Regassing Aircon with Propane?
Ted
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.
John_H
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
Ted
>
> 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?
John_H
>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
Noddy
"Ted" <Te...@Bigpond.com.au> wrote in message
news:13m43hh...@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.
John_H
>"Ted" <Te...@Bigpond.com.au> wrote in message
>news:13m43hh...@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
James
"John_H" <john...@inbox.com> wrote in message
news:ssb4m3929fl3pgcoo...@4ax.com...
> Noddy wrote:
>>"Ted" <Te...@Bigpond.com.au> wrote in message
>>news:13m43hh...@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
John_H
>
>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
the_dawggie
> Noddy <m...@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.
>
>
> 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.
John_H
>
>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
Noddy
> 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.
Noddy
"Athol" <m...@privacy.net> wrote in message
news:11976185...@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.
Noddy
"Paul Saccani" <sac...@omen.net.au> wrote in message
news:cmq4m3dbjd1ktgi9f...@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.
Yvan
>> 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 **
/__/\____/--\__\ ** http://counter.li.org/ **
John_H
>
>Re HC12.
>It IS legal to buy the stuff in QLD - and to use it.
Legal to buy but not legal to use in a mobile system (automotive)
unless the law's been changed recently (last twelve months or so).
What the law actually says is that the system has to signed off by an
inspector (same as a lpg fuel conversion). You wont find an inspector
to sign one off (department policy), even if anyone could be bothered
with the crap and paperwork.
The loophole is to have it serviced interstate.
>The suppliers will claim they can only sell the material to 'licenced' A/
>C people.
>Duh.
>That's wrong.
>Check with Hychill.
It's their way of keeping it under the counter while they continue to
lobby Govco. I haven't spoken to HyChill for over 12 months so it's
possible Govco have backed down in that time... if they have it should
be on the suppliers shelves.
>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.
The main opponents are Vasta (with the backing of Dupont no doubt) who
see Qld as the last battleground. They've been brainwashing their
members (and no doubt lobbying Govco for themselves) ever since
Montreal. If the battle is still raging (or even if it's been lost)
you'll certainly find plenty of anti-hydrocarbon propaganda on their
website.... http://www.vasa.org.au/
--
John H
John_H
>On Fri, 14 Dec 2007 17:38:35 +1000, John_H <john...@inbox.com> wrote:
>>
>>As an aside... Americans can still buy R134A in disposable containers
>>(which were banned here back in the eighties).
>
Of course we didn't... the small disposable containers were banned in
Oz long before R134A was introduced... about 1983 IIRC. R134A
appeared around 1991 (in large disposable containers).
>
>I can still buy as much R12 as I want in Malaysia....
You can still buy it here (in non-disposable containers) if you're
prepared to pay the going price. It's only illegal to manufacture or
import. I've still got enough of it to last me until I die, whence my
estate will no doubt cash it in. :)
>
>> 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.
Technicality noted... but I think you'll find the regualtions refer to
it as ozone depleting.
>
>> 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).
Who said it was R290 being used in fridges? :)
--
John H
John_H
>
>IIRC, the numbering of the various types of HC gases matches BOC's
>numbering of equivalent HC refrigerants.
It actually makes sense to use both IMO.
Hadn't caught with BOC's entry into hydrocarbons... though it's
probably inevitable with its now universal acceptance in domestic
refrigerators.
I'll continue to support HyChill on account of their being very much
the locally based pioneers of the products (plus the shit they've had
to endure from Dupont's lackies). :)
--
John H
John McKenzie
That sounds right. I didn't post it here (out of embarassment) but some
genius decided to defrost a fridge with a hammer and chisel to prove it
could be done in under 30 seconds. Well, technically it was.
Anyhoo, durafix - the alloy solder - works fucking great. It was
re-gassed with new oil and gas from a couple of propane torches (to get
enough in there, I heated the second one in hot water with the fridge
running.
I did the math back then, and 1/3 seems to ring a bell.
