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The Trithermogulator

2

Comments

  • Eastman
    Eastman Member Posts: 927
    Sorry, I'm speaking of the top side connection and the bottom side connection.
  • Gordy
    Gordy Member Posts: 9,546
    In that case I see strange things happening with DHW tank temp being called for because its cooled from buffering, and otherwise would not need be satisfied. Stranger things on the system side, and boiler side. Lots of hardware to keep flow going where you want it. I still dont think the characteristics would be similar to a hydro seperator. To unpredictable.
    RobG
  • Eastman
    Eastman Member Posts: 927
    edited December 2014
    I think I figured it out Gordy. They don't typically want the indirect hooked with hot to the top because it creates a greater scalding risk if there isn't a safety device on the DHW output.

    Hmm, or maybe the location of the tank sensor?
  • Gordy
    Gordy Member Posts: 9,546
    So you mean this?
  • Eastman
    Eastman Member Posts: 927
    Yeah, but again, I want the reds to got to the top side port, blues to the bottom.
  • Gordy
    Gordy Member Posts: 9,546
    Zthis may stand a chance
  • Gordy
    Gordy Member Posts: 9,546
    But my previous mention of DHW tank temps still applies
  • Eastman
    Eastman Member Posts: 927
    edited December 2014
    That would be convenient but they're not needed. Why do you want the two sets of tappings?

    EDIT: No they are not convenient. No I do not want to use any theoretical extra set of tappings. The configuration your proposing (see image reposted below)requires space heating temperatures to mix with DHW temperatures during every mode of operation. The version of the Trithermogulator that is the subject of this thread was specifically designed to selectively avoid unproductive mixing during a space heating call. This was outlined in Part 1. There is another version that I have designed that is similar in function to what you have illustrated but I was going to present this in a later posting.



  • Gordy
    Gordy Member Posts: 9,546
    Eastman said:

    I think I figured it out Gordy. They don't typically want the indirect hooked with hot to the top because it creates a greater scalding risk if there isn't a safety device on the DHW output.

    Hmm, or maybe the location of the tank sensor?


    I don't think scalding is an issue. The hottest part of the tank is at the top regardless. I believe it's more about getting the coldest water the hottest supply temp, and sensor location was probably determined once the best hea transfer strategy was determined. Some indirect manufactors still don't have optimal sensor locations.
    Eastman said:

    The Smarts don't come with those tappings; it would be convenient but they're not needed.


    I know they don't but it would be much more conducive to what you are trying to accomplish.
  • Eastman
    Eastman Member Posts: 927
    Why is it more conducive?
  • Gordy
    Gordy Member Posts: 9,546
    Enough I'm going to bed. Now I'll be having nightmares as a water molecule swimming around in the outter shell of a tank in a tank indirect trying to find my way out.
  • Eastman
    Eastman Member Posts: 927
    The Trithermogulator never sleeps.
  • Gordy
    Gordy Member Posts: 9,546
    Eastman said:

    Why is it more conducive?

    Last one. More conducive in flow characteristics, and transferring Btus inner, and outter shell more even both sides of tank instead of one side.
  • Eastman
    Eastman Member Posts: 927
    edited December 2014
    Oh man, you totally got me twisted around. No I do not want to use any theoretical extra set of tappings. The configuration your proposing (see image reposted below)requires space heating temperatures to mix with DHW temperatures during every mode of operation. The version of the Trithermogulator that is the subject of this thread was specifically designed to selectively avoid unproductive mixing during a space heating call. This was outlined in Part 1. There is another version that I have designed that is similar in function to what you have illustrated but I was going to present this in a later posting.



  • Zman
    Zman Member Posts: 7,610
    I like the name, alot...
    If you were entering a contest where you you were forced to build the system but could only use incorrect parts (or trying to fix an existing system without a major overhaul) it is a winner.
    Here are a few things that don't seem to be addressed:
    You suggested it for a mod/con setup, many of these systems can run in the condensing zone much of the time.Some would run most efficient below 120 degrees. These temps won't work well for DHW.
    It is generally a good idea to prioritize the DHW. I don't see how you are even controlling DHW.
    You really don't have a way to control the indirect at all. It just gets what it gets after the heating takes what it wants.
    If the lowest heating temp you needed (or could use) was 130 degrees or higher, I like the reverse indirect arrangement Gordy posted. If your system is designed for lower temps and high efficiency, A conventional buffer tank makes sense.
    I like "outside the box", this one just seems clunky.

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    RobG
  • Eastman
    Eastman Member Posts: 927
    edited December 2014
    Zman, the discussion I had with Gordy got way off into the rough. I started to confuse some issues with a posting that was/will be presented again in a future installment of the Trithermogulator. I apologize for not maintaing a clarified line of thought throughout this thread.

    Zman said:
    Here are a few things that don't seem to be addressed:
    You suggested it for a mod/con setup, many of these systems can run in the condensing zone much of the time.Some would run most efficient below 120 degrees. These temps won't work well for DHW.


