Pumping away

Brian_6

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!

Steve Eayrs

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

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

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

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