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Ext User(Ted)
14-12-2007, 05:03 PM
Someone told me it is possible to regas an aircon with propane from a bbq
bottle, is this correct? They said a lot of taxi drivers use this method all
the time because it's just as good if not better than the official aircon
gasses.
They said it's no more flammable or dangerous then the old type gasses?
I woulsd like to hear from any refrigeration guys here if this is possible,
how effective it is and how to dit, what pressures etc. Thanks.

Ext User(John_H)
14-12-2007, 05:23 PM
Ted wrote:
>
>Someone told me it is possible to regas an aircon with propane from a bbq
>bottle, is this correct? They said a lot of taxi drivers use this method all
>the time because it's just as good if not better than the official aircon
>gasses.
>They said it's no more flammable or dangerous then the old type gasses?
>I woulsd like to hear from any refrigeration guys here if this is possible,
>how effective it is and how to dit, what pressures etc. Thanks.

It works fine, especially in the old R12 systems.

Pressures are higher and so is the condenser temperature. You can
avoid these pitfalls by using the appropriate Hychill hydrocarbon
refrigerant (HR12) which is a mixture of propane and butane and hence
much closer to the same physical properties of the Dupont products
(including 134A). It's readily available (and completely legal) in
all states except Qld. There's also heaps of useful info on their
site.... http://www.hychill.com.au/

It would help considerably if you've got a good working knowledge of
automotive air conditioning service procedures.

--
John H

Ext User(Ted)
14-12-2007, 07:03 PM
> It works fine, especially in the old R12 systems.
>
> Pressures are higher and so is the condenser temperature. You can
> avoid these pitfalls by using the appropriate Hychill hydrocarbon
> refrigerant (HR12) which is a mixture of propane and butane and hence
> much closer to the same physical properties of the Dupont products
> (including 134A). It's readily available (and completely legal) in
> all states except Qld. There's also heaps of useful info on their
> site.... http://www.hychill.com.au/
>
> It would help considerably if you've got a good working knowledge of
> automotive air conditioning service procedures.
>
> --
> John H

Thanks John.
What pressure should I use for propane.
Do I need to vacuum the lines before using propane?

Ext User(John_H)
14-12-2007, 07:13 PM
Ted wrote:
>What pressure should I use for propane.

A small word of advice, which I hope you'll heed, is... _never_ to
charge an a/c system according to pressure readings. You'll need to
either weigh the charge or use a sight glass. The HyChill site has
the charge weights for HR12, which are near enough for propane.

The pressure readings are merely an indication that the system's
working properly. 250kPa low side, and 1500kPa high side, at 30
ambient, is about typical for straight R290 in a healthy system. A
crook Tx valve, or a worn compressor, will throw out the low side
pressure. The high side is highly dependant on condenser temperature
(and can rapidly reach dangerous levels on an accidental overcharge).

If you're using a sight glass... use extreme caution, and monitor the
high side pressure, when the sight glass is nearing clear.

The static charge (pre-charge) will be about 600kPa if the car (or
cylinder) has been left out in the sun. You'll still need to jump the
low side switch (if it's got one) following the pre-charge.

>Do I need to vacuum the lines before using propane?

If the system is still has gas, and doesn't pull into vacuum on the
low side, you can get by at a pinch by topping up (R290 is compatible
with all CFC's and HCFC's and the oils commonly used).

If the system is out of refrigerant, you'll need to repair the leak,
replace the receiver drier (or accumulator) and possibly the Tx valve
(or orifice tube -- depending on the make of car)... it's also good
practice to change the compressor oil (ROC is best). You should
evacuate the system to below the vapour pressure of water, and test
for leaks under vacuum. Some people simply flush with refrigerant but
doing so will get you into trouble sooner or later.

Depending on the make and model, and the previous refrigerant, you
might also need to use a different Tx valve (or orifice tube) and/or
high pressure cutout to get the system to work properly.

--
John H

Ext User(Noddy)
14-12-2007, 07:43 PM
"Ted" <Tedb@Bigpond.com.au> wrote in message
news:13m43hhm1fjlub1@corp.supernews.com...
> Someone told me it is possible to regas an aircon with propane from a bbq
> bottle, is this correct? They said a lot of taxi drivers use this method
> all the time because it's just as good if not better than the official
> aircon gasses.

