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can I add a zone like this?

heatingFun Member Posts: 84
Please refer to this diagram (attached or this link) to see my existing piping and my plan to add a new zone:

<a href="http://www.flickr.com/photos/oldyoungguy88/4796411070/sizes/l/">[color=#417394][u]http://www.flickr.com/photos/oldyoun...11070/sizes/l/[/u][/color]</a>

We converted from oil to gas last year and now we are thinking add two rooms into the system as a separated zone. It is a hot water heating system.

Please tell me "Option 1" is valid or not? if not, how about "Option 2"?



  • Charlie from wmass
    Charlie from wmass Member Posts: 4,322
    2 not one

    lots of other ways too. are TRVs used on one?
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • heatingFun
    heatingFun Member Posts: 84
    a better way?

    can you tell me one of them, which you think is better and simpler? thanks
  • Dave in QCA
    Dave in QCA Member Posts: 1,786
    Use Option 2

    The problem with the first option.  If the new zone was running, and the original zone was not, you would likely set up some strange back flow patterns in the 2 original rooms closest to the boiler.  The water doesn't know where it is supposed to go, and any time there is even a very minor pressure difference, it will flow.  Water flow passing through a tee fitting is enough to draw water from the side branch of the tee, and cause unintended circulation.  ( am speaking from real experience)

    Option 2 should work great.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
  • hot_rod
    hot_rod Member Posts: 22,268
    what type of boiler?

    cast iron, copper tube, mod con? You may not need that pump at the boiler?

    As drawn it is not primary/ secondary, if you have a mod con boiler, that may be suggested.

    One pump and zone valves could be another "energy saving" option.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Tony Massi
    Tony Massi Member Posts: 86

    Use option 2.  I don't know why you would use a circulator on the return when you have one on the supply.
  • heatingFun
    heatingFun Member Posts: 84
    mod cond boiler

    yes, the boiler is a mod cond gas boiler from Burnham.
  • heatingFun
    heatingFun Member Posts: 84
    recommended by boiler manufacturer

    that circulator is suggested by the boiler provider. the boiler is Burnham Alpine gas boiler: http://www.usboiler.burnham.com/products/residential-boilers-indirect-water-heaters/alpine
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666

    I imagine the boiler wants to see a primary|secondary near-boiler piping setup. Hence the circulator up next to the boiler. The connection between supply and return that comes next and the related Ts are almost certainly supposed to be the closely spaced Ts of the primary|secondary setup. (You could use a low-loss header there instead if it comes out cost effective.) After that you need at least one circulator in the secondary side.

    On the secondary side, either the heat emitters are precisely what the user wants, or there are balancing valves in there that are not shown. Also a flow check valve in each zone to prevent accidental flow through a zone where the circulator is not running?

    Options 1 and two seem almost the same to me (a non-professional), but Option 1 would be more difficult to analyze and seems to present no advantages. Option 2 seems the way to go. Also, in all three diagrams, why is the supply directly connected to the return at the end (away from the boiler) of each zone?

    However, has others have pointed out, you could probably save energy by using one circulator in the secondary side and zone with zone valves. If you do that, you would probably be wise to use an ECM motor in the circulator because otherwise you would probably need a differential bypass valve and that would be inefficient.
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