Fridge works better than before (and far better than when I made it
spring a leak.
> 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 McKenzie
tos...@aol.com ab...@yahoo.com ab...@hotmail.com ab...@earthlink.com
ab...@aol.com vice.pr...@whitehouse.gov pres...@whitehouse.gov
swee...@accc.gov.au u...@ftc.gov admin@loopback ab...@iprimus.com.au
$LOGIN@localhost world's #1 sardine whisperer ro...@mailloop.com
$USER@$HOST $LOGNAME@localhost -h1024@localhost ab...@msn.com
ab...@federalpolice.gov.au frau...@psinet.com ab...@asio.gov.au
$USER@localhost ab...@sprint.com ab...@fbi.gov ab...@cia.gov
John McKenzie
Well, even though I posted it after the post you are replying to - I'm
running it in a house fridge, and have confounded everyone who thought
I'd lost the plot (again).
Noddy
> Huh? Bottled LP gas is supposed to be Propane, not Butane.
It is indeed, and some suppliers will give you straight propane, but a great
many will give you good old autogas propane/butane mix.
--
Regards,
Noddy.
Yvan
>>I fitted all the a/c parts and I plan to use old refrigerator
>>compressor to vacuum the system.
>
> You won't get anywhere near the level of vacuum required. The issue
> is boiling all the water away, and that requires a hard vacuum. Some
> people get the idea that leaving a soft vacuum on for long enough will
> do the job. It won't.
So what is "hard vacuum" in kPa, bar... and what is "soft vacuum"?
> Also, have you drained the oil from the compressor? You will also
> need to find a suitable oil to put in. Steer clear of PAG, which by
> the way, is nasty toxic. It also degenerates in any system which has
> had R-12 in it.
Yes, I plan to add oil. I'll get some R-12 compatible oil.
>>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.
>
> Although straight propane is not an ideal replacement for R-12.
LPG here contains butane too. I do not know how much, but it does have
it. And Noddy wrote that he reffiled his a/c with LPG.
> Don't forget to replace every O ring that you have disturbed with a
> refrigerant compatible O ring.
I will, thank you.
John_H
>On Sat, 15 Dec 2007 06:04:30 +1000, John_H <john...@inbox.com> wrote:
>>Paul Saccani wrote:
>>>> 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).
>>
>>Who said it was R290 being used in fridges? :)
>
Who said anything about LPG in domestic fridges? :)
--
John H
Noddy
"Yvan" <m...@privacy.net> wrote in message
news:5shk52F...@mid.individual.net...
> LPG here contains butane too. I do not know how much, but it does have
> it. And Noddy wrote that he reffiled his a/c with LPG.
I did.
I use autogas (or more commonly called "LPG") in everything I own that's
supposed to run on Propane, from barbeques to water and garage heaters and
don't have the slightest problems in doing so. In my neck of the woods LPG
for vehicles is sold as a mixture of roughly 60% Propane and 40% Butane, and
in my experience that works *very* well in systems originally designed for
both R-12 and R134a.
Some interesting information on hydrocarbon refrigerants can be found here:
http://www.es-refrigerants.com/reports/
--
Regards,
Noddy.
Yvan
>> Should I flip the bottle upside down?
>
> Yes, you want liquid.
I believe that you add refrigerant into low side. If I put liquid LPG
in, may it get in compressor in liquid state? That will not be good.
And another question. Since I had put in my car a/c system that was not
new, I would like to flush it. How do you do that? And with what?
John_H
>Nedavno Paul Saccani piše:
>
>>>I fitted all the a/c parts and I plan to use old refrigerator
>>>compressor to vacuum the system.
>>
>> You won't get anywhere near the level of vacuum required. The issue
>> is boiling all the water away, and that requires a hard vacuum. Some
>> people get the idea that leaving a soft vacuum on for long enough will
>> do the job. It won't.
>
>
>So what is "hard vacuum" in kPa, bar... and what is "soft vacuum"?
