Automotive Air Conditioning Information Forum (Archives)

hjc149 on Wed August 16, 2006 12:04 PM

Country of Origin: United States

Is there a relatively inexpensive product than can recapture freon for later use. I have a hose to change and don't want to pay someone to evacuate the system, etc. I'm just a DIYer.

Edited: Wed August 16, 2006 at 12:37 PM by hjc149

rbinc on Wed August 16, 2006 6:42 PM

No there is not. Take it to a shop. Even if you vented R-12 into the atmosphere (which both the EPA and I most vehemently discourage), you would still need a vacuum pump to evacuate the sytem before recharging.

Have a shop recover and recharge and do the mechanical yourself in between. If you are going to convert to 134, do your homework. Takes more than the irresponsible ripoff kits sold at the parts stores...

Good luck.

NickD on Wed August 16, 2006 6:56 PM

This was posted by Gary some time ago.

Recovery of Refrigerant

Regarding recovery, I used the described vacuum pump system to recover a small amount of R12 into a converted propane bottle that I had evacuated. As the other poster said, you have to be very careful. This is not the best way to recover refrigerant for the DIY'r. Following is a method that I plan to use next time I need to recover a charge:

1) Prepare a propane bottle for refrigerant storage by installing a fitting from your hardware store. The fitting connects to the propane bottle and presents 1/4" male tubing end for connection of R12 hose end. Cost
2) Throughly evacuate the bottle for 1/2 hour w/ vacuum pump.

3) Place the evacuated bottle in a washtub full of water w/ a large amount of ice. Keep ice handy to resupply.

4) Start and warm the vehicle w/ AC system to operating temperatures.

5) Hook up gauges and purge hoses to AC system. Close hood to retain engine heat.

6) Open high and low side of manifold gauges and allow refrigerant to flow from AC system to propane bottle in ice bath. An inline filter is used to stop any oil/debris from entering the bottle.

7) This will recover all refrigerant down to about 30 psi. This may take a while.

8) Close manifold gauge valves and propane bottle valve.

Steps 9-14 involve a certain amount of hazard and require special care. You may want to simply stop at this stage. You decide what to do with remaining small charge. If you want to recover every last molecule you can, then proceed.

9) Reconnect manifold gauges and propane bottle w/ vacuum pump in series w/ charge hose (center hose) of manifold gauge leading to vacuum pump and on to your propane bottle. You'll need a spare R12 charge hose. Vacuum pump suction to manifold gauge side, and discharge to propane bottle.

10) Purge Propane bottle to vacuum pump discharge line, and suction side of vacuum pump to manifold gauge.

11) IMPORTANT TO DO THIS IN CORRECT ORDER. Open hi/lo side of manifold gauges and propane bottle valve. At this point system pressures should be roughly equal on both sides of vacuum pump.

12) Start vacuum pump and and allow AC system pressure to draw down to near zero. Don't draw below zero or you may pull air into your bottle. This won't take very long so watch pressure carefully.

13) IMPORTANT. KILL vacuum pump!

14) Immediatly after killing vacuum pump, Close propane bottle valve.

Note, if you close the propane valve before shutting the vacuum pump off, you'll have the short hose length from pump discharge to propane tank valve being pressurized by your vacuum pump discharge and you could burst the hose. That's why you kill the pump first. BE DELIBERATE AND CAREFUL.

Good Luck.

hjc149 on Wed August 16, 2006 11:43 PM

Thank you.

TRB on Wed August 16, 2006 11:50 PM

Nice post Nick, shows how to mix up their own HC refrigerant. Would love to run a refrigerant analyzer on that after the refrigerant had been reclaimed and reinstalled.

