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Now with pictures. Triangle tube pte 110 prestige excellence. Pump speeds?

bassobenottobassobenotto Posts: 5Member
edited July 2018 in THE MAIN WALL
First things first. A long overdue, and hearty, thankyou to everyone here, for the wealth of information you share.
With your guidance, two years ago, I was able to narrow my choice of boiler, and more importantly; I was able to track down one of the better installers in my community.

I would very much like to achieve near constant circulation, all winter long, with minimal cycling.
To that end, this coming heating season, I would like to optimize the pump speeds for the three variable speed pumps in my system. Especially the internal pump in the prestige. The other two are circulating pumps, each on one of two loops. All three have been on middle setting since install. So my overarching question is largely theoretical. Should I consider changing the speeds at all? If so, How do I determine in which direction?

I will follow up to this original post with any information people would ask for. But the basics are as follows. Two story DC townhouse, with newly renovated basement unit. Cast Iron radiators throughout the main house. Three panel radiators plus towel warmer, all with TRV's, in the basement unit. Currently configured as two zones (main/basement). almost certainly want to reconfigure to one zone this year.

It has become clear that the basement zone is so small that near constant bouncing off of high limit is a problem.

I have used the new system for two heating seasons. The first season the basement was unoccupied and kept relatively cool. This past year we kept the basement heated to livable temperatures. I was able to experiment with water temps and ODR the first year, and came up with pretty decent results. Last year the results were not great.

I realize I probably could have ended up with the solo 60 and an indirect water heater. But, overall, I am quite happy with the current setup

That said, I am hopeful that controlling the entire house, as one zone, from first floor thermostat will alleviate much of the cycling, and that the extra load from keeping the basement warmer will actually extend run times.

I appreciate and look forward to any thoughts.



  • JackmartinJackmartin Posts: 129Member
    edited July 2018
    Garrett I hate to be someone who pours water on an idea:but, according to your message your system was installed by an excellent contractor. I would suggest you contact them and have a serious on site disussion on what you would like to do. In my opinion ,the worse thing you could do is try to run your heating system off one main stat. Think about it for a moment ,you are giving up individuslized control per space, to one control that will only truly sense the temperature in that space. I feel confident that if you explain your basement problem with your contractor they will come up with an effective way to bring it into control. Please remember, your contractor set the pumps at their present setting for a reason. Noise,water moving too rapidly is noisey. Heat transfer, if you rush the water to quickly, your Delta T will suffer, hard to get heat out of water going by at a tremendous rate of speed. The system has been sized for a calculated flow rate change that parameter and all sorts of interesting things happen ,unfortunately none of them good. All the best Jack Canada
  • hot_rodhot_rod Posts: 11,157Member
    Not exactly correct jackmartin
    if you rush the water to quickly, your Delta T will suffer, hard to get heat out of water going by at a tremendous rate of speed.

    The higher the flow rate thru a heat emitter be it fin tube, radiant slab, wall ceiling, or fan coils, the higher the heat output.

    Higher flow rates = higher AWT thru the heat emitter. Hotter heat emitters = higher output.

    The question becomes how fast is too fast. Pumping power needs to be part of the answer as well a fluid velocity the piping. Excessive noise, wear, and power consumption result from excessive over pumping.

    This Idronics issue correlates circulation and heat transfer.

    Tune in July 26 noon central for a 90 minute Coffee with Caleffi where we talk at length about heat exchange, and all the factors involved.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • bassobenottobassobenotto Posts: 5Member
    Thanks both.
    HotRod, I remember reading so many of your posts. Thanks for the hydronics perspective.
    Jack Martin, my hope is that the basement can be effectively independently controlled by the TRV’s. If,that is, as I hope, the panel rads over-emit relative to the rest of the house. The envelope certainly is much tighter down there.

  • bassobenottobassobenotto Posts: 5Member
    Thanks again. I did a little bit more searching. Still haven’t cleared things up for myself. Hoping for a little bit more input.

    Let’s start with just the system pump. What happens if I slow it down? What about if I speed up?

    Looking forward

  • hot_rodhot_rod Posts: 11,157Member
    Check the installation manual to see if they have a minimum flow rate or pump speed for that boiler. I don't know if that boiler has an output to modulate the boiler pump with the firing rate, that would be ideal.

    For the zone circulators, run them on the lowest speed that will provide adequate flow, and heat output.

    You could calculate each zone to determine required flow rate, or just try adjusting the speed on a design or coldest day condition.

    Probably what you will find is on mild, or moderate days a low speed may be adequate, on design or below temperatures you may need addition flow.

    So, again that is why the constant circulation with temperature modulation is so desirable. Adjusting heat output by modulating flow rate is very non- linear.
    Ideally let the circulators(s) run and modulate SWT based on indoor and outdoor input.

    That being said, not all systems will be conductive to that mode of operation, sounds like your boiler is oversized and may not modulate to a low enough output, and small micro zones pose a challenge, as does multiple on off zone control either with a circulator or zone valve.

    The Euro method involves properly sizing the components to the load, constant cir with TRV controlled zones, or delta P circs with TRVs, all in an attempt to get away from bang/ bang control. With that type of control logic the boiler, pump and TRV are all constantly modulating to try and exactly track the load, they work together well.

    There have been some great posts here over the years on how to dial in ODR control, it takes some time and observation and tweaking to get it to you needs and liking.
    You many not get to the exact operating condition you seek.

    I think Kurt from SWEI had a good thread on his ODR adjustment method a few years back if you search for it.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • DZoroDZoro Posts: 725Member
    If piped correctly you should be able to run the boiler on low pump speed. Like Hot Rod said, if needed you could always turn it back up. Did that boiler come with the internal pump? I know the older ones came with a 3spd internal pump.
  • bassobenottobassobenotto Posts: 5Member
    I have done so much reading on the wall. There were a couple threads that were real brain twisters for me.

    I have decided to put the entire house on one zone. I have also decided to set the boiler pump to its lowest setting. I will most likely put both of the secondary circulator pumps on their lowest setting as well. At this point I i’m content to just hope that the basement stays warm enough. And can be throttled with the TRVs. If not, I will take the appropriate steps.

    It seems like a lot of people like to see pictures. So I will try to attach a few.

    Thanks again. Looking forward
  • bassobenottobassobenotto Posts: 5Member
    I am reviving this thread. The installer of this system is coming by this week. Trying to get an early start on yearly maintenance. We are also going to take care of tying the two zones together into one. We are going to switch the system pump to the slower speed. It’s easy enough for me to change the circulator pump speeds throughout the season. Does anybody have a suggestion as to what speed to use for the shoulder season? As I mentioned in the last post, I’m thinking about starting them both on the slower speed. Is there anything else I should have looked at while the system is being serviced for the upcoming Heating season?

    Looking forward.
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