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Reverse Indirect

Wayco Wayne_2
Wayco Wayne_2 Member Posts: 2,479
I remember thinking once that a reverse indirect would make a good buffer tank in the right situation. That was a long time ago, but I think I find myself in the right situation. What brands  of reverse indirects are out there these days?  Does anyone use these?

Comments

  • Zman
    Zman Member Posts: 7,561
    Siggy

    John Siegenthaler has written some good stuff on these. You should be able to google some articles.

    I think for it to work well it needs to be a high temp heat system and the indirect needs to be stainless on both sides and have plenty of surface area. The heat flow models look like would work well.

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • gennady
    gennady Member Posts: 839
    reverse indirect

    Reverse indirect is in effect external DHW heat exchanger. it has high peak capacity and lower storage capacity then conventional tank. to size it as a buffer tank will be at least double price compare to indirect water heater. On commercial jobs i use inverted indirect as inter-cooler to bring boiler return temp down.
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,479
    I'm not sure

    I understand what you mean by external. HX. What I'm picturing is like the Thermomax. I need a buffer tank and an indirect but the capacity on the indirect is not very high. Just for hand washing and cleaning crew usage. No showers. I'd love to put the buffer tank and Domestic hot water on a single footprint,
  • hot_rod
    hot_rod Member Posts: 22,022
    Ergomax

    has added two additional taps, which makes it easier to use as a buffer tank.



    The DHW output will drop off if you run lower tank temperatures, if that is important. Their performance use to be rated at 200F boiler side temperature!



    I suspect, seeing as they have a belly full of copper that they are $$ ?



    I've used them for drainback tanks also with so much copper they perform well. I've also buffered wood boilers with them to provide DHW.



    I'm not sure it needs to be a stainless tank if it is for boiler water in the tank and DHW in the coppoer.



    I know of two all stainless versions, one out of Canada with a spiral HX inside.



    Another is an import that a solar drainback manufacturer in Kansas imports.



    I'll dig around for that info if you need all stainless for some reason?



    http://www.ergomax.com/New-Tanks.htm
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Zman
    Zman Member Posts: 7,561
    Clarify

    My suggestion on the stainless was to stay away from tanks that have steel or other materials that are not suitable for potable water. The triangle tube smart for example would be a bad choice due to the steel in the outer tank.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • gennady
    gennady Member Posts: 839
    $$$

    They are about 80% more $$ compare to same capacity regular indirects.
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,479
    Thanks

    Z man. the thought had crossed my mind. I'm having trouble finding distributers for Thermoax or Ergomax. Did they go out of business?
  • hot_rod
    hot_rod Member Posts: 22,022
    Ergomax

    I think are sold via EFM dealers. Go to that site and use the dealer locater.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • hot_rod
    hot_rod Member Posts: 22,022
    TurboMax

    Rathe and Associates in L.I. NY is one rep I know of. They do training on the tank in their classroom with a working display, and a lighted cutaway



    www.ratheassociates.com
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,479
    Thank you

    Hot Rod. I found a brand new distributer for Thermomax right down on VA. not far from us. The Joyce Agency has just taken on this product line. Thanks for your help.
  • SWEI
    SWEI Member Posts: 7,356
    Reverse indirect as buffer tank

    is looking more and more like it may be the optimal upgrade for a conventional boiler.  ODR-controlled mixing valve on the system side, boiler @140F minimum anyway, ought to play nice with a tempering valve on the DHW outlet.



    Heat-Flo coil appears to be at the bottom of the tank (looks like another Dejong?)



    Does anyone make an indirect with the coil at the top of the tank?



    Ergomax and Turbomax coils are full height, which may be the only viable option.  Anyone used both and have an opinion?  I believe Ergomax beefed up their insulation awhile back.
This discussion has been closed.