It is and it works very well, but you'll get better results by using
"autogas" or lpg sold for vehicle fuel which already has Butane in the mix.

> They said it's no more flammable or dangerous then the old type gasses?

Not entirely, but it's not dangerous.

Bear in mind that your average car's air conditioner would hold anywhere
between 400-600g of lpg if you were to fill it from bone empty, and that is
a *very* small amount of gas to worry about in the event of a collision.
It's also a drop in the ocean compared to what any gas powered car holds in
it's tank when it's full, so if you were worried about half a kilogram of
lpg in your air conditioner a full lpg tank in the boot would make you shit
your pants on the spot.

Normal refrigerant isn't flammable, but when mixed with the oil in the
system it tends to be, and the difference between it and lpg would be next
to nothing on the "danger" scale.

> I woulsd like to hear from any refrigeration guys here if this is
> possible, how effective it is and how to dit, what pressures etc. Thanks.

How you go about it depends on where your air conditioner is currently at.

If it's completely empty as in having been pulled apart, then it'll need to
be vacuumed as per normal. You would then fill it with roughly half the
weight of what the manufacturer specifies for their refrigerant (be it R-12
or R134a) and then check the sight class or the air vent temp and small
amounts of lpg at a time until you reach the desired result.

I run lpg in both my car's air conditioning systems (one of which is r134a
while the other is R-12) and it provides excellent results. I've found that
lpg requires a tad more than half the weight normally recommended for both
r-12 and r134a in most a/c systems to work well, and much more than this
puts the pressures on the high side of being acceptable.

--
Regards,
Noddy.

Ext User(John_H)
14-12-2007, 07:43 PM
Noddy wrote:
>"Ted" <Tedb@Bigpond.com.au> wrote in message
>news:13m43hhm1fjlub1@corp.supernews.com...
>> Someone told me it is possible to regas an aircon with propane from a bbq
>> bottle, is this correct? They said a lot of taxi drivers use this method
>> all the time because it's just as good if not better than the official
>> aircon gasses.
>
>It is and it works very well, but you'll get better results by using
>"autogas" or lpg sold for vehicle fuel which already has Butane in the mix.

Not where I am! :)

LPG and autogas comes out of the same tanker (I think it might be a
standard thing in the remoter parts of Oz).

If you need a hyrocarbon refrigerant with known physical properties
HyChill HR12 is the way to go. It's also available in disposable
containers.

As an aside... Americans can still buy R134A in disposable containers
(which were banned here back in the eighties). Currently we need to a
licence to buy R134A (because it's an ozone depleting substance) as
well as a licence to use it. Hydrocarbon refrigerants are legal for
mobile use (cars) in all states except Queensland... domestic fridges
nearly all use it these days (even in Q).

--
John H

Ext User(Athol)
14-12-2007, 07:53 PM
Noddy <me@home.com> wrote:

> I run lpg in both my car's air conditioning systems (one of which is r134a
> while the other is R-12) and it provides excellent results. I've found that
> lpg requires a tad more than half the weight normally recommended for both
> r-12 and r134a in most a/c systems to work well, and much more than this
> puts the pressures on the high side of being acceptable.

Here's a related question. I may have asked it before and forgotten...

I've got a vacuum pump that I've never got around to sorting out.

I suspect that it should get an oil change before I even think about
trying it out, but have been too slack to even look at it.

Attached to it is a measuring cylinder. The scale is in grams and
ounces IIRC. There are different scales for various refrigerants such as
R12 and R22, obviously correcting for the fact that it is actually
measuring volume, not mass.

So the question is, is the volume of liquid refrigerant needed equal
between R12 and propane or propane/butane mix? If so, I could simply use
the R12 "weight" on the scale and it would give the correct volume of
LPG...

--
Athol
<http://cust.idl.com.au/athol> Linux Registered User # 254000
I'm a Libran Engineer. I don't argue, I discuss.

