say makes me think your an f-gas industry shill. But other times you say stuff that not even they would. Like these:


Well, that was pretty much the response from you I was expecting. Twisting and more twisting. Of course they don't exist, that was my point. Without statistics, you pretty much have to rely on common sense which you are not doing.


Who's avoiding what? If you insist that I must show you that something doesn't exist, at least have the common courtesy to show me how I might go about proving that (and rewrite the rules of proof logic at the same time).

20 years of widespread HC use as a direct drop-in replacement for R12 and R134a with ZERO cabin fires IS a statistic. Just because the statistic has a value of ZERO doesn't mean it is does not convey statistical information. This is high-school level mathematics.

All you need to do is show me a trend of real-world cabin fires and you have me on a skewer. But you can't even show me one!

Then this one:



The point you have failed to acknowledge is the proximity of the flammable gas in an automotive A/C system. Of course there are other flammable gases and liquids in the engine compartment. However, they are near the middle of the engine. This is way different that putting it up front in the vulnerable area where the condenser is.

Your understanding of how this kind of flammable material burns and it's relationships to other risks in an engine bay is clearly lacking.

There are many ways to approach this matter. All of them will go a long way to exposing the lack of expertise that you clearly possess in assessing such failure modes, thereby reconciling your false assertion with reality. But none of them will convince you, I can be sure of that. Nevertheless, for the sake of the other forum readers, here goes some of the approaches:

1. Once again, look at the historical record. Has any fire authority in any jurisdiction in any country where HC's are used in significant quantities in MACS (that is, USA, Australia, North Africa, Asia) ever published any findings identifying a significant trend of "explosion-like" (as I believe 69roadster put it) incidents and the use of HC's in MACS? Answer: None.

2. Alternatively, consider more flammable substances in an engine bay and collisions which result in releases of those substances. Specifically, try regular petrol/gasoline and a side-on collision. Petrol/gasoline is a Class 3 flammable hazard, and hydrocarbon refrigerants are the (lower risk) Class 2. Many kinds of collisions can cause leaks of pressurised fuel lines. Petrol/gasoline being more likely to catch fire and having similar flame characteristics (except Petrol burns for a very long time, whereas HC's flash and extinguish in under approx 1 second, part of the reason why they are a lower hazard class). No doubt some fires do occur here. They are a small percentage of all collisions and not regarded by any road safety authority as an unmanageable issue.

3. Take a look at the situation through the eyes of someone who actually knows what they are talking about when it comes to light hydrocarbon flammability. Consider 69roadsters frontal collision scenario again. If the RAC lines are punctured and HC is inside, you will get a hissing release of gas and lubricant into the open air (and possibly onto hot surfaces). As real scientists (and even mythbusters!) will all agree, the act of puncturing the RAC system does NOT cause ignition (because there is no spark at the right time and not the right fuel/air mixture and not the right gas velocities). OK, so what about the release to open air... Well, lets imagine that some dastardly spark is lurking due to a loosened battery terminal or metal fanblade still spinning. Under that scenario there is some chance of ignition of the HC, but also the petrol (if fuel lines were involved in the accident). But for the HC to ignite, the spark must occur in precisely the right instant, in presence of precisely the right air/HC mixture, with the gas velocities within a specified limited range and with outside air currents quite still (not very likely in a collision scenario) to permit the HC to pool as a cloud and not be disbursed, and not too soon after the collision or gravity will disperse the HC below a flammable mixture. So, what about hot surfaces? Well, actually the lubricant (whether it is R134a or HC in the system) has a lower auto-ignition temperature than the HC refrigerant, so the oil vapour will likely ignite first, if at all. And it is the oil-vapour that will sustain a fire and cause continuing risk to (potentially unconscious) occupants.

So, in short, in the worst case an HC expert could not reasonably conclude anything more than a marginally higher risk of fire in a frontal collision for all the reasons mentioned above. If the fire was to occur, the HC's would be consumed in under 1 second and self extinguish in a NON-explosive "flash fire". If R134a were leaking out in the same scenario and there was a lubricant or fuel fire, then toxicity issues exist which do not when using HC's. The toxicity risk is even greater with HFO1234yf.

4. Don't believe me? Well, try GM. 69roadsters advice about HFO1234yf is old news. GM has already announced it will be using HFO1234yf in vehicles from 2013. See here:

General Motors to use new car refrigerant from 2013 | News | Refrigeration and Air Conditioning (http://www.racplus.com/news/refrigeration/general-motors-to-use-new-car-refrigerant-from-2013/8603813.article)

These HFO1234yf cars will have condensers at the front of the engine bay just like any other car. That's right, a flammable (and highly toxic when combusted) refrigerant in the condenser.

So, there you have 4 different ways to look at it, 69roadster. No doubt you'll find all of them utterly flawed and meaningless.

