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    Hot Rod,caleffi hydro air seperator vs p/s piping (11 Posts)

  • jonny88 jonny88 @ 8:48 AM
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    Hot Rod,caleffi hydro air seperator vs p/s piping

    Im giving consideration to scrapping p/s piping and using caleffi hyronic air seperator.When I use p/s I have a primary pump,spirovent,dirt seperator,pipe and fittings.Does it make sense use the low loss header,mainly for space issues, and when you break it down there isnt much of a difference in $$..Thanks John.
  • hot rod hot rod @ 10:16 AM
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    yes, all the above

    it gives you multi functions in the air, dirt, and hydraulic separation. Also some additional fluid capacity and an excellent location for the boiler sensor.

    Most of the Caleffi brand include a nice insulation jacket to limit heat loss. New versions also have a magnetic band to handle the small iron ferrite products in some systems.

    It really cleans up the piping and should take a few hours labor out of an installation.

    Size the branches (headers) generously and you will not have temperature drop from one take off to the next as you do in series P/S.

    A buffer tank is a super-sized separator, properly piped.
  • Stephen Minnich Stephen Minnich @ 3:13 PM
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    "Generously sized headers"...

    Is a phrase we hear or read often. Is there a rule of thumb or better yet a mathematical equation, to determine how big? One size up? Two sizes up?
    It's all in the details.
  • hot rod hot rod @ 4:34 PM
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    size using flow velocity

    we suggest "generously sized" defined by flow velocity. Size that header so it can handle the combined flow of all the attached zones at a flow velocity of 2 fps. Generally we size hydronics for 2-4 fps velocity, some suggest 1.5-5 fps, as acceptable range.

    Falling below that 2 fps flow rate and air elimination can be tough as the fluid will not always move the air along with the flow. This is especially noticeable in vertical piping where the fluid needs to be able to shove the air back down to the central air elimination device.

    I use Siggys HDS program for pipe sizing, the B&G System Syzer will do the calc, as well as some of the free, online, pipe sizer programs or formulas. is where I found this calculator

    10 gpm in 1" copper= 4 fps
    10 gpm in 1-1/2 copper= 1.81 fps
    So 1" for the 1000,000 btu boiler (10 gpm), 1-1/2" for the "generously sized" headers.

    We try and indicate the concept by the line size in the drawing, notice the "header" piping lines compared to the boiler input size, but crunch the numbers to get the correct size.
    This post was edited by an admin on February 9, 2014 5:23 PM.
  • Stephen Minnich Stephen Minnich @ 9:17 AM
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    Thanks Bob

    I'm not a big fan of rules of thumb. This is by the book. Very helpful!!
    It's all in the details.
  • knotgrumpy knotgrumpy @ 9:46 PM
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    Hot Rod -

    Should the indirect come off before the hydro sep on the boiler side?

  • knotgrumpy knotgrumpy @ 10:43 AM
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    Coffee with Caleffi

    Hi Johnyy88 -

    I'd suggest viewing the Coffee with Caleffi that Hot Rod just finished.  He goes over primary/secondary and hydro separators. 

    I think it was an hour well spent.

    Here is the link:

    It is the one on mod/con piping...

    This post was edited by an admin on February 9, 2014 10:44 AM.
  • Rich Rich @ 1:36 PM
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    view that webinar and use the hydraulic seperators or a buffer tank to provide separation of the circuits . You are right that they cost roughly the same but that sep goes in much faster also .
    You didn't get what you didn't pay for and it will never be what you thought it would
  • Paul S Paul S @ 7:13 PM
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    Hydro seperator

    I have this job in progress now. ... First time ever using it. ... boiler is peerless purefire 110.... pipe size is 1" 1/4".... Hot Rod , should I have used bigger pipe for the systems supply and return headers? For future knowledge Paul s
    This post was edited by an admin on February 9, 2014 7:15 PM.
  • superdave superdave @ 10:38 PM
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    I have been using them they are great no problems...
  • jonny88 jonny88 @ 6:54 AM
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    great pics

    thanks for sharing,nice work.
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