Ext User(Andy)
14-12-2007, 08:13 PM
In article <cm34m39f4grhm564p6ptr8bema3gcc93nt@4ax.com>,
John_H <john4721@inbox.com> wrote:

> Ted wrote:
> >
> >Someone told me it is possible to regas an aircon with propane from a bbq
> >bottle, is this correct? They said a lot of taxi drivers use this method all
> >the time because it's just as good if not better than the official aircon
> >gasses.
> >They said it's no more flammable or dangerous then the old type gasses?
> >I woulsd like to hear from any refrigeration guys here if this is possible,
> >how effective it is and how to dit, what pressures etc. Thanks.
>
> It works fine, especially in the old R12 systems.
>
> Pressures are higher and so is the condenser temperature. You can
> avoid these pitfalls by using the appropriate Hychill hydrocarbon
> refrigerant (HR12) which is a mixture of propane and butane and hence
> much closer to the same physical properties of the Dupont products
> (including 134A).

I believe it's now called 'HyChill Minus 30'. I have it in my car and
it works *brilliantly*.

Cheers,
Andy.

Ext User(James)
14-12-2007, 08:33 PM
"John_H" <john4721@inbox.com> wrote in message
news:ssb4m3929fl3pgcooen5f6soa5orq174gg@4ax.com...
> Noddy wrote:
>>"Ted" <Tedb@Bigpond.com.au> wrote in message
>>news:13m43hhm1fjlub1@corp.supernews.com...
>>> Someone told me it is possible to regas an aircon with propane from a
>>> bbq
>>> bottle, is this correct? They said a lot of taxi drivers use this method
>>> all the time because it's just as good if not better than the official
>>> aircon gasses.
>>
>>It is and it works very well, but you'll get better results by using
>>"autogas" or lpg sold for vehicle fuel which already has Butane in the
>>mix.
>
> Not where I am! :)

I've found it varies from fill to fill. The servo I usually go to is almost
always straight Propane at the bowser but they sometimes get a bit of butane
in the mix. This is handy to know for filling the BBQ bottle (45kg) from the
bowser, since butane is a tad on the shit side for barbies. The manager of
the servo probably shouldn't be telling me this though :)

James


>
> LPG and autogas comes out of the same tanker (I think it might be a
> standard thing in the remoter parts of Oz).
>
> If you need a hyrocarbon refrigerant with known physical properties
> HyChill HR12 is the way to go. It's also available in disposable
> containers.
>
> As an aside... Americans can still buy R134A in disposable containers
> (which were banned here back in the eighties). Currently we need to a
> licence to buy R134A (because it's an ozone depleting substance) as
> well as a licence to use it. Hydrocarbon refrigerants are legal for
> mobile use (cars) in all states except Queensland... domestic fridges
> nearly all use it these days (even in Q).
>
> --
> John H

Ext User(John_H)
14-12-2007, 08:43 PM
Andy wrote:
>
>I believe it's now called 'HyChill Minus 30'. I have it in my car and
>it works *brilliantly*.

The cylinder I've had for a couple of years is marked 'minus 30' IIRC,
however they still call it HR12 on their website and in all their
literature.

Buggered if I know why they ever attempted to change it. :)

--
John H

Ext User(the_dawggie)
14-12-2007, 08:53 PM
Athol wrote:
> Noddy <me@home.com> wrote:
>
>> I run lpg in both my car's air conditioning systems (one of which is r134a
>> while the other is R-12) and it provides excellent results. I've found that
>> lpg requires a tad more than half the weight normally recommended for both
>> r-12 and r134a in most a/c systems to work well, and much more than this
>> puts the pressures on the high side of being acceptable.
>
> Here's a related question. I may have asked it before and forgotten...
>
> I've got a vacuum pump that I've never got around to sorting out.
>
> I suspect that it should get an oil change before I even think about
> trying it out, but have been too slack to even look at it.
>
> Attached to it is a measuring cylinder. The scale is in grams and
> ounces IIRC. There are different scales for various refrigerants such as
> R12 and R22, obviously correcting for the fact that it is actually
> measuring volume, not mass.
>
> So the question is, is the volume of liquid refrigerant needed equal
> between R12 and propane or propane/butane mix? If so, I could simply use
> the R12 "weight" on the scale and it would give the correct volume of
> LPG...

