Now I see why the Grundfos person posted the video on You Tube.........

CMadatMe

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. 

Anchorage

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?

Unknown

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??

Unknown

attachment

didn't see drawing  i'll try again

CMadatMe

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.

Unknown

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_6

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

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...



ME

Bill Clinton_6

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_46

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

ONLY 10,000 .....

Bill,



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.



http://www.pmmag.com/Articles/Column/9b2042f2480d7010VgnVCM100000f932a8c0____



http://www.pmmag.com/Articles/Column/BNP_GUID_9-5-2006_A_10000000000000099907







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.



ME

Unknown

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.

Unknown

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.

Unknown

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

Steve

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

Unknown

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.

Unknown

And Mr. Eatherton and Pres Clinton

I have heard of blue balls, but what are Red Rocks?

bill_105

Dear Bob

I hope you guys are old friends.

Mark Eatherton

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.



ME

Ironman

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. :~)

Unknown

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.

NRT_Rob

quirks?

the only quirk I can see is autoadapt. what are you seeing? we always use fixed speed 1, or a constant pressure mode.

NRT_Rob

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.

archibald tuttle

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 **** 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.



brian

Bill Clinton_6

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

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.

Unknown

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_6

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.

Unknown

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

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.



brian

Roland_18

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.

Unknown

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?

Unknown

TEST THE BOILERS TOO

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

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.

Unknown

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

prediction

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)

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.  



http://contractormag.com/features/biggest-loser-1234/

Mark Eatherton

Perfect...

and concise explanation Dave. Great article, as usual.



That pretty much shoots holes in most questions.



ME

Dave Yates (GrandPAH)

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).  

NRT_Rob

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%.