Vauum is measured in Torr (mm of Mercury), where 1 atmosphere = 760T.
To effectively evacuate your system you need a pump capable of
reaching a vacuum which is below the vapour pressure of water at the
temperature you're working at. While there's water present the vapour
pressure is what determines the best vacuum attainable, so you need to
maintain that vacuum to remove the water.
The catch being that the standard gauges used in a/c servicing can't
measure that sort of vacuum to the accuracy needed. The laboratory
type gauge for the job is a McLeod Gauge, which is a a special form of
mercury manometer. Google any of the terms you're not familiar for a
detailed explanation.
>
>
>
>> Also, have you drained the oil from the compressor? You will also
>> need to find a suitable oil to put in. Steer clear of PAG, which by
>> the way, is nasty toxic. It also degenerates in any system which has
>> had R-12 in it.
>
>
>Yes, I plan to add oil. I'll get some R-12 compatible oil.
>
>
>
>>>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.
>>
>> Although straight propane is not an ideal replacement for R-12.
>
>
>LPG here contains butane too. I do not know how much, but it does have
>it. And Noddy wrote that he reffiled his a/c with LPG.
>
>
>
>> Don't forget to replace every O ring that you have disturbed with a
>> refrigerant compatible O ring.
>
>
>I will, thank you.
--
John H
John_H
>Yvan wrote:
>>So what is "hard vacuum" in kPa, bar... and what is "soft vacuum"?
>
>Vauum is measured in Torr (mm of Mercury), where 1 atmosphere = 760T.
>
>To effectively evacuate your system you need a pump capable of
>reaching a vacuum which is below the vapour pressure of water at the
>temperature you're working at. While there's water present the vapour
>pressure is what determines the best vacuum attainable, so you need to
>maintain that vacuum to remove the water.
>
>The catch being that the standard gauges used in a/c servicing can't
>measure that sort of vacuum to the accuracy needed. The laboratory
>type gauge for the job is a McLeod Gauge, which is a a special form of
>mercury manometer. Google any of the terms you're not familiar for a
>detailed explanation.
Apologies for that... I accidently posted it before it was complete.
What I was intending to add is that a vane type vacuum pump is right
at the limits of its ability to achieve the vacuum necessary. It
needs to be in top order to do the job, and most importantly it needs
to have the correct oil which has to be changed regularly. Vacuum
pump oil in good condition will have a vapour pressure lower than
water.
Vapour pressure of water also increases dramatically with temperature
so you can assist the pump by working with the a/c components at the
highest temperature possible... eg stand the car out in the sun on a
hot day.
My personal opinion is that only about 10% of the vacuum pumps in use
in the air conditioning service trade throughout this country are
capable of the job they're meant to do. The inference is obvious. :)
--
John H
tim
> It works fine, especially in the old R12 systems.
Here's a conference paper describing the theory, and some practical
instructions for mixing and charging your own propane-butane mix into
an R12 system:
http://patch.bpa.nu/pub/archive/HC/papers/gfqmcw93.pdf
I've done it on my own car using this method, and it's very, very
effective.
As for safety - it's a small charge of BBQ fuel running through the
engine bay and cabin of your car, which is not without risk. But
carrying a big tank of BBQ fuel in the cabin (look behind the seat in
an LPG powered wagon one day...) is not without risk either... nor is
carrying a plastic box of octane (aka petrol) under the car.
"Doctor Mac", who wrote that paper linked above, used to do "worse
case scenario" demonstrations by releasing the equivalent of a full
charge of hydrocarbon refrigerant into the cabin of his car then
lighting a match. He did this many times with no ill effects... but it
only has to go wrong once, and next thing you know...
http://www.vasa.org.au/pdf/memberlibrary/hydrocarbons/maclaine-cross.pdf
tim
John McKenzie
>
> Nedavno Paul Saccani piše:
>
> >> Should I flip the bottle upside down?
