smart circulators

Larry (from OSHA)

I've heard that some manufacturers are building low watt circs such as the alpha pro. As seen here:

http://net.grundfos.com/doc/webnet/energy/int/index.html

Whether this low power consumption is possible in typical American residential installations is what I'm trying to find out. Most likely I'll still need a 26-99 for a boiler pump and same for the indirect pump, but I'm intrigued by what may be just down the road for "certain" applications.

Larry

Larry (from OSHA)

low power pumping

As I prepare for bringing my system into the current century with a Knight install, the thought of being able to use a system circ that draws only 5 watts or so is very interesting if possible. Looking at the Grundfos Alpha Pro and the Wilo Stratus has me asking if these are available, appropriate and come with flanges like a 15-58 or 007. Secondly, what about the boiler pump? Are these smart circs smart enough to live with a high head hx like those in a mod con?

Perspectives are greatly appreciated.

Larry

hot_rod

sure

if the "smart" boiler circ was programed to watch, and operate via delta T across the heat exchanger.

Isn't the boiler circ on the Vitodens operated that way? Although I'm not sure it is a "smart circ" ECM type.

If you get a chance catch Steve, from Wilo, seminar on smart circs. Ideally one where he has the "Brain Box" demo panel.

Also Siggy's current seminar where he shows the math behind circ efficiency and low wattage pumping.

hot rod

Mike T., Swampeast MO

No return temp sensor in the Vitodens--just a single supply temp sensor and two fixed high limit switches. All are installed right after the HX. I've looked and looked (both in the boiler and the schematic) and find nothing else.

Circulator in the Vitodens has five wires. Two for true 220, one for a safety ground and the remaining two [presumably] to control the speed. Nothing fancy with the 220 as the leads are directly connected right after the main power switch. There doesn't even [appear] to be a feedback loop unless it manages both control and feedback over a single pair of wires.

Only pressure sensor is a safety switch with two wires that's obviously part of the "safety chain" as it's wired in series with the fixed high limit switches.

With the LLH (and its' temp sensor installed) I do know that it varies the circulator speed to maintain target at the LLH. Considering it strives to keep primary flow less than secondary that means the boiler temp will normally be somewhat higher than the LLH temp.

Without the LLH, I have no idea how it varies the circulator speed as there [appears] to be no way to sense either delta-t or delta-p. Decreasing outdoor temp generally seems to increase the circulator speed. Using a heating curve with less "headroom" (heat authority) will also increase the circulator speed, but this takes some time.

kal_2

dont do it ..

mod-con boilers need head and flow or they will self destruct – only if the boiler itself controls the speed can this work – external delta-T mesuremtns aren't good enough!!!!, if you want to save money – close tee the boiler into a low loss header, and close tee a buffer tank into same, now you can use really low wattage pumps to go to the loads – heck, you can use a Laing DC 5 Vario Ecorcir pump (http://www.lainginc.com/D5_Vario.htm) to go to each radiator or radiant loop etc – the only problem is that the really low wattage pump lists for $238 so you better calculate the lifetime savings well up front – I don’t understand that with a gazillion Electronically ComMutated (ECM) computer fans and hard disk drives out there – why Taco, B&G, Wilo, Grundfos, Armstrong, and Laing haven’t produced inexpensive ECM pumps yet - it's not like the planet is out of molybdenum magnets yet – sorry for the rant.. I am frustrated by slow moving technology

Larry (from OSHA)

efficient use of energy

As I browse through the grundfos and wilo sites, my thought is that they must do things a lot different across the pond than we do here. Seems like constant circulation and trv's must be standard fare. Perhaps I am just impatient. If saving natural gas is such a good idea with mod cons, then isn't saving electricity a logical next step?

In the past few years, I've gone from one circ to two and with the new boiler I'll have three. I know it's not that many when seeing the multi/mega circ systems that are created by the talented people here, but just as btu's are btu's, watts are watts and I'm not into carbon trading to lower my energy footprint. I don't want to trade the savings from all those low watt light bulbs I'm using for a couple of high watt circs.

I think I share Kals frustration on the pace of new product introduction by a few key companys.

Thanks for everyone's perspectives.

Larry

Unknown

smart circulators (ST)

Regarding smart pump applications - not all applications are smart pump applications. Shunt pumps (boiler pumps) might require constant circulation hence are not a VFD (smart pump) application. To take advantage of smart pumps' high energy savings, they should be installed where something is changing - not constant circulation (this "smart pump" application specific thing is similar to condensing boilers being installed in medium to low temp systems - the right application gains the best payback).

The good news is there are millions of pump locations where small "pocket" circulators are installed in "dynamic" applications where flows are changing. One example is our typical "zoned" systems using zone valves (either electric or non-electric). The circ sees various flows (and various friction loss curves) hence is a smart pump application.

Regarding product, check out the new "Green" page on this site (just to the right and above "The Wall"). Once there click "Green Products" there is information on the Wilo Stratos, an ECM smart pump that the UL approved models will be in stock in North America mid July. More smart technology is on the way - just not 100% sure when - please stay tuned.

zeke

quote:

"As I prepare for bringing my system into the current century with a Knight install, the thought of being able to use a system circ that draws only 5 watts or so is very interesting if possible".

