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    Now I see why the Grundfos person posted the video on You Tube......... (106 Posts)

  • Mark Eatherton Mark Eatherton @ 11:26 AM
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    Now I see why the Grundfos person posted the video on You Tube.........

    I got my copy of Contractor Magazine, and the whole front cover (Advertisement) is ALL about Taco's variable speed controller based on delta T, and they are claiming that energy savings associated with ECM motors are garbage, and that their product holds a significant potential for electrical savings. Now, I know this is going to create some controversy, but being as familiar with the ECM circulators that are on the market, I'd like to take Taco to task, and have them prove to me, and the rest of the hydronic world how it is that they arrived at this conclusion.In my little minds eye, there is NO WAY that a conventional Taco 00 motor could possibly be more efficient than an ECM motor, regardless of the ECM manufacturer.They are claiming that Delta T is more efficient than Delta P, which is what most ECM circulators are programmed to run on.I'd love to see more of their assumptions...Anyone? Taco,WILO, Grundfos, Buehler??? Buehler???ME

    PS, heres a link to their article

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
    This post was edited by an admin on October 19, 2009 11:27 AM.
  • NRT_Rob NRT_Rob @ 1:24 PM
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    I could see the arguement

    if you base on delta-T, your flow requirements range from 0 to full flow with the load.

    if you base on pressure, it only varies with how many zones are calling. if you have a good reset curve, most zones should be calling most of the time all winter.

    So if an ECM motor can do the same pumping power with 50% of the energy, just for round numbers, the question would be... how much are you at less than 50% load, where the delta-T method would have an advantage?
  • Jean-David Beyer Jean-David Beyer @ 2:42 PM
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    Thinking about delta-T

    It is not very cold here today, about 55F outside.

    My upstairs baseboard system has lots of baseboard for the calculated heat loss.

    So today, when it was running (mod|con boiler with outdoor reset), the hot water supplied was about 100F and the return between 98F and 99F. The circulator is just a Taco 007-IFC supplying 2.8 gallons/minute (calculated, not measured)..

    But thinking about a delta-T circulator, what would happen? I assume it would slow down until the loss was 10F or whatever I set it for. Now the flow required for that must be pretty low. So would the delta-T slow down to about 0.56 gallons per minute? At some point does not the curve reverse? At the extreme of no flow at all, the two temperatures would be equal and it cannot slow down any more. At some point, slowing the circulator down will reduce the temperature difference. In other words, the circulator must go fast enough that the cooling in the supply and delivery pipes is negligable, but slow enough to get the set temperature drop. In my upstairs, where heat loss is quite small, these two may be contradictory.

    Things will probably be all right when it gets really cold outside, but right now it cycles pretty fast because of the small heat load up there. The circs. run, but the boiler cannot modulate below 16K BTU/hr and the load up there, even on the design day, is only about 6500 BTU/hr, and it is a lot less than that right now. Downstairs, where the load is about 23K BTU/hr things appear just fine, even on a day like this. And if both zones were asking for heat at the same time (in cold weather), the boiler would have no trouble keeping up.
  • NRT_Rob NRT_Rob @ 1:26 PM
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    though the cost savings they report are pretty weak

    they claim $3/heating season for ecm pump savings.

    not sure how they get that. I could see that per MONTH, but not for a heating season.
  • Leo_G Leo_G @ 7:00 PM
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    if the old saw is true that running one of these small circs is the same as a 60 watt light bulb, then yes, I can imagine not a heck of a lot of over season savings on the electrical. But what I got from the article was not the electrical draw, but how the delta T circ, would insure that for a majority of the season, your boiler and system are working at the design parameters of 20* drop. This would insure that the boiler was right on its highest effeciency, therefore would be using markedly less fuel, which in most cases would save the consumer more money. We've all seen the dreaded waterout/waterin being very close in temp. and the boiler cycling like there is no tomorrow. Not only does this waste extravagent amounts of fuel, but also wears the controls out before thier time.

    I for one am very interested in this technology and can barely wait to get my hands on it and give a go!

    Leo G
  • NRT_Rob NRT_Rob @ 11:46 AM
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    hi leo

    at ten cents per kwh, a standard 15-58 circulator on high speed (90 watts) costs about $5/mo if it's on contuously.

    an ECM pump can do the job at 45 watts, which is half the cost, or about $2.50/month.

    even at 50% duty cycle, that's $3 every two months or so... not for the whole heating season.
  • NRT_Rob NRT_Rob @ 7:57 AM
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    now I see the disconnect

    john was talking about savings compared to the variable speed pump, not a regular pump.
  • MarkPFalade MarkPFalade @ 3:01 PM
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    You're going to love this,,,

    I just installed one on a hydro air circuit. I haven't started it yet. Thursday may be the day. Oil fired Crown CT-3 with an MS-40 and a Bryant Evolution HP setup. It's a variable speed air handler and I'm wondering how they're going to get along. My thought was I already need 180* for the indirect so instead of getting involved with reset I'd try the delta t pump on the coil instead and see what happens. If worse comes to worse I have the 007 that came with the boiler to swap out if it doesn't work. So I'm just fiddlin' again. It was a promo "sample" supply guy had sitting on his desk when I approached him about it. I tell him about it and he says, "You mean like this?"  It wasn't even in stock yet. lol...
    I'll keep you posted. I wasn't thinking about electrical usage when I went for it. I understand that it uses the same amps regardless of speed whereas the others reduce amps as speed drops. Is this the issue?
  • Paul Pollets Paul Pollets @ 5:33 PM
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    A Matter of Opinion

    Taco also bought the cover of PM mag and 2 pages in the back. I've never seen that before.

    The Germans would argue Delta P, Taco argues Delta T. 

    I've been logging the Grundfos Alpha in our shop this first week of heating season...the pump runs 2gpm 15w (AM) and levels off at 1 gpm at 12w late AM  I'll do the calcs when I return to the office tomorrow.

    I wonder who wrote the "white paper" ?
    This post was edited by an admin on October 19, 2009 5:34 PM.
  • Dave Yates (GrandPAH) Dave Yates (GrandPAH) @ 7:03 PM
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    Zero: nose-diving to make a point!

    Unless you're flying a plane with a big fat red red sun on its side, you'd have had to ignore the fact that Grundfos has had a delta-T circ for more than a decade. So why did they go to the delta-P and ECM motor technology?

    Saw the Alpha years ago at ISH in Germany. It was a 7-watt deal back then and hits 5-watts at times now.

    If the delta-P circs go ECM, then, and only then, will they be able to go head-to-head where energy conservation is concerned and even then, I can see lots of times where delta-T would cause (think hi-mass) circs to over-amp while climbing the energy ramp to meet a DT that doesn't need to be met in order to deliver comfort.

    Stuppose you had a job with ten zone circs and a primary loop circ sucking down more than 1,200-watts 24/7 & that you swapped out those 10-circs for 10-zone valves that draw just 3-watts each along with two circs that ramp up/down from 5-watts to 28-watts to do the same work.

    At 11-cents per kWh, you'd go from $450.00+ per year (using outdoor reset - therefore longer run hours) to just north of $26.00 per year. Then toss in utility deregulation that might double your rate in the next year.  

    While we've been designing systems for specific delta-T's all these years, I have yet to see one that adheres to the numbers because virtually every single system zone is over-pumped by default.
  • Mark Eatherton Mark Eatherton @ 9:03 PM
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    If 20 degrees is considered the "ideal" temperature differential...

    then why even offer an adjustable DT of between 5 and 50? Why not make it a fixed 20 and be done with it?

    I have been told by more than one knowledgeable senior engineer that the 20 degree delta T is an American invention, and it was done so to make the "math" easy. Each GPM delivers 10,000 btuH.

    I also have it from knowledgeable European engineers that their Delta T is significantly larger than 20 degrees... more like 50?

    Having been in the field a LOT during design conditions, I have seen ONE (count 'em) system achieve a 20 degree delta T, and that was a hot water BBR system being started on a new house, at design conditions. ONE....

    And what about the hydraulics? If I place all my cards in the basket (heating system) in the fixed delta T arena, what is going to happen to that 1/2" zone serving the master bedroom on the far end of the system at mid design conditions if a closer zone is open? I'm thinking that the pump will not generate the proper head to give me the required flow to generate a reasonable flow to the far zone, and my delta T on THAT part of the system is going to be BIG, and the delivery of heat is going to be small, and I'm going to have a dis-satisfied, uncomfortable customer.

    Now if the circulator is watching the delta T, regardless of how many zones are opened, I can be assured that the pump WILL maintain the pressure differential necessary to deliver comfort.

    Delta T is a function of load being imparted, not choking simulate load.

    The soap box is clear, for now.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • hot rod hot rod @ 9:40 PM
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    if and when Taco has a delta P, ECM circ this discussion becomes a mute point.

    What if a delta T, ECM circ came onto the market? I'll bet they are not far away.

    Doesn't the Grundfos Miximizer and Taco delta T circ both have tekmar "brains"?

    And of course tekmar and others offer delta t controllers to fit just about any circ.

    Many of the solar controllers have delta T functions, along with BTU metering and data logging, digital display, multiple outputs, etc, etc for about the same money as a delta T stand alone control.

    Speaking just from electrical consumption, no question ECM saves big energy. This technology is and has been showing up on many electric motor applications. Fans, pumps, compressors, lots of potential energy savings.

    I see a lot of applications for delta T circs, return boiler protection, especially for wood or biomass boilers could be a good market.

    Delta T works nicely on solar collection circs also.

  • Mark Eatherton Mark Eatherton @ 10:06 PM
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    WILO has had DT for a long time...

    It requires the use of a third party (Honeywell) controller to put out a 0 to 10 VDC signal, but none the less, it is here. It can't be used for cooling applications. can the Taco DT be used for cooling app's?

    Lots of questions, but no official answers... yet.


    BTW, who DID write the "White Paper"? What are their qualifications?

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • N/A @ 10:50 PM

    Well, I have a Taco 008VDT on,

    my Solo 60,,, the system is mono-flo (3 zones), and I have CIBB,,, not very knowledgeable on the voltage consumption side, but I have had to experiment on the Taco sensor placement side.

    If I used ECM (depending on a smaller zone returning earlier),, would that not "relax" the pump into thinking no-flow is needed elsewhere?
  • Paul Pollets Paul Pollets @ 8:58 AM
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    Mark, why don't you set up a bench test that would show flow rates and watts with the 3 pumps available? It would be relatively easy to log the differences, especially with a ZV or 2 on the piping array. It would be reasonable to compare the differences, so contractors really know what they're purchasing and the true advantages of smart pumps.
  • NRT_Rob NRT_Rob @ 11:56 AM
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    that wouldn't answer the question

    the question is how it would behave on a real multizone system, not what it is at given flow rates. that information is pretty easily extrapolatable from the power ratings of the pumps, I believe: figuring out how often you are at a given flow rate in the field is the real trick.

    to address your other post, the euros do delta-P, but they are also doing mostly analog flow control valves too.. constant circ, where pressure resistance is actually related to your heat load (how closed a zone is).

    for american systems where we are just ON or OFF, that's not the same think, and delta-P has very little to do with heat load. unless you're using Uniboxes or TRVs like a euro.

    as much as I think the claims are overblown, I think there are significant number of systems where delta-T might have a real advantage. any constant circ system without TRVs/Uniboxes, or zone valved system.

    but that's "might". I also suspect that the difference is not huge in terms of yearly energy savings.. cutting it in 50% with ECM tech vs more than that during the shoulder seasons and maybe not cutting at all on design day... you'd need some bin data and serious modeling to answer that. I imagine the difference would be $10/year at most for most residential systems between the two... kind of esoteric.

    but i'm just making that up too.
  • Some other considerations......