> >
> > Yes, you want liquid.
>
> I believe that you add refrigerant into low side. If I put liquid LPG
> in, may it get in compressor in liquid state? That will not be good.
>
> And another question. Since I had put in my car a/c system that was not
> new, I would like to flush it. How do you do that? And with what?
Good question - ANYONE?
Noddy
"John McKenzie" <jmac_me...@bigpond.com> wrote in message
news:47662E...@bigpond.com...
> Good question - ANYONE?
R-11 used to be the chemical of choice, but it used to be vented into the
atmosphere while doing so and that's a no-no today.
The process normally involves disconnecting the compressor and dryer from
the system and blowing the crap through the hoses, condenser and evaporator,
and then vacuuming the crap out of it once it's hooked back up to get the
moisture out. As to how often you need to do it I can't tell you, but I've
never had to do it yet.
Some a/c people who take things to the nth degree will no doubt tell you
that you need to "do this" and it has to be done "precisely this way", and
that may be so but you'll often get away with not having to be super
critical.
It may sound rough & ready, but I've put a few systems in using used
components that have sat around open to the air for a while, and all I've
ever done is drained & refilled the compressor, replaced the dryer, given
the other components a quick blow with some compressed air and hooked them
up and gassed it.
All but one worked well for quite a while (as long as I was aware of what
was happening with the cars anyway) and the other had a compressor failure
not long after it was installed (which had a crook compressor from the
beginning, but that's the one the owner wanted to use). They all needed an
annual top up (as most do) which required about 18 cents worth of lpg to get
them through summer without an issue.
--
Regards,
Noddy.
John_H
>Yvan wrote:
>
>> And another question. Since I had put in my car a/c system that was not
>> new, I would like to flush it. How do you do that? And with what?
>
>Good question - ANYONE?
Shellite (petroleum spirit) works for me. There is a solvent sold for
the purpose, but it costs an arm and a leg.
If you're doing it in situ you'll need a large syringe of some
description to flush the condenser, evaporator and lines. Use the
syringe to agitate the solvent before removing it (work from the
lowest connection on each component).
Don't flush the compressor, remove it from the car and drain it. Nor
the receiver drier... replace it.
With the system drained and flushed, add the correct amount of oil to
the compressor. A synthetic oil, such as ROC, is best... it's also
compatible with all refrigerants (Repco stock it in Oz... there's
bound to equivalent product available in Europe). Don't use PAG and
best not to use the old R12 mineral oil.
--
John H
John McKenzie
>
> John McKenzie wrote:
> >Yvan wrote:
> >
> >> And another question. Since I had put in my car a/c system that was not
> >> new, I would like to flush it. How do you do that? And with what?
> >
> >Good question - ANYONE?
>
> Shellite (petroleum spirit) works for me. There is a solvent sold for
> the purpose, but it costs an arm and a leg.
Would acetone (assuming new seals were used after the fact) be a drama?
> If you're doing it in situ you'll need a large syringe of some
> description to flush the condenser, evaporator and lines. Use the
> syringe to agitate the solvent before removing it (work from the
> lowest connection on each component).
>
> Don't flush the compressor, remove it from the car and drain it. Nor
> the receiver drier... replace it.
>
> With the system drained and flushed, add the correct amount of oil to
> the compressor. A synthetic oil, such as ROC, is best... it's also
> compatible with all refrigerants (Repco stock it in Oz... there's
> bound to equivalent product available in Europe). Don't use PAG and
> best not to use the old R12 mineral oil.
I've got an r-12 compatible mineral oil in the fridge (castrol, and
notably, it's the only castrol product I've bought (or any oil/grease)
that had the quantity listed in imperial units).
