Page 1 of 2 12 LastLast
Results 1 to 13 of 18
  1. #1
    Join Date
    Jun 2008
    Location
    Southern,N.J
    Posts
    1
    Post Likes

    Line set sizing?

    What affects or damage can occur when running smaller diameter lines for a discharge or suction line? I know deff higher head pressures. I'm new to the field experts please chime in..Also new to the site hello everyone..

  2. #2
    Join Date
    Jan 2004
    Location
    PA
    Posts
    69,647
    Post Likes
    Lower capacity
    Lower efficiency
    Possible shortened compressor life.

    Welcome
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  3. #3
    Join Date
    Sep 2003
    Posts
    139
    Post Likes
    If the suction line is too small, you may not get proper oil return to the compressor. You also can have a reduced capacity.

  4. #4
    Join Date
    Jan 2004
    Location
    PA
    Posts
    69,647
    Post Likes
    An undersize vapor line doesn't hurt oil return.
    Too large of a vapor line can.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  5. #5
    Join Date
    Sep 2003
    Posts
    139
    Post Likes
    WOW! I hope you don't do refrigeration! OOPS... Read it wrong Beenthere! Need to assure proper velocity Horizontal increase size, vertical decrease.
    Last edited by heatingairman; 07-06-2008 at 10:12 PM. Reason: Read wrong

  6. #6
    Join Date
    Jan 2004
    Location
    PA
    Posts
    69,647
    Post Likes
    Both A/C and refrigeration.
    A vapor line 1 size undr will never hurt oil return.
    The next size up however can on installs with the condenser vertically above.

    Recommended min suction line velocity is 1000 FPM. I have vapor line sizing charts for unit that allow the vapor line to be sized for up to 3000 FPM.

    I don't have any that approve less then 800 FPM. And they don't want a vertical rise to the condenser.

    If you have line set sizing charts that allow 500FPM velocity in the vapor line, post them.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  7. #7
    Join Date
    Sep 2003
    Posts
    139
    Post Likes
    I don't think anyone will go out on a limb with 500fpm

  8. #8
    Join Date
    Apr 2007
    Posts
    6,341
    Post Likes
    So is it safe to say it's a trade off of capacity for smaller sizes and velocity is not so much a concern or oil return......and the LL is way more important to capacity?

    Also how important are traps in vertical rises of 50+ ft? I might be subjecting myself to these before to long. Not sure if they even put traps in @ the recommended heights.....for oil return?

  9. #9
    Join Date
    Jan 2004
    Location
    PA
    Posts
    69,647
    Post Likes
    Involved topic Jon.

    Within reason, you can compensate a little for a slightly smalled liquid line, more then a vapor line.

    Did you get that email I sent you. It has some line set sizing info in it.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  10. #10
    Join Date
    Apr 2007
    Posts
    6,341
    Post Likes
    I'll check....I didn't think this was the right forum to get to involved.


    was that just now or recently in the past?

  11. #11
    Join Date
    Sep 2003
    Posts
    139
    Post Likes
    I sent yo an email too bigjon.

  12. #12
    Join Date
    Jan 2004
    Location
    PA
    Posts
    69,647
    Post Likes
    Within teh last few days..
    I don't remmember which.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  13. #13
    Join Date
    Apr 2007
    Posts
    6,341
    Post Likes
    i'll go back over I'm sure i got it.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.
Comfortech365 Virtual Event