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Circulator Pump Recommendations-

ced48
ced48 Member Posts: 469
I am looking for a pump that will deliver 6 gallons per minute, working against 8 feet of head-Looking for quiet and energy efficient operation. Any suggestions?

Comments

  • Robert O'Brien
    Robert O'Brien Member Posts: 3,541
    Grundfos Alpha
    To learn more about this professional, click here to visit their ad in Find A Contractor.
    johnnyrockettZman
  • ced48
    ced48 Member Posts: 469
    The Alpha, in speed II, looks a little on the weak side. Am I missing something?
  • Paul48
    Paul48 Member Posts: 4,469
    Taco 007
  • Ironman
    Ironman Member Posts: 7,373
    ced48 said:

    The Alpha, in speed II, looks a little on the weak side. Am I missing something?

    Speed 3, or "auto adapt" cover that range. Therefore, it wouldn't matter what a lower speed does. You wouldn't be using that speed.

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • SWEI
    SWEI Member Posts: 7,356
    Don't forget that on a variable speed circ (regardless of whether it's a conventional 3-speed switched design or a 'smart' ECM circ) the highest curve has the highest hydraulic efficiency. Translation: If you size to the maximum curve, you get maximum turndown in part load conditions. Size matters!
  • icesailor
    icesailor Member Posts: 7,265
    FWIW, I was going through some magazines this PM for delivery to the dumpster. The November issue of P&M has an interesting article by Siggy that really covers your point. You can put the biggest hydraulic mining pump on it, and it will reach an equilibrium and balance. Probably around what a 007 will do.
  • ced48
    ced48 Member Posts: 469
    I can't use a variable speed pump as I am using it for a direct pumped Modcon-I am looking for something a bit weaker than a 007, but slightly more powerful than a 005. I would like to use an ECM pump, but that choice seems unavailable. I see that there is a pump made by AquaMotion, an AM5-F1 that has a curve that works great, never heard of them, but might give it a try, unless someone knows how I could adjust the Grundfos Alpha to work in my situation.
  • Paul48
    Paul48 Member Posts: 4,469
    Why can't he use a DT circ to pump through a mod/con? I understand the min. flow requirements, but those are at high fire. It would seem that at lower firing rates that required rate would also be lower.
  • Eastman
    Eastman Member Posts: 927
    ced48 already tried a dT pump. I'm sure he'll chime in to elaborate on what went wrong.

    @ced48 I don't see why a variable delta P pump should not work as a boiler pump. There isn't a potential conflict with the modulation rate.
  • Ironman
    Ironman Member Posts: 7,373
    Also keep in mind that most all mod/cons allow flow rates that will produce anywhere from a 20 - 35* delta T. It doesn't have be exactly 20*.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • ced48
    ced48 Member Posts: 469
    edited December 2014
    Paul48 said:

    Why can't he use a DT circ to pump through a mod/con? I understand the min. flow requirements, but those are at high fire. It would seem that at lower firing rates that required rate would also be lower.

    Because as the boiler modulates, the circulator tries to adjust it's speed, and the two things just get all tangled up. I tried using a Taco Bee, and had issues with Delta-t lockouts-Just to be clear, the issue was not with the pump, or the boiler-just putting two things together that were not designed to work together-
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,239
    As of yet, the only plausible variable speed pumping on a ModCon, that I am aware of, is when the boiler controls the pump.

    Look at the B&G Vario. It is an Ecm circ that has an adjustable, step less variable speed. You just turn the knob till you are at the right speed. The pump will remain in that speed. They also have a delta-p circ but that one probably wouldn't be suitable for your application.
  • SWEI
    SWEI Member Posts: 7,356
    You need to let the WHN controls run the circ.

    The only real option right now is a Taco VVF series circulator. What ΔT are you assuming for the 6 GPM requirement? 007-VVF5, 005-VVF2, and 006-VVF4 are all potential candidates.

    Once again, to all the pump manufacturers: We REALLY need 0-10V inputs on your residential sized ECM circulators. Please?
  • Paul48
    Paul48 Member Posts: 4,469
    I can't dope it out myself. There's too much going on there, for this small brain. But, did you contact Taco? That's not to say it could ever work, just, they would know how to make it work, if it was possible.
  • ced48
    ced48 Member Posts: 469
    edited December 2014

    As of yet, the only plausible variable speed pumping on a ModCon, that I am aware of, is when the boiler controls the pump.



    Look at the B&G Vario. It is an Ecm circ that has an adjustable, step less variable speed. You just turn the knob till you are at the right speed. The pump will remain in that speed. They also have a delta-p circ but that one probably wouldn't be suitable for your application.

