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Thread: Superheat

  1. #1
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    Apr 2012
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    Edmond, Ok
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    Superheat

    Whats a good accurate general rule of thumb for superheat? txv and fixed bore? Just curious about different opinions and views?

  2. #2
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    Apr 2012
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    Pasadena,Maryland
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    If you have an iPad or iPhone their is an app called Hvac buddy that I like,it has a build in chart it will tell you what you sh should be given the condition at your particular location after you fill in the info like wet bulb,dry bulb,sat temps and so on,I don't know if any one here uses this app,but I find it helpful.

  3. #3
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    A while back hvacrmedic came up with a formula that works pretty well for target SH. I put it on a web page here:
    http://www.loadcalc.net/superheat.php
    Gary
    -----------
    http://www.oceanhvac.com
    An engineer designs what he would never work on.
    A technician works on what he would never design.

  4. #4
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    Quote Originally Posted by Priceless32 View Post
    Whats a good accurate general rule of thumb for superheat? txv and fixed bore? Just curious about different opinions and views?
    Try to keep it above zero. Not sure how "compliant" a compliant scroll is.
    Most compressors are designed to pump vapor.

  5. #5
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    Nov 2011
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    Phoenix,AZ
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    So saturday I had a 95 degree od db and a 56 degree indoor wet bulb (yes there is no such thing as humidity here)

    Acoording to my Fieldpiece Srh2

    and that calculator http://www.loadcalc.net/superheat.php

    I Should be flooding the compressor

    What does that mean?

  6. #6
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    Feb 2012
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    1,268
    Dupont has a nice app out now...although out of 5 guys in my class that downloaded the app all on android phones two worked properly....the other guys did not have the toolbar at the bottom of the screen.


    http://www2.dupont.com/Refrigerants/...lator_app.html

  7. #7
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    Have not seen that one on android,but I carry my iPad on service calls,the app I have will even let me email my results to my company or to the customer if they like.

  8. #8
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    Apr 2012
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    If you send me your email address I can send you a link to the app I have so you can check it out to see if you like it? I guess that's allowed on this site.when I first got on this forum I posted on the wrong place by mistake,as I wasn't familiar with how to post things.they were not happy about it.

  9. #9
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    Quote Originally Posted by KevinAdv View Post
    So saturday I had a 95 degree od db and a 56 degree indoor wet bulb (yes there is no such thing as humidity here)

    Acoording to my Fieldpiece Srh2

    and that calculator http://www.loadcalc.net/superheat.php

    I Should be flooding the compressor

    What does that mean?
    It means you need to be very careful charging under those conditions because your SH is going to be real low. I would probably look for 4* or 5* SH & leave it but some of the guys who work in your area might have a better solution. If you look at any manufacturers SH chart I'm pretty sure you will not find a reading at those temps. Here's two SH charts from two different manufacturers & you can see those conditions are blanked out on both.
    Attached Images Attached Images  
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    Gary
    -----------
    http://www.oceanhvac.com
    An engineer designs what he would never work on.
    A technician works on what he would never design.

  10. #10
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    Feb 2002
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    Azle, Texas/ Fort Worth
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    Quote Originally Posted by Flashg21230 View Post
    If you send me your email address I can send you a link to the app I have so you can check it out to see if you like it? I guess that's allowed on this site.when I first got on this forum I posted on the wrong place by mistake,as I wasn't familiar with how to post things.they were not happy about it.

    Me Too !! please .
    Last edited by Dad; 05-01-2012 at 05:24 PM. Reason: email in post
    An air conditioning or refrigeration unit never signs a check for me! PEOPLE do that,and you should never allow yourself to forget that WE fix the problems of people,not machines.They are at the heart of our business,one way or another,and polishing the skills required to provide solid customer service will never be a waste of your time

  11. #11
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    Quote Originally Posted by garyed View Post
    It means you need to be very careful charging under those conditions because your SH is going to be real low. I would probably look for 4* or 5* SH & leave it but some of the guys who work in your area might have a better solution. If you look at any manufacturers SH chart I'm pretty sure you will not find a reading at those temps. Here's two SH charts from two different manufacturers & you can see those conditions are blanked out on both.
    I set it around 9-10 degrees I didn't really feel comfortable going lower because in the summer its between 105 and 110 normally and we still don't have humidity

  12. #12
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    Sep 2008
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    Western PA
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    Quote Originally Posted by KevinAdv View Post
    So saturday I had a 95 degree od db and a 56 degree indoor wet bulb (yes there is no such thing as humidity here)

    Acoording to my Fieldpiece Srh2

    and that calculator http://www.loadcalc.net/superheat.php

    I Should be flooding the compressor

    What does that mean?
    In that case, you need to either wait until system conditions change or weigh in the factory charge plus lineset adjustments.

  13. #13
    Join Date
    Feb 2006
    Location
    USA
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    Quote Originally Posted by garyed View Post
    A while back hvacrmedic came up with a formula that works pretty well for target SH. I put it on a web page here:
    http://www.loadcalc.net/superheat.php
    is this the: SH=(3xIWB-OD-80)/2 equation?

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