A friend had me remove a section of drywall to see why there was moisture damage at the baseboard height on one wall.

I found the refrigerant line that runs from outside compressor to attic mounted air handler was poorly insulated and dripping in the wall cavity.

Upon close inspection I also found that the larger copper line,the suction line, was nearly flat where a 90 degree turn to the outside was bent into it.

I estimate 10% of the capacity of the line is available due to the severity of this bend.

The A/C is brand new and cooling well.

The Home was built 15 years ago and this is the third AC replacement. The kinked line was done during construction.

I believe this kinked line is the cause of premature failure of the last 2 units and if left unfixed will lead to a third unit failing.

Tell me what can happen to a system over time in a case where the 3/4 suction line is crushed like this.

enter image description here

Edit: the kinked section was cut out and new line put in.

Here is a photo of how bad the kink was. enter image description here


A kink in the line starves the system and it should be pumped down cut out and a 45 or 90 put in its place. If it did not matter they would not use a line that much larger On the suction side.

  • When you say starves the system are you referring to the compressor being deprived of lubricant?
    – Kris
    Sep 10 '20 at 3:37
  • mainly it makes the compressor work harder. it's costing you money.
    – Jasen
    Sep 10 '20 at 3:44
  • I would suggest trying to breathe through a straw. This is the difference the large line allows the flow at low pressures some even are sub atmospheric so the large line that supplies the compressor is like a snorkel size and it has been pinched down to a straw, the oil will make it back but the increased workload is costing you $ and wear and tear on the compressor.
    – Ed Beal
    Sep 10 '20 at 16:10
  • I’m sure you are correct. The new install was only a couple months ago. The company has come out to do post install inspection and has determined that they must add another return air intake which they are scheduled to do at no customer next week. I can imagine that they are not thrilled at tye or idiocy of having to evacuate repair and recharge system. I don’t think they should be expected to fix the suction line at no cost. I do think it will have to be fixed to keep American Standard from voiding the warranty.
    – Kris
    Sep 10 '20 at 16:44
  • That should not take long they can close the discharge valves on the compressor start it and run it until the suction is at a vacuum (gauge reading) a quick clean and cut , purge with n2 sweat, pressure check then pull a vacuum with a pump if it is not open for more than a couple of minutes the vacuum only takes a couple of minutes because no moisture has had time to get in the system. If it is open as far as easy to get to a good tech could do this in many cases under 2 hours and with a big vacuum pump possibly under 1.
    – Ed Beal
    Sep 10 '20 at 17:57

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