When I read 'best not to use the old r12 mineral oil' I'm reading it in
the context of 'best not to use the old oil already in it' or do you
mean mineral oil full stop? The reason I used it was because it was an
old fridge, that I fucked up myself, and so if the repair 'didn't work'
I'd be out $17 for the oil (with plenty left over, vs $150 odd for
synthetic, through repco, not sure if that was their optimistic price,
or the going rate) and $10 for the alloy solder
Noddy
> Sure does. Being a cautious kind of a fellow, I prefer to run such
> things through the cheapest receiver dryer or accumulator that I can
> find into the dial-a-charge. You never know what kind of contaminants
> could be in it, especially if it comes from petrol refining. You can
> usually find some on special for around $6 at most times. Small price
> to protect the gear. Or I use a recycler to clean it. If you want to
> be really tricky, you can also do a mass volume analysis with
> temperature correction. It'll be a mix of propane and butane with
> only traces of other materials, so the calculation is straight
> forward. 'Course, no such worries with hychill, but crikey, what a
> price difference!
It sure is :)
The A/C system on my jeep works incredibly well, and needs a quick top up
once every 18 momths or so. The system on my Falcon ute is worth all of 20
bucks in total, and I'm fucked if I'm going to fill it with double it's
value of refrigerant :)
> Over here, autogas is quite variable, whilst bottled gas is propane
> with trace contamination.
Most of the 'swap and go" places over here are propane, but the larger
servo's tend to be autogas. Particularly the ones that have the large 1000
litre bottle refilling stations (although these seem to be dwindling these
days as it takes a console operator away from his job to use).
> I'm surprised that they allow butane in significant proportion in your
> bottled gas. Not kosher at this end of the country. Are they simply
> getting away with it, or do your standards allow for it? We have no
> propane shortage here, whereas you chaps need to import it, so we may
> have different regulations.
I think they're just getting away with it.
--
Regards,
Noddy.
Yvan
>>So what is "hard vacuum" in kPa, bar... and what is "soft vacuum"?
>
> 30 microns, and the kind of compressors used in refrigeration plants
> don't pull anything close to it - nor do they need to, in their role.
40 bar! That is a "hard vacuum"!
>>Yes, I plan to add oil. I'll get some R-12 compatible oil.
>
> I find RoC oil good - get the stuff with the dye in it. Make sure you
> know how much oil is required for the *system*, not just the
> compressor recommendation. These may be the same, but not always.
I do have specifications for a/c system in my car. I do not know what is
available here, but I'll try to find compatible oil with dye in it.
> The thing is, he really knows what he is doing - you don't. Always
> bear this in mind. Many things are so obvious to him (and most others
> in this thread for that matter) that they will not mention them. But
> not knowing these things could get you into a pickle.
That's why I ask questions. And I do sometimes do things the wrong way,
but that's how you learn. I know LPG (and high pressure a/c system) is
good for making mistakes, but I'll be cautious, double-check everything
and ask here again (probably in the spring).
Yvan
>>> And another question. Since I had put in my car a/c system that was
>>> not new, I would like to flush it. How do you do that? And with
>>> what?
>>
>>Good question - ANYONE?
>
> Shellite (petroleum spirit) works for me.
Is this the stuff that was used in small heaters (I think that my
grandmather had some, and used it before she got electric heater). I
think I used it to clean the carburetor. I ask this, as I need to find
out if the stuff is available here.
Yvan
>>> >> Should I flip the bottle upside down?
>>> >
>>> > Yes, you want liquid.
>>>
>>> I believe that you add refrigerant into low side. If I put liquid
>>> LPG in, may it get in compressor in liquid state? That will not be
>>> good.
>
> Absolutely, and it isn't good. All of this is why mechanics do
> practical courses on this, rather than just having to read a brochure
> or ask questions on the net.... Sorry to be a kill joy.
Again, that's why I ask questions. Some errors can not be avoided, but
if you know how stuff works, you can ask the right questions (as I
think this one was). I am not mechanic, but I like fixing (or at least
trying to fix) things around the car (and other stuff).
> You need to add liquid refrigerant at such a rate to the vacuum that
> it doesn't reach the compressor in liquid state.
