Author Topic: Is refrigerant flammable? (getting a compressor from an old air conditioner)  (Read 15314 times)

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Offline XOIIO

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Alright, so no guarantee, might not even be there when I go to check, but there is a fairly beefy air conditioner for free, working, just old.

Now, these compressors are capable of some awesome pressure, 400psi+ from what I have seen looking around.

Now, the issue is the refrigerant, it's not exactly a nice thing for the environment, and illegal to just dump out, though I'm sure plenty of people do.

Thing is, I don't have the money to pay someone to reclaim the refrigerant, which would have to be done to get that compressor out.

I was thinking, if I crimped the pipe flat in several places near the end, maybe, jut maybe I could cut the pipe, and very quickly weld the end shut to seal it off.

I don't think the refrigerant is flammable, but it does have oil in it I think, not sure if there is a risk of a fire, or even a miniature flamethrower by doing this.

Offline Richard Crowley

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Are we to assume you mean Freon when you say "refrigerant"?
A quick check of Wikipedia says....

Quote
Most uses of CFCs are now banned or severely restricted by the Montreal Protocol as they have shown to be responsible for ozone depletion.[3] Brands of Freon containing hydrofluorocarbons (HFCs) instead have replaced many uses, but they too are under strict control under the Kyoto protocol as they are super-greenhouse effect gases. They are no longer used in aerosols, but to date no suitable general use alternatives to the halocarbons have been found for refrigeration which are not flammable or toxic, problems the original Freon was devised to avoid.
 

Offline XOIIO

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Well, I am not sure how old it is, I think Freon stopped being used 20 years ago or so? I'd have to check it for a date when I have it.

Offline Richard Crowley

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You must have skipped right over the part that says: " to date no suitable general use alternatives to the halocarbons have been found for refrigeration which are not flammable or toxic, problems the original Freon was devised to avoid."

Let me break that down for you....

1) Freon is still used because there is no suitable substitute.
2) Freon is not flammable which is why it was invented in the first place.

bonus...
3) If you cannot identify what the refrigerant is, then nobody can tell you whether it is flammable or not.
 

Offline kolbep

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There should be 2 small taps on the pipes where they go into the outdoor unit. Just use an allen key to close those off. That will trap most of the coolant gas/liquid in the compressor and outdoor radiator.
you can the cut the pipes, or unscrew them. The small amount of gas that escapes from the indoor unit should not cause a problem.

or, if you want, you can do a pumpdown, where you shut one of those taps (dont know which one), then start the aircon. It will then pump all the refrigerant into the compressor and outdoor unit. Give it about a minute, then close offthe other tap before switching off.

Once younhave removed the outdoor unit, still with its gas, then on the way home, stop at an aircon dealer, and ask them to reclaim tbe gas.

I highly doubt that the coolant is flammable.
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Offline romantronixlab

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My daily job involves working around automotive a/c systems and electronic controls and other systems. Wont say brand as it has nothing to do with the Freon information.
Freon in general is not flammable but under the right conditions like pressure and the amount of air in terms of percentage it can become volatile. One example R134 used in many refrigerators and vehicles. One big exception is R22a, also known as 22a Refrigerant, is a highly flammable colorless gas. If enough R-22a is concentrated in one space, and the refrigerant comes in contact with an ignition source, it could burn or even explode.
Not to mention that refrigerant overexposure may cause dizziness and loss of concentration. At higher levels, CNS depression and cardiac arrhythmia
may result from exposure. Refrigerants displace air and can cause asphyxiation in confined spaces. At higher temperatures,(>250°C), decomposition products may include Hydrofluoric Acid (HF) and carbonyl halides which is harmful to the lungs.

So before taking apart that compressor make sure at least that it is not R22a.
Will think about it.
 

Offline Richard Crowley

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If the unit is running poorly, then it may already have some of its refrigerant leaked out.
Are those compressors good for other applications (besides refrigerant cooling systems)?
Is there a good way to connect to the input and output of the compressor?
Is the tubing a standard size that you can get coupler fittings for?

You would need 1,000 of those units to equal one day's production of greenhouse gasses from all those sheep in New Zealand.
 

Offline XOIIO

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Picked it up, it was still there so that's good. I've had a migrane all day and lifting it made it 10x worse so that's bad.

Anyways, I was expecting it to be twice this size, but its quite compact. It's an in window one, I figured based on the description/close up image it was one that sat on the deck but was still one piece or something. Have yet to open it up, going to wait for an asprin to kick in first.

You must have skipped right over the part that says: " to date no suitable general use alternatives to the halocarbons have been found for refrigeration which are not flammable or toxic, problems the original Freon was devised to avoid."

Let me break that down for you....

1) Freon is still used because there is no suitable substitute.


