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cast iron modulating comercial

Big Will
Big Will Member Posts: 394
I am bidding a Federal job. I have a walk through in a two days. The spec. book is asking for design build but specifically asks for cast iron modulating energy star rated. I don't know the exact BTU I will need but they included pics of old boilers that look like they are in the million BTU range. Any Ideas. I know about the Ray but its probably not big enough.


  • hot_rod
    hot_rod Member Posts: 15,064
    A mod non-con boiler

    I'd like to see modulating non condensing boilers developed. Times were when we had step fire or mechanical modulating copper tube boilers. I know Raypak offered two step and mech mod gas valves, probably other manufacturers also.

    With todays burner technology maybe it's time to re-examine modulation cast iron also. Not necessarily a cast iron condensor, like the rAY. But a line of residential sized cast iron with modulation for 140F and higher supply temperatures.

    There may be some commercial products already available?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Big Will
    Big Will Member Posts: 394
    Commercial energy star

    I have seen Bryan flex tube commercial boilers from the 70s with variable rate gas valves tied to a aqua stat that sends floating point control. And I know parker makes a four stage cast iron. But energy star rated. Do they even rate commercial boilers with energy star?
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,195
    try the KN boilers

    They are the big brothers to the Ray, actually they are the Ray just more sections.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Henry
    Henry Member Posts: 988
    Mod/con cast iron

    The KN series are Energy Star rated. They are even more efficient at low fire than high fire. You also don't have to do a pr/sec but you need to use a reverse return on multiple boilers. They use RBI's HeatNet protocol that lets you control 10 boilers.

    Check the new line of KN boilers as they will go up to 2 million.

    Here is the link:


  • Glen
    Glen Member Posts: 855
    several good choices for this

    dedietrich and viessmann both make a CI boiler with modulating burner, this is off the shelf stuff. and I would bet Buderus has a similar product in the lineup. either of these will make you smile - especially if you couple them to the digital Weishaupt mod burner.
  • CMadatMe
    CMadatMe Member Posts: 3,085
    Vitocrossal Baby

    Get a Viessman rep in on that job! 98% efficient!
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
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