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J.C.A._3 Member Posts: 2,981
Here's your chance!

I hear that Triangle Tube has the answer in the works. A stainless, high flow adaptable...yet low mass (and price competitive) boiler that will fit the bill.

Let the pigeons fly! Chris


  • Rich Kontny_5
    Rich Kontny_5 Member Posts: 116

    While on the topic of indirect tanks I have been wondering about the following:

    1. Using an on demand water heater such as a Rinnai Continum firing at about 199,000 BTU max as a heat source.

    2.Using a double coiled (double walled) indirect tank as the domestic water source.

    3.The demand on the highly insulated indirect would prevent short cycling??? while keeping the hydronic side very low mass?

    4.Using the Rinnai like a boiler not on the potable water side at all.

    5.Using the second coil as a lower temp source for in-floor needs.

    6. Or using the top coil as a secondary heat source from solar, wood etc.

    Is this feasible or have I been sniffing too much glue and cleaner???

    Notes: I researched an Amtrol tank that has two heat exchangers but have since learned that Amtrol has had serious financial troubles.I also realize that the indirects are not rated properly as a boiler.

    Rich K.

    Make Peace our Passion while Supporting our Troops!
  • hot_rod
    hot_rod Member Posts: 22,120

    keep trying to fool those instantanous WHers into thinking they are boilers?

    I haven't had a lot of sucess with the coils connected to a boiler to act as a buffer. I tried a few MZ's with the coil in series as a buffer. Then I tried the tank capacity as a buffer, like the old Trianco indirects. DHW in the coil, boiler in the tank side. That worked much better, but DHW production was lackluster.

    The Ergomax comes to mind but you need to drive them with 180 temperature to get much DHW performance. Seems silly to run that type of heater to 180 for DHW production then mix down for radiant.

    Foot on the gas with the brakes as speed control, comes to mind.

    All things considered the properly sized mod con is hard to beat. the HTP Phoenix does one up the mod concept with on-board buffer :)

    hot rod
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Glenn Sossin_2
    Glenn Sossin_2 Member Posts: 592
    application -


    While you certainly can use it that way, and I have on several occasions, keep in mind the heat exchanger has a very high head loss. These units require minimum water pressure to operate properly which can translate to 35ft of head pressure at the unit - plus your system head losses.

    FYI - Noritz makes a wall hung boiler - similar to the heaters - modulating burner, but the exchanger is designed differently - has less head loss but still would require a pump like a Taco 0013 or Grundfoss UP26-99 to get sufficient water flow. I've attached a spec sheet.

This discussion has been closed.