PS: This site does not endorse the procedure listed above! As it fails to follow any regulations concerning the proper usage of refrigerants.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

NickD on Thu August 17, 2006 7:13 AM

That thread was actually posted here several years ago, by Gary, no comments back then, D Andrews also posted a similar post with some discussion as I recall, exactly what to use for a container, can't exactly use a zip-lok bag or a Mason jar. Old refrigerant tanks won't work, have an internal check valve so can't be refilled. A fresh new 20 pound propane tank would work, but would require lots of ice and a big container to put that tank in. Also was mentioned that dry ice works much better. Mixing in salt like an old fashion ice cream maker also reduced the temperature.

Can only speculate as to how much propane would be left after drawing a vacuum on a used container for 30 minutes, what about drawing a vacuum for a day?

Can always find a used recovery machine, but I suppose the same questions could be asked as to what was in there, would certainly spend hours cleaning it first and replacing all the filters and oil.

To my knowledge, no such simple ice activated recovery device is on the market. Know of no shops around here that will recover your R-12 and give it back, most would not only keep it, but charge you to remove it.

Maybe Hecat will take an interest in this and market something, or maybe we should just recommend that all DIYer's take it to a shop if they don't have the equipment.

It's an unsolved problem.

Chick on Thu August 17, 2006 7:31 AM

Nick,
never hear about D Andrews anymore. Ever hear from him?


-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

NickD on Thu August 17, 2006 7:59 AM

Considered Dave a great net friend, last I heard from him was 10/12/01. Dave did have both health and work problems, was going in for surgery and his plant was closing and being moved to Mexico, that was the last word I received from him and wondered often myself, what happened to him?

mk378 on Thu August 17, 2006 11:07 AM

Use a new propane tank. If you pull a vacuum on an empty used tank, the propane will soon be long gone, but the stinky chemical added to propane fuel is much less volatile and about impossible to remove. Your refrigerant will end up smelling like propane and no one will touch your system because they think someone put propane in it.

Cussboy on Thu August 17, 2006 3:02 PM

Here's how I recovered R-12 a few times. I had a metal cannister, about 12 inches by 4 inches diameter, with a 1/8 inch FPT and I installed a shut-off and flare fitting. I attached it to my gauge set (middle fitting), attached high side hose to the vacuum pump, and low side hose to low side fitting, and had the cannister sit in a dry-ice-alcohol bath in a bucket. I pulled a vacuum from the cannister (only) then closed it off and opened the cannister to the low side, and my R-12 all went into my cannister for future use. With correct adapters, could be also used for R134a recovery.

George Bray on Fri August 18, 2006 8:17 AM

I'm thinking of buying an old secondhand domestic freezer for the purpose of cooling a recovery cylinder. I trust the freezer would get colder than an dry-ice based mix. Is that a fair assumption? And it should cost less to pick up an old freezer than buy a single quantity of dry ice.

The plan is to drill a hole straight through the door of the freezer to pass a hose through, with sealant and insulation all round. The recovery cylinder will sit in the middle of the freezer.

An alternative approach is to use my existing domestic freezer. I would remove the door temporarily and replace it with a temporary wooden door (insulated) than I can drill a hole through. This might be more convenient than having two freezers kicking around.

Regards
George

George Bray on Fri August 18, 2006 8:19 AM

Amendment:

The word 'an' in the second sentence of my posting above should read 'any'.

I do wish there was an edit facility, at this forum, like for many other forums.

Regards
George

mk378 on Fri August 18, 2006 9:24 AM

Use a chest type freezer that opens at the top. You can simply close the door on the hose with no modifications to the freezer. The cold air will stay inside quite well since it falls to the bottom. It would work better to surround the tank with a liquid that doesn't freeze and use that as a reservoir of cold.

Dry ice and alcohol is much colder than any household freezer. However as long as you get all the liquid R12 out of the car, there really isn't much difference to be made by lowering the pressure of the remaining gas. I'd be concerned about the metal the container is made of at extreme low temperatures. Some types of steel become weak and brittle.