    If the pump is set at a fixed delta tee, what happens when loads are light on a system.  Take a loop baseboard system through several rooms designed for 20 DT at design load with 70 F interior temp on reset.   On a warmer day, the control will be calling for 90F supply and the return will be at 70F.  The first room on the loop will be too warm and the last too cold because there will be heat output at the beginning of the loop and none at the end.  This heating imbalance will diminish as water temps rise, but will always be there until design conditions.
    Taking the same situation with radiant floor will be even worse, since supply temperatures typically do not get as hight.  A 10F delta tee in warmer weather will cause the beginning of the loop to heat while the ends leav the floor cold.  If you figure a floor with a design supply of lets say 110F (probably typical for many floor systems), on the typical day it would be running about 95 sup and 85 return.  The heat output would be about 60% higher at the beginning of the loop as opposed to the end.
    The only place where delta tee would work well, I believe,  is in systems where every heating unit is supplied directly with boiler water.... no series loops or monoflows.
    I think Taco has missed a fundamental of hydronic heating.  Most systems designed for X delta tee are designed for this delta tee only at design conditions, not thorughout the load profile.

    The Steam Whisperer (Formerly Boilerpro)
    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • NRT_Rob NRT_Rob @ 12:03 PM
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    this is an interesting point

    for emitters with non-linear output compared to water temp (like baseboard) you make a really good point.... not that you should ever be installing series baseboard IMHO, but if you're stuck with it you're right, the relative temps between them stay the same but as water temps drop they drop faster for the lower temp emitters.

    that's good thinking right there. but if it's not series emitters, you are just talking about the average temperature across the emitter when you are talking about delta-T, and backing down flow to keep the average a specified target compared to the supply temp isn't crazy. you could argue our regular way of doing it is just "CYA" for the shoulder seasons. on design day your average temp is supply minus half delta T, but on shoulder day it's supply minus much less.... kind of a "hedge" on the reset curve.
  • John Barba John Barba @ 3:06 PM
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    Beware -- Marathon Post!

    Boy, isn’t this fun…
    First, some particulars:  I wrote the white paper, basically ‘cause I can do math.  Haven’t had anything I’ve written cause this much of a stir since the mid-80’s, but my name and address were withheld by request, anyway.
    The particular white paper Mark references discusses the difference between Delta T variable speed circulators and Delta P variable speed circulators.  Both circulators try to get to similar places using different technology.  I read it again, as well as its companion piece on electrical efficiency, and I can’t find anyplace that says a 00 –series motor is more electrically efficient than an ECM motor.  It ain’t in there...
    Of course ECM motors are more efficient, but the point to remember is that we’re dealing with a 1/25th HP motor.  Not a 1 HP motor.  Not a half HP motor.  1/25th!
    We based electrical consumption on some assumptions.  First, we based it on the circulator running an average of 12 and half hours a day over 162.5 days – basically 6 months.  Of course, the circulator will run more in the colder times and less in milder conditions, but this was assumed as a heating season average.  We looked at an ECM circulator running between 5 and 60 watts during the heating season, with an average of around 30 watts; we looked at our 00-VDT circulator running between 25 and 80 watts, with an average of about 60 watts. 
    We based the cost of electricity on a national average of .09 cents per kilowatt hour.  Your rates, of course, may differ.  We also accounted for standby electrical usage of ECM circulators, which need power for their electronics to remain in standby mode and to “learn.” This was determined as best we could by reading technical literature and instruction manuals.  Once everything was factored in, the ECM circulator saved an estimated $3.16 worth of electricity per year…based on these assumptions, your mileage may differ.  If your electrical rates are higher, the difference you see will be greater.  For instance, .18 cents per kilowatt hour would lead to a difference of $6.32 per year; .36 cents per kilowatt hour would be $12.64 cents per year, and so on. 
    As far as the 00-VDT is concerned…this is not new technology for Taco.  We came out with the 00-VS variable speed circulator in early 2004.  This was, and still is, a multi-function circulator that can be used as a Delta T circulator (the 00-VDT), as well as for chilled water applications (yes, it can be used for cooling!), injection mixing (fixed temperature – etc.), fan coils, boiler protection, etc.  The 00-VS was not all that successful, however, due to the fact it simply had too many features (thank you for that lesson, Robert Bean!).  It’s still available, but we also have the 00-VDT now available. The Delta T is adjustable so the circulator can be used for a variety of applications.
    As far as heat delivery is concerned, I think everyone here knows that GPM equals BTUH divided by Delta T times 500, and this IS a fundamental of hydronic heating.  As the heating load changes in a system, the required flow in a system changes, not the required Delta T.  For example, a properly designed and installed radiant loop may require 110 degree water and 1 GPM worth of flow at 0 degrees outside, but may only require 100 degree water and half a gallon worth of flow at 35 degrees outside at a 10 degree Delta T. 
    With a fixed speed circulator, you’re kinda stuck on the pump curve, and the system has to adapt to what the circulator can do.  A system designed to a Delta T of 10, 20 or even (gasp) 50 would very likely NEVER see the designed for Delta T due to the fact that the system works where the system curve intersects the pump curve.  As Mark points out, you would be hard pressed to find a system with a fixed speed circulator actually working at the designed for Delta T – but that’s a function of a fixed speed circulator forcing the system to operate on its terms.  Does this mean those systems don’t work?  Hardly…but this is the reality we’ve been living and working in when using fixed speed circulators. 
    With a Delta T variable speed circulator, the circulator adapts to what the system needs.  By monitoring the designed-for Delta T -- and 20 is what’s been generally used for baseboard applications, 10 for residential radiant, but you can dial in whatever the heck you want for whatever application you want – the circulator will speed up or slow down to maintain that Delta T, and provide the system with the flow necessary to do the job.
    As for distant zones opening—as soon as that zone opens and receives flow, the return water temperature will drop, prompting the circulator to speed up, increasing both the flow and head pressure, and delivering comfort – again, reacting to the real world demands of the heating system.  Loads change, so should flow. 
    Here’s a tit for your tat, Mark – what would happen if, say you had 4 zones of whatever you want, relatively equal in length and head loss, but two zones have lots of windows and a higher load, while the other two have fewer windows and a lower load.  How would a Delta P circulator know the difference if only the two higher load zones were calling?   I don’t know, either.
    One thing you will always hear from Taco is nothing but the utmost respect for our competitors.  Grundfos and Wilo are both excellent companies – I have friends working for both outfits -- and both provide fine products.  We do, too, and that's what makes competition fun.  ECM circulators do use less electricity than a 00-series circulator, but when you’re talking about a 1/25HP circulator in a zone valve or multi-zone radiant application, it ain’t that much in terms of dollars and cents.  A Delta T circulator will help control return temperatures at the boiler, which will help the boiler run more efficiently…that energy savings typically more than offsets electrical savings.
     I’m glad Mark posted the questions…as usual, they’re really good ones….and I’m really glad people are interested enough to keep the discussion going. 
  • tim smith tim smith @ 11:06 PM
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    Re: delta t vs delta p

    One question I have is how will the delta t respond to zone closures and respond quick enough to keep velocity noise down??
  • Mark Eatherton Mark Eatherton @ 3:26 PM
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    Ferris Bueller to the principals the principals office now...:-)


    I respect you as a fellow plumber, former trades person and edutainer. Having been through your classes with your previous employer, I can vouch for your zest and zeal, and knew when you went to work for Taco, that you would take them to places they had never been. It is quite obvious that Taco has a dedicated group of contractors. More power to them. Somehow, I knew that your hand was attached to the pen that wrote the white papers.

    I have to give you and your organization credit for having the moxie to change , or at least attempt to change the course of hydronic mankind as it pertains to fluid dynamics. I can only assume that Taco has done its' homework in the field prior to introducing the product. I have heard back from a few people who were not satisfied with the operation of the VS pump, but did not have enough experience or knowledge to help them out.

    Oddly enough, I think I had something to do with their introduction. I mentioned it to Mr Sweet many years ago, and shortly thereafter, they came out with the product. Funny how that works, and even funnier how many times it has happened to me. If I had a dollar for every idea that I'd concived prior to it coming out, I could retire comfortably, and wouldn't be here in Clinton NJ teaching hydronic heating contractors :-)

    But then again, if that were the case, I wouldn't have had the opportunity to go out for dinner with my good friend Gregg Jannone, so it all works out in the end.

    I realize now that you probably have the pressure drop requirements covered due to your use of the steep curved pump. Funny that you should mention Mr Bean, because he is the one that taught me that the ideal pump had a perfectly flat curve, like the VS DP pumps have.

    Regardless, it is you and Taco that will have to answer the question of time and exposure, and wether or not your mathematical formula is correct. I would only caution you that bending the average numbers to make your equation look good based on certain assumptions is not a good idea. Kind of reminds me of the use of averaging thermostats in warehouse conditions. 50 degrees F and 90 degrees F are an average of 70 degrees F, but neither are acceptable as it pertains to maintaining decent comfort.

    I look at the boiler industry over the last 12 years, and more recently the last three, and I note that there a very few manufacturers who have not yet jumped onto the mod con band wagon. I look at the pump/circulator manufacturers, and I see the same situation happening as it pertains to DC-ECM motors, and it leads me to ask one last question. When is Taco going to be introducing a new line of DC-ECM circulators?

    Thank you in advance for responding, and best of luck to you and yours.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Brain Ross Brain Ross @ 8:09 PM
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  • MarkPFalade MarkPFalade @ 6:05 PM
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    Questions for John

    How do you think the 008VDT will play with a variable speed air handler? I'm thinking if they settle in together it's a beautiful thing but if they decide to hunt the party is over. Has anyone tried this at your end? I'm under the assumption, or was anyways, 20* DT was where I should be heading. Any input on that?
  • Steven Gronski Steven Gronski @ 8:30 PM
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    My 2 cents

    I just installed a Taco 008-VDTF6 on my heating system, replacing the 007. I have 4 zones,set up on constant circulation withwith out door reset on a Vitoden 200   6-24, and the thermostats are basically high limit switches at this point. I only have 1 zone that will usually shut down. My shortest zone is the zone with the most heat loss. This zone never seems to ever quite feel like a warm, evenly heated room . Last night it got below freezing and this was the first test on te VSD pump. The room felt warm and evenly heated like it was being heated with 180 degree water and my boiler was only making 119. The thermostat had actually shut down in this room, and it never does. I agree with JMB that a Delta P pump would not have known or sensed the rooms heat loss. I cant wait till its really cold and below freezing consistantly to see how this pump will really perform.I may have to start shifting the curve a little bit to not let the boiler catch up with the t stats. You can blow all the energy saved by a Delta P pump real easy, just leave a garage or basement light on. I bet its cheaper to zone with zone valves and a Delta T pump versus multiple Delta P pumps as well. As for myself, I have been installing  and promoting Delta T pumps on all my boiler replacements and new heating jobs. I just recently finished a heating system on a 130 victorian rehab. Its 15 zones. zoned with Taco ESP zone valves 0013 VSD pump with 28 cast iron radiators and 2 zones of radiant.All designed on 150 degree water on a zero day, with Tacos Flo Pro designer software. a perfect application for a Delta T pump. My competition bidding this heating job told the owner my proposed system would never work. The owners love it. Enough said.
    Steve Gronski
    Gronski Plumbing and Heating Inc.
    Cranston RI
  • Paul Pollets Paul Pollets @ 9:53 PM
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    TT not Vitodens

    The boiler pictured in Steve's post above is a Triangle Tube, not a Vitodens...
    This post was edited by an admin on October 20, 2009 9:53 PM.
  • John Barba John Barba @ 10:55 PM
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    Paul --  I think Steve was referring to his own home, which has a Vitodens, while the pictures are of a job he's been working on. 
    Peace out...
  • Steamhead Steamhead @ 9:40 PM
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    As I read all this

    I am reminded that gravity-return steam requires no pump at all.