    You suggested low temperatures won't work well with DHW. The DHW tank is not heated with low temperature water. Zman, can you take a look at the description following Part 1 of The Trithermogulator? Can you see that a low temperature space heating call never results in low temperature fluid entering the tank while the boiler is on? The production and consumption of low temperature water is directed around the tank by virtue of synchronized flow. There is never an unproductive attempt to heat the tank with low temperature space heating fluid. However, high temperature fluid is drawn off the tank for space heating while the burner is off, since flow is no longer synchronized when the boiler pump ceases. One could say that the tank is being cooled by low temperature return water from the emitters, but this is by design. The tank's job is also to serve as a thermal battery, maintaing a high temperature at the top for DHW, while allowing heat to unload from the lower portion to reduces boiler cycling.
  • Eastman
    Eastman Member Posts: 927
    Zman said:

    It is generally a good idea to prioritize the DHW. I don't see how you are even controlling DHW. You really don't have a way to control the indirect at all. It just gets what it gets after the heating takes what it wants.

    I hope to erase the rest of your concerns in Part 3 of The Trithermogulator.
  • Zman
    Zman Member Posts: 7,610


    You suggested low temperatures won't work well with DHW. The DHW tank is not heated with low temperature water. Zman, can you take a look at the description following Part 1 of The Trithermogulator? Can you see that a low temperature space heating call never results in low temperature fluid entering the tank while the boiler is on? The production and consumption of low temperature water is directed around the tank by virtue of synchronized flow. There is never an unproductive attempt to heat the tank with low temperature space heating fluid. However, high temperature fluid is drawn off the tank for space heating while the burner is off, since flow is no longer synchronized when the boiler pump ceases. One could say that the tank is being cooled by low temperature return water from the emitters, but this is by design. The tank's job is also to serve as a thermal battery, maintaing a high temperature at the top for DHW, while allowing heat to unload from the lower portion to reduces boiler cycling.


    I like these reverse indirect/ buffer tank setups with conventional boilers. I think they make good sense.

    With a mod/con, you lose the efficiency of the return low water temps.

    Looking forward to part 3...
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Ironman
    Ironman Member Posts: 7,511
    TriangleTube has a drawing similar to what's being proposed in their applications manual. I've used this setup and it works well, but has the limitation of only supply mid to high temp water unless mixed down.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Gordy
    Gordy Member Posts: 9,546
    Anyone know how many gallons the putter tank of the TT smart series holds?
  • SWEI
    SWEI Member Posts: 7,356
    From page 3 of http://www.triangletube.com/documents/2/SMART Literature.pdf
    5 to 43 gallons depending on size.
  • Ironman
    Ironman Member Posts: 7,511
    Gordy said:

    Anyone know how many gallons the putter tank of the TT smart series holds?

    @Gordy‌
    I'm not sure if it's in their specs or not, but with diagram I posted it also has the buffer from the domestic storage since heat is transferred directly to the outer tank and the sensor to call for heat is obviously in the domestic side.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Ironman
    Ironman Member Posts: 7,511
    Sorry SWEI,
    I did see your post since it came up on page 3 and I was on 2.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Gordy
    Gordy Member Posts: 9,546
    Thanks kurt
  • SWEI
    SWEI Member Posts: 7,356
    I've stayed out of the discussion up to this point, but have experimented with combined indirect/buffer setups and there are always compromises. At times, the DHW can end up just warm. We added a tankless electric on the output of one of them to make the owners happy.
  • Eastman
    Eastman Member Posts: 927
    Unfortunately, I have to run some errands today, so just a few comments on comments for awhile.

    @Ironman Yeah, heat drawn off of the DHW would generally be mixed down for space heating. This is not necessarily a limitation, though, since the return temperature to the boiler is typically the greater indicator of mod/con thermodynamic efficiency.

    @‌Zman regarding:

    With a mod/con, you lose the efficiency of the return low water temps.

    All low temperature water is returned directly to the boiler while the boiler is responding to a space heating call.
    The Trithermogulator will condense.
  • Gordy
    Gordy Member Posts: 9,546
    That's what I was seeing happening, or the boiler running to keep the indirect up to temp unnecessarily if one was not doing the buffering.
  • Gordy
    Gordy Member Posts: 9,546
    What the industry needs is 10:1 modulation 1-3k low end if everyone wants to zone the powder room.
    IronmanSWEIRobG
  • Ironman
    Ironman Member Posts: 7,511
    edited December 2014
    Gordy said:

    What the industry needs is 10:1 modulation 1-3k low end if everyone wants to zone the powder room.

    They have it overseas. Why can't we get it here? Are trying to keep it on the cheap to compete knowing that a lot of installers are just slapping mod/cons in as replacements and most of them are clueless about proper design?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • SWEI
    SWEI Member Posts: 7,356
    Higher turndown would be even more forgiving of knuckleheads.