Mine needs a regas. I'll take it to no bubbles in the recievier
drier sight glass. Oil change is a bit more difficult. The oil must
be miscible with the LPG. It's fairly much with all refigerants
using R290 (propane), R134a ain't.

I don't really judge it, just shove the R290 (propane) unto
what I what I want to see in the sight glass of the reciever
drier. Tends to work well.

Ext User(Andy)
14-12-2007, 09:03 PM
In article <erf4m3l35hjan1nm6aaqu1jaqq0v4qbpba@4ax.com>,
John_H <john4721@inbox.com> wrote:

> Andy wrote:
> >
> >I believe it's now called 'HyChill Minus 30'. I have it in my car and
> >it works *brilliantly*.
>
> The cylinder I've had for a couple of years is marked 'minus 30' IIRC,
> however they still call it HR12 on their website and in all their
> literature.
>
> Buggered if I know why they ever attempted to change it. :)

Indeed - I can only assume they were hoping to have their products take
off and be recognisable by some kind of lame 'branding'. Pretty
pointless really considering only 'enthusiasts' actually seem to give a
shit what goes in their system.

Cheers,
Andy.

Ext User(John_H)
14-12-2007, 09:03 PM
Athol wrote:
>
>I've got a vacuum pump that I've never got around to sorting out.
>
>I suspect that it should get an oil change before I even think about
>trying it out, but have been too slack to even look at it.

To keep the vacuum pump working efficiently you'll need to change the
oil regularly to prevent moisture buildup and sludging. Some fussy
operators I know change the oil every time they use the pump (which
has a lot to recommend it).

>
>Attached to it is a measuring cylinder. The scale is in grams and
>ounces IIRC. There are different scales for various refrigerants such as
>R12 and R22, obviously correcting for the fact that it is actually
>measuring volume, not mass.
>
>So the question is, is the volume of liquid refrigerant needed equal
>between R12 and propane or propane/butane mix? If so, I could simply use
>the R12 "weight" on the scale and it would give the correct volume of
>LPG...

I've never used one of those, since I've got a weighing machine, but
the answer to the question is yes to my understanding... provided you
know the R12 charge weight. A lot of R12 systems didn't specify the
charge weight as thay had sight glasses.

I'd be looking to add another scale, which you can probably get off
the HyChill site (use the HR12 figures). From memory, lpg is around a
third the weight of R12 for an equivalent charge (I've got my own
figures written in the log books of the vehicles involved)... IIRC a
1kg R12 system takes around 350g lpg (by weight).

Generally I'm happy to use the sight glass if there is one... but
watch the high side pressure as you approach a full charge. It's also
a good way to check if the scale is correct (as we're both assuming).

--
John H

Ext User(Noddy)
14-12-2007, 10:13 PM
"John_H" <john4721@inbox.com> wrote in message
news:ssb4m3929fl3pgcooen5f6soa5orq174gg@4ax.com...

> Not where I am! :)
>
> LPG and autogas comes out of the same tanker (I think it might be a
> standard thing in the remoter parts of Oz).

It's the same down here, with the autogas and domestic bottle stuff coming
from the same supply, but just delivered in different trucks :)

They both have Butane in them.

--
Regards,
Noddy.

Ext User(Noddy)
14-12-2007, 10:33 PM
"Athol" <me@privacy.net> wrote in message
news:1197618516.124128@idlwebserver.idl.com.au...

> So the question is, is the volume of liquid refrigerant needed equal
> between R12 and propane or propane/butane mix? If so, I could simply use
> the R12 "weight" on the scale and it would give the correct volume of
> LPG...

I *think* so, but I'm not sure. I've got a set of scales and have always
gone by weight.

I've generally found that on r-12 systems an lpg fill of half the
manufacturer's recommended r-12 charge weight is generally in the ball park
as far as gauge pressures go, with a slight "squirt" or two after that being
all that's necessary to make the sight glass happy. I did my old ute the
other day after hooking the air back up after I finished the gas conversion
and the book calls for 1300g of R-12. I vacuumed the thing and then hit it
with 650g of lpg and all it needed was a quick zap to remove the last few
bubbles and it's working fine.

