3 Speed Circ ?

[Bricks]

For you technology experts can a three speed circ be set up to change speeds using a thermastast or zone valve?

 

[Nofossil]

For you technology experts can a three speed circ be set up to change speeds using a thermastast or zone valve?

Yes, but not easily - that's not what they're designed for. Here's a link:

https://www.hearth.com/econtent/index.php/forums/viewthread/15270/

 

[flyingcow]

On that subject line, I have a Grundfoss 3-speed. It's set in on high, any big diff versus med or low? The circ is in my boiler room, about 100ft away to my tank and manifold in basement. High seems to work well. The hx's perform well. My installer and myself figures it would work the best. But...................

 

[in hot water]

the new delta P or pressure differential circulators automatically adjust speed based on the system load. So as zone valves shut off they rev down vice versa as valves open or modulate. This Grundfos Alpha reads out GPM and Watts to show you where the pump is operating and how much flow it is moving.

They also have ECM motor technology so power consumption is 1/2 of that of a typical wet rotor circulator. That alone can pay the cost difference over the life of the pump.

hr

 

[chuck172]

The way I understand it, the Grundfos Alpha uses delta p, where the competing Taco uses delta T.

 

[jebatty]

I have a Grundfoss 3-speed. It’s set in on high, any big diff versus med or low?

Yes, no or maybe. This is complicated, as increasing flow (by increasing pump speed) increases pump head by roughly the square factor. I have the same and I have a flowmeter on my system, 1" pumbing. If my memory is correct, on L I get about 2.5 gpm, M about 4, and H about 4.5, which makes lots of sense, as pump head is increasing significantly as flow increases.

I think the real benefit of the 3 speed is some ability to "tune" or tweak your system to achieve the design rate flow, understanding that a pump head calculation is not an exact science in the field, although it may be in the lab.

 

[Nofossil]

...calculation is not an exact science in the field, although it may be in the lab.

That's true of a lot more things than just head loss!

 

[in hot water]

The way I understand it, the Grundfos Alpha uses delta p, where the competing Taco uses delta T.

The Taco delta t circ is basically a standard circ with a tekmar control built in. Grundfos sells the same animal as a 15 -42 MixiMizer, same tekmar circuit board to vary the speed.

I don't believe Taco has a delta P circ available, yet. At least in the small residential size.

hr

 

[Bricks]

For you technology experts can a three speed circ be set up to change speeds using a thermastast or zone valve?

Yes, but not easily - that's not what they're designed for. Here's a link:

https://www.hearth.com/econtent/index.php/forums/viewthread/15270/

Now I remeber this post... What I was wondering if the relays could be set up on 24volts. So when there is no call for heat the circ would run on low until a valve opened sending 24 volts to a relay on the pump to ramp up.

 

[jebatty]

It would be easy for a mfr to provide terminals to do just this, but not too easy to re-wire existing 3 speeds to achieve the same result, as the link above shows.

My practical need to increase flow is the opposite, I think, from that met by the delta-T circs. Mine relates to increase in the boiler output temp. I have a 007 in series with a 15-58. The 15-58 is the "base" circ controlled by the boiler. But when boiler output hits 185F, the 007 is turned on by a separate aquastat, moving more water and btu's through the boiler and to storage, and just about completely eliminating any boiler idling as storage moves to the high end (> 180F).

 

[jebatty]

...calculation is not an exact science in the field, although it may be in the lab.

That's true of a lot more things than just head loss!

Huh? My head is at a loss.

 

[chuck172]

I really think that a delta T variable speed circ. used as the load pump (to heating zones) on a system where two pumps are used in series, would work very well.
The resistance applied by the delta T pump would throttle just the right amount of heated water to storage.
I know Taco makes this pump. I can't seem to find the Grundfos model.
The pumps do get expensive.

 

[Tony H]

Anyone care to explain the advantages of running at different speeds. I have the 3 speed Grundfoss running at high speed and am not sure when / why I might want to use ither settings.

 

[Nofossil]

Anyone care to explain the advantages of running at different speeds. I have the 3 speed Grundfoss running at high speed and am not sure when / why I might want to use ither settings.

Two advantages:

1) Lower speeds use less power and create less noise. There's no system benefit from pushing more water than you need.

2) You can vary speeds to match the heat output or heat loads in your system.

For the boiler, you might want higher flow rates when it's really cranking to keep the outlet temperature from getting too high (with a gasifier, that will cause it to idle). As the fire dies down, you might want to reduce the flow rate to keep the outlet temperature high enough to be useful.

For the heat loads, you want a higher flow rate when there's a bigger heat demand (more zones calling for heat, or each zone needing more heat).

If you notice that these objectives could conflict, congratulations! That's one of the reasons for storage - to match heat load to the boiler's heat output.

 

[Fred61]

I know little about electric motors but was wondering if someone could make use of one of those three speed remote controls that are used for controlling ceiling fans. I know the fans are not capacitor start and circs are but don't know if there are any other differences in the way they function.

 

[Chris S]

wilo stratos eco does the same as the grundfoss, without the cool display though. Wilo is delta p, ideal for multiple zoned systems. Both pumps work at significant electrical savings ( ecm technology)

The advantage is that you can set your head in the field to actual conditions, and only pump as much as your system requires at any time, saving electrical costs on the circulator side, while meeting the varying flow needs of your system.

 

[Medman]

Does anyone have sources/pricing for the grundfos alpha? I can't seem to find a North American supplier.

 

[DaveBP]

http://www.pexsupply.com/Grundfos-59896832-ALPHA-15-55-F-LC-Cast-Iron-Circulator-Pump

 

[Medman]

Thanks. I looked there, but must have missed it. That's a hefty price tag, but it's a large pump. I could probably replace the Taco 1400-10 I am using for the main system pump with the Alpha.

 

[dogwood]

Patriot Supply has it for $230.11. Google "Patriot Supply Grundfos Alpha".

Mike

 

[Bricks]

How well would the Grandfos Alpha circ work in a system where inlet boiler temp is controlled by a zone valve?

Another ? My water to air exchanger in the garage is roughly going to be 12 feet above my boiler. Would the granfus Alpha handle this or would I be better to put a seperate circ on this zone instead of a valve?

 

[DaveBP]

Patriot Supply has it for $230.11. Google “Patriot Supply Grundfos Alpha”.

Mike

Big price drop since they started carrying them. Hopefully, it's a trend.

 

[Gooserider]

The stuff I've seen mentioned thus far on the ECM pumps all seem to have them connected to a delta-T or delta-P internal control so that the pump works to hit a single preset target point... Does anyone make an ECM pump that can be externally controlled by a central control system (i.e. a NoFo box) so that there is more of a variable control on the pump? I figure this would allow setting different targets for different circumstances, or pretty much allow the same sort of thing that NoFo is accomplishing with his PSC pump controls while getting the additional energy savings that you get from the ECM motor?

Gooserider