NickD on Fri August 18, 2006 9:26 AM

There is, but you have to be logged in first before that edit box will appear. An environmental chamber is nice, can cool most of those down to -100*F, but very expensive, even for a used one. A lid on top chest freezer is most ideal, same principle as the ones in the grocery stores where they don't even have a lid on top so you don't have to fool around making a door, but if fussy, just pack some rags around the top.

graeme on Fri August 18, 2006 10:27 AM

Quote
Originally posted by: NickD




13) IMPORTANT. KILL vacuum pump!



14) Immediatly after killing vacuum pump, Close propane bottle valve.



Note, if you close the propane valve before shutting the vacuum pump off, you'll have the short hose length from pump discharge to propane tank valve being pressurized by your vacuum pump discharge and you could burst the hose. That's why you kill the pump first. BE DELIBERATE AND CAREFUL.
.
Dont really understand the ^. How would the pressure in the hose increase if the pump has already evacuated all the refrigerant from the system?

NickD on Fri August 18, 2006 12:02 PM

Let me post a disclaimer, just copied and pasted an old post on this subject in quotes and posted the source. Feel any vacuum pump should come with a valve, they can put a valve on the cheapest can tap hoses and would make life a lot easier if all pumps had that valve too for various reasons.

I'm not much into home made things anymore, takes too much time and like something neat that can be put away in a box, principles are pointed out in that post, if someone would care to market such a device and even buy standard low cost tanks before they were filled with something else. Now, home made homes is a different story, there you have something that is of value.

ryan212 on Thu July 08, 2010 10:20 AM

delete me.


-------------------------
1998 Pontiac Trans AM M6 WS6 #370
2006 Pontiac GTO M6

Edited: Thu July 08, 2010 at 12:00 PM by ryan212

mikecap67 on Mon July 12, 2010 4:42 PM

Quote
Originally posted by: rbinc
Even if you vented R-12 into the atmosphere (which both the EPA and I most vehemently discourage),
Good luck.


So the ozone hole has gotten smaller in the last several years because no more R-12 is being produced and used, right?

-------------------------
72 Cutlass 455

Gunnery Sergeant USMC (Retired 2007)

CCWKen on Mon July 12, 2010 10:54 PM

Quote
Originally posted by: mikecap67
Quote
Originally posted by: rbinc
Even if you vented R-12 into the atmosphere (which both the EPA and I most vehemently discourage),

Good luck.





So the ozone hole has gotten smaller in the last several years because no more R-12 is being produced and used, right?

Of course not. The EU is now blaming 134A for the problem.


-------------------------
Ken Kopsky

Custom Car Works
"Rules are for the guidance of wise men and the obedience of fools."

mikecap67 on Tue July 13, 2010 1:28 AM

Thats because the patent on 134 is up also.

-------------------------
72 Cutlass 455

Gunnery Sergeant USMC (Retired 2007)

Gordon Shumway on Sun July 25, 2010 12:22 PM

Hydrocarbons solve all the problems.
They're cold and don't polute.
There is only one documented case of a fire and that was not due to a collision.
Besides, pressurized oil in any type refrigerant is highly flammable.
Consider the gasoline in your tank and fuel lines.

TRB on Sun July 25, 2010 1:01 PM

Quote
Originally posted by: Gordon Shumway
Hydrocarbons solve all the problems.

They cure cancer and provide wealth for all 3rd world countries. WOW we need more of this stuff.



-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Gordon Shumway on Sun July 25, 2010 2:32 PM

I apologize to everyone for ever mentioning HC, even though they are legal in 32 states in vehicles (according to the EPA site) and do cool very well.

I promise to never mention HC again.

TRB on Sun July 25, 2010 2:52 PM

Quote
Originally posted by: Gordon Shumway
I apologize to everyone for ever mentioning HC, even though they are legal in 32 states in vehicles (according to the EPA site) and do cool very well.



I promise to never mention HC again.

They can't be legal in 32 states. All R12 vehicles required a specific retro fitting. Does the HC have a specific retro fitting. No so they have to use a R134a fitting and it is illegal to do a sham conversation using any HC refrigerant. Mention it all you want! Just don't expect those in the industry to buy into the BS as we have all been through this before and have since 95.



-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com