>
>>> And another question. Since I had put in my car a/c system that was
>>> not new, I would like to flush it. How do you do that? And with
>>> what?
>>
>>Good question - ANYONE?
>
> HC refrigerants
Sorry If I ask dumb questions, but apart from "not knowing what I'm
doing", I have a problem with the language, especially with the
technical terms and product names (for markets on a different
continents). So, aren't refrigerants gaseous? Any links to such a
products (like the one below)?
> are reasonable flushing solvents, you could use them
> for flushing. They aren't as good as the old R11, of course.
> Otherwise, you could use something like Rx-11, but you are getting in
> to the realm of more equipment to do this properly.
>
> Rather than explain everything myself, you might get some illumination
> from this site
>
http://www.nucalgon.com/nucalgon/nucalgon_products.nsf/All/0693B682EC63D0F38625667400779761?OpenDocument
Thank you.
John_H
>Nedavno John_H piše:
>
>> Shellite (petroleum spirit) works for me.
>
>Is this the stuff that was used in small heaters (I think that my
>grandmather had some, and used it before she got electric heater). I
>think I used it to clean the carburetor. I ask this, as I need to find
>out if the stuff is available here.
Probably.
It's known by various names in different parts of the world. If you
google either term you should come up all the possibilities (language
differences aside).
--
John H
John_H
>John_H wrote:
>> John McKenzie wrote:
>> >Yvan wrote:
>> >
>> >> And another question. Since I had put in my car a/c system that was not
>> >> new, I would like to flush it. How do you do that? And with what?
>> >
>> >Good question - ANYONE?
>>
>> Shellite (petroleum spirit) works for me. There is a solvent sold for
>> the purpose, but it costs an arm and a leg.
>
>Would acetone (assuming new seals were used after the fact) be a drama?
I'd be inclined to stick with something milder. Shellite is readily
available at almost any supermarket of hardware outlet, and is cheaper
than acetone.
>
>> If you're doing it in situ you'll need a large syringe of some
>> description to flush the condenser, evaporator and lines. Use the
>> syringe to agitate the solvent before removing it (work from the
>> lowest connection on each component).
>>
>> Don't flush the compressor, remove it from the car and drain it. Nor
>> the receiver drier... replace it.
>>
>> With the system drained and flushed, add the correct amount of oil to
>> the compressor. A synthetic oil, such as ROC, is best... it's also
>> compatible with all refrigerants (Repco stock it in Oz... there's
>> bound to equivalent product available in Europe). Don't use PAG and
>> best not to use the old R12 mineral oil.
>
>I've got an r-12 compatible mineral oil in the fridge (castrol, and
>notably, it's the only castrol product I've bought (or any oil/grease)
>that had the quantity listed in imperial units).
>
>When I read 'best not to use the old r12 mineral oil' I'm reading it in
>the context of 'best not to use the old oil already in it' or do you
>mean mineral oil full stop? The reason I used it was because it was an
>old fridge, that I fucked up myself, and so if the repair 'didn't work'
>I'd be out $17 for the oil (with plenty left over, vs $150 odd for
>synthetic, through repco, not sure if that was their optimistic price,
>or the going rate) and $10 for the alloy solder
IIRC Suniso HS5 was the old R12 oil, and there were plenty of
equivalents from the various oil companies... which will all be
mineral oils. What I'm suggesting is that the modern synthetic oils
like ROC, which are multi compatible (with refrigerants and other
oils) are a much better way to go.
Since you asked about flushing I'm presuming that what's already there
is an unknown, or else a compressor has shat it itself and filled the
system with filings. Otherwise I'd just do as Noddy suggests and blow
the old stuff out with air... before adding the ROC. :)
Problems can also arise with systems previously converted from R12 to
R134A. The trade had all sorts of shonky tricks designed to save them
the trouble of removing the the original mineral oil (which isn't
compatible with PAG, or R134A). One that was popular for a while was
to add a quantity of the Japanese spec ester oil (which isn't PAG) to
the existing mineral oil. You'll probably also want to flush any of
those you might happen upon.
