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Thread: Trane XL14i

  1. #1
    Join Date
    Jul 2005
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    16
    I recently had two XL14i heat pumps installed, 1.5 ton second floor, 2.5 ton first floor. The 2.5 ton is very quiet, but the 1.5 has a noise coming from the compressor. Shouldn't both have the same noise levels. Interesting enough the 1.5 appears to have a larger compressor based on the compressor cover sizes.

  2. #2
    Join Date
    Mar 2002
    Location
    Concord, CA
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    Sound quality is product of the installation and not just the equipment. If both outdoor units are on the ground level but the air handler for the upstairs unit is in the attic, then the upstairs unit has to push its refrigerant against a much larger column of liquid. In other words, BTU for BTU it's working a little harder than the downstairs unit to accomplish the same task.

    That is not to say that your problem is normal. In reality I have no clue why the sound quality is so much different. The upstairs unit should be able to run fairly quietly despite the circumstance I just described. Being overcharged is a definite cause of a noisy compressor. You may wish to ask about that. Obviously you need to have your installing contractor address this.

  3. #3
    Join Date
    Jul 2005
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    16
    Thanks. The distance to the airhandler in the attic is approx 43 ft, the downstairs distance is approx 27 ft. Good info to have ready for the installer when he comes back wednesday.

  4. #4
    Join Date
    Jul 2005
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    16
    Irascible,

    Forgot to ask: The upstairs unit (1.5 ton) has a 1/4 refrig line and a 5/8 suction line, is this adequate for the application?

  5. #5
    Join Date
    Mar 2002
    Location
    Concord, CA
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    I took a look at Trane's application guide for refrigerant piping. Even with the 43 foot length and the 20 foot lift those line sizes are acceptable (unless you have a LOT of turns and elbows) for both R-22 and R-410A systems. 410A especially has plenty of head room in that regard.

    Just a wild theory: 1/4 inch tubing is so small that it wouldn't be hard to accidentally partially fill the tube with brazing alloy (or refrigeration grade solder) when the lines are being put together. If that happened then the unwise and/or uninformed installer might be tempted to add excess refrigerant to compensate for the restriction. IF that happened you would most certainly get a noisy compressor as a result.

  6. #6
    Join Date
    Jul 2005
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    16
    I am just a dumb homeowner but the brazing material drop through theory did occur to me since the technician was applying the material heavy according to him, and he also had to rebraze to correct a leak. Good info, thanks

    Homer

  7. #7
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    Mar 2002
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    Concord, CA
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    Another way to determine an overcharge is to find out how much refrigerant was added. Even with the length you'd probably only need to add about one-half to three-quarters of a pound of refrigerant.

  8. #8
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    Mar 2002
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    Concord, CA
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    Just to add fuel to your already worried fires: Did they purge the lines with nitrogen when they brazed? If not then ash formed in the lines. The ash can collect at the metering device and cause a restriction. And again they could have compensated by adding extra refrigerant. That can be even harder to diagnose.

    When you have a restriction in the middle of the line then from that point on the line is often noticeably colder than before the restriction. But if the restriction is at the metering device then you won't be able to tell by feeling the temperature of the line. You’d end up with high head pressure, high subcooling and a noisy compressor - though it would most likely still cool. If you have those symptoms then they’ll probably need to pull the refrigerant out and take a look at the metering device.

  9. #9
    Join Date
    Jul 2005
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    16
    You are right on the money....they added 11 ounces.

  10. #10
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    Mar 2002
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    Hmm. Then it shouldn't be grossly overcharged. Though if I had to add two pounds to a system when I know I shouldn't of, I wouldn't exactly document that. :^)

    Anywho, don't bang them over the head with this thread. I could be off my rocker. You could have unreasonable noise expectations. We don't know yet.

  11. #11
    Join Date
    Jul 2005
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    16
    I have been known to be unreasonable but this time I have a standard to compare it to, the other new very quiet unit sitting beside it. My wife can even tell the difference which says alot.
    I really appreciate your help.
    Homer

  12. #12
    Join Date
    Jun 2005
    Location
    Clearwater,FL.
    Posts
    34
    Most likely noises in the new 14i are from a simple hot gas pipe up against the plastic base of the unit,i will find this alot on new units,just takes a little bend,an suprise homeowner no more noise,But Please! No contractor wants joe homeowner directing him on diagnosing problems,had too many times joe homeowner with too much time on the internet coming up with garbage ideas he read from web sites, let the pro's do their job, don't try to micromanage the contractor,if not satisfied contact the manufacture,they have field service reps that will help you get the problem cleared up,most good dealers will contact the FSR on their own,if they are having trouble figuring it out.This is a message to all homeowners who post questions on this forum,this is'nt a DIY forum or a get ammunition to ride the contractor forum please! there are too many variables in diagnoising problems in the hvac trade,Let the Pro's do their job.PLEASE!

  13. #13
    Join Date
    Mar 2002
    Location
    Concord, CA
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    I take it all back. Bill is right. We must not disturb the delicate genius that is the typical HVAC contractor.

    But wait... The typical HVAC contractor is a dolt. That's just my opinion and I'm entitled to it. You forget Bill that contractors on this forum are just a little smarter than the average bear. And certainly we've come up with no bad theories. But if you think so then I guess hrc can't say anything about your discharge line observation. We wouldn't want to annoy his professional technician who likes to apply ample amounts of brazing alloy with our garbage internet theories, now would we?

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