    Check out http://www.sermeta.com/en/product/bluejet-burner/
  • Gordy
    Gordy Member Posts: 9,546
    Thinking about it a 15-20k output 1 1/2 venting with 5:1 turndown 3-5?k low end would be sweet if the cost was cheap enough. multi staged micro boilers to the heat loss. Seems the heat losses seen around here would be easy to customise a fitting sequence of boiler sizes and staging. Would rather stage small boiler size combinations than buffer especially if the cost of the boiler was the same as a decent buffer tank.........touch to ask?
  • Eastman
    Eastman Member Posts: 927
    Part 3 of The Trithermogulator:

  • Gordy
    Gordy Member Posts: 9,546
    edited December 2014
    Trick is to avoid the Trithermogulator through proper design........initially. But there is a lot of trauma surgery in the field to existing fubar systems. Save a life not a limb.
  • Eastman
    Eastman Member Posts: 927
    edited December 2014
    Part 3: Boiler responding to a combined thermal buffer and space heating call.

    Earlier in part 1 I described how synchronized flow in the primary and secondary loops results in 0 flow across the DHW heat exchanger, allowing the boiler to service a low temperature space heating call while leaving high temperature DHW undisturbed in the tank. In part 2, I described how desynchronized flow during a space heating call initiated the thermal buffer function of the Trithermogulator. This occurs after the boiler reaches it's space heating temperature differential high limit and shuts off the flow in the primary loop.

    In part 3, we will examine the function of the Trithermogulator while the boiler is firing to accommodate a combined thermal buffer and space heating load.

    Durring this mode of operation, the boiler is assumed to prioritize the higher temperature DHW heating fluid set point. The mix valve will modulate on this high temperature flow to maintain the mix target ODR curve. The resultant flows in the primary and secondary loops initiates downward flow through the indirect's heat exchanger, recharging the thermal buffer.

    The DHW set point (the boiler heating fluid target, not the desired temperature of the DHW in the tank) is an important variable in this arrangement. If this value is too low and nearly identical to expected space heating ODR targets, a potential conflict arrises, since the mix valve will remain fully open, directing DHW heating fluid to the space heating loop and preventing priority recovery of the tank. If the boiler supports multiple ODR temperature loads, it is recommended that the indirect tank be supplied on a suitably higher ODR curve. The ratio of heat delivered to DHW tank and space heating systems during a combined call is ultimately controlled by the difference between the two target set points.
  • Zman
    Zman Member Posts: 7,610
    Ok, I get it.
    Still don't like it with a mod/con.
    I looks like it would make a decent band aid for oversized atmospheric systems.
    The expression "it is a solution in search of a problem" comes to mind
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    GordyRobG
  • Eastman
    Eastman Member Posts: 927
    edited December 2014
    This is The Trithermogulator Mark II, fully intended for condensing systems and able to capitalize on low return temperatures. However, there is an Mk I model intended for boilers that can not tolerate condensing return temperatures. I actually posted a version of this in an older thread somewhere. It is not particularly complicated and I'm sure it's considered old hat by many. There is also another advanced Mk III condensing version that trades fixed flows for fixed delta Ts, a much more practical design when you consider that zoning or some other method of flow modulation is most likely causing the majority of the problems that need to be trithermogulated.

    I take issue with the statement, "it is a solution in search of a problem." At the end of the day, I believe most systems installed are roughly twice actual design day heat loss. Unfortunately, modulation seems to have resulted in even less thought being put into the process of equipment selection.
  • Zman
    Zman Member Posts: 7,610
    My average boiler output temp is 105 degrees. On the coldest day I need 120. I would like my dhw to be 120 all the time. I would like my boiler to heat the space at the lowest temp possible to maximize efficiency.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    GordyRobG
  • Eastman
    Eastman Member Posts: 927
    Hi Zman,

    Is there a particular mode of operation during which you feel the trithermogulator would negatively impact the performance or efficiency of your system?
  • Zman
    Zman Member Posts: 7,610
    When I am heating 105 degree water for the heat , It will drag my DHW down to to 105.It might not with all the zones calling but certainly will with only some of them calling. I have quite a few days when the target is 90 degrees. I don't want to give up the efficiency of the lower return temps.
    I could pipe it your way and add an instantaneous booster, but why?
    I think what you are doing is inventive and interesting. I think it will work better for systems that need to run at temps 120 and up. A mod/con powering a fin tube baseboard would be a good application.
    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Eastman
    Eastman Member Posts: 927
    edited December 2014
    @Zman‌

    In your example, when the boiler is producing water to a target of 105, it will not go through the indirects heat exchanger. The assumption is that the mix valve is fully open to receive this low temperature space heating call. When the valve is fully open synchronized flow occurs and bypasses the tank.

    Now, while the boiler is off, the tank is being cooled by the return fluid from the space heating system. So during this phase of the operation, one may be concerned. But this action is identical to the effects of a DHW demand. Also, the flow is from bottom to top. With this arrangement, the tank heat exchanger is being utilized in a pseudo countercurrent exchange manner. This form of transfer is highly efficient if the demands are kept relatively low, and will leave the top of the tank hot and the bottom at system return temperatures. Eventually, a DHW demand will be initiated, but this should occur before the the tank is depleted of usable hot water.

    Wikipedia has some useful information on countercurrent heat exchangers at this link:
    en.wikipedia.org/wiki/Countercurrent_exchange

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