5 watts? Somebody musy be dreaming.
The minimum power at 100% efficiency is determined by the product of mass flow rate and system pressure drop and 5 Watts is not even close.

Weezbo

Larry , you would really have liked Siggys class....

there were quite a few things that i would liked to have caught a "glimmer" however , the time was just unavailable...

one of the questions as it were was on a similar idea ...i have seen modulating flow through a modulating boiler and was curious as to how that technology works in principle...

to give you an idea of what i am babbling about, last winter i was working day time as an installer night time as a security guard/boiler system control *~/:)

as i have a fairly comprehensive grasp of the "Variables" and handy with a pencil on my off time of valve twisting and zone tweaking and boiler monitoring...i was spending a fairly good chunk of the time reading and using copy repetition of formulas to determine what to do next and what exactly was happening when.... I definitely spent some time with flow rates and wire to water thoughts as i had One circulator,4 miles of tubing,and constantly changing environment outside and in side, with ever changing schedules for various trades to "close in " the place ...

over at the shop/soon to be night school, are note pads with many ideas written down pictures on cardboard boxes many books open in the process of being scrutinized for Precise meaning and pictures of products offered across the pond...sheets of attempts to get them here from various distributors ...a couple parts that "madeit" ) shhhh

and more questions tacked convieniently here & there at every corner and flat surface:) i may have a few questions that were written in my dreams on things just because they were the first place handy to tack them down...at the time...:)

so, the thing is i am fairly sure that indeed your system might very well have {(currently) i am practising speaking electrician} an over pumped system...i call it 'Pump habby'

the devil is in the details though..one being, while we have variable speed drives and variable speed controllers that help the wire to water equation ..there is still quite a bit of efficiency to be gathered by equipment selection, pipe sizing ,products, control strategies and mind set ...that enter into the equation...in saying that, i mean to roll the idea past the eyes of the interested, there does seem to be some real opportunity to improve systems .

so,....the last Friday i get a call from the Rick Mayo the tour across the surface area of the planet continues for the Siggy class any way...i have asked him to send along some additional copies...only problem is is that Anchorage seems to "BushWhack" things that are supposedly "on their way" here being of sound mind i spent it all....:) sorry

so i went to Kinko copiers and asked them for a copyright infringement release to send to Siggy to have ten copies made here figuring 1. it would get it to happen sooner

2. the train robbers along the way wouldn't be a variable *~/:)

3. some of Siggy's work could make it into the hands of oh say...a few local mechanical/plumbing inspectors , engineers ,architects , electrical and mechanical contractors...like that ...or say possibly.... an interested OSHA inspector *~/:) named Larry


there is some interesting reading on the Internet check out SAVELEC in England....there is a section or two that delve a little more deeply into the question at hand.... *~/:)

hot_rod

maybe not with the current Knight, but with a

Triangle Tube Prestige with an extremely low pressure drop... Now things start to look better for flow with low, low power consumption.

The current wet rotor circs, at their very best, operate at about 25% wire to water efficiency. See below JPG. Run 'em off the "sweet" spot and the efficiency is in the toilet quickly

The real question is how much power is required to move the load.

Take a look at a 5gpm flow of 180F water thru 200 feet of 3/4 copper, with 9.11 feet of head. Or a 50K load.

Mechanical wattage= .4344 X flow X delta P or in this case 8.3 watts.

Now you need to figure the actual wire to water efficiency which is merely the mechanical wattage from above divided by the motor watts. "borrowing" Siggy's formulas that calcs to 33.2 watts needed to move that amount of heat.

From what I gather the soon to be available "smart circs" are in the 50% efficiency, or more than double as efficient as todays wet rotor offerings.

So the above load could be "moved" with about a 17 watt electrical consumption.

Currently we throw about 70- 80 W at that load. Or in some cases with circs on every zone, possibly several hundred watts.

To further leverage low power consumption circs we need to look at wider delta t's for one.

And no more high pressure drop systems aka 5/16" tube common in some above floor panel systems

hot rod

Weezbo

Well there you have it ! a quick synopsis

Hot Rod to the rescue what He said ,Larry

Boilerpro_5

Some easy ways to get those wide delta tees...

> Triangle Tube Prestige with an extremely low

> pressure drop... Now things start to look better

> for flow with low, low power consumption.

>

> The

> current wet rotor circs, at their very best,

> operate at about 25% wire to water efficiency.

> See below JPG. Run 'em off the "sweet" spot and

> the efficiency is in the toilet quickly

>

> The

> real question is how much power is required to

> move the load.

>

> Take a look at a 5gpm flow of

> 180F water thru 200 feet of 3/4 copper, with 9.11

> feet of head. Or a 50K load.

>

> Mechanical

> wattage= .4344 X flow X delta P or in this case

> 8.3 watts.

>

> Now you need to figure the actual

> wire to water efficiency which is merely the

> mechanical wattage from above divided by the

> motor watts. "borrowing" Siggy's formulas that

> calcs to 33.2 watts needed to move that amount of

> heat.

