ECM circulators?

[pybyr]

I know there are many ECM circs in Europe- but just barely beginning to arrive here- Wilo Stratos and Grundfos Magna (with the Magna seemingly being too big and expensive to sanely think about for normal residential use)

anything else out there that anyone can point me to that's roughly in the residential size category?

the main appeal to me of the ECMS is much higher electrical efficiency + speed control

also, any opinions on what the reliable lifespan of an ECM circ is likely to be compared to a standard "wet can PSC" circulator?

for that matter, what are the usual "failure points" in consumer-grade wet can circulators?

buying a more expensive circ that'll gradually pay for itself with electric savings + longer life is something I am open to thinking about- but if a much more expensive ECM circ is unlikely to outlast a "regular" one, it's harder to consider justifying

thanks

 

[in hot water]

Looks like the Laing 120V ECMs are making their way to the shelves.

Google around for the Grundfos Alphas. I know a few installers are buying them online from a UK website. Although they are generally 230V when purchased from abroad.

I have a few prototypes of the Grundfos Alphas in the 25-40 and 25-60 size. They sent them to me with a 120V- 230V step up transformer. Radio Shack sells the same transformer for around 40 bucks if you want to go with a 230v version.

Hit the Grundfos website in Denmark for a look at their European selection.

Here are some of the solar pumps, including ECM versions Grundfos builds for OEMs. Notice some high head drainback specfic circs. They run on high speed for a few minutes and drop back once the siphon starts. Clever stuff out there.

 

[pybyr]

Looks like the Laing 120V ECMs are making their way to the shelves.

Google around for the Grundfos Alphas. I know a few installers are buying them online from a UK website. Although they are generally 230V when purchased from abroad.

I have a few prototypes of the Grundfos Alphas in the 25-40 and 25-60 size. They sent them to me with a 120V- 230V step up transformer. Radio Shack sells the same transformer for around 40 bucks if you want to go with a 230v version.

Hit the Grundfos website in Denmark for a look at their European selection.

Here are some of the solar pumps, including ECM versions Grundfos builds for OEMs. Notice some high head drainback specfic circs. They run on high speed for a few minutes and drop back once the siphon starts. Clever stuff out there.

Thanks HotRod-- any chance you can share or point me to the pump curves for those Grundfos Alphas- and also any particular UK website that's known to be reasonable/ good service/ trustworthy for us in the "Colonies" to source from? Also, with the Euro-market Grundfos circulators, which look as if they use different flanges (more like a threaded union than the 2 bolt flanges we're used to) is there a difficulty in adapting to US-diameter pipes- of for that matter, a known solution on how to handle that?

Thanks

 

[in hot water]

Plenty of suppliers if you google Grundfos Alpha including one on E-bay UK at 9 Euros. Looks like 70 euro and up for prices. Pump curves and links to Grundfos directly are at all of the UK websites I visited.

Caleffi and others have adapter nuts for that threaded volute. Or you can unbolt the powerhead and it fits into the 15-42 and 15-58 flanged volutes. This pic shows both styles of volutes, one with Caleffi 1-1/4 nuts and 1" fip adapters. I prefer flanged style, but the two threaded nuts sure are quick and easy. Most of the solar pump stations have the smaller threaded versions shipped in them.

I need to ship mine back to Grundfos for the newer Alpha 2 version. Grundfos can can pull data off of the ones I have been using! Who knew?
They shared some really cool features they are considering for US versions. Possibly a readout to show the BTUs the circ is moving (built in btu metering). Mine have just digital watt meters on the wiring housing.

(broken link removed to http://cgi.ebay.co.uk/grundfos-alpha+15-50-130-central-heating-pump_W0QQitemZ250290125799QQcmdZViewItemQQimsxZ20080903?IMSfp=TL0809031517r28562)

 

[pybyr]

I need to ship mine back to Grundfos for the newer Alpha 2 version. Grundfos can can pull data off of the ones I have been using! Who knew?
They shared some really cool features they are considering for US versions. Possibly a readout to show the BTUs the circ is moving (built in btu metering). Mine have just digital watt meters on the wiring housing.

Thanks- when I grow up, I wanna be like Hot Rod... both in the stuff you're trying and the relationships you have with all of these companies from across the pond who have all this technology that we're just beginning to get glimpses of.

Speaking of which, I'd REALLY REALLY like to be a beta tester for a batch of Grundfos Alpha 2s in my new system that I am going to start putting together really soon. With an Econoburn 150 + 1200 gallons of stainless "lego" storage tank + primary secondary with Taco Twin Tees, I guarantee them a showplace. Sound expensive? no, as a good friend of mine once said, I am "too poor to buy cheap" 'cause with the price of oil, an income that's been frozen, rising costs on everything in sight, & etc., it's a matter of do this once, do it really well, in a long-haul kinda-way, so that I can ditch most of my energy needs/ costs except what I can cut myself on 70 acres of mixed woodlot

Hot Rod= _please_ PM me on how I might be a US tester of some Grundfos Alphas

thanks

 

[heaterman]

ECM vs Standard

While ECM motors are inherently more efficient than their standard wet rotor counterparts, there are many cases where the difference in KW consumption is not all that great. Circulating a constant flow primary loop for example.