    Harvey-That B & G Vario is just what I'm looking for- thank you-

    Paul- I think as others have said, the only way it can work is if the boiler's computer controls the pump speed, and even then, I wonder wether or not things still might get tangled up?
  • SWEI
    SWEI Member Posts: 7,356
    If the WH is controlling the pump speed, it simply will not allow things get out of line. In the event the pump does not deliver the flow needed, the boiler will back down on the firing rate.
  • SWEI
    SWEI Member Posts: 7,356

    As of yet, the only plausible variable speed pumping on a ModCon, that I am aware of, is when the boiler controls the pump.

    The one exception would be when we are controlling both the mod/con and the pump from an outboard controller.

    I have experimented quite a bit with tuning PID loops using ΔT control, but honestly the simplest route is straight proportional control of both the pump and the boiler. Set the limits so the pump speed is correct at the minimum firing rate and correct at the maximum firing rate and just vary them together.
  • SWEI
    SWEI Member Posts: 7,356
    edited December 2014

    Look at the B&G Vario. It is an Ecm circ that has an adjustable, step less variable speed. You just turn the knob till you are at the right speed. The pump will remain in that speed.

    The ecocirc e3 Vario has similar functionality with much lower curves. The e3-4 works great on 40-60k firetube mod/cons as a primary pump. The e3-6 will direct pump those in a low head system or work as a boiler circ for 70-90k firetube mod/cons. I've been asking Laing/B&G for a 0-10V option on these for 3+ years now to no avail.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,239
    The ecocirc e3 Vario has similar functionality with much lower curves. The e3-4 works great on 40-60k firetube mod/cons as a primary pump. The e3-6 will direct pump those in a low head system or work as a boiler circ for 70-90k firetube mod/cons. I've been asking Laing/B&G for a 0-10V option on these for 3+ years now to no avail.
    They are coming. There is a certain American Boiler manufacturer that has them sitting on his desk. As soon as they complete their boiler overhaul to control variable speed pumping, we'll see them on the market. If American pump manufacturers don't step on it, they stand to lose quite a bit of market share.

  • Paul48
    Paul48 Member Posts: 4,469
    They seem so absorbed in fighting for their own technology, and the fact that their technology is what is needed, that they have stopped looking at what people are saying. " Can't see the forest through the trees"
  • Using a circ with a brain that moves water through a boiler with a separate brain has a high possibility of causing issues unless the brains talk to each other. Delta P is definitely not a good idea (think about what causes a delta P circ to change it's flow - it does not have a direct - "repeat direct" relationship to the boiler's firing rate).

    Delta T makes a little more sense (circ reacts to temp as does the boiler) but as noted in previous posts there is the possibility of cycling under low load (low flow) conditions unless the circ is set up right (let's not forget setpoint temp as an option as well - control return water temp? - Just sayin...).

    Best is 0-10Vdc (or PWM) direct circ speed control, with the signal generated from the boiler's control (mainly for circs dedicated to the boiler flow, not boiler AND system flow).

    The most sensible option, today at least ;-) if you want ECM is an ECM that has a manual variable speed.

    ced48, have a look at the control options on the attached new VR 1816 circ. You have the ability to dial it in to meet various 00 Series performance curves. Contact me (stetho@taco-hvac.com) if you want to try one of these out - would love to get your opinion.
  • ced48
    ced48 Member Posts: 469

    Using a circ with a brain that moves water through a boiler with a separate brain has a high possibility of causing issues unless the brains talk to each other. Delta P is definitely not a good idea (think about what causes a delta P circ to change it's flow - it does not have a direct - "repeat direct" relationship to the boiler's firing rate).

    Delta T makes a little more sense (circ reacts to temp as does the boiler) but as noted in previous posts there is the possibility of cycling under low load (low flow) conditions unless the circ is set up right (let's not forget setpoint temp as an option as well - control return water temp? - Just sayin...).

    Best is 0-10Vdc (or PWM) direct circ speed control, with the signal generated from the boiler's control (mainly for circs dedicated to the boiler flow, not boiler AND system flow).

    The most sensible option, today at least ;-) if you want ECM is an ECM that has a manual variable speed.

    ced48, have a look at the control options on the attached new VR 1816 circ. You have the ability to dial it in to meet various 00 Series performance curves. Contact me (stetho@taco-hvac.com) if you want to try one of these out - would love to get your opinion.


    Steve- This new circulator sounds perfect-I will be in touch-Thank you and Taco for all of the help I have received from you now, and in the past-Walter
  • Paul48
    Paul48 Member Posts: 4,469
    I'm 54, but I gotta do this....See! I told you so!!!.....LOL