To other forum readers: 69roadster has also mentioned the EPA various US laws etc. I hope to go into more detail later, but here's some thinking points for the readers on that subject:

Firstly, the EPA laws make fitting of HC's to R-12 based systems illegal, but it has no jurisdiction over fitting HC's to R134a systems and the latter is, in fact, legal under the EPA's laws. Why is this the case? Well, the f-gas lobbyists weren't at all happy with National Highway Traffic Safety Administration (NHTSA) ruling that found there was "no safety defect trend" using HC's in US car AC systems, and so failed to lobby the NHTSA to erect bans on HC's. Fearing that they'd actually have to compete with HC's in an open market, they scurried for other regulatory means to erect trade barriers to competition from HC's. They found they had influence at the US EPA and in some state legislatures. After the usual rounds of lobbying, fear mongering and "exploding car" video stunts, they secured bans against HC's in some US states and they got the EPA to use the regulatory power Congress gave it FOR THE PURPOSE OF MINIMISING RELEASE OF OZONE DEPLETING GASES (such as R-12) as a device to erect a trade barrier to the use of HC's. Because Congress didn't intend for the EPA to be a safety regulator (that was, and still is, the NHTSA's job), it only empowered the EPA to act on matters relating to R-12. So the EPA is powerless against retrofitting HC's to R134a systems (other than to spit fire and venom at anyone trying to do it). So the truth is, for the USA, that:
- Fitting HC's to R134a systems is legal, except for states where the f-gas lobby secured outright bans
- Fitting HC's to R12 systems that have first been legally retrofitted to R134a is also legal, except for states where the f-gas lobby secured outright bans.

Secondly, according to real-world MAC system sampling and analysis by the organisation MACS Worldwide (which, I might add, is staffed by people with ties to the f-gas industry and therefore is officially and strongly opposed to HC's), they found that (as at 2004) approximately 4 million vehicles contained HC's in their MACS and were silly enough to publish that fact. Secondly, again remember that the NHTSA has publicly denied any safety defect trend with HC's in MACS and has never recanted their view, nor issued a recall nor published any evidence suggesting they were wrong in their original view. In all matters of road safety it is the NHTSA which is finally and ultimately responsible. The EPA doesn't even have powers to issue recalls on road transport matters as far as I'm aware. In short, the EPA commandeered the matter of HC's at the f-gas industry's behest, to distort the purpose of the powers given to it by Congress and to act outside it's own mandate (who decided the EPA should now become a safety regulator?).

Lastly, I am advised that (just like here in Australia), the USA has consumer protection laws which, if there really was a safety defect trend with HC's in MACS, could be employed to sue-into-oblivion and shut down HC's suppliers supplying their refrigerants into the MACS market if they actually had a provable case. All they would need would be a trend of cabin fires or an extraordinary trend in engine bay fires. But in 20 years that has never occurred, and so neither have the lawsuits.

OK... that took much longer than I had budgeted for. I'll leave further responses until later.

Regards,

John W Clark
Technical Advisor
HyChill Australia

PeterAC
14th August 2010, 04:13 PM
Hello,

Sorry I have not replied earlier to the use of HR12 in my merc but there is another problem with the system not related to the gas. Hence, I have not replied as I won't till the system is up and running to properly comment regarding the merc.

I do have a new tech question for John as everything else has been well answered to my satisfaction regarding explosive/fire risk. I was speaking to a auto air compressor repair technician regarding use of HR12/Minus 30. He said the usual scare info but also mentioned that HR12 does not circulate the lubricant well as the pressure in the system is a third of that used with 134a??? I look forward to your reply.

Please not that I do not believe everything that I hear i.e. biodiesel/veg oil and its effects on cars from engine destruction to flat tyres. What this forum does is debate and help others through sharing practical experiences and available knowledge.

Regards

Peter<><

Qwarla
14th August 2010, 05:56 PM
PeterAC, one thing to remember is that the high pressure in the system is only from the compressor to the expansion valve. After that it is low pressure.
In this high pressure section you have, firstly high pressure gas, then it is condensed to a high pressure liquid.

No matter what gas is in the system the compressor will pump the same volume.

When you have a gas at much higher pressure the flow rate of that gas will be slower as the gas is compressed to a much higher density.

Therfore with HC being at a lower pressure in the high pressure side the gas is not compressed to the same degree and will actually be flowing faster.

Also the fact that HC has been used for over 20 years should show that lubrication is not an issue, and remember the compressor is not working as hard as it would with R134A

PeterAC
14th August 2010, 10:35 PM
Thanks Qwarla.

Can the system be over pressurised with HR12 to where it can be damaged. Or, how easy is it for someone to overpressurise the system with HR12?

Peter<><

Qwarla
15th August 2010, 11:45 PM
Thanks Qwarla.

Can the system be over pressurised with HR12 to where it can be damaged. Or, how easy is it for someone to overpressurise the system with HR12?

Peter<><

I'm wondering if you mean, "over charge the system".

