Buried Exterior Line?

[dallasbill]

Forgive for not knowing the correct terminology:

For one of our 2 outside Carrier units, the copper refridgerant line exits the wall and will run about 25 feet to where the Carrier unit sits on its pad. As is typical, this line is wrapped in a thick foam sleeve.

The HVAC guy wants to bury it in a shallow trench so it does not just sit there on the ground along the exterior wall. Is this acceptable? If so, should the foam sleeve be wrapped in something additional??

[Senior Tech]

buried for years with no side effects...and no additional insulation....but hang on, I'm sure some will beg to differ.

[t527ed]

i have seen many units with lines direct buried with no problem. less chance of them getting damaged than running exposed.

[pecmsg]

Only problem with buried line sets in shallow trench is someone digging in that area. Have set run through 2 or 3" plastic conduit. You will pay a little more now but save a lot later.

[dallasbill]

Thanks... I have no worries now!

It will be almost flush & parallel to the wall and well inside any future fence line.

Thanks again guys!! ;-)

[Shophound]

Originally posted by dallasbill

The HVAC guy wants to bury it in a shallow trench so it does not just sit there on the ground along the exterior wall. Is this acceptable? If so, should the foam sleeve be wrapped in something additional??

Has you considered having the lineset neatly attached along the lower half of the house wall? It's an easier solution than burying the lineset and sure looks better than the lineset just sitting on the ground, subject to weed whackers, dogs, etc.

Some buried linesets have posed refrigerant migration problems in installations where the evaporator is higher than the condenser. This is where refrigerant in the suction (vapor) line is cooled in the off-cycle to the point where it condenses to a liquid. When the compressor goes to start again, it can suddenly be faced with pumping a big "slug" of liquid from the suction line and compressor sump. Compressors aren't supposed to pump liquid, only vapor. A compressor can be damaged or destroyed in this fashion.
This can be alleviated by compressor crankcase heaters, and in more extreme cases by a liquid line solenoid that allows for a pumpdown phase at the end of the cooling call.

And, as others have already said, many buried lineset installations work perfectly normal. Circumstances dictate which precautions are necessary to ensure long compressor life.

[tinknocker service tech]

shop hound is 100 percent right
if you do want to bury it some codes now require it be put in to some type of liner pvc or abs plastic pipe
this is to make sure it cant be hit by some thing beeing stuck in the ground. also be cause if a rock is sitting agaisnt the copper it can cut into it in time and cause a leak and contaiminate the ground and or ground water
before doing this check with the code department and see what they require
best to strap it to the house and hide it with a cover of some sort

[djken]

I wouldn't worry about 'code' as much as I would worry about Carrier. Carrier says "DO NOT BURY LINE SETS".

[dash]

Originally posted by djken
I wouldn't worry about 'code' as much as I would worry about Carrier. Carrier says "DO NOT BURY LINE SETS".

Ditto.

[beenthere]

You can bury that line set and the unit might last 30 years, or might die in 30 days.

If you want warranty on the compressor, better get Carriers ok first.

[airconman]

ol tin is right....... burying line was ok years ago till they figured out that the ground acts as a heat sink..... burying line in PVC is the only way to go and make sure no water where you come out of the ground gets into the pvc...or poof heat sink again. the ground brings down the efficiency on it. Remember going over 50 feet see what the line set size needs to increase with the distance too.


[Edited by airconman on 04-28-2005 at 12:43 AM]

[dallasbill]

Thanks guys... I'm on it... both confirming proper diameter as it's greater than 50 ft and getting them to call Carrier on what to do.

It's a nice 3 foot high stone wall covering the exterior of the slab's perimeter beam, so a boxed-covering running along there might look a little hokey.

But I'd rather have hokey than a failure... with no warranty!!