On systems without a sight glass, like my Jeep with it's r143a system, I had
to top that up a few weeks ago when it started to loose it's cool and the
compressor would cycle every couple of seconds. In that case I simply stuck
a fill hose on the low pressure line and ran the air with a temp probe over
the centre air vent and gassed it until it pulled down to the recommended
temp and the compressor cycled as often as the book said it should.

Hardly scientific, but it works. Very well.

--
Regards,
Noddy.

Ext User(Paul Saccani)
15-12-2007, 12:23 AM
On Fri, 14 Dec 2007 18:12:27 +1100, "Noddy" <me@home.com> wrote:

>If it's completely empty as in having been pulled apart, then it'll need to
>be vacuumed as per normal. You would then fill it with roughly half the
>weight of what the manufacturer specifies for their refrigerant (be it R-12
>or R134a) and then check the sight class or the air vent temp and small
>amounts of lpg at a time until you reach the desired result.
>
>I run lpg in both my car's air conditioning systems (one of which is r134a
>while the other is R-12) and it provides excellent results. I've found that
>lpg requires a tad more than half the weight normally recommended for both
>r-12 and r134a in most a/c systems to work well, and much more than this
>puts the pressures on the high side of being acceptable.

Agree generally with your post - but it might be worth noting that it
isn't that hard to make up a mixture roughly equivalent to HR-12.
You just need about 20% W.W. of butane. That brings the boiling point
closer to R-12, instead of R-22. Most relevant to FOT systems, of
course, you don't want a slug of liquid getting past the accumulator.
Even in a throttled system, with propane you are still likely to miss
out on the superheat in the evaporator that the original designer
intended.

Without wanting to disagree with you, in either case (propane or
HR-12), the theoretical recommendation is around a 1/3 by weight of
the original charge. So it might be best to work up to your
recommendation (of a pinch over half weight), rather than start there.
Particularly for someone without as much experience as you. Again,
more relevant to FOT systems.

'course, it is a lot easier just to use a dial-a-charge and put the
same volume as the original charge (with the R12 and R134 scale),
rather than mess around with calculations etc... and much less chance
of making a blue. And the same volume will usually be just *under* a
third of the charge *weight*.
--
Cheers
Paul Saccani
Perth, Western Australia.

Ext User(Paul Saccani)
15-12-2007, 12:34 AM
On Fri, 14 Dec 2007 17:38:35 +1000, John_H <john4721@inbox.com> wrote:

>Noddy wrote:
>>"Ted" <Tedb@Bigpond.com.au> wrote in message
>>news:13m43hhm1fjlub1@corp.supernews.com...
>>> Someone told me it is possible to regas an aircon with propane from a bbq
>>> bottle, is this correct? They said a lot of taxi drivers use this method
>>> all the time because it's just as good if not better than the official
>>> aircon gasses.
>>
>>It is and it works very well, but you'll get better results by using
>>"autogas" or lpg sold for vehicle fuel which already has Butane in the mix.
>
>Not where I am! :)
>
>LPG and autogas comes out of the same tanker (I think it might be a
>standard thing in the remoter parts of Oz).
>
>If you need a hyrocarbon refrigerant with known physical properties
>HyChill HR12 is the way to go. It's also available in disposable
>containers.
>
>As an aside... Americans can still buy R134A in disposable containers
>(which were banned here back in the eighties).

We never had 134a in consumer top up containers.

I can still buy as much R12 as I want in Malaysia....

> Currently we need to a
>licence to buy R134A (because it's an ozone depleting substance)

It isn't. It is a scheduled *green house* gas, which is regulated
under the Ozone depletion regulations for convenience.

> as
>well as a licence to use it. Hydrocarbon refrigerants are legal for
>mobile use (cars) in all states except Queensland... domestic fridges
>nearly all use it these days (even in Q).

I wonder why? R290 is actually crap in domestic fridges. R600a or
R600 is the go, and it is uncommon in Australia (unlike R290 in
domestic fridges, which is virtually non-existent).
--
Cheers
Paul Saccani
Perth, Western Australia.

Ext User(Noddy)
15-12-2007, 01:03 AM
"Paul Saccani" <saccani@omen.net.au> wrote in message
news:cmq4m3dbjd1ktgi9fre63jinttptjrt4ua@4ax.com...