    BTW- Steve, nice work.
    "Reducing our country's energy consumption, one system at a time"

    Steam, Vapor & Hot-Water Heating Specialists

    Oil & Gas Burner Service

    Baltimore, MD (USA) and consulting anywhere.
    This post was edited by an admin on October 20, 2009 9:59 PM.
  • MarkPFalade MarkPFalade @ 11:01 PM
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    I just did two gravity conversions

    I used the Solo110 for one and the Excellence for the other. Both running on low speed. Warm and toasty is the report, which is a very good thing to hear. I like that I can put some gravity to work there as well. Kind of neat. Here's two shots of each and two shots of the Crown with the VDT. I did not do any of the iron work on either conversion. The had both been converted to oil in the 50's. Everything after the valves is me. Neutralizers ala Hot Rod ;-)
    This post was edited by an admin on October 20, 2009 11:10 PM.
  • Dave Yates (GrandPAH) Dave Yates (GrandPAH) @ 8:44 AM
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    JB - need clarification please

    You wrote: We also accounted for standby electrical usage of ECM circulators, which need power for their electronics to remain in standby mode and to “learn.” 

    Why would an ECM delta-P (or delta-T for that matter) circ be treated any differently electronically than the way we currently treat circs - by turning them on/off via a relay. Seems to me they'd be without any power when idle. 

    Switching to the energy-production side for HVAC systems using ECM VS motors, the stand-by power consumption is being utilized to analyze indoor & outdoor conditions and how fast those conditions are changing in order to "know" how fast each of the ECM motors needs to run in order to meet comfort-demand. Indoor blower; compressor motor; and outdoor fan motor all must be coordinated by the brain. However, it looks to me like our hydronic systems brains are either mounted on the wall (Tekmar, Honeywell, etc) or housed inside the boiler & they draw a minimal amount of current in stand-by modes. The constant-draw wattages I've monitored (using a Kill-a-Watt meter) for my relay box and modcon during stand-by mode has been much less than I would have guessed.

    What am I missing here? 
  • N/A @ 4:18 PM

    Delta t vs Delta P

    Here is a little food for thought
    - Think overall system efficiency improvements as well as circ efficiency (collectively circ power consumption in the USA is huge – there are a lot of these little guys out there - over 3 billion watts annually)
    - Operating circ efficiency is dependent on the system load profile (degree days).  Kind of like steady state vs AFUE with boilers
    - Laws of thermal dynamics – changing heat output (or input) mainly requires changes in flow (at least that is what the BTU calculation shows us)
    - Circs provide flow by overcoming piping friction.  Pipe friction varies with flow

    Joe Gibbs wrote “Statistics can be manipulated to favor your own argument”
  • MarkPFalade MarkPFalade @ 5:34 AM
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    Guess I'll be finding out all by myself

    about what happens when you hook a VDT to a variable speed fan coil. I'll know when I get home tonight. I can share if you'd like.
  • Using the Fundamental Formula to check system balance....

    Let’s apply the heat transfer formula to look at system balance and I’ll ignore factors such as the reduced output from laminar flow in some heat emitters and the non linear output of most emitters.  For simplicity, let’s assume a 3 room baseboard loop, each room with the same heat loss, the thermostat is in the middle room, with a total loss of 20,000 BTU /hr and a delta tee of 20F at design conditions of 70F interior temp and 170F supply.  The loop is on full outdoor reset.  At design conditions with a 2 gpm flow based on 20F drop across the loop, the average temp in the first room’s baseboard is 166.6, the middle 160, the last 153.3.    The average output per foot of the last rooms baseboard is about 86% of the first rooms, so the number of feet of baseboard in the last room would need to be bumped up a little bit to keep the rooms heating evenly and the first reduced a little bit to balance against the middle room where the thermostat is at. 
    Now, using a fixed flow of 2 gpm, taking that same loop, but in warmer weather at only 20% load, (170supply-70room temp)  x 20%, = 20F, giving us 90F supply water and a 4F delta tee,  the average temp in the first rooms baseboard is 89.35, the middle 88, and the third is at 86.66.  Once again the output of the last room’s baseboard is 86 percent of the first, so heat between the three rooms remains balanced.
    Using a fixed delta tee if 20F in that same loop, also in warmer weather at 20% load, and running that same 90F supply, the average temp in the first rooms baseboard is 86.6, the second 80F, and the last 73.3F.   The average output per foot of the last room’s baseboard is only 20% of the first room’s baseboard and the all rooms would be running cold because the reset curve is too low.  Now let’s bump the reset curve up to compensate for the higher temp drop.  The middle room with the thermostat is satisfied with 88 degree supply water, so the new supply would be 98F and 78 return at 20% load at a fixed 20F delta tee.  The first room’s baseboard average temp would be 99.6, the middle 88 and the last 81.3.  The average output per foot of baseboard in the last room is still only 38.2 % of the first, so the system is still out of balance.  Remember that at design conditions at 20F temp drop the output the last rooms baseboard was 86% of the first and now it is only 38% of the first. 
    With a fixed flow and variable delta tee  the relationship of the outputs of each room’s baseboard is linear, where at a fixed delta tee and variable flow it is not.  A fixed delta tee circulator cannot provide even heat distribution to a building with a series type of heating system, which includes series loop baseboard systems, monoflow systems, and radiant floor systems.   In radiant floor systems it is likely even room temps would be maintained, but the temperature across the floor from the beginning of the loop to the end would drop dramatically in warmer weather. 
    Fixed delta tee flow would work fine with other systems where all units receive heater water directly from the source,  such as converted gravity systems and any other system that uses a ladder type piping layout with each heating unit on its own rung of the ladder.
    The Steam Whisperer (Formerly Boilerpro)
    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • Mark Eatherton Mark Eatherton @ 6:45 PM
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    What will i do with a non electric thermostated system?

    I'm trying to work it out in my minds eye...

    Normally, the valve works proportionally to the load. If it needs just a little heat, there is just a little flow. If it needs a lot of heat, it allows a lot of flow. What will the pump do when it is calling for just a little heat?


    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • NRT_Rob NRT_Rob @ 10:22 AM
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    with TRVs, etc

    that is when a delta-P pump is a good choice. the valves close down to slow down flow, flow slows down, they find a balance point.

    with delta-T, I can see two possibilities:

    1. you have a bypass. valves close down, more bypass occurs, delta-T shrinks and pump slows down.

    2. You do NOT have a bypass: valves close down, slowing flow through the zones and raising delta T by some amount... speeding the pump up. Seems like this could quite a waste of energy.

    I would use delta-P or a bypass on a TRV/non-electric flow control valve system.
  • Mark Eatherton Mark Eatherton @ 10:59 AM
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    Egg Zachary my thoughts...

    That is what I saw in my minds eye. Did you see it wink? :-)

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Mike Mike @ 2:31 PM
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    when your say older or ladder are you referrring to mono-flows?

    when your say older or ladder are you referrring to mono-flows?
  • Mark Eatherton Mark Eatherton @ 7:32 AM
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    I think he's talking about parallel direct return...

    Base board with mono flow tee's would be ideal for this VDT pump because it is a series parallel system.

    BP, if I'm wrong, correct me.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • MarkPFalade MarkPFalade @ 3:51 AM
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    I think

    it it reduced usage along with flow it would be an excellent fit for variable speed air handlers. Question is, does it offer any advantages to that type of system otherwise? Like ME says, "I'm trying to wrap my mind around it" but I ain't makin' it. ;-) My thought so far is if you can keep the correct number of btus going to the coil at all times it must offer some type of advantage.

    Another question I came up with is, in that application, if I widen the differential to say 30* or 40* wouldn't it serve in a similar capacity as outdoor reset? I believe you can further approach the optimum # of btuh required at any given time by doing so. Example being the smallest coil I could get was twice what the heat loss called for. Therefore at 20* delta tee I am still providing twice the btus necessary. Widening the differential should help alleviate that.
  • Anchorage Anchorage @ 11:41 PM
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    Noisy Taco 0013 VDT circulator....emit's loud modulating buzz while operating that wakes the house!

    Noise from VDT variable speed circulatorsI have just installed a new 0013VDT and it appears to be functioning OK (from the hydronic heating perspective) with the TACO 702 reset controller master and ZVC 406 exp panel, a 175kbtu/hr boiler feeding 6 zones.

    I have one big problem though....and that is with serious operating noise issues from the circulators electronics/motor windings! These electrical noises are loud enough to wake people sleeping in the house.. Flow noise is not a problem even at maximum throughput into one zone. Specifically the 0013VDT sets up a very audible "modulating buzz" when it is operating, particularly when it is changing the rpms. It's a little like sleeping next to an operating dish washer....even though it is one floor below and in the garage. The "electical" noise is propagated through the copper pipes direct to the convectors....not good!I have checked all the dip settings on the motor drive card, and even forced the controller with dip 2 to operate in the upper 60% RPM range where it is less noisy. I have tried using normal and log characteristics, fast and normal response curve. No major improvement. Left to it's on devices the motor will slow down and basically emit "tack-tack-tack-tack" cogging sound at very low speeds...Dip 2 off.Did TACO intend these devices for residential applications? I suspect the motor drive card needs some LC filtering to smooth or damp the triac switching/clipping, and I also think the windings need to be potted.Any ideas how I can get this $500+ investment in new hydronic heating technology to be silent like a fixed speed circ? I will contact TACO customer service this week and see what they advise...Thanks Ryan (in Anchorage , Alaska)
    This post was edited by an admin on November 30, 2009 4:14 PM.
  • Chris Chris @ 6:35 AM
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    Sounds Like

    the pumps to big. Why the 13 and not the 8?
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Anchorage Anchorage @ 3:59 PM
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    Choice between the 0008VDT and 0013VDT based on BTU throughput....not really head loss.

