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-   -   Badly corroded AC copper line (http://www.diychatroom.com/f17/badly-corroded-ac-copper-line-148553/)

miamicuse 06-28-2012 10:04 PM

Badly corroded AC copper line
 
I have a soft 3/8" copper line that runs from an air handler on the second floor, out to the front of the house, then runs along the exterior wall for about 80 feet and eventually connects to the compressor outside.

This 80' run is completely exposed and strapped to the exterior wall about 12" above the foundation, EXCEPT where it runs into a sliding glass door, then it drops below ground about 2", runs below ground for about twenty feet where it meets the compressor.

http://i173.photobucket.com/albums/w...t/P1030316.jpg

http://i173.photobucket.com/albums/w...t/P1030315.jpg

http://i173.photobucket.com/albums/w...t/P1030314.jpg

Is this the return line?

The problem is the portion that is below ground. It is buried very shallow, some spots 1", some spots 2", and covered with granite pebbles. It is badly corroded, dented in many spots, and pitted in others.

If I wish to repair this section of bad pipe, what is the best approach?

Do I cut the bad section out, and re-solder a new section with conventional copper fittings? Or do I need to braze it?

What is the best way to protect the underground section? Do I lay in a 2" PVC pipe and pass the copper line across on the inside?

carmon 06-28-2012 10:11 PM

thats the liquid line..... and yes you need to braze it.... i imagine the suction line will look the same.....:eek:

Doc Holliday 06-28-2012 10:12 PM

Holy hell, that system has never been running properly. That bigger line is the return vapor line, the smaller line is the high pressure liquid line, sending refrigerant to the evaporator where again, refrigerant comes back to condenser in vapor form via the bigger line.

I'd be willing to bet that if you cleaned that condensing unit your pressures would greatly drop as well. After that line is lifted/repaired and INSULATED your system would stand a chance of containing a proper charge. You're going to need to call a tech to perform the work, EPA certified and has all the tools. It will cost you some money, but hopefully he can recover and re-use the old refrigerant.

I can't see you taking on this work yourself, without a recovery machine, a recovery tank, a vacuum pump, gauges, a brazing rig, etc.

Doc Holliday 06-28-2012 10:15 PM

And you need to keep those three main sides completely clear, not a good idea to store those aluminum siding panels or anything else near the condenser. You're restricting air flow, higher head pressure, less efficient, higher electrical bill.

As it is the condenser sits too close to the home.

miamicuse 06-28-2012 10:31 PM

Thank you.

This home is a new purchase and I just did the inspection. So I have a bunch of things to sort out.

Thanks for the advice to move the hurricane panels, I was thinking they need to be stored somewhere else as well.

What I don't understand, is why the liquid line runs separately from the return line. Don't they usually run together? However this liquid line runs totally independently and took on a different path. I wonder if this was previously replaced.

I do plan on hiring someone to do this. I just wanted to get an idea of the approach, because if he replace with a new section under the sliding glass door in two years the new section will be dented from the gravel being walked on again. It needs to be buried deeper or have some sort of a rigid sleeve around it, right?

Now the next question, which is more expensive? To cut a 10-12' section out, and rebraze a new section? Or to replace the entire 80' run with a new coil of soft copper - I assume I need to buy a new 100' coil.

carmon 06-28-2012 10:33 PM

Quote:

Originally Posted by Doc Holliday (Post 953737)
And you need to keep those three main sides completely clear, not a good idea to store those aluminum siding panels or anything else near the condenser. You're restricting air flow, higher head pressure, less efficient, higher electrical bill.

As it is the condenser sits too close to the home.


I agree with doc...move all that stuff..... kinda close to house should not cause a real problem ...just hard to get at to clean

scottmcd9999 06-29-2012 05:42 AM

Quote:

What I don't understand, is why the liquid line runs separately from the return line. Don't they usually run together? However this liquid line runs totally independently and took on a different path. I wonder if this was previously replaced.

I'd bet that the liquid line had trouble at some point - either leaks, or a system replacement and they needed to upsize the line.

Regardless, as others have said you need to get that line away from the ground. In our area (southern US) copper in contact with the ground will deteriorate rapidly. I've seen linesets in direct ground contact corrode to the point of failure in just 5 - 6 years. If you're on a slab, then the lineset really needs to be run overhead to the airhandler. Most of the time that means you must go up the outside wall and penetrate the house to get into the attic area, and then route the lines over to the air handler/coil area (you can cover the lines outside with a lineset cover).

If you can't get it away from the ground, then run it in a PVC sleeve that is sealed and protected from the soil. This needs to be done anywhere the line is in contact with the ground.