> Without wanting to disagree with you, in either case (propane or
> HR-12), the theoretical recommendation is around a 1/3 by weight of
> the original charge. So it might be best to work up to your
> recommendation (of a pinch over half weight), rather than start there.
> Particularly for someone without as much experience as you. Again,
> more relevant to FOT systems.

Generally I do, the only exception to that rule is when doing the ute the
other day I was in a hurry to get it finished and out of the garage and that
having done it once before previously I remembered what it took.

> 'course, it is a lot easier just to use a dial-a-charge and put the
> same volume as the original charge (with the R12 and R134 scale),
> rather than mess around with calculations etc... and much less chance
> of making a blue. And the same volume will usually be just *under* a
> third of the charge *weight*.

I've actually got one, and old unheated Robinair that's calibrated in
ounces. I should get off my arse and dust it off one day.

--
Regards,
Noddy.

Ext User(Toby Ponsenby)
15-12-2007, 01:43 AM
On Fri, 14 Dec 2007 15:17:40 +1000, John_H blathered on in :

> Ted wrote:
>>
>>Someone told me it is possible to regas an aircon with propane from a
>>bbq bottle, is this correct? They said a lot of taxi drivers use this
>>method all the time because it's just as good if not better than the
>>official aircon gasses.
>>They said it's no more flammable or dangerous then the old type gasses?
>>I woulsd like to hear from any refrigeration guys here if this is
>>possible, how effective it is and how to dit, what pressures etc.
>>Thanks.
>
> It works fine, especially in the old R12 systems.
>
> Pressures are higher and so is the condenser temperature. You can avoid
> these pitfalls by using the appropriate Hychill hydrocarbon refrigerant
> (HR12) which is a mixture of propane and butane and hence much closer to
> the same physical properties of the Dupont products (including 134A).
> It's readily available (and completely legal) in all states except Qld.
> There's also heaps of useful info on their site....
> http://www.hychill.com.au/

Re HC12.
It IS legal to buy the stuff in QLD - and to use it.
The suppliers will claim they can only sell the material to 'licenced' A/
C people.
Duh.
That's wrong.
Check with Hychill.
I have HC 12 in one of the cars here and it works a treat.
NB. Particularly important is the weights table mentioned in a table on
the Website.

Meanwhile, the 'industry' is very busy using FUD...and beating up the A/C
guys by saying warranties are voided and all sorts of other stuff that
defies logic in the extreme.
>
> It would help considerably if you've got a good working knowledge of
> automotive air conditioning service procedures.





--
Toby

Ext User(Yvan)
15-12-2007, 06:51 AM
Nedavno Noddy piše:

>> Without wanting to disagree with you, in either case (propane or
>> HR-12), the theoretical recommendation is around a 1/3 by weight *of
>> the original charge. *So it might be best to work up to your
>> recommendation (of a pinch over half weight), rather than start
>> there. Particularly for someone without as much experience as you.
>> Again, more relevant to FOT systems.
>
> Generally I do, the only exception to that rule is when doing the ute
> the other day I was in a hurry to get it finished and out of the
> garage and that having done it once before previously I remembered
> what it took.


This is interesting! I did not know that you could put LPG into a/c.

Apart from what I am busy right now (for you that do not know I just
went from dual fuel to LPG only), I am in a process of fitting a/c
system from a wrecked car. I stopped for now, it's winter here (and it
just started snowing), but I plan to continue as soon as weather allows
me to.

I fitted all the a/c parts and I plan to use old refrigerator compressor
to vacuum the system. Now it looks like that I can fill it too (I like
to do as much as I can, without the professionals).

I guess that I can get one 2,5 kg LPG bottle (that is available here),
put it on a scale (to measure how much lpg goes in), connect it to the
a/c, open the valve, and that's it. Should I flip the bottle upside
down?

But it would be nice if someone could post a link to some photos of how
do you fill a/c system with lpg? Or take some photos next time you
refill?

Of course I plan to get the gauges and fittings first, but this sounds
interesting, as it is much cheaper if it leaks (I am not sure if I have
a leak somewhere, I probably do), and it's environmentally friendly.



--
___ ____
/__/ / \ ** Registrovani korisnik Linuksa #291606 **
/ / \/ /\ \ ** Registered Linux user #291606 **
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