You have to remember that these circs were designed in Europe where the most common form of heating is a panel rad with a TRV. When you have a house full of these you have a very dynamic system that is nearly constantly changing the demand for flow as the TRV's throttle up and down. In that application an ECM is perfect. It can and does cut electrical consumption by a very large percentage. The system that most closely approximates that effect here in the US would be a one that uses zone valves. Flow demand can change a fair amount but not nearly the degree that a TRV'd system can. A zone valve system will typically be piped using 3/4" copper that will easily flow 2-3GPM per loop. In contrast, a panel rad system using TRV's can squeeze flow down to a virtual trickle while still emitting the required heat to the structure. Tenths of a GPM are possible as well as full flow which may be upward of 10-15 GPM. An ECM on a system like that can show its true capabilities.

Getting back to the afore mentioned primary loop, the only real application for an ECM circ in a constant flow design like that would be to use something like the Stratos which can regulate flow based on temperature also. In that way one could achieve boiler protection without a bypass loop or a Termovar type valve. When you have a loop or system that calls for a constant flow rate, a correctly sized circ and piping system will provide nearly the same efficiency as an ECM type circ. Certainly close enough to make the payback far down the road at today's electrical costs.

 

[pybyr]

Thanks heaterman- that's an incredibly informative counterpoint to the Euro design parameters and assumptions.

With my big old farmhouse, I am basically going to have one big gasifier boiler, one big (1200-1300) gallon unpressurized storage, and one big sinle zone heated by big water-to-air (24x24 inch 4 row 1600 cfm) duct coil.

So maybe "normal" right-sized circs are not that far off for my application ( for what it's worth, assume that my "marginal rate" of $/kwh is about 0.17).

Can anyone please point me to some sources and specs for "little" (residential size) 3 phase wet can circulators that I could use with inverter drives to fine-tune flows, btus, and kwh usage- especially for my fan coil?

 

[heaterman]

I don't know of any motors that can be used for your fan other than purchasing one that's made for a current variable speed furnace along with the control to run it. (But then I've never professed to know everything so there may be such a beastie lurking out there somewhere. Whether it could be adapted for your use is a question I can't answer. There are however many manufacturers who make complete variable speed fan coil units, Goodman, Trane, Carrier, Lennox, and Rheem to name a few. Carrier says the reduction in electrical use will pay the difference in cost between a standard blower and the variable speed is 5-7 years depending on KW rates.

Another option........
You may find that oversizing the coil in your plenum would offer a substantial reduction in electrical operation costs merely from the fact that it will run less due to greater heat transfer.

 

[in hot water]

ECM vs Standard

While ECM motors are inherently more efficient than their standard wet rotor counterparts, there are many cases where the difference in KW consumption is not all that great. Circulating a constant flow primary loop for example.

But even in a constant flow condition the ECM will consume 40% less energy doing the exact same job. the Grundfos I have include 3 fixed speeds, and 3 positions for Delta P.. No delta t function at this point. So that may or may not pencil out to a KW savings depending on the cost difference between the two circs, your hours of operation, and cost of KWH.

But if you could in fact buy them for the same money, or 9 Euros like the e-bay example

You have to remember that these circs were designed in Europe where the most common form of heating is a panel rad with a TRV. When you have a house full of these you have a very dynamic system that is nearly constantly changing the demand for flow as the TRV's throttle up and down. In that application an ECM is perfect. It can and does cut electrical consumption by a very large percentage. The system that most closely approximates that effect here in the US would be a one that uses zone valves. Flow demand can change a fair amount but not nearly the degree that a TRV'd system can. A zone valve system will typically be piped using 3/4" copper that will easily flow 2-3GPM per loop. In contrast, a panel rad system using TRV's can squeeze flow down to a virtual trickle while still emitting the required heat to the structure. Tenths of a GPM are possible as well as full flow which may be upward of 10-15 GPM. An ECM on a system like that can show its true capabilities.

Getting back to the afore mentioned primary loop, the only real application for an ECM circ in a constant flow design like that would be to use something like the Stratos which can regulate flow based on temperature also. In that way one could achieve boiler protection without a bypass loop or a Termovar type valve. When you have a loop or system that calls for a constant flow rate, a correctly sized circ and piping system will provide nearly the same efficiency as an ECM type circ. Certainly close enough to make the payback far down the road at today's electrical costs.