# Grundfos Alpha uses only 7 watts ?



## Pat53 (Nov 9, 2011)

Gents, I have the Alpha running my 2 baseboard zones and from what the read-out on the pump is saying is almost too good to believe. It says I'm using 7, yes only 7 watts and pumping approximately 2 GPM to heat the upstairs right now. I installed return line temp gauges and get a nice 22-24 degree delta T. I have the Alpha set on constant pressure speed 1. Even a Taco 007 uses about 10X that much juice !  Incredible !


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## afblue (Nov 10, 2011)

I have an alpha supplying a 10 port manifold with 5 radiant loops, and 3 radiators, and I am only drawing 13 watts and 3gpm  when the house is calling for heat on all zones. You should switch to Auto Adapt it will drop down to 3watts when the zones are closed and its idling. It is truely an amazing pump, it completely simplifies the control logic, and the ECM design uses less power to run. Working smarter not harder!


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## Pat53 (Nov 10, 2011)

afblue said:
			
		

> I have an alpha supplying a 10 port manifold with 5 radiant loops, and 3 radiators, and I am only drawing 13 watts and 3gpm  when the house is calling for heat on all zones. You should switch to Auto Adapt it will drop down to 3watts when the zones are closed and its idling. It is truely an amazing pump, it completely simplifies the control logic, and the ECM design uses less power to run. Working smarter not harder!



Wow, that is awesome. Hard to believe that little amount of power can supply 8 zones.


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## willworkforwood (Nov 10, 2011)

This pump appears to live up to (and maybe even surpass) all the hype.  Do you happen to know roughly what the flow rate/delta T was with the previous pump for the 3 combinations of your 2 zones?  Did you just cut/cap the wires connecting the ZV end switches to the (old) pump and controller?  As afblue said, Grundfos promotes the Alpha auto mode as the way to go, particularly to deal with the various combinations of multiple zones.  Is there something about auto that you don't like?


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## afblue (Nov 10, 2011)

There are 3modes to the pump. 3 fixed rotar speeds, 3 constant pressure settings, and Auto Adapt. Reading the instruction manual, the fixed rotar speeds completely defeat the purpose of the pump, because it just runs like a grundfos 3 speed pump. The constant pressure settings are great because it will throttle the pump to maintain a pressure differential. But as stated, they promote the Auto setting, and what it will do is learn the pressure drop characteristcs of your system and will adjust accordingly, and only run at the lowest level that supports your system load. When all zones are off it goes to "screen saver mode" and runs at 3 or 5 watts and checks back every 30 secs or so to see if it has a load. To the OP, once you go beyond a 20 deg delta, I would think you want to step up a pressure setting or try auto, because you start inducing large temp changes in the system and it reduces performance. After reading through John Steg's book, new systems are running on a Delta T 10. Especially in high mass radiant systems where you have to run a lower water temp or you will never be able to control temp in zones.


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## afblue (Nov 10, 2011)

willworkforwood said:
			
		

> This pump appears to live up to (and maybe even surpass) all the hype.  Do you happen to know roughly what the flow rate/delta T was with the previous pump for the 3 combinations of your 2 zones?  Did you just cut/cap the wires connecting the ZV end switches to the (old) pump and controller?  As afblue said, Grundfos promotes the Alpha auto mode as the way to go, particularly to deal with the various combinations of multiple zones.  Is there something about auto that you don't like?



Don't want to steal the OP's thunder, but I am sure you won't need the end switches on the zone valves unless you have a different purpose for them, like I a mixing demand signal. I was able to save some $ on zone actuators because I could use 2 wire actuators.


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## heaterman (Nov 10, 2011)

The variable speed circ from Wilo and Grundfos are the future. 3x the starting torque of a typical wet rotor and current draw that is as much as 20x less. I replaced a 3hp Taco with a Wilo Stratos that pulls only 187watts where the Taco was using over 3100. 
You can't measure the current draw on the residential sized circs with a typical amp meter. It won't go low enough.


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## 711mhw (Nov 10, 2011)

I've got one in my sys. and allways wondered if the display was very accurate because of these low wattage draw numbers. You guys think that they are pretty close to real values?


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## Pat53 (Nov 10, 2011)

711mhw said:
			
		

> I've got one in my sys. and allways wondered if the display was very accurate because of these low wattage draw numbers. You guys think that they are pretty close to real values?



Yes, I tested mine with a Kill-O-Watt and it is right on


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## kabbott (Nov 11, 2011)

Those circs are great... only problem is for the price difference from an 007 if it run 12 hours a 
day 365 days a year it has to last like 42 years to pay for itself. Hopefully they will become the
norm and the price will drop.


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## nate379 (Nov 11, 2011)

Ok so 55 watt reg pump vs lets say avg 10 watts on that pump.  If the pump runs 6hrs a day for 6 months (winter) that would save about $7 on electric.  hahaha.


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## heaterman (Nov 11, 2011)

kabbott said:
			
		

> Those circs are great... only problem is for the price difference from an 007 if it run 12 hours a
> day 365 days a year it has to last like 42 years to pay for itself. Hopefully they will become the
> norm and the price will drop.



In a lot of cases the custom flow rate available with these circs can really help out the entire system. The ability to dial in virtually whatever supply/return temp difference you want can lead to significant savings on fuel use, and that's any type of fuel.

 It's more than just the raw electrical savings but you are right in that a single speed circ really doesn't cost that much to operate. YET.  There will come a time in the near future when electricity is $.30/KW that a variable speed will pay for itself in short order.


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## PassionForFire&Water (Nov 11, 2011)

NATE379 said:
			
		

> Ok so 55 watt reg pump vs lets say avg 10 watts on that pump.  If the pump runs 6hrs a day for 6 months (winter) that would save about $7 on electric.  hahaha.



That's 80% less of electricity.
I know, these pumps are much more expensive right know, but we need to start somewhere.


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## DaveBP (Nov 11, 2011)

The price has come down a lot in the last year.

They are down to about $150 new from Patriot Supply on ebay. 

Be interesting to see what  their long term durability proves to be.


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## Frozen Canuck (Nov 11, 2011)

With NG mod cons hitting the 90's AFA eff goes & biomass hitting the 80's, these pumps do a nice job of addressing what is probably the last eff in hydronics, the wire to water ratio.

AFA price of these