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flat plate heat exchanger questions/ sizes

i have a job where we are replacing an old utica coil boiler with a vitorond 100. the problem is that there is absolutley no way to put an indirect in the boiler room, no basment, boiler room is off the kitchen...is it possible to use a flat plate heat (with no holding tank) exchanger and provide enough hot water for a 4 person house hold?? i kno system 2000 does it but with a tank for storage.

any links for flate plate info would be great! thanks!
Skilled labor isn’t cheap, cheap labor isn’t skilled.


  • papashawngo
    papashawngo Member Posts: 7

    the vitodens 100 have an available add on called the combiplus which is basically a plate heat exchanger in a fancy box with a built in circulator. so i dont know why if there is no other option you couldnt do something similar. is this an oil or gas system?  is there no option for a wall hung unit that would do both heating and domestic ie triangle tube pte110?

  • hot_rod
    hot_rod Member Posts: 21,888
    edited September 2013
    HX sizer

    at this site http://www.gea-phe.com/index.php?id=509&L=9\

    Sizer here


    I have a 5x12 30 plate on my system to provide instant DHW. A Grundfos 15-58 on speed 2 supplies energy from a solar or wood heated storage tank. Even with the tank down to 130F I can still get a decent shower at around 2 gpm.

    Some boilers have onboard HX that are smaller, but they allow the boiler to run up to 180F or so to provide the extra input.

    I have a system with a Laars 130 with DHW via a plate HX and Lochinvar Cadet 120 with a plat HX inside, both have smaller dimensioned HXers compared to my homemade 5X12- 30.

    Incoming cold supply makes a difference, my well doesn't drop below 55F. Some utility water supplies can drop to 40F or colder in winter.

    Pre-heat it with solar or a storage tank to help HX performance if you can.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
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