The pressure in the system will only be high enough to make the gas condense to liquid form. The actual pressure is dependent on, the pressure and the temperature of the gas.

Over charging is another matter. That happens when too much gas is put into the system. If you are charging the system and not sure what you are doing you can over charge the system.

PeterAC
16th August 2010, 08:05 AM
Yes, 'over charge' is what I meant.

Peter<><

johnnyhc
9th September 2010, 10:08 PM
Hello,

Sorry I have not replied earlier to the use of HR12 in my merc but there is another problem with the system not related to the gas. Hence, I have not replied as I won't till the system is up and running to properly comment regarding the merc.

I do have a new tech question for John as everything else has been well answered to my satisfaction regarding explosive/fire risk. I was speaking to a auto air compressor repair technician regarding use of HR12/Minus 30. He said the usual scare info but also mentioned that HR12 does not circulate the lubricant well as the pressure in the system is a third of that used with 134a??? I look forward to your reply.

Please not that I do not believe everything that I hear i.e. biodiesel/veg oil and its effects on cars from engine destruction to flat tyres. What this forum does is debate and help others through sharing practical experiences and available knowledge.

Regards

Peter


Peter,

Sorry for the delay in replying to you. Since you posted I've been regularly trying to post a reply, but there is some bug with this site - I'd get a blank screen after hitting the 'publish' button and nothing would get posted. I'm working with the webmaster to try and sort it out.

Qwarla has given you a good 'leg up' already. Here's the full details:

1. Regarding lubricant.

Lubricant miscibility (affinity for mixing with the refrigerant) and velocities of the the refrigerant vapour (to "sweep" oil around parts of the circuit) are the main issues that effect the supply of lubricant to/from the compressor. These are complex topics that I don't have the time or space to elaborate on here, so I will take the easier "by example" path and repeat what Qwarla said - we haven't had any issues by way of tech support calls or warranty claims related to compressor failures due to lack of lubrication. In short, this claim by the workshop guy is incorrect. He very likely is just repeating misinformation that someone else told him or he read it in some VASA blurb.

In fact, it's one of the standard mis-information lines that is promoted by VASA and other f-gas propaganda arms. I've been hearing it for more than a decade.


2. Regarding pressures.

Your workshop guy is just plain wrong on this point.

A properly charged R134a or R12 system will generate somewhat lower pressures on the high side (condenser side) of the system. I don't have the numbers in front of me, but they are no where near 1/3 lower. I can give you some comparative figures if you need - just let me know.

Perhaps in his ignorance he was confusing pressures with charge quantity. The charge weight of Minus 30 is around 1/3 the charge weight of R134a. This corresponds to an approximately equal charge quantity by VOLUME, but because Minus 30 is much less dense than R134a the charge WEIGHTS are so different.

3. Regarding "Can the system be over-pressurised/over charged"

The most complete answer is "only in the same way you can overpressurise/overcharge the same system with R12/R134a. That is, by putting too much in."

Naturally, it's best to have existing skills in servicing AC systems, but by the same token it isn't rocket science. The key thing to remember with Minus 30 is that the total charge, by weight, is around 1/3 of the weight of the R134a/R12 charge.

Finally, I'll close by saying the combination of:

Lower high side pressures
Improved performance/efficiency
Easier compression
Lower corrosiveness

...results in lower strain and wear on the compressor per unit of cooling output (compared to R134a/R12) will result, which will result in longer system life.

For what it's worth, one of the only remaining compressor rebuilders in Australia, C.A.R. (Compressors Automotive Remanufactured) offers DOUBLE the regular warranty on compressors that will be used ONLY with hydrocarbon refrigerant. They have no vested interest in hydrocarbons in any way. Hychill has no financial interest in them. C.A.R. simply recognises the improved lifespan of automotive AC compressors that results from using hydrocarbons instead of fluorocarbons and so is able to extend the warranty at no additional risk to their own bottom line.

Kind regards,

John W Clark
Technical Advisor
HyChill

PeterAC
10th September 2010, 02:40 PM
Thanks John

Peter<><

JanR
10th September 2010, 05:56 PM
I've had HyChill HR12 before in R12 equipped system, rather than converting to R134a. It runs better, cools better, corrodes less and is ECO-friendly.

mrphantuan
27th November 2010, 08:18 PM
mmm, interesting I found the MSDS and PDF files very good information. One last question - It was mentioned that the prcedure was for a R12 system only not R134a, is this true or is there enough eveidence to suggest its equally possible. The hychill site tends to suggest it will.

Thanks.
__________________
Biodiesel Bandit


Landcruiser 98 B100 (100,000km and still going)
Peugeot 306 xtdt B100
Peugeot 2004 2L 307 HDI Does not like B100

PeterAC
10th December 2010, 10:59 AM
My understanding is that it will work in both systems equally as well, I have it in my 2001 Landcruiser and there are no problems. It cools very well.

Peter<><