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36x48 Pole Barn PEX layout/design


New user to the forum here! I was hoping to get some advice on the layout for my radiant heating system in a 36x48 pole barn that i had built here in MN. I'm planning on placing a vapor barrier below the 1" foam that my PEX will lay on top of. Rebar and 4" of concrete above that.

I currently have the floor plan as being open; one zone?

Boiler and pumps will be in the middle of the 48' wall.

Floor drain will be placed in the center.

Any advice or help would be greatly appreciated. If someone has LOOP CAD and knows how to use it, a layout would be very helpful if available.

Kind regards,



  • kcopp
    kcopp Member Posts: 4,432
    You need to give more....

    information. Design temp, window and door schedule, ceiling height, etc.

     For starters I would be placing 2" on the floor and 1" along the perimeter. You need at least 10- 250' loops off of a central manifold in 1/2" pex tubing. You really should get a design from a reliable source...like a plumber/ heating contractor or a supply house that will work w/ you.
  • KCA_2
    KCA_2 Member Posts: 308
    A couple of things

    That you can think about...

    1.  If  you are giving yourself a place to work...  with a workbench of some sort.. make

          a zone around that by about 10' or so... 

    2.  Run more tubing than they tell you to...  Lol..  Tubing is cheap and the more you

         put in the slab the quicker it will react to even low temp water..

    3.  Run your centers at +- 4-6" near the front door and the window ares...  equal to +-

          the height of the door or window out from the wall..

    4.  Stay away from the overhead door by oh...  2' inside..  Otherwise the floor temp

         can melt the snow and when it refreezes it can stick the overhead door...

    5.  Use indoor outdoor reset and injection....

    6.  I would also recommend 1 1/2" or 2" on the floor...  Not 1"

    7.  If you are going to put rebar down you should tie the tubing to it...  Not the

         insulation because if you tie it to the insulation the tubing may be to deep in the

         concrete to affect the slab quickly.. 

    8.  Is there water in the soil?  Hope not..

    Well....  that's all I can think of right now..  And anyway...  I need a new cup of coffee....

    Hope it helped....

    :-)  KCA
    :-) Ken
  • NRT_Rob
    NRT_Rob Member Posts: 1,013

    2" minimum underneath and on the vertical slab edges, and many people are doing more these days.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
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