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Pumping away

Brian_6
Brian_6 Member Posts: 4
I have read about the theory of "pumping away" in one of Dan's books on Hydronic Radiant Heating. Can anyone expand on this a bit more?? I originally thought that it referred to the boiler, but now realize it is in reference to the expansion tank. What are the pro's and Con's of this method of locating the circulating pump?
Thanks!

Comments

  • Steve Eayrs
    Steve Eayrs Member Posts: 424
    You need to get the book called..........

    PUMPING AWAY, by Dan, and you will see it is not only a theory, but a fact.
    Steve
  • Brian_6
    Brian_6 Member Posts: 4


    Yes,
    Thanks Steve! I know that would be the logical thing to do..........but.........I was looking for the quick route!
    Thanks! LOL
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    In a nutshell

    The circulator(s) in a system CANNOT change the system pressure at the point where the expansion tank is connected.

    With small pipes and high-head circulators (both compared to days of the "dead men") a circulator mounted pumping towards this point will achieve its motive force by REDUCING the pressure at its inlet--even to the point that the pressure on the suction side is below atmospheric pressure. This is a certain prescription for air problems.

    If however the circulator is mounted AFTER the expansion tank, it produces motive force by increasing pressure through the supply--exactly what you REALLY EXPECT!

    BUY THE BOOK! It's inexpensive, informative, useful AND entertaining!
  • Brian_6
    Brian_6 Member Posts: 4


    Thanks Mike! I have two of Dan's books now....and you are correct! They are entertaining and very informative.
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