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Flow rate in copper pipes

But if the velocity is too low don't you end up with air trapped at the high sections?


    WV EGBERT_2 Member Posts: 98
    Flow rate in baseboard loops

    We are updating an existing heating system that has finned baseboard on the second floor. They are all piped in with ¾ copper.

    In calculating flow rate with a 10° temp drop and the various heat loads I get values ranging from 1.5 to 2 gpm which according to what I can tell is too low to sweep any air bubbles from the system.

    One chart recommends 3.2-6.5 gpm.

    Question: Should we increase the flow rate to say 3.5gpm and let the temp drop fall where it may?

  • kpc_36
    kpc_36 Member Posts: 21
    you're fine.

    you don't want much more than 4 gpm or you will get noise from velocity.
  • kpc_36
    kpc_36 Member Posts: 21
    not if you pipe....

    it properly. Pipe it w/ the circ. pumping away from the expantion tank and leave the pressure @ 18psi. Have you read any of dan's books? kpc
    WV EGBERT_2 Member Posts: 98

    We intend to pipe it as you suggested. It's not that way now.

    The only book I have is "Modern Hydronic Heating" by Siegenthaler which led me to belive I needed a velocity of 2-4 ft/sec.

    More books are good. Can you point me toward "dan's books"?
    WV EGBERT_2 Member Posts: 98
    Outdoor wood boiler

    To complicate things a bit we want to use an outdoor wood boiler from Central Boiler.

    The sales person/installer says we don't need a flat plate heat exchanger even though the wood boiler is vented to the atmosphere. It seems to me that maintaining 18 psi would be a problem with a boiler vented to the atmosphere.

    Any comments on this would be appreciated.
  • kpc_36
    kpc_36 Member Posts: 21
    you need a HX.

    My opinion of these wood boilers is not very high. I am working w/ a friend on one who did not take my advice. It can get very pricey w/ flat plate hx. big circs. and lots o' eco-flex pipe. Pumping away is a great book....
  • k
    k Member Posts: 38
    wood boiler

    have you considered a wood gasification boiler. for in the house. Look at tarm or econoburn
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