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  1. #1
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    SH in high humidity climates

    So I live in SE Texas near the gulf where the outside humidity is 70-90%. I had high SH on a unit at 29°SH. Target SH according to the mfr should be 7-8 in accordance with their chart. I was talking to another tech and he said that "with the high humidity areas, he likes to see it around 14-15". I would think if humidity was a big enough factor, the mfr would include that in their target? Right? Just wanted to see if there are any facts behind this.

    Thanks,
    Thomas

  2. #2
    Join Date
    Aug 2012
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    if you have a high heat load you will have a high target superheat. if office and 90 degree indoor temp... likely after breakdown your tag could be 29 plus. you are free to overcharge the system if you like to make your sh 9 or 10 but that would not be good idea.

  3. #3
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    Thread Starter
    Here are the measurements I took
    Attached Images Attached Images  

  4. #4
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    ok what's the problem.

  5. #5
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    Aug 2016
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    Looks like the other tech is spot on. If you look at r22 fixed orfice/superheat chart with 80 oddb and 67 idwb your superheat should be about 16-17 degrees

  6. #6
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    Aug 2012
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    just to let you know goodman are very high quality when it comes to guaranteeing leaks.

  7. Likes Blake79 liked this post.
  8. #7
    Join Date
    Jun 2013
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    Northeast Wi
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    With the sheet you posted I came up with a target SH of 19.75. If my math and remembering the target SH calculation were right.

  9. #8
    Join Date
    May 2014
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    I copied this to my notes from somewhere on this forum:


    Target superheat with orifice system:

    IWB x 3 - 80 - ODB / 2 = target superheat



    That said, outdoor humidity or wet bulb doesn't mean much when looking for proper superheat.

    And, where are you measuring the superheat? Bottom line, if you are getting good cooling back to the compressor and not flooding, then you are good for the time being.

    Oh, and lastly, what is your subcooling?

  10. #9
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    ^^^ that's what I used. Hope the math was right.

  11. #10
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    just how do you have that high of SH with a delta T dry bulb of 25 and a delta T wet bulb of almost 16.

    those deltas scream low air flow which then the high SH says low charge or restriction.

    somethings really wrong with the system or your readings......
    my boss thinks its possible to repeal the laws of physics

  12. #11
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    evaporator temperature difference = 41 something, condenser temperature difference = just under 11.

    wow. maybe missing two things. airflow and freon
    my boss thinks its possible to repeal the laws of physics

  13. #12
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    May 2014
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    Be sure you define temp difference [TD].

    Too many 'techs' I speak with and see on this forum do not know the proper definitions of TD, TS, SH, and SC.


    Which means all the information is worthless. Just sayin'.


    Quote Originally Posted by ch4man View Post
    evaporator temperature difference = 41 something, condenser temperature difference = just under 11.

    wow. maybe missing two things. airflow and freon

  14. #13
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    didnt have to, i knew you were watching this thread!

    i used delta T and TD correctly.
    my boss thinks its possible to repeal the laws of physics

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