    Hi Chris,
    I mulled over the decision to install the 0008VDT or 0013VDT. The 0008 did not have the BTU throughput required for operations at -20DEGF, when all zones called for heat on a given setback thermostat program. It would certainly have been sufficient to hold a constant temp in all zones, but I suspect not for programable setbacks. If the pump curve were a little flatter it would do the trick...but the advice I got from TACO was that the 0013 would operate OK in the lower RPM range. They didn't mention the switching and winding noise though....
    This post was edited by an admin on November 30, 2009 4:14 PM.
  • Chris Chris @ 7:23 PM
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    I'm Kinda of Confused

    A pump is sized to deliver GPM at a given head. A pump doesn't care what temp it is outside. You stated that the pump would be ok if it had to be constant. If it can overcome constant it can overcome any zone in the system.
    I belive from your early post you stated that the boiler is 175,000 btus. That's fine, but what is the heat loss of the structure that you are trying to overcome? What is the total length in feet of your longest zone? For example, you want to deliver 150,000 btus at a 20 degree delta-t. That's 15GPM, let's say your longest zone length is 125 feet. That gives you a head of approx 7.5 ft head. The 0012VDT would be a better choice. Its exactly what you state. A flatter head pump.
    I attached the PDF file on the pump. 
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Anchorage Anchorage @ 11:36 PM
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    VDT Circulators

    In some respects you are correct....the 0012VDT would be better suited to my application, but because all VDT pumps are variable speed they should operate at reduced rpm, shifting the response curve down and left to match the thermal load.....which is a function of measured DT. Taco's charts should show the pump curves at various RPM's but do not for some reason.

    The 0012VDT has a bigger frame than the 0008/0013VDT so I selected a circ that didn't require any mod's to the current boiler set-up.

    Either way I suspect the electrical noise levels during operation (source of my problem) will be similar across the range unless I have a dud. There is no question that the variable flow rates at a given DT across my convectors does the job...even when 4 zones call for heat at once, sometimes the DHW as well in the morning (restoring setback) and I can watch the boiler barely keeping infront of the demand. i.e almost balanced.

    Any advice on mitigating the electrical noise generated from the triac chopper circuit or motor windings?
  • N/A @ 12:25 PM

    I hope everyone has learned more about the ALPHA since 2009

    Please look at my attachment.  ALPHA with their UP - ZV valves could not be more simple.  Anyone using 10 pumps for 10 zones is in the dark ages.  I don't know why Grundfos complicated the system in the attachment, but if you are using one water temperature to all zones, you need one manifold with 10 zone valves, and the ALPHA will pump the correct amount of water to heat the home evenly, it will be quiet, the pipes will be quiet.  If you go outside of the pump curve, you need two ALPHAs, and split the system side into two with 5 zones on each ALPHA.  It will work properly with no differential bypass valve and no balancing valves.  All that you need to do is get the correct amount of radiation in each zone. Instead of the one ALPHA being on the horizontal section of the manifold, in the attached example, you would have two ALPHAs on the short vertical take-offs.

    With a Webstone ISOLATOR flange and ball valve kit, you can swap out an ALPHA in 5 minutes, including wiring and bleeding the system.  If you don't see how, just ask.  For what you spend on pumps, you can greatly increase the efficiency of the system (even with a Modcon) by using a buffer tank.  On collar heating days with 5 zones running (maybe less) on your ten zone system, your Modcon will be putting out 25-30,000 btus when the system only needs 10,000, maybe less.  The buffer tank can cut your cycles to less than half.  If your customer is willing to pay for and maintain 10 pumps instead of 1, then a buffer tank is an easy sell.
    With a buffer tank, you are also simplifying the wiring.  On the system side, you have two wires to each valve (no need to connect to the TT terminal) and not the three that a Taco 570 valve has. 

    In my home, I have one zone with large radiators with 70 gallons, and two zones with baseboard in the rear with a few gallons each.  I have three Taco 570 valves, no balancing valves and I installed the ALPHA.  I wondered how this all would work with one high flow requirement and two low flow requirements.  The answer is, it works fine.  The pump is quiet, the nearby piping is quiet, and the piping upstairs is quiet.  And my temperatures are never more than 1 degree off the setting.  The manifold should be 1-1/4, but is 1.  I realize with two divergent flow requirements that two ALPHAs could be better, but why redo the piping on my 40 year old boiler when everything thing is quiet and working fine??
  • Chris Chris @ 7:45 PM
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    Like the Perception

    The perception that the pump will deliver what the zone needs is a stretch. The pump has no clue as to the gpm requirement. It only knows pressure. I've used close to a hundred Alphas and they have their quirks. I've also used many Taco VDT's and find that that systems perform better based on control of delta-t. Isn't delta-t what all our design math is based on?

    With the Alpha you still need to find the curve. I'll give you the electrical savings today over the VDT and agree with you on the zoning. Valves and these types of variable speed pumps are all that is needed. We are also seeing more of this on the commercial level with the Magna's.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • NRT_Rob NRT_Rob @ 11:16 AM
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    the only quirk I can see is autoadapt. what are you seeing? we always use fixed speed 1, or a constant pressure mode.
  • N/A @ 12:29 PM


    didn't see drawing  i'll try again
  • N/A @ 6:09 PM

    Hi Chris

    Home systems generally are simple ones, and if I was in the business, I would want to keep them that way, particularly in my own home.  When my large zone is calling for heat (with the small zones, not), it flows properly having six large radiators, 3-4" feeds in the basement, and a 1" black pipe from the boiler area.  It generally wants to run 6-8 GPM.  If one little zone comes on, it pumps 1-2 gallons, and 2-3 when both small zones are on, and sometimes 4 GPM.  If works well, and is quiet.  So, if my ALPHA only knows pressure, it also seems to know what flow it needs, because it is right on.
    With my 80% boiler with six inch vent, I haven't seen a reason to even worry about Delta-t.  When I installed the ALPHA the first time, I also installed a digital temp reader off of the supply and return and watched everything run for 4 hours.  My return temps were all over the place and quite often well below 140 F.  You should also know, I found no evidence of condensation in the vent.  The benefit of a dinosaur.
    I, also, do not believe in hi-efficiency boilers.  This belief was confirmed by Burnham when they came out with their ES boiler.  Good efficiency with the dependability of a cast iron boiler.  Even Weil has done a turn around with its new GV90+ boilers.
    More important than the boiler is a buffer tank.  I spent months talking back and forth with one of the B & G engineers who has totally sold me on buffer tanks.  I know installers do not like lugging heavy stuff around, but it is worth it for the homeowner.  Even a Modcon burns lost energy without a buffer....see comments above.
    I am also not sure what you mean about still having to find the curve on an ALPHA.  I look at it and say, it doesn't matter to me as long as you keep the total zones within the curve of the ALPHA.  In other words, with approximations, one skilled in the business can look at the system at hand, and ALPHA will make it work (without by-pass or flo controls), as long as you do not go outside the ALPHA's curve.  If it works well on my abominable system, it will work. 
    If I were selling these systems, I would use a boiler with the buffer tank giving you hydraulic separation and control of the return temps without considering the system side as much.  It would also give you ODR and a temperature spread as to when the boiler comes on again.  With this setup, designing the system side would be a simple and easy. 
  • Bill Clinton Bill Clinton @ 8:28 PM
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    What is the savings, really?

    Everything I see touting the savings to be had with a delta T or delta P pump compares them to the rating plate found on plain-jane circulators: 60-90 watts. Those circs usually do not cosume that much current as power use is at least somewhat proportional to flow rate with lowest draw at zero flow and highest at zero pressure differential (which of course never happens).  So, correct me if I'm wrong, but my information suggests that a rating plate stating an 80 watt draw is stating that is the MAXIMUM current draw.  In most circumstances it will be somewhat lower, maybe 50 or 60 watts.  This puts a substantial dent in the savings that can be claimed by the hotshot designs.  As John Barba says, these are usually 1/24th hp circs.  The savings compared to the extra costs are actuallly pathetic.  Just my two cents.
    Bill Clinton
  • Mark Eatherton Mark Eatherton @ 8:32 AM
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    I've tested this before up at Red Rocks...

    I was hoping to be able to generate a chart that showed that for a given pump, under a given flow, the pump would use "X" watts of electricity.

    Interestingly enough, there was no big discernable, or at least plottable difference between 0 GPMS and maximum GPMS. Bear in mind these are small wet rotored pumps I was testing. Larger pumps could be completely different.

    I have found that Taco 00 series pumps drew the same amperage with locked rotors as they do minimal load versus maximum load.

    I anticipate a day in the not too near future where the only motors available will be DC-ECM motors, on anything that moves fluids (air or water). It will be that way in Europe next year I believe...

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • NRT_Rob NRT_Rob @ 11:19 AM
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    power use for regular circ

    varies very little. meanwhile, on a multi zone system we are seeing the alpha averaging numbers like 25 watts.

    the savings are real and significant. at $100 or so to upgrade, the payback on any pump that runs a significant amount of time is there.

    nevermind the "drop a bypass" savings on day one offsets the upgrade cost.
  • Bill Clinton Bill Clinton @ 2:01 PM
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    Mark: Remember when..

    about six years ago, I'd guess, you posted here on the wall your measurements of a small circulator--yes, you had done the measurements at Red Rocks.  You included flow rate, head, and amperage draw.  There was indeed a difference in amperage with flow rate. I used your figures and calculated efficiency and posted the the results here.  At various heads and flow rates those circs calculated out at 9% to 14% efficiency.
    We're both getting older, but if you dig in your memory, or your years old notes, it should still be there.  Maybe the archives of the wall would have it, but I can't figure how to search through 10,000 ME posts.
     I believe that under optimum conditions, those circulators might, just might, reach 20% -25% efficiency but no more than that. The delta p or delta t circs might possibly reach 50%.  Again: the difference in  energy costs is not worth crossing the street for.
    C'mon John Barba: You have access to the numbers.  I know you might get in trouble if you release them, but it would be nice to get authoritative confirmation. An authoritative denial accompanied by real world numbers would be welcome too.
    Bill Clinton
  • bob bob @ 8:51 PM
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    Power factor

    I wonder how many of the watt readings in the above posts were made with a watt meter?
    In a DC circuit the current and voltage are in phase and amps X volts = watts. In AC circuits
    because of inductance and capacitance they are usually out of phase so the formula is
    amps X volts X power factor. To measure watts in an AC circuit you need a watt meter.
  • Mark Eatherton Mark Eatherton @ 8:09 AM
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    ONLY 10,000 .....


    Ain't none of us getting any younger. Maybe in spirit, but not in mind and body.

    I will have to dig DEEP into the personal ME Archives to find that information. Not even sure if I kept it ;-(

    The wire to water efficiency of the small wet rotor circs has never really been in question. It has ALWAYS been poor. At least the balance of the energy is showing up in the form of heat. Too bad its stays in the mechanical room...

    Siggy has done numeorous articles on it, as well as others in the industry.

    I am up to my butt in alligators right now with the Sleeper House remodel, so no sure when I will find time to look it up, but will effort it soon.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • N/A @ 1:31 PM

    This is why I like the Grundfos

    Keep in mind that some folks are using 10 plus circulators.  While that makes no sense to me, multiply the circulator problem by 10.
    This is another reason why I like Grunfos pumps with the cord.  You plug the cord into a meter, and you plug the meter into a normal wall outlet.  In my case, I needed an extension cord to do that.  I will try to find my Kill-O-watt, and plug it in from Dec 1 to Feb 28, and see how many Kwhs it uses. That would be the only meaningful measurement to me.
    Plugged in, the ALPA uses 5 watts at idle, 10 watts for a small zone, a little more for two small zones, and I maxxed out two years ago when we hit -17 f, and the ALPHA and my Kill-O-watt read 43 watts and 7-9 GPM.
  • N/A @ 1:48 PM

    Another thought

    We seem to have over-looked something here.  START-UP.