>

> From what I gather the soon to be

> available "smart circs" are in the 50%

> efficiency, or more than double as efficient as

> todays wet rotor offerings.

>

> So the above load

> could be "moved" with about a 17 watt electrical

> consumption.

>

> Currently we throw about 70- 80

> W at that load. Or in some cases with circs on

> every zone, possibly several hundred watts.

> To further leverage low power consumption circs

> we need to look at wider delta t's for

> one.

>

> And no more high pressure drop systems

> aka 5/16" tube common in some above floor panel

> systems

>

> hot rod





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Boilerpro_5

Some easy ways to get those wide delta tees...

It seems we often forget that the design delta tee is only at full load and drops as the load drops. So if you have a 20F delta design and are running on the typical winter day, you would only have a 12F delta, using a single speed circ. If you use a variable speed circ with a fixed delta tee, you would simple run slightly higher supply (3F hotter) and slightly cooler return (3F cooler) in that tyical day. Of course cooler returns are better for condensors, so variable speed circs are a good match. It seems that the combination of a mod con with a fixed delta tee circ, with panel radiators running at a 30 to 40F delta tee would make for a very efficient system for both use of heat and electricity. These Pex radiant floor systems that require 10F delta tees at design really are bottom of the barrel for electrical efficiency. The EPDM systems that run 20F delta tee due to alternating supply and returns in each bay use alot less power.

My recommendation for an efficient system in frame construction is definitely leaning towards generously sized panel rads with TRV's running 30F delta tee, a mod cond and a fixed delta tee pump, and limiting radiant floor to critical areas under tile in baths, etc running on straight outdoor reset. Radiant floor is quickly loosing its appeal when looking at this simpler and very flexible alternative. It seems we are coming full circle, right back to the same type of heating found from those wonderful old cast iron rads. Funny, older once again trumps much of the new stuff. Helps keep us modest....the dead men really did have it all figured out!


Boilerpro


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Uni R_3

Careful...

If you're talking a direct-piped system, my fear would be that as the boiler's fan speed rises, the ΔT of the boiler HX will rise long before the circ can detect any changes in the ΔT of the return water. The HX is either going to have to shut itself down to protect itself or ummm... ouch.

There may be a couple of ways around this. The Honeywell / Glascom MCBA controllers have a parameter 37 which I think may exist solely for the purpose of controlling a VS pump (the Knight may have something similar - and the larger Vitodens can probably do this same as the 6-24). The other option might be to wire the fan speed voltage to a special relay for setting the speed of a VS pump.

Larry (from OSHA)

somehow I think

that no matter how interesting Siggys classes are, it would be WAY over my head very quickly.

I'm looking forward to seeing the way my simple baseboard system works with a mod con providing the btu's and how closely I can match the output of the boiler with the input capabilities of the indirect that I have. (I know it won't take everything that the boiler can give it since it's a double wall coil). Won't be tracking as extensively as ME with his Munchkin or Mike T. with his Vitodens, but as far as I can figure, the Knight has lots of capabilities for tweaking. I might have to spring for the data logging software and figure out if I can hook up a wireless connection to the computer.

Thanks very much to all who have provided such good insight.

Larry

hot_rod

Exactly! B-pro

after spending a week in Germany surrounded by TRV-ed panel rads I am a believer.

Many of the old shops and commercial buildings where we stayed had been retrofitted with panel rads. Most with press fittings!

In many cases it is much easier and less expensive to get a pair of S&R to a room vs tube on the entire floor, in retro fits.

Save the radiant floors for baths, maybe tiled kitchens. Panel rads elsewhere.

I agree with Kal, the "smart" circs, when used with a mod con boiler should be driven by the onboard control.

Tank type condensors and maybe the Solo would be a better match, perhaps for VS boiler circs driving wide delta T's.

hot rod

hot_rod

You'll be pleased with a Knight standing by!

spend some time learning and playing with that control. It has a boat load of features that are often overlooked.

hot rod

Unknown

Knight Controls (ST)

Hey Hor Rod - can you send me (or advise where I can get) info on the Knight controller.

Thanks

hot_rod

Lochinvar at 615-889-8900

ask for the R&D dept. Charles, I believe.

hot rod

Boilerpro_5

Was thinking about that....

However, if the boiler input starts rising and the pump speed stays the same, then the supply temp will rise. When the supply temp initially rises, the return is still the same, so the delta tee will widen. A wider delta tee will cause the pump speed to increase in order to re-establish its delta tee setpoint. I certainly would not use this setup for the extremely low water content boilers (Munchkins, for instance) but for ones with some water content and mass, it probably would work great. I use the Tubes myself, since some water content is a good thing for control in general. I need to talk to TT about this as I develop the concept.

Boilerpro

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Boilerpro_5

Yeah, Man.....

Someday I plan to get overseas. I want to especially visit the german cathedrals. If I remember right, the Tubes will begin backing off the input if the supply temp rises too quickly, so there is some room to play, but I would not want to depend on this under normal operating conditions.

Boielrpro

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