In more recent times they probably add ROC (or one of the equivalents)
which doesn't lead to any problems AFAIK. I've _never_ converted an
R12 system to R134A, but for hydrocarbon conversions I've done a lot
that way (topped up the oil without flushing) and never had a problem.
ROC is bright red, so you can normally tell if it's been used
previously (either straight or for top up).
ROC is available in 1L and 4L containers IIRC and it's vastly cheaper
(per unit) in the larger container. Since you probably only need
100ml or so for a single system you might find a friendly user who
buys in bulk and who'll sell you the little bit you need (ask your
Repco branch who buys the stuff).
--
John H
Patrick
> Nedavno Paul Saccani piše:
>
>>> So what is "hard vacuum" in kPa, bar... and what is "soft vacuum"?
>> 30 microns, and the kind of compressors used in refrigeration plants
>> don't pull anything close to it - nor do they need to, in their role.
>
>
> 40 bar! That is a "hard vacuum"!
>
I wish I could get some 40 bar vacuum. That would be very useful for
somethings at work.
John McKenzie
>
> I can't speak for him, but I'd be changing the oil at a minimum, but
> not "full stop not using mineral oil". I prefer the multi-compatible
> oil. Gotta say, however, that I don't know much about domestic
> fridges. Have you got some pierce fittings?
No I quite literally silver soldered an extension pipe to the fill pipe
on the compressor that was filled, crimped and soldered over, and made
my own setup. It's barbaric looking, and I doubt I've gotten enough vac
into it by the standards people are discussing here, but it's working.
> Last time I got RoC oil it was less than $20 for a litre, and it
> forgives a lot more sins than mineral oil will. Sounds like Repco are
> overcharging. I can see why you would rather stick to what you have
> at that price, but for less than $20, you might find the RoC oil is
> more the go.
If I ever get around to doing the charger's a/c system (it was one of
the few with factory air, but the system was drained when I got it, and
I removed the pump for storage, and converted the belt drive, because
every time you rip an engine mount with factory air, the twin belts tear
through the upper radiator hose, and with the amt of towing I do....)
I'll look it up then.
Yvan
I searched for a while, and it seems that what I thought was shellite is
actually denatured alcohol. I'll have to search more... Perhaps to
contact some local chemist that speaks english...
Yvan
>>40 bar! That is a "hard vacuum"!
>
> ?!
>
> 1 Bar = 759,968 microns
>
> The smaller the micron number, the lower the absolute pressure.
>
> Not an SI unit, but it is the commonly used unit.
>
> 30 micron or less is a reasonably hard vacuum.
I have some linux converter application, and it says:
"Micron. Used in vacuum technology. Equal to 1 millitorr."
And "1 bar=0.750061682704 micron"
So 30 micron=39.9967105263 bar.
And when I wrote "hard vacuum" I was just quoting what you wrote, not
being funny.
John_H
>Nedavno John_H piše:
>
>>>> Shellite (petroleum spirit) works for me.
>>>
>>>Is this the stuff that was used in small heaters (I think that my
>>>grandmather had some, and used it before she got electric heater). I
>>>think I used it to clean the carburetor. I ask this, as I need to find
>>>out if the stuff is available here.
>>
>> Probably.
>>
>> It's known by various names in different parts of the world. If you
>> google either term you should come up all the possibilities (language
>> differences aside).
>
>I searched for a while, and it seems that what I thought was shellite is
>actually denatured alcohol. I'll have to search more... Perhaps to
>contact some local chemist that speaks english...
Shellite is a low boiling point petroleum fraction that's free of
additives (ie it's very clean). It's often used as a fuel (called
Coleman fuel in some places) and as a cleaning agent for clothes
(called white spirit in some places). In Australia it's commonly sold
in supermarkets and hardware stores.