    It is true that a variable Taco can use as little as 1/2 the rated wattage, but no less, this according to my inquiry to them a while back.  I also asked about them having a 15-25 watt circulator to run a boiler and buffer tank only.  They don't have a circulator anywhere near that level.

    So, lets take an 80 watt.  When that motor starts up, it is belting the old watt meter at about twice the circulators rating.  Normal for a motor, and may be low.  The following could be a low number in some systems, but what if the boiler cycles 10 times per hour times 24 hours of the day.  That is 240 startups, as opposed to a constant run.  It is easy to see how this could add up if we doubled the cycles.  Now lets take 10 pumps going on and off like church bells.  No, lets not.

    It would seem that the ECM motor isn't using anywhere near the startup juice, and it is probably doing the start-up more efficiently.  If my ALPHA is using 5 watts sitting idle, and it goes to 10 watts to run on of my small zones, it has to be using a lot less energy.

    The only way is to plug the circulator into the Kill-O-watt, and let it run to see the total Kwhs over time.
    This post was edited by an admin on September 26, 2011 2:52 PM.
  • N/A @ 6:52 PM

    Power Consumption Based on Load Profiles

    Our WILO selection software calculates annual electrical costs, based on a typical system load profile.  These load profiles are very close to being consistent in all heating areas on the planet, the only variant is the number of operating hours.

    Running a system 5500 hours annually, at 0.14/kWh the cost to run one circ at 10 USGPM and 7' of head ranges from $70.45 for a standard circ (WILO brand) to $11.95 for ECM (10 USGPM is approx 100,000 BTU) per yer.

    Same data, but 30 USGPM and 20' of head ranges from $332.27 to $60.13 per year.

    I have attached a word doc with this information.  The software does not take into account the effects of using fewer pumps, eliminating by-pass valves, overall system energy savings, the effects of condensing boilers actually condensing and so on.
  • Robert O'Brien Robert O'Brien @ 7:30 PM
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    5500 hours? That's over 7.5 months of 24/7 operation. I used the same numbers with customers,until one of them pointed this out. Even with more realistic run hours the ECM still is vastly superior
  • N/A @ 7:54 PM

    Steve 2

    Statistical profiles can mean something or they can be used to hide the facts, because many of the assumptions are wrong. As an aside, I went to your company's website, and did not find a residential circulator.  Please point the way.

    People like Al Gore use statistical models and computer analysis that all require basic assumptions to be made.  Those assumptions can be real or they can be false, misleading, and in the case of our former VP, an outright lie.  Al Gore has since buried his head, as well as his rotund body, having been totally discredited in the last year. 

    Be environmentally responsible, but also be realistic.  Plug a couple of meters into two systems in two identical buildings, and see who ends up on top.  If I sold the best boiler or best circulator, I would drive the point home, assuming that I was on top.

    Can anyone introduce me to the Grundfos girl?  Hopefully, she adores father figures.
    This post was edited by an admin on September 26, 2011 7:56 PM.
  • Ironman Ironman @ 1:03 AM
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    Wilo Statos and Real Numbers

    I have found Wilo numbers to be very realistic and not exaggerated

    Example: A couple of months ago, I installed a Stratos on a Drake 12.7 ton chiller that had a 1 1/2 Goulds chilled water pump, factory installed. The chiller is a 240V, single phase unit with 3 scroll compressors that we installed two years ago. The owner had complained about the high power consumption of the standard pump. I had Wilo size the replacement circ. using their software. The program predicted an 88% reduction in power consumption vs. the standard circ. I thought that might be a little exaggerated and wanted to see the actual results. A couple of days later, I talked with one of the Wilo factory reps at NAOSHM and he ran the numbers and assured me they were correct and that we would indeed see that kind of reduction

    To make a long story short, the standard circ was pulling 8.3 amps. The Wilo Stratos is pulling 1.1 amps doing the same job. If my math is correct, that's an 87% reduction in power consumption! I guess that I ought to sue Wilo for not delivering what they promised. :~)
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • N/A @ 8:02 PM

    And Mr. Eatherton and Pres Clinton

    I have heard of blue balls, but what are Red Rocks?
  • bill bill @ 8:56 PM
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    Dear Bob

    I hope you guys are old friends.
  • Mark Eatherton Mark Eatherton @ 10:57 PM
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    Right Church.... Wrong Pew.

    This Bill Clinton has no political aspirations, to my knowledge.

    Red Rocks Community College, Lakewood Colorado where I used to teach hydronics.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • N/A @ 10:12 AM

    University of Denver graduate, 1967 (talk about old)

    A little trivia:  Did you know that there is a party cave across the street from the Red Rocks Theater?  It is directly across the street.

    To get inside the cave you have to follow the paths, back and forth until you get near the top of the rock formation.  I remember that near the top, you have to make one or two short vertical climbs of 4-5 feet.  To get in the cave, you have to squeeze between the two rock formations for 15-20 feet.  It is not for those who fear tight spaces, especially at night, when the parties happen.

    If you are less adventuresome, you can climb a few more steps to the top of the formation (not with leather shoes, please, as the "top" could be pitched as much as 30 degrees), and find the hole in the top where the open cave is, and you can see inside of it.  I believe you can follow the crevice from the cave opening WNW to find the opening in the crevice.  People who are much more than 6' tall or have more than 20% body fat may not wish to attempt the crevice.  And, never go with fewer than three people.  One could make it to the cave, and the second who gets stuck or freezes up in the crevice will keep number one from getting out to call for help.  A cry for help from inside the cave will never be heard.  Scarey.
    This post was edited by an admin on September 27, 2011 10:16 AM.
  • Mark Eatherton Mark Eatherton @ 11:20 AM
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    I feel like a Spring chicken :-)

    I am VERY familiar with the cave with which you speak. Have been to numerous parties there. Am also aware of another cave that my grandfather introduced me to (he worked for the WPA program that built the amphitheater) on the face of the big rock to the left of the amphitheater. It used to serve as a "Special Guest Only" spectators box back in the day, and you have to know where and how to go to get there. It too is quite chlosterphobic access.

    See the attached article, and if you look above the head of the woman in the picture, you can see where the cave actually comes out, I was there when Jethro Tull played, and the DPD decided it was necessary to use tear gas on the concert goers because of gate crashers. Got a snoot full up in that cave...

    They now post guards at the caves entrance to make sure that no one gets into the cave. Great vantage point for a pop bottle rocket war :-)

    It is (and has been forever) illegal to climb on these rock formations, but people ignore the warnings all the time. Note that a recent rock fall is believed to have been caused by people climbing on the rocks during a concert.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • archibald tuttle archibald tuttle @ 12:10 PM
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    Rebooting delta T delta P questions that got skipped

    So one thing that never got addressed by Joe from TACO (and is not addressed in his TACO university presentation on variable speed pumps either) nor have I seen any delta P champions explain how delta P segues this question, is programming to address varying the delta target which was asked earlier in this thread - albeit that might have been a year or two ago.

    It seems that most of the assumptions are based on the idea that desired Delta T would not vary, but if moving to outdoor reset on finned baseboard I don't think that would be the case and cowrong me if I'm wrecked but isn't that like 75% of work at the moment in hyrdonics around here (southern new england).

    So either of these discussions seem more relevant to non-reset systems, but that would be virtually no systems in the near future (I talked to Dan last week about bringing back vacuum steam so we could reset on steam too, but I digress).

    My seat of the pants engineering here tells me that reset is the most effective way to control system efficiency by limiting losses and returning colder water to modulating boilers. (50 deg. delta T anyone? and even if 50 deg. delta T can only keep people comfortable in europe -- or more to the point smart controls that can anticipate the end of setback periods for certain thermostates and use a higher delta T like that to bring the space up 10 or 20 degs. in a shorter time but still approach condensing temps where this anticipation helps alleviate concern about comfort levels on loops with that kind of delta T).  That is not only because reset lowers temperatures most of the time by its very nature but also because it is easier to vary the output - i.e. the delta T of the conditioned space - by varying temperature than flow rate. Regardless of whether a pump is responding to delta T or delta P the efficiency is much more dependent on what range the actually delivery temperatures are  . . . no?

    Here the performance curves  could help us out because the higher delta would help when you have higher delivery temperatures to get returns down but when you have lower delivery temperature baseboard performance falls off so you'd probably get more stable performance from a 5 deg. delta "T" when reseting baseboard toward the low end of your reset parameters.

    So the question for Joe B is ,when they are going to make the delta propotional or learning variable -- or maybe it already is and you cans set my mind to rest?

    And the question to Grundfos and Wilo folks is, isn't a fixed delta P limiting in the same arena, with the exception that pressure has a much smaller effect on BTU transfer than temperature so the impact of varying P would not be as great and the principle reason in a reset system for a variable pump is just to compensate for opening and closing of zones  (maybe I just answered by own question, but also offered one way that TACO could program to meet the competition and I do think that delta T is a more performance oriented statistic than delta so if you could control delta T but vary the delta you might have the best of both worlds, with the possible exception that noone, unless I missed it, answered the question of when we might get an ECM delta T pump?

    Of course, the last question, which is one I should have buttonholed the Teledyne reps about at gasnetworks, but I was too busy boiler shopping, is that measuring delta T on some loop is a surrogate for what is happening in the space that loop is meant to condition, so presumably the smartest control strategy would vary delta T across a circuit based on the speed of change of the actual room temperature in that zoned area. As best I can understand it, this is the control strategy that Teledyne has been pursuing and aside from the rewiring burden it seems pretty smart to me is a little pricey.  Of course if more people took this approach is wouldn't be so pricey, look at the fall off in cost vs improvemnt in features for reset control from a decade ago.

     So presumably this smart contol would, if you were coming up from a setback, give you a higher delta T than simply a call for heat to maintain when the room was within a differential range of the set temp.

    Ironically, as I think about it, to get a lower delta T you need a higher flow rate, so you are actually increasing flow rate during times when less heat is required (at least in baseboard systems with relatively low BTU delivery at low temps.). But if the smart control also spoke to the reset control it could increase delivery temp as well as delta T just for comeback from setback.

    So now my head is spinning and I'm only thanking god that the house I'm about to work on had baseboard installed in the day when you put fins everywhere rather than baseboard cover with no element based on the heat load of the given space at the 180 deg. rating.  So all that science they told us to do back then turns around and bites us in the ass when we do find a job with minimal fin per room and want to use reset esp. to take advantage of mod/cons. But back then it would have been a sign of a sloppy lack of professionalism not to size radiation to them room.  I always figured, what the hell were those adjustable covers for anyway and blank baseboard cover cost just about as much as the baseboard with element in it, so I never ran without element.

    Last question is one of balance between zones - that is begged above by my celebrating my earlier lack of sophistication although that was more a question of balance between parts of a single zone to which I would close the swinging cover on the baseboard.

     I believe there have been first person testimonies in this thread about success across varying kinds of radiation and sizes of zones with both the Delta T and Delta P approach.  I could not distinguish whether these delta approaches were running on top of an aggressive reset control. 