And as others have said - this is not something a typical homeowner can do, unless you have the necessary EPA licensing and such. Call your local contractor to get this done. Unless you have an established relationship with your contractor, then call family and friends for recommendations, and get more than one estimate.

COLDIRON 06-29-2012 06:03 AM

To replace the line would cost quite a few$$$ and you still have a low seer unit that is several years old. I would just take care of what ever else you need to in the house and run the unit until you get some $$$ and have a new high eff system installed.

biggles 06-29-2012 09:54 AM

that condenser needs to home run to the air handler on the shortest route possible ..comng off the condenser and go vertical to keep the sun off it and minimize the charge.i pro could strap a new suction armaflexed and wire tie a 3/8 LL on to it run it up vertically into the second floor.if it is the front of the house hiding it in a rain gutter or go vertical on an exsisting one for low pofile....that unit might of had a previous compressor burn out with a suction line dryer..is there one up at the air handler on that LL?

miamicuse 06-29-2012 09:54 AM

Quote:

Originally Posted by scottmcd9999 (Post 953845)
Regardless, as others have said you need to get that line away from the ground. In our area (southern US) copper in contact with the ground will deteriorate rapidly. I've seen linesets in direct ground contact corrode to the point of failure in just 5 - 6 years. If you're on a slab, then the lineset really needs to be run overhead to the airhandler. Most of the time that means you must go up the outside wall and penetrate the house to get into the attic area, and then route the lines over to the air handler/coil area (you can cover the lines outside with a lineset cover).

This may be slightly off topic, but you got me curious. I am in Southern US as well, Southeast, Miami, Florida and I see soft copper pipes being used for water supplies installed underground all the time. It runs from one manifold to another manifold under the slab with no sleeves and much of them are still working after 40, 50 years. Now those are type L copper and are in direct contact with the ground (mostly sand), and the only thing they do is to have a section of sleeve where the lines pass through the slab.

Is the HVAC copper different from water supply copper to cause a problem when in direct contact with ground?

biggles 06-29-2012 12:25 PM

HVAC copper is smaller ID meaning it is thicker from the actual diameter as compared to plumbers...R-22 systems run as high as 275PSI on th eLiquid Lines then 410A is up in the 800PSI ranges...want that line running in a backyard with wife and kids hanging out.....that is wht when an old system is ripped out and they use the old line wit the new freons very dangerous if it was all brazed your good to go but if somebody used 95/5 or stay brite soft solder....:no:you have a Liquid Line snap at an elbow with liquid refrigerant spraying out at 800 PSI go help anything in line of fire will take the heat right out of whatever it hits....

COLDIRON 06-29-2012 12:46 PM

Stay Brite #8 good to 15000# if done right. Come on big if that 3/8 line breaks yeah liquid will come out, I don't think he's in that danger with this post. Run it till it dies then replace system. If it's running and cooling the house don't mess with it.

miamicuse 06-29-2012 06:53 PM

OK the system IS cooling at this point. It is an investment property for me so I am buying it from a bank and no one knows much about past history.

But there is a bunch of pictures showing a bit more what I am talking about.

Here is the air handler in an upstair closet. See how the copper liquid line runs in a different direction from the big line? The big line just drops down below. The copper line takes a turn.

http://i173.photobucket.com/albums/w...t/P1030342.jpg

http://i173.photobucket.com/albums/w...t/P1030343.jpg

http://i173.photobucket.com/albums/w...t/P1030345.jpg

Why do they run the copper line inside of a metal electrical conduit? To protect it? Never seen that before.

It goes past a closet and runs along the bottom of the baseboard.

http://i173.photobucket.com/albums/w...t/P1030347.jpg

This is where it exits the house in the front.

http://i173.photobucket.com/albums/w...t/P1030305.jpg

Runs across then down.

http://i173.photobucket.com/albums/w...t/P1030306.jpg

http://i173.photobucket.com/albums/w...t/P1030311.jpg

Then it starts to run almost at ground level.

http://i173.photobucket.com/albums/w...t/P1030312.jpg

Then it goes inside metal electrical conduits again and goes below the ground where the sliding glass door is. The electrical conduit is COMPLETELY corroded and fallen apart. The copper pipe inside is also corroded. This is the section I am concerned.

http://i173.photobucket.com/albums/w...t/P1030313.jpg

Then it runs past the sliding door and eventually emerges from the ground to connect to the compressor.

Doc Holliday 06-29-2012 07:23 PM

I'm assuming there was a problem with the original high pressure line (which I'd also have to assume was originally running with the low pressure line) and that's a replacement.

Dig around, see if you can't find it buried in the ground somewhere.

ben's plumbing 06-29-2012 08:33 PM

all i can say is wow:no::eek::(:mad: what a mix of feelings on this one....replace it in time....agree with cold on this heep...


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