For laboratory use it's labelled petroleum spirit (as sold by chemical
suppliers). I think I've also seen it called naptha.
In days gone by it was used in various heating appliances as a cleaner
alternative than petrol. 'Petrol' clothes irons and camping stoves
come to mind. Some of these devices also used kerosene and a few used
alcohol (alcohol isn't a suitable solvent for refrigeration oils and
kerosene is dirty, oily, smelly stuff). Denatured alcohol is called
methylated spirits in Australia (just to confuse things further).
I'd be very surprised if 'shellite' (presumably named after the Shell
Company... 'Shell light') isn't readily available worldwide, once you
find out what it's called in your country.
--
John H
the_dawggie
Yup, and mentioned here a very nice additive to waste veggie oil,
in diesel engines to increase performance (I still don't have a complete
understanding of that)
It's pretty much this:
http://www.shell.com/static/nz-en/downloads/shell_for_motorists/fuels/shellite_2004_09.pdf
However, yup, it is a good solvent.
Patrick
> Nedavno Paul Saccani piše:
>
>>> 40 bar! That is a "hard vacuum"!
>> ?!
>>
>> 1 Bar = 759,968 microns
>>
>> The smaller the micron number, the lower the absolute pressure.
>>
>> Not an SI unit, but it is the commonly used unit.
>>
>> 30 micron or less is a reasonably hard vacuum.
>
>
> I have some linux converter application, and it says:
>
> "Micron. Used in vacuum technology. Equal to 1 millitorr."
>
> And "1 bar=0.750061682704 micron"
Nah. That's all wrong and back to front.
Much more like one millibar = 0.75 torr
See here: > http://www.digitaldutch.com/unitconverter/
Yvan
>> I have some linux converter application, and it says:
>>
>> "Micron. Used in vacuum technology. Equal to 1 millitorr."
>>
>> And "1 bar=0.750061682704 micron"
>
> Nah. That's all wrong and back to front.
>
> Much more like one millibar = 0.75 torr
Aha! I have "micron" and "micrometer of mercury (0C)".
1 bar = 750061.682704 micrometer of mercury (0C), and
1 bar = 0.750061682704 micron
So your micron is my micrometer of mercury (0C) :-)
And than a "hard vacuum" of 30 micron is 0.00004 bar. I thought it would
be some negative value, so when I wrote "40 bar" I was thinking of
negative pressure of 40 bar. It seems it does not work that way :-)
I think that I found somewhere that I can get 20 bar pressure from the
refrigerator compressor.
And what is the vacuum that you can get from it?
Yvan
>> Shellite is a low boiling point petroleum fraction that's free of
>> additives (ie it's very clean). It's often used as a fuel (called
>> Coleman fuel in some places) and as a cleaning agent for clothes
>> (called white spirit in some places). In Australia it's commonly
>> sold in supermarkets and hardware stores.
>>
>> For laboratory use it's labelled petroleum spirit (as sold by
>> chemical suppliers). I think I've also seen it called naptha.
>>
>> In days gone by it was used in various heating appliances as a
>> cleaner alternative than petrol. 'Petrol' clothes irons and camping
>> stoves come to mind. Some of these devices also used kerosene and a
>> few used alcohol (alcohol isn't a suitable solvent for refrigeration
>> oils and kerosene is dirty, oily, smelly stuff). Denatured alcohol
>> is called methylated spirits in Australia (just to confuse things
>> further).
>>
>> I'd be very surprised if 'shellite' (presumably named after the Shell
>> Company... 'Shell light') isn't readily available worldwide, once you
>> find out what it's called in your country.
>
> Yup, and mentioned here a very nice additive to waste veggie oil,
> in diesel engines to increase performance (I still don't have a
> complete understanding of that)
>
> It's pretty much this:
>
>
http://www.shell.com/static/nz-en/downloads/shell_for_motorists/fuels/shellite_2004_09.pdf
>
> However, yup, it is a good solvent.
Thank you, I'm sure I'll find how it's called here.