    Again resorting to seat of the pants theory -  which is to say general theory as opposed to the particular numbers associated with the piping, radiation and loads in an example -- my guess is that this balance is achieved because the sensing of either Delta P or Dela T is system wide.  So the post about the far off small loop and how that would work on a Delta T regulated system, seems to me that the far off  os smaller diameter radiation loop would have a higher Delta T and the near or larger diameter radiation loops a smaller Delta T while the pump targeted an average. Especially at significantly downward resets I think this has to mean that the distant zone would be slower to come to comfort during 'comeback' or less likely to maintain with a narrow differential but that once the other zones were satisfied it alone would be addressed with the target Delta T or Delta P improving the performance.

    So, one other possible control avenue in the long run, which seems like a somewhat simple bit of programming, vs. going nuts trying to get perfectly balanced loads in and flow rates in all zones across a range of reset curves is some kind of zone notification to the pump controller so it can learn the best operating scenario when varying combined loads are on.

    Yeah, I think they'd charge more for this at the outset, but if it is largely a matter of programming and you already have the integrated circuitry on board I wonder if this isn't another way to make these smart pumps even smarter -- and allow for us stupid plumbers.

    Nuff said.

    Joe if you don't have time to go into this in detail, no worries, I'm going to ask Dave Sweet to sit me next to you at the dinner next week -- but I promise not to talk during the movie.

  • Bill Clinton Bill Clinton @ 3:35 PM
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    Reply to Steve Thompson

    I just went through your figures to see how they apply to the systems we install.  First, heating hours around here are more like 2000 hrs per year, 1/3 the amount you base your calcs on, therefore 1/3 the amount of electric would be needed.  Second, you assumed a 0.14Kw/hr pump which I translate to mean 140 watts. As noted several times in this thread, we are mostly talking about 1/24th hp pumps which are typically moving about 4 gpm, not 10 gpm.  I think those facts justify estimating actual usage of about 1/3. 1/3 x 1/3 = 1/9 or 11%.
    If we take your estimate of $70.45 cost of electric for a standard circ and subject it to the 11% factor, the resultant cost is $7.45 per year.  If we posit that your pump is so efficient that it only uses 1/3 as much power, that calcs to $2.48 annual cost.  That saves us a full five bucks a year.  Underwhelming to say the least.
    If you factor in the experience proven fact that more complexity brings with it more breakdowns, and these circs must be more complex, they are going to be replaced more often and that will vaporize any savings right now.
    Probably--I'm not totally certain--it takes more energy to manufacture these pumps than  the standard circs. Certainly it takes a great deal of energy to drive a repair truck out and fix it.  In the end, we may well be looking at an energy saving that is on the red side of the ledger.
    Open to rebuttal.
    Bill Clinton
  • NRT_Rob NRT_Rob @ 4:31 PM
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    This is not difficult

    Standard circ, call it 75 watts typical. and that's being a bit charitable.

    DeltaP ECM pump on a multizone system is max watts 50 under similar conditions (actually less) and we are observing a reality of more like 25 watts average once you take multizone modulation into account.

    If you need max speed, you would also need close to max on a 90 watt approx. 3 speeder and you'd still be around 50 watt improvement. Any way you slice it, you're probably doing 50 watts improvement by going ECM.

    run time? six months for heating. 100% Runtime for constant circ/indoor feedback. 75% for outdoor reset. 50% for standard fixed temp. That's about 4300 hours, 3200 hours, or 2100 hours. yes, I'm rounding.

    PER 0.10/kwh of electric rate, you save about $0.005 per hour of run with 50 watt hours of savings.

    constant circ: $21.50/season per 0.10/kwh.
    Outdoor reset: $16
    Standard: $10.50

    we pay 0.15/kwh, so we would add 50% to those numbers. that's PER PUMP.

    Save a bypass, and the cost difference is zero up front. We are not seeing any reliability problems as of yet... and it's not like this is new tech. Just new here.
  • N/A @ 10:32 AM

    Responce to Bill

    Bill, good questions/observations for sure.  Regarding reliability:

    - ECM technology is based on using permanent magnet rotors
    - PM rotors have 3 to 4 times more starting torque than a std wet rotor circ (tested and proven)
    - PM pumps are soft start and run substantially cooler than standard wet rotor pumps, less heat less typically translates to longer life.
    - As ECM pumps lower head as flow/system loads goes decrease they are less stressed than a constant speed circ at low flows (think of slowing your car down by keeping your foot on the gas and hammering on the brake)

    End result is our % failure rate on the ECO and Stratos is actually much lower than our standard pumps (that are running at less than 1/2 of 1%).  This is the main reason we increased our warranty to three years a while ago (of course I can't speak for Grundfos and B & G but I would assume they are seeing similar results).

    We all could argue (discuss is a better word) the energy and cost savings - I have attached a independent analysis done by an engineering group up in Canada a few years ago.  Granted it is a commercial project but it does show real world stuff.
  • Bill Clinton Bill Clinton @ 12:12 PM
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    Thanks, Steve

    And thanks, all.  I stand corrected--somewhat.  I think the savings to be had using a small permanent magnet circulator is believably between $5.00 and $10.00 per heating season (in my area at least).  The premium I pay for a Grundfos Alpha over a Grundfos 15-58 is about $85.00, so the payback is 8 1/2 to 17 years. Still not "Oh, wow!" but yes, I might consider crossing the street for it.  The freeway, now, would be another matter.  Only a year or so ago, the premium for an alpha was twice that and the payback time demonstrably non-existent.

    I am very pleased at the information that the starting torque is so much higher with a permanent magnet motor than it is with the old style--what do you call it? Inductive rotor, maybe?-- that is good news.  Never tried a Wilo, but for thirty years I was on the merry go round of Taco, Grundfos, B&G, Taco, Grundfos, B&G, changing as I got disgusted with each in turn, watching as they kept announcing increases in starting torque so often that they should have been wrenching the earth out of orbit each time they started. The failure was always a matter of not enough starting torque, locked rotor, overheated motor, minerals plating out on bearings, stuff warping from the heat.
    For the past five or six years, I have been very pleased with the 15-58.  Grundfos finally got it right.  I don't know about the others because when I find a good thing I usually stick with it.

    So, the increased starting torque is a good thing and your reasoning about cooler running makes sense.  I'll try the Alpha.  Maybe even try a Wilo if my suppliers start stocking them.

    Thanks for your input, Steve.
  • N/A @ 9:04 PM

    Reply to Bill Clinton

    You are very welcome Bill.

    I've got to tell you, after 37 years in the pump business (sold them all) this ECM, sensor-less, variable flow "smart pump" technology is waaay cool.  As far as innovation goes I rate it up there with condensing boilers, radiant pipe with oxygen barrier and good outdoor reset and multiple staging boiler controls.  Honestly - no bias...

    There must be something to it - all manufacturers will have this some day.  We (the pump industry) needs to keep it reliable (as you mentioned) and simple (like our one page quick start manual).

    We have distribution all over USA and Canada now - let me know where you are located and I would be happy to give you some distributor names in your area.

    One thing new we recently did with our ECO was to add a check valve and rotating flanges to enable you to replace brand X or brand Y (which, by the way are very good at what they do, make great products and are formidable competitors).

    I appreciate your honesty - you calls em like you sees em!  Good luck this heating season - hope it's as cold as hell so we all sell lots of equipment!
  • archibald tuttle archibald tuttle @ 9:04 PM
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    bill clinton

    so the only problem in my mind with your dropping the pump hours is that strategies for efficient control and comfort, insofar as I'm aware, are moving towards 24/7 operation or at least 75% such as proposed by NRT Rob. So for a dwelling that isn't just getting a replacement pump but is being updated with reset technology and maybe a mod/con, I think 2000 hours undeshoots.

    That said, I agree with whomever said plug each on of these things into a kill-o-watt on two identical tract houses with similar systems for year and then check the kilowatt.  This debate started in 2009 and nobody seems to have done that yet.

    I'm also not sure why in trying to figure this out theoretically the power factor makes a difference on the watts. if you know the volts and the amps, doesn't that define the watts regardless of the power factor?

    These savings don't look like much compared to the price of pumps unless these ECM units average 10 or 12 years of life.  Who's been working in europe and can tell us if they last that long.

    I would think that you could save more electricity by not piping primary secondary and if an ECM could handle that straight through setup better then you could double the savings.

  • Roland Roland @ 10:55 AM
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    Cost and R.O.I.

    This is something I wrestle with whenever I buy something that uses less energy
    but is more expensive. I don't often think about a payback period for the privlege
    of conserving energy. It's kind of a GREEN tax if you will. I can forsee the day
    when energy frugality will be mandated by law as it is in some parts of Europe.
  • N/A @ 5:47 PM

    ROI ECM vs Standard and Performance Ratings

    Here's the deal regarding electrical savings and pay back - IT DEPENDS!

    A standard wet rotor pocket circ runs at about 100 watts (real wattage measured with a watt meter - the wattage we pay for).

    ECM runs at an average of 15 to 20 watts (max is 58, min is 6).  Reason this is not midway between is 99.9% of our systems are over sized and they run partial load at least 40% of the time (this is where load profiles come into play).  Let's use 20 watts to be fair.

    Difference is of course 80 watts.  Times 4,320 hours (6 months @ 24 hours/day) is 345,600 watt hours or 345.6 kWh. Times $0.14/kw is $48.39 annual savings.  Payback varies based on region, based on sell prices.  This would involve a discussion on pricing - I am not going to open up that can of worms.  However, rule of thumb is ECM is 2.5 to 3 times more dough.  Safe to say payback is less than 4 years.

    Scenario 2:  8 month season, pump is operated of a relay panel so only runs 6 hours/day.  Cost of electricity is $0.09/kWh.  8 x 30 x 6 = 1,440 hours. 1,440 x 80 x 0.09/1,000 = $10.37 annual savings.  Payback based on power consumption only is a very long time.

    Scenario 3:  5 zone system using five 100 watt zone pumps.  Replace with zone valves and one ECM pump.  No, I ain't doing the math but I am sure you get the drift (brand X zone valve is 0.9 amps at 24 volts or 21.6 watts).  The wattage of a larger ECM pump to replace the five 100 watt pumps would average 80 to 100 watts max (total, not times 5).

    Note:  Payback considerations should also include the install.  ECM means no by-pass and no control wiring/relay/transformer back to the pump required.

    Last point, when using ECM on a primary loop think about better flow control, lower return water temp so a condensing boiler might even start to condense - how cool is that?
  • N/A @ 6:46 PM


    I brought up using two Kill-O-watts on two identical systems.  And for the same reason, I wish someone would do a Modcon vs. two 80% cast irons with a proper-sized buffer tank with controls, but I doubt that will happen either.  I do know that carrying a cast iron down the stairs is less fun than a 100# Modcon.  Anyone drop a boiler?

    I do notice, however, that no one has commented on my thoughts about Start-up.  Calculating what a traditional motor will cost per year based on a steady run-time for so many hours seems to be forgetting that motors spike the meter at start-up.  I do not think this can be ignored....therefore, the only test is with a meter it seems.  Does anyone think otherwise on start-up?

    When I put the Kill-O-watt on my refridgerator, it spiked to 560-600 watts, yet it runs at a steady 160 watts or so.  That spike is 3.5 times the 160 watts.  With a circulator of 90 watts, that would be a spike to 315 watts.  I am from Missouri, show me the meter. 

