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6" centers

I have a basement job with 2" insulation below the pex and on the perimeter. I am using 1/2" pex. Because the wire mesh boxes are 6" square, I was going to run my 1/2" pex at 6" centers, just  for convenience of fixing. I don't see a problem with this. Could anyone give me some advise, I will of course keep my loops less than 300 ft.

Any advise would be greatly apprectiated.



  • digger_2
    digger_2 Member Posts: 39
    6" centers

    I am not an expert. However I feel I can advise on this subject. My radiant floors are also 1/2" pex and set on 6" centers. It will work  fine like that.

    Having said that, I would advise keeping the individual loops short, 200' max. Head loss will become an issue with longer loops. Also be sure you are using 02 barrier tubing. 

    When I installed my tubing, 6" spacing was recommended for 1/2".
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,840
    You can, butt....

    And there's a butt in every crowd, ain't there :-)

    WHY? If it is not necessary, why do it. The only advantage would be to use extremely low temperature water (80 to 90 degrees F) to heat your basement.

    Spend your time and money on conservation instead of distribution and you will see a better R.O.I.


    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • EricAune
    EricAune Member Posts: 432
    Have to disagree

    Mark is right, if its not necessary you do not have to do it.  But,  lower operating temps throughout the life of the system will show the largest savings (wouldn't this in fact be conservation in the form of energy) giving you an actual ROI on the extra tubing. 

    More tubing in this case = lower h2o temps.  I can only equate this to overall savings/conservation.
    "If you don't like change, your going to like irrelevance even less"
  • brad_14
    brad_14 Member Posts: 25
    maybe not all 6"

    All 6" seems a little overkill I went first run 12" from the outside walls then 3 runs 6" spacing from the outside walls after that 12". Boiler room I went 18". If you have any appliances ex. washer dryer freezer avoid their footprint. I went 250' max runs. My temp varies 80 - 118 depending on the outdoor temp. It works excellent, but I'm not an expert just a tech geek. brad
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    in a basement

    your heat load will almost never break 10 BTUs/sq ft.

    at that load, going tighter than 12" o.c. is a waste of money. If you do *anything else* in the system, on the upper floors, they will already require hotter water than this so you are saving exactly nothing dropping your water temperature another, at most, 5 degrees here.

    and in basements you can routinely run very long loops without problems too. we do 12" o.c. 400 to 500 foot loops regularly in insulated, buried basements, and we do NOT upsize system pumps NOR do we raise water temperatures in our systems to make it happen. without design, 300 is safe in a basement.

    Exception: walkout areas, which aren't really "basement", and perhaps greatly exposed areas with carpet flooring. In those areas you might tighten up the on center.

    or do 6" o.c., it's only money.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
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