Ac refridgerant line

Can this line be buried underground? I have never seen this!

You would have to use the proper type of copper, and protect it.
Much easier to run on the surface.

Yes!

Here that would be a no go unless the line was protected inside a conduit. It can be made of any plastic accepted by AHJ. Foam insulation is not protection.

From what I remember you should keep the buried part as short as possible.

SUCTION LINE ACCUMULATORS AND BURIED LINE SETS

From what I’ve read it depends on the manufacturer.

Trane…
Avoid installing refrigerant piping underground. It is very difficult to maintain cleanliness during installation or to
test for leaks. If underground installation is unavoidable, each line must be insulated separately, and then the
lines must be waterproofed and protected with a hard casing (such as PVC).
http://www.njatc.org/downloads/trc006en.pdf

Says nothing about “Not”.

Do avoid not putting the suction line in the dirt.:mrgreen:

You guys are not making any sense how do you suppose they get from the exterior condensing unit to the inside closet located furnace/A-coil on a slab foundation. Have you never observed the refrigerant lines coming out of the cement in the closet@ the furnace:shock::wink:

Thanks!
This was a very short distance. It surprised me because there was plenty of room to leave it above ground. The client was okay with it. That’s what matters!

Charley that is protected. Op was talking about into the ground.

Does anyone put water lines in the ground?

How do you suppose you get under the slab perhaps thru the attic???

Best practice is to sleeve the line set from point A to Point B, would I write up what the OP asked No I would not

I see no problem with it buried, we a lot buried for the company i worked for in Canada

We use to do the same with oil lines also but now you need a sleeve to protect it.

You guys didn’t read the links I posted.
It should be buried only a short distance or this can happen…

From York
“One such scenario is when a line set is buried for 10 feet or more. During the off cycle the vapor in the suction line can condense back to a liquid. When the compressor starts, this liquid is pulled back into the compressor and can damage it. Compressors are designed to compress vapor only, they do not like liquid.”

During the off cycle the vapor is turned to a liquid regardless of where it is located. The refrigerant temp in the suction line is 35 to 45 degrees if its in the attic where its 140 degrees shut the unit off and what happens to that vapor in the suction line its stationary not moving do you suppose its gona stay in the vapor form. There is not enough liquid in the line to create any kind of damage to the compressor. A scroll compressor has no valves and it is capable of pumping almost straight liquid for a short time as long as the oil in the compressor is being returned to the compressor;-)

I read it Roy and I can’t remember seeing any AC line unprotected into the earth on any of my inspections but I have seen one on Mike Holmes that was buried and well over eight feet covered in dirt. Must be a South Ontario thing.:wink:

I for one am not an expert, but that was from the York company.
It would seem to me that they are the experts with their products.

The equipment and their metering devices are set up for “normal” installation practices. Burying the lines a great distance underground is not a normal installation practice.

There is a potential to slug the compressor due to excessive sub cooling of the suction line (when the metering device was not adjusted for that installation practice)! Maybe in Alaska where there is permafrost!

“In the off cycle” it really doesn’t matter what the refrigerant does because as soon as the compressor turns on it changes the pressure on the entire Low side system and any liquid immediately “flashes off” back into a gas before it makes it to the compressor.

Next, burying a small section of suction line in the ground is not going to affect the overall temperature/pressure of the refrigeration system. The “off cycle” refrigerant pressure is the average of the temperatures that the equipment is exposed to. This is the outdoor air and the indoor air.

In order for refrigerant to turn to a liquid you must reduce the pressure on the gas to a point where it is sub cooled in reference to its pressure.

Normal operating suction pressure is 70 PSI G. That’s 41°F. The ground is 50 to 60° (at the surface) or higher in most cases. That means you must reduce the refrigeration pressure on the entire system below 93 PSI G from an average outdoor temperature/Pressure of about 165 PSI G. That means the little bit of pipe buried in the ground must reduce the overall temperature of the system 72°F. That is not going to happen Within any 24-hour period of time. There are no 24-hour “Off cycles” either.