    I found my KILL-A-WATT, and will plug it into my ALPHA come Dec. 1.  The only trouble, my 105 INPUT weil overcycles with my two small baseboard circuits. The large circuit is OK.

    Anyone with a comparable situation up to this sort-of unscientific challenge?  My house is 2,350 square feet, two stories, two feet of the basement is above grade, 60% of the house is brick and frame and uninsulated, R-38 in 85% of the attic, the balance is R-13 in the walls (40%), and my boiler is full-on when I hit somewhere around 0 to -5f.  1975 thermopane double-hungs in 40% and 1930 double-hungs with aluminum storms in 60%.  I believe my gas bill was about $1,800 last year, and my 105 IN and 74 OUT Weil boiler is 40 years old and is about 15,000 btu short of the minus 17 f   we hit the winter before last.   It is Chicago, and it is windy.

    Anyone have a comparable situation and a 90 Watt taco and a KILL_A_WATT?  And don't use a rewire or the lack of credibility of the test as a reason not to give it a try.  If there is a large disparity, it could be from start-up. One boiler, one pump systems only.
  • NRT_Rob NRT_Rob @ 8:51 AM
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    how much cycling are you talking about

    even if it spikes to 10x the amount of power for ten seconds, that's only like adding a minute and a half of run time.

    any real spike would be a lot less than that.

    this might be a measureable impact, but it won't be a big one except in the most extreme cycling circumstance.
  • N/A @ 7:11 PM

    You may be perfectly correct

    Hi Rob...
    If a system did three cycles per hour, do you realize that over an 8 month heating season, that is 17,280 starts per year with only 1 pump?  The soul with 10 pumps would be at 172,280 starts in one season.  This year, in Chicago, we could have a 9 month season this year.

    Even with 17,280, it is hard to fathom that it would not have more than a negligble impact on the electric bill. 

     I might also be wrong about this, but I think my ALPHA used about 10.5 kWh in Dec and Jan last year.  60 cents a month? 

    It is always the contractor that is the last one to make repairs on his (hers, for the ladies) own house.  There has to be someone out there that is willing to put their non-ECM, 80-90 watt pump on a Kill-A-Watt on their system for comparison. 

    I am going to put my ALPHA on my Kill-A-Watt tonight, and see how it goes. 
  • NRT_Rob NRT_Rob @ 9:43 AM
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    the real spike is a lot less, for a lot less time than I posited.
    Startups are not really 3x an hour for most systems on average
    startup draw becomes fairly negligable as a concern as a result.

    but I'm a fan of making predictions only to risk looking like a fool ;) happy to see the numbers if anyone posts any.
  • Dave Yates (GrandPAH) Dave Yates (GrandPAH) @ 10:19 AM
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    Bobtheplumber: already done

    When I sat down to write about this study on my own experiences with ECM pumps, I was, at first, inclined to call it a White Paper because I had always had the impression a White Paper had to be grounded on cold-hard-facts. I Googled the term and was surprised to discover a White Paper is typically nothing more than a PR-piece designed to promote a product or idea and that the author can pretty much take whatever libeties they wish where facts are concerned. Given that my 'paper' is grounded in cold-hard-facts, it had to have a different title.  

    I don't doubt for one second that the Doubting Thomases will continue to doubt the reality that ECM technology is going to become the norm. We need the doubters as much as we need the pioneers who forge ahead with technology. Evolution is part of the inevitable conclusion IMHO. Currently (no pun intended) there is a place for both induction and ECM motorized products - like circulators - and justification (primarily basded on up-front costs vs. projected operating costs) exists for both to be utilized. Circulators are getting smarter and the premium cost will continue to fall.
  • Mark Eatherton Mark Eatherton @ 10:28 AM
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    and concise explanation Dave. Great article, as usual.

    That pretty much shoots holes in most questions.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Dave Yates (GrandPAH) Dave Yates (GrandPAH) @ 10:39 AM
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    and, one more thing....

    Thanks ME!

    Proposals that include the system-wide ECV (Energy Conservation Value) and ROI (Return On Investment) will provide the ability to win more consistently while being the higher bidder. Adding in the hidden and overlooked power consumption is a real eye-opener for customers.

    Provide a 20-year ECV & ROI projection with an annual percentage increase & you can knock the socks off of the other bids.

    In March, I'll be teaching a class at Thaddeus Stevens College on how to apply ECV & ROI to what they have learned from their professor while he's away getting some advanced training of his own. When he returns, they can teach him(G).  
    This post was edited by an admin on October 1, 2011 10:42 AM.
  • NRT_Rob NRT_Rob @ 10:43 AM
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    we're starting to play with this too

    it's a great way to show the real value of efficiency. It's even illuminating to a fire breathing efficiency believer such as myself.

    Are you using a 5% electrical inflation rate though? I just saw an interesting article that seemed to indicate traditionally electricity has a 2% inflation rate while liquid fossil fuels have a 5%.
  • Dave Yates (GrandPAH) Dave Yates (GrandPAH) @ 12:04 PM
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    annual percentage rates


    A number of years ago, I researched those stats on the DOE web site and (at that time) the graphs indicated a bit more than 7% average over a lengthy time-frame & I chose 5% to be a bit more conservative. With deregulation pending, our Governor pronounced we would see an 80% increase from 11.4-cents to 20.6-cents per kWh. Within months, the projections fell off to 40% and so on until no one was willing to provide us with a projection from the Governor's office. Our local rep pried it out of the Gov's office for me prior to writing that article and I trimmed it even lower thinking I'd be on solid ground. Akin to playing pin-the-tail-on-the-donkey! During our mandated training for a PA assistance homeowner loan program, we were shown electric utility rate increases for other states and several exceeded 100%.

    Then came the marcellus shale nat gas bounty and that's (according to the elec utility co) kept our rate post-deregulation to 12-cents per kWh. Also bear in mind that when they were promoting the construction of Three Mile Island, we were told electricity would be too cheap to meter.   

    Granted, we're taking crystal-ball shots-in-the-dark, but the reality is the costs are going to steadily rise and not fall. Electric utility co's have fallen way behind by not building more power-plants while deman and populations expanded. Lucky for them that increased appliance efficiencies have provided some slack with total demand in decline for many areas. What happens when the decade of purchasing the Energy Star appliances is past? Demand will rise and do so at a steep pace (I think) & with deregulation, the brakes are off for dramatic rate increases. Time will tell if the past Gov was right about the increases.

    The nice thing about the ECV & ROI is that when utilizing an excel spread sheet 'live' with customers to illustrate the percentage of their choice, they get to buy-into the process, It's easy to change the annual percentage in the base-cell, which can be copied and pasted to cascade through the rest to deliver results. ROI is linked to the ECV cells results, so that goes along for the ride.  
  • davidd davidd @ 6:00 PM
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    DAVE YATES: great research, two questions

    That really was a great bit of research you did. Thanks for sharing the results. I work in the computer industry and am a big fan of empirical evidence when troubleshooting, comparing different options, etc.

    I do have a couple questions:

    1) Am I correct that your electricity usage comparison tables were derived by comparing fixed speed, on/off style circulators vs variable speed ECM circulators? I'd be curious to see a comparison to variable speed induction motor circulators. My guess is that the savings wouldn't be as impressive, as the savings are not just coming from the type of motor, but also the fact that the new circulators were varying their speed, thus varying their power usage.

    Likewise, the design of the system is different (zone valves in place of many of the pumps), so that isn't a savings of ECM vs induction, but a savings of pumps vs valves.

    Please correct me if I'm wrong above. The reason I'm bringing up these points is because I'm trying to decide on a design for a new system for my house. I have no axe to grind about brands or technology differences. I simply want to provide the most efficient and reliable system I can at this point in time (taking gas and electric savings into account).

    2) You originally used pumps in all zones, but I didn't see it mentioned if you have mixing valves in all zones, or one mixing valve shared for all the low heat emitters. I'm asking, because I'm wondering, aside from electricity usage, whether comfort might be suffering vs providing a variable speed delta T circulator for each zone and/or a separate mixing valve for each zone to account for zone differences.

    In my future system, just about every zone is unique (different heat loss, different floor coverings, etc.), so I'm debating comfort vs gas/electric/equipment savings in a design like yours. If all your zones are ceramic tile and all have the same height ceilings and all have the same outside exposure and are all the same loop length, then maybe this wasn't a consideration for you. If you do have zone differences, do you feel that you are compromising some comfort for reduced electricity usage?

  • STEVEusaPA STEVEusaPA @ 10:56 AM
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    to Mr Yates...

    That was a fantastic article.  Research and data logging done better then almost any manufacturer, and a great read to boot.  That's way better then...."buy my product, you'll save 'x' percent.  I'm constantly experimenting on my system (an unhealthy obsession as my wife puts it), and I think I found a new spring project, with my 9 circs.  Thanks
  • meatball meatball @ 5:01 PM
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    WHA: Massive Savings

    Hey, i worked on a project at WHA last December. cookie cutter campus of two family houses that were "energy" upgraded in 2009. Major pumps failures that the competition took care of for a while.
    We provided pumps with ECM motors to the boiler room of Building A, and left Building B as is with the PCS motors.
    Two houses were both occupied with families of the same count and each boiler room was separately metered so the Housing Authority could easily show savings off of their NSTAR bills (an independent third party? I'd say yes)

    Anyway, we installed the ECM motors v the PCS motors for the month of January, February and March 2011.

    Building B (PCS motor house) had an electric bill of: $167, 175, 153 respectively.
    Building A (ECM Motor House) had electric bill of: $16.50, 19.32, and $15.20 respectively.

    I dont think NSTAR bills could be tampered with that much. (and i have copies of these bills to prove this)

    Thats energy saving the ECM Motor way.
  • archibald tuttle archibald tuttle @ 12:50 AM
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    WHAt massive savings?

    I'm not sure I can buy this because i have 6, count them 6, PSC circulators running on my system including 1 24/7 on my floor radiant loop, I as the primary boiler loop that runs when any zone is calling, 3 heat zones and domestic hw zone, , and I can't generate an electric bill of $175 a month in my highest month including electric cooking, and everything else in my house. And I'm in RI with some of the highest rates in the country.

    What size houses are these and what is the system description?
  • meatball meatball @ 5:10 PM
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    WHA: Massive Savings

    Hey, i worked on a project at WHA last December. cookie cutter campus of two family houses that were "energy" upgraded in 2009. Major pumps failures that the competition took care of for a while.
    We provided pumps with ECM motors to the boiler room of Building A, and left Building B as is with the PCS motors.
    Two houses were both occupied with families of the same count and each boiler room was separately metered so the Housing Authority could easily show savings off of their NSTAR bills (an independent third party? I'd say yes)

    Anyway, we installed the ECM motors v the PCS motors for the month of January, February and March 2011.

    Building B (PCS motor house) had an electric bill of: $167, 175, 153 respectively.
    Building A (ECM Motor House) had electric bill of: $16.50, 19.32, and $15.20 respectively.

    I dont think NSTAR bills could be tampered with that much. (and i have copies of these bills to prove this)

    Thats energy saving the ECM Motor way.
  • N/A @ 1:02 PM


    I am writing this, as I am now dumbfounded about what I learned over the weekend.  You are not going to believe this, and it will likely make you laugh.

