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Forced air

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Steve_210
Steve_210 Member Posts: 646
I have  a customer who is heating his home with forced air (I know - that's what they want) the home is very well insulated with foam spray insulation - probably bordering passive. I am considering running the supply and return to reach hot water coil with Pex (home runs from the boiler). Is there a good type of insulation for pex? Or what is the best? Or is it even necessary? I have really only used pex for radiant heat before now.

Thanks in advance.

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  • Jamie Hall
    Jamie Hall Member Posts: 23,318
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    I'd use

    the same closed cell foam snap on stuff I'd use for any hot water pipe...



    Main thing with PEX and hot water is support -- the stuff sags like crazy when it gets hot.  I might even put it in a tray.   But you probably know that...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • gennady
    gennady Member Posts: 839
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    Copper

    Why not use copper. What is actual reason for using pex?
  • Steve_210
    Steve_210 Member Posts: 646
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    reasons are

    Less cost and less labor

    Is copper really any better?
  • Jamie Hall
    Jamie Hall Member Posts: 23,318
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    Yes, copper is better

    in my humble opinion -- if only because it doesn't need as much support.  That said, I use PEX in applications where it is difficult to "thread" copper into an existing chase, or where copper solder joints would be very close to old wood (fire hazard).  Both of which are problems in the building I superintend and maintain...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • gennady
    gennady Member Posts: 839
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    less labor

    actually if you do proper support it is more labor. and after you install 90 degree fittings it will be even more labor and much higher flow resistance.
  • Steve_210
    Steve_210 Member Posts: 646
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    Does anybody use

    Insulation on pex if so what type
  • RobG
    RobG Member Posts: 1,850
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    Dumb Question

    Why aren't they just going with a HE forced air furnace? Do they already have a boiler for other parts of the home?



    Rob
  • Steve_210
    Steve_210 Member Posts: 646
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    Condensing boiler

    We are using a knight with an indirect.

    It's hard to explain but in this situation its easier to use pex and bracket it properly than use copper