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gurgling with central a/c

The TWE048C air handlers are rated at 4 tons. I will look into the orifice sizes.


  • Dave_61
    Dave_61 Member Posts: 308
    gurgling with central a/c

    Our house is about 5 years old. It has 3 central a/c units. The first summer (2001) we had no a/c on 2nd floor. The contractor came out and repaired a leak in the system and recharged it. It was OK for a couple of summers and then we had no A/C again. The contractor came out again and found a leak outside which he repaired. As long as I can remember, this air handler makes a gurgling/percolating/rushing sound when running (almost like when water in a teapot is just starting to heat up). Unfortunately, the piping goes through the walls of 2 bedrooms. The contractor says the gurgling is normal and is due to the refrigerant going through an orifice on the air handler (and it is most noticeable at the air handler). It is also the loudest when the a/c starts and stops, but it seems that you can still hear it when it is running too (just not as loud).
    We don't notice it with the 2 other air handlers (one in basement and 1 in attic).
    Could we still have a leak/low refrigerant, or is this normal? Is there any way to make it quieter?
  • Eugene Silberstein
    Eugene Silberstein Member Posts: 1,380

    Typically, there is some noise that can be heard when the system is initially started up, as the high pressure refrigerant is flowing to the low side. This is most evident on systems with expansion valves and almost non existent (in comparison) to systems equipped with fixed bore metering devices.

    Excessvie refrigerant flow noise can be the result of a number of factors including an improper air handler/condesning unit match, an improper metering device or piston size, a refrigerant charge related problem or improperly sized refrigerant lines.

    The bottom line is this. If you are hearing excessive noise resulting from the refrigerant flowing through the lines on an ongoing basis, the velocity of the refrigerant is too high. Since you mentioned a gurgling sound, it may be that you have some liwuid refrigerant flashing into a vapor before entering the metering device. At any rate, the gurgling sound, even after the system has been running for a period of time, is an indication that, at the very least, the system is not operating as efficiently as possible.

    Of course it is impossible to evaluate and troublehsoot your system from my vantage point, or any other vantage point other than right in front of your system.

    I would definitely have someone come in and look at the situation, possibly requesting another technician who would be able to evaluate the system with a fresh pair of eyes... and ears.

    Hope this helps.
  • Dave_61
    Dave_61 Member Posts: 308
    Thank you. Don't know if this helps

    at all, but the air handler in question is Trane TWE048C with 2 ton Trane outdoor compressor unit. The air handler says it is equipped with Orifice 83.

    Our 1st floor air handler is also a TWE048C but with a 3 ton compressor and is equipped with orifice 86.

    The attic air handler has no orifice (it is just piped directly to the smaller pipe). I believe it is a Trane TWE036C.

    Would it be possible to have the orifice removed as in the attic unit and still have it function properly?
  • Techman
    Techman Member Posts: 2,144
    Gurgling noise

    Hi Eugene and Dave Dave, having your mechanic check for proper superheat at the evap coil and at the same time check for a "full line of refrigerant" at the evap coil. I like using an "electronic sight glass" .In several situations of mine ,adding freon to fill the "sightglass" has stopped that type noise problem for me.
  • don_163
    don_163 Member Posts: 67
    Ditto to

    what the tecman said.

    Wow!! a four ton coil on a two ton condenser..sure hope you have a dehumidistat and variable speed on that thing.
    Thats is acourse if its humid in your area..If not then carry on.
    CHARLES_4 Member Posts: 61

    Now for something completely different: Any possibility what you hear is condensate in the air handler/drain piping etc? If it's a pull-through design and "they" (who are those guys?) didn't trap the drain, that thing will have you running to the can every 15 minutes. Just another idea...
  • Dave_61
    Dave_61 Member Posts: 308

    the drain does have a trap...it is definitely the refrigerant you hear.
  • Dave_61
    Dave_61 Member Posts: 308
    We're in Northern CT...

    never have noticed any problem with humidity inside the house in the summer.
  • Wayne_16
    Wayne_16 Member Posts: 130
    Non condensables in the refrigeration system?

    > the drain does have a trap...it is definitely the

    > refrigerant you hear.

  • Wayne_16
    Wayne_16 Member Posts: 130
    Non condensables in the refrigeration system?

    Is the liquid line hot or warm to the touch? Warmer than ambient air temperature? If so, there may be non condensables in the refrigeration system. Have the refrigerant recovered from the system, install a new filter dryer, evacuate to system to under 500 microns, using a reliable micron gauge, no manifold gauge readings allowed here. Recharge the system according the specifications of the unit and the metering device used.

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