    It has been cold for a while here in Chicago area, and I turned on my boiler weeks ago.  When I did, I found that two of the upstairs bedrooms, a 3 gallon baseboard zone did not deliver heat.  The other two zones were working fine.  I assumed something happened with my Taco 570-2 valve, and that it failed, somehow.  I put two other heads (that I had lying around) on the body, and nothing.   I checked for 24 volts, yes.  Did the head warm, yes.  Pulled the head and pushed the spring in, yes.  Pulled the lever to open the valve, but nothing happened.  The ALPHA pump did nothing.  I put in a whole new Taco valve, but still nothing.  This dumbfounded me. 

    I, now, noticed that the ALPHA was flashing between 6 watts and 0 GPM.  That was strange, as when it was idle, it always flashed between 5 watts and 0 GPM.  I turned my attention to the pump.  For whatever reason, it did not see that one valve when it was open.  Therefore, no heat.  Something is going on with the pump.  The pump was connected all summer, so I assume it did its periodic exercise, but the computer inside of it apparently failed.

    Rob at NRT is great at what he does, and we have had a number of discussions about Modcons v. Cast Iron.  One more time, technology has proven my point.  Not only did technology fail, but it made it harder to get to the bottom of the problem. My home has a 94,000 BTU loss, and I am going to replace my boiler with two 50,000 or so IBR rated, 80%, cast iron boilers and a buffer tank (a gas valve, a high-limit switch, a Honeywell L4006, and a standing pilot).  I am sorry, I am not going to spend twice as much for something that will only last half as long.

    It is interesting that both Burnham and Weil are coming back to cast iron boilers, but they are they are also computer hybrids, again doomed.  Weil has a video on their website that states, "while we can't guarantee that you will receive 30 years of life, our products' history speaks for itself."   Personally, I expect a Weil boiler to last 40 years.  I imagine that their stainless secondary heat exchanger will be dripping in 5-15 years, and any computer parts will have a limited lifespan.  I just don't see a 1% failure rate in 100,000 hours for these parts.  I think people make up these numbers.  When did you last have a harddrive last that long?

    Does anyone want a one year old used pump? 
  • N/A @ 1:09 PM


    That is my 35 year old Weil boiler sitting next to the paint cans.  You can't see all the rust at the bottom of this baby, but it sat on open ground for the first 25 years of its life.  I am thinking of picking it up and moving it to the front of the house to run the 70 gallon 6 radiator system, and buy a 38,000 IBR rated for my two small zones.  This is where the buffer would then go.
  • NRT_Rob NRT_Rob @ 1:09 PM
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    rule number one

    when in doubt, reboot. did you power cycle the pump? We did see a "hiccup" on the one in our shop once, kind of like you mention, but it went away with a power cycle.

    we use relays just like with regular pumps and have seen no such issues in the field... even if it's happening, apparently as soon as it loses that heat demand it restarts and the problem would go away.. I have no idea how many alphas we have out there now. a hundred, I imagine, at least. No issues like that last year from our clients in the field: we'll see this winter, but I don't expect to see any major issues this time either.

    In fact, the GPM readout on the pump allowed me to troubleshoot two systems last spring much faster than I would have otherwise... had some bad flow meters, and the pump was right.

    but if you're just doing constant demand, I could see this being a bigger issue.

    edit: you can say what you like about technology as well, but we have brains on nearly every system we've done for the last 15 years... thousands... with abysmally small failure rates. lightning strikes have been the biggest issue and a surge protector/UPS would fix that. Meanwhile, those brains have saved those clients many times the cost of the controls and labor in fuel and maintenance reduction... and delivered superior comfort to boot. You have to look at the whole picture, not just the downside.

    I think the benefits of cycling control, post purges and outdoor reset are pretty much proven at this point. You can choose not to incorporate them if you want, but energy isn't getting any cheaper, and if you have to buy a boiler every 15 years now instead of every 30 you can STILL save significantly more than the cost of the boiler in that time with better tech. that will only become more true in the NEXT 15 years.
    This post was edited by an admin on October 4, 2011 1:16 PM.
  • N/A @ 1:18 PM

    Power cycle, as in....

    unplugging the pump?  Not only did I do that, but earlier on, I connected the power lead from the prior pump, and ran it to an electric outlet next to the boiler.  I plugged the ALPHA into that outlet, and it still did nothing (AUTO MODE). 

     It works in a constant speed mode, however.

  • NRT_Rob NRT_Rob @ 1:28 PM
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    we only do constant pressure modes, maybe that's why we don't see it. I think autoadapt is garbage for any system with reset.

    buffer tanks are low tech cycling control, sure. now you still have ODR and purge control... and viola, it's tech time ;)
  • N/A @ 1:22 PM

    Cycling control?

    That is what the buffer tank is there for.  I can still do the ODR, though.
  • N/A @ 1:59 PM

    Until H*ll freezes over....

    or I see a quality system that will save 20%-30% or more actually running in a relatively uninsulated home like mine, I don't want high tech.  I am talking about seeing something running in a home, like mine, for $1,200 in annual gas bills.  And,  showing me a new system that "saved the owner 25% is meaningless.   My bill was $1,800 last year, so it would take a savings of about $400-600 each year to pay for all of the visits from the repairman each year. 
    $9-1,200 for a stainless heat exchanger?
    $7-900 for a computer module?
    $150 for an ALPHA?
    Now add another $150-400 for labor on each.
    And replacing the system twice as often at twice the cost  just is of no interest.  I have had a 50 year old Weill and now a 35 year old Weil, and until this ALPHA did not work properly,  I have had zero problems in 21 years.  Having said that, I now take back my first statement above.  It just is not worth having no heat, for any length of time.  No Modcons
    Rob, maybe you would like to do a 40 year projection on the cost of an 80% vs. Modcon including installation(s), maintenance and gas usage.
    This post was edited by an admin on October 4, 2011 2:02 PM.
  • NRT_Rob NRT_Rob @ 2:36 PM
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    20-30% is easy

    cast iron on an indirect is about 30% efficient in the summer on DHW demands. Post purge control can double that. that and outdoor reset control are both built into a $300-$400 boiler control. one season or less in payback, easy, and better comfort in the winter to boot.

    modcon can easily beat atmostpheric cast iron by 20%+ all winter, probably more. AFUE doesn't pay attention to that makeup air loss.

    I had a weil mclain cast iron unit in my basement when I moved into my house. 12 years old, it died in the middle of winter the day before I was going on vacation for week, during the coldest snap of the season. Cast iron is not a guarantee of 40 year lifespans, and it sure as heck is not the economical choice moving forward, no matter how you want to stack the deck.

    simple, yes. Fireplaces are simple too. Can't lock out on a power failure either. Course, they are about 10% efficient on a good day, but hey, let's not quibble ;)

    Of course if your home is not insulated well, that's the first thing you should be dealing with anyway. boiler selection is a distant second at that point.
  • N/A @ 3:20 PM

    I see you have a Triangle Tube boiler (it seems)

    I have $5,000 in wall paper in three rooms, which means that I can only knock off 10,000 btus on my demand of a  94,000, and foam insulation would cost about $2400  to save those 10,000 btus.  It doesn't excite me.

    When were the first ones installed and how has the maintenance been?
  • NRT_Rob NRT_Rob @ 3:26 PM
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    I love the solo

    but I have an Ultra. Have had it for about 5 years, get 1 yearly cleaning for about $100 done. No other problems beyond power outage lockouts which are, admittedly, annoying.

    Most of my clients who get solos though are very, very happy with the selection. Very few issues to report.

    If you have a 94k demand I suspect spray foam would do a LOT more than 10kBTU of reduction if you used it. Unless you live in a 5,000 square foot house?
  • Jean-David Beyer Jean-David Beyer @ 5:12 PM
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    I have an Ultra 3, and I get frequent power failures.

    I do not get lockouts on power failure, and I do not have a UPS hooked up to the unit. Some power failures are only a second or two; during the hurricane, I lost power for 215 seconds. The boiler was powered on (indirect hot water heater), but was probably not firing. Sometimes the power goes off for an hour or more.

    I infer from the age of your boiler that yours is an Ultra 2 that had a different control board (PhD) from mine (U-Control). Could that be the difference?
  • NRT_Rob NRT_Rob @ 5:18 PM
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    the lockout is power failure while operating. My reset curve is very aggressive and so it's almost always operating. but if they fixed that with a later control, GREAT!!!!!! I do have the older control.
  • Jean-David Beyer Jean-David Beyer @ 6:04 PM
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    I do not remember if the power ever failed when running.

    I, too, have a very aggressive reset curve. For my downstairs zone, radiant slab at grade, it can run up to 18 hours straight, though 12 hours is more likely. I would guess, but do not know, that the power may have failed for a few seconds while running. I will try to notice when the heating season gets started. Well it started yesterday and ran my upstairs zone for a little while (under an hour), and my downstairs zone ran for 53 minutes today. It is 66F outside right now and the thermostats are set for 69%. But it went down to 48F the last two nights. The first night, the downstairs zone did not run at all.

    I get most of my power failures in the summer. Sometimes because power company cannot keep up with the air conditioners. Sometimes from rainstorms and wind. Often because numbskull drivers drive into a particular power pole about a block from here.  In the winter, they skid into the same power pole. NJ drivers for you. And Ice on the wires. I have not figured out how much a UPS would cost that would run my system for a while. Probably over $1000. It could have to drive 3 TACO 007 circulators, a relay box, and the boiler itself. Perhaps 750 watts. I wonder how long to make it go? An hour? 3 hours? ...
  • N/A @ 4:25 PM

    2,300 SQUARE FEET

    and we use about 4 rooms + two bathrooms only on a regular basis.  40% of the house has R-13 fiberglass, in who knows what shape.  This leaves only 3 rooms that I could foam.  I checked my demand in those rooms, and that is the 10,000.  I have over 600 sf of window area in the house, and that is close to half my heat loss.

    When you get a "lockout," can you reset the boiler or do you have to call someone to do it?   What is involved to get the boiler going again?
  • NRT_Rob NRT_Rob @ 4:38 PM
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    you're still heating the rest of that space

    though it may be a lower temp, you're still bleeding heat in here.

    lockout requires hitting a reset button. nothing more than that, but still it's stupid... the unit should be smart enough to reset itself after a power outage. that's a major concern here in rural maine where power outages are common... imagine I was on vacation at the time!

    I'm not saying tech is *without* issues. just that it's normally worth it.
  • N/A @ 5:39 PM


    I would find a way to monitor it online.  I know there are home management tools that allow you to monitor you temperature at home while online.  You just need a way to push the button, now.
  • N/A @ 3:45 PM

    80% v modcon

    Rob, you had me thinking there, but here is the answer for me, having 7 enormous radiators in one zone plus two baseboard zones.....taken directly from the Burnham website.....(CLICK ON  ONE OF THE ATTACHMENTS)

    AND....... Honeywell has the L4006A for the buffer tank.  Can this be used with an ODR?  Or else, is there a buffer tank control that has both an adjustable lo-hi limit plus ODR?
    This post was edited by an admin on October 6, 2011 3:57 PM.
  • N/A @ 4:50 PM

    mixing valve

    I see that Taco is selling a 2 & 3 & 4-way mixing valve that does an outdoor reset, in addition to setpoint.  The 4-way goes to 1-1/4" pipe which would work with the manifold I want to use. 

    Anyone use these on a project have any thoughts?
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