What about R14 and R12 like in automotive systems? I thought that AC systems for houses moved over to that as well.

Offline Richard Crowley

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According to Wikipedia, both R12 (aka. Freon-12) and R14 (aka. Freon-14) are non-flammable.
http://en.wikipedia.org/wiki/Dichlorodifluoromethane
http://en.wikipedia.org/wiki/Tetrafluoromethane
 

Offline XOIIO

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Ah so those are just variants of Freon then. Interesting

Offline nctnico

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When I was a kid I harvested compressors from refrigerators this way:
- position the fridge so I can access one of the pipes on the compressor with a hack saw
- keep the hack saw at arm's length and saw until the tube goes 'sssshhhhh'
- stand back a few meters
- wait for the 'sssshhh' to stop and then remove the compressor
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline XOIIO

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Well, quite a large sized compressor in it, didn't have my phone on me, will head out in a bit, will probably record the process (though I took the case off. Everything is directly hooked together, no valves that I can see. Nothing much on the compressor except some painted/stamped numbers, nothing about the pressure it produces, or info about the refrigerant type. The plan is to use a c clamp to clamp it shut as much as possible before cutting it then wending the coil side. No fittings either but I can probably creatively find a way to get one on there, probably will just have it go to a 1/4" quick connect.

Here's a picture of the front I took while picking it up.



When I was a kid I harvested compressors from refrigerators this way:
- position the fridge so I can access one of the pipes on the compressor with a hack saw
- keep the hack saw at arm's length and saw until the tube goes 'sssshhhhh'
- stand back a few meters
- wait for the 'sssshhh' to stop and then remove the compressor


Possibly what I will have to do, I will use metal shears to cut the pipe though, that will also crimp it shut a bit, and I should be able to get through it. My hacksaw is DOA because the stupid blade retaining bit vanished, and I have to buy a whole new hacksaw :/

Offline Rory

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R170 (refrigerant grade Ethane) is flammable and can be explosive. You won't come across it unless you are into cryogenics.
 

Offline nanofrog

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Here's a picture of the front I took while picking it up.
Does it still work (blow cold air)?

Units of that age tended to be well built, and might actually be worth hanging on to if it's working properly. If not, the stuff you don't use after salvaging the compressor has scrap value (i.e. copper tubing & coils).

Also, R-22 was used prior to legal changes for stationary A/C systems in the US/CAN (think home/industrial HVAC, refrigerators & freezers), while R-12 was used for automotive. Both types are non-flammable, and are more efficient at cooling than what's currently in use.

EDIT: Never mind, you've already opened the system.  8)
« Last Edit: August 11, 2014, 12:29:56 am by nanofrog »
 

Offline XOIIO

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Well that didn't work, still don't have an auto darkening helmet but I was hitting the tube and it wouldn't start an arc, so it's just venting in the garage with the door open now. Even documented my failure  :palm:

Offline houdini

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Arent those pipes usually copper? also welding while gas is pushing out of the pipe would probably just end with molten metal being blown out of the weld and a bigger hole.
 

Offline kc9qvl

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 R22a, also known as 22a Refrigerant, is a highly flammable colorless gas.


US and Canada would have used R22 not R22a. R22a is basically propane.


Also, R-22 was used prior to legal changes for stationary A/C systems in the US/CAN (think home/industrial HVAC, refrigerators & freezers), while R-12 was used for automotive. Both types are non-flammable, and are more efficient at cooling than what's currently in use.

R410 the long term replacement for r22 is much more efficient. And r134a is also more efficient than r12.
[/quote]
 

Offline XOIIO

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Arent those pipes usually copper? also welding while gas is pushing out of the pipe would probably just end with molten metal being blown out of the weld and a bigger hole.

Yeah, probably for the best I guess. I'll just chop the rest of it now, there is a larger pipe (I believe for low pressure) that goes to another coil, doubt that has anything left in it but I'll check anyways.


Anyways, I think I got a small whiff of it, not sure but I smelt something mildly sweet as I was getting out of there. I had a super fucking massive migrane all day which ended up in the worst damn one I've had in my life, unrelated to the air conditioner (actually has me somewhat concerned, want to get a CT scan).

Anyways not sure if it was from the refrigerant or from pushing a pillow on my forehead hard for half an hour but my nose felt kind of numb, a bit like anesthetic was used, could have just been from the pressure but maybe from the whiff I got.

No residual effects today, so not a big deal, but if it has an anesthetic effect it could result in a pretty bad death I imagine if someone didn't know what they were dealing with (maybe suffocation or whatever other effect breathing in something with an anesthetic affect would have)
« Last Edit: August 11, 2014, 10:19:26 am by XOIIO »
 

Offline amyk

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Mild sweet smell? It's probably not propane.

All refrigerants are asphyxiant.
 

Offline XOIIO

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Mild sweet smell? It's probably not propane.

All refrigerants are asphyxiant.

Yeah, thought of that a short while ago, and mentioned it in the video, I'm going to edit it and upload it, at least bits, and the part where I have the compressor running, it's very quiet, I was expecting a bit louder. A bit unsure if it could reach 400 PSI or not, certainly not one of the big ones you get from outdoor units like aussie50 has for a high pressure air supply (which is what I'd like to make ideally), but plugging the end with my thumb for a short period does get some decent pressure up. Need to solder some copper fittings to the pipe to try and get it up to 1/4" threading to stick a pressure gauge or quick connect on (probably the latter as I can just connect it to my small air cannon that has a pressure gauge, though is a 7 liter fire extinguisher so it would probably take some time to get up to that pressure.

Another option is a vacuum pump but I don't really have anything to make a chamber out of. Another possibility though, and what originally got me wanting an A/C compressor.

Offline XOIIO

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There were some markings on the compressor I missed, looks like this was an R22 system, hopefully I can find the compressor PSI looking up the model number.

edit: hmm can't find anything. It's marked "aspera 138 BG 14", also has 10 FLA 46 LCA (or something similar to that, not in the garage right now)
« Last Edit: August 11, 2014, 02:43:37 pm by XOIIO »
 

Offline SeanB

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Wll it is old and runs R22, which does not burn but which decomposes in a flame to give a nice green colour, and a byproduct of hydroflouric acid ( yummy) so do not try to weld on it with gas venting! You will find it will give a pressure of around 200-250PSI into a closed valve ( not good as it can blow the piping) and will suck down to about 0.1PSI on the suction side.

It will blow a small amount of oil out the high pressure side, so will eventually run out of oil at some point running open loop. Suction line will be the 1/2 in pipe going in the side of the compressor, and the HP side will be the 1/4in pipe coming out the side. There will be another 1/4 pipe that is crimped off with either a valve ( if it has ever been opened) or with a crimp and brazed end, which is the fill line when it was made. Make a good not where the connections inside the compressor cover go, as there are 3 and if you get it wrong it will burn out fast. Keep the thermal cutout there as well ( on one terminal and connected to the black wire, with the red and white going to the other 2. Note the wiring as well to the 50uF capacitor there and keep it as well. It will need it.

If oyu are going to use this to compress air you will need to get a pressure shut off switch and set it to around 140PSI so you can use it with standard air tools. It is likely a small 1200 BTU compressor, and draws 10A runnig. You will need to cool the case with a fan while it is running, as it is designed this way to need cooling air.

Take the coils and separate them from any steel, and take to the scrapyard, where you get around $1 per kilo.
 

Offline paul23

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 R410 the long term replacement for r22 is much more efficient. And r134a is also more efficient than r12.

R410a is a medium term replacement.  It has already been replaced in Japan by R32 and will be replaced in the rest of Asia, Europe and South America over the next few years.  No idea on North America.  R134a has been replaced by R600a on almost all domestic refrigeration systems and will likely be phased out soon on commercial applications along with R404a.
 

Offline XOIIO

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Sounds like you have worked on these before XD

Output is indeed 1/4", and I am working on connecting that, like I say in the video I have yet to publish my air hose Is rated for 300 PSI, not using this on tools, but maybe for a duster and primarily my small (and smaller yet) air cannons.

I am working on getting the output to a quick connect which is proving a tad difficult.

Went to the hardware store, after finding that a 3/8ths pipe fits the 1/4 inch one perfectly I was going to solder those together, however I talked with a guy and he mentioned compression fittings. Knew of them but never really used em before so it didn't occur to me. Got one from 1/4" to 3/8ths, now the issue is getting that to either male or female NPT, preferably female but if I have to I can buy the female connection quick connect.

I have the coiled nylon hose from the air compressor, the one I used before I upgraded to a nice 25 foot rubber one, it has a working pressure 200psi and burst pressure 400psi, and seems close to the 3/8ths diameter, so I think that might fit in the compression fitting. Not sure but it seems like it might work. Not going to use this hose again and couldn't sell this for a few bucks anyways, so I'll cut it and see.

Offline XOIIO

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Hmm, it's considerably smaller, I wonder if the compression ring inside would bite down onto it enough to make it work properly. Hrmmmm

Should have gotten a couple spare rings while I was there  |O

I don't know, do you guys think that the compression fitting will work properly even with a couple millimeters extra space? I don't know if they have anything the size of that hose or not. Can't really return this if I use the ring anyways, was just a few bucks but still. I do want to just try it though. Might lead to a trip back either way.
« Last Edit: August 12, 2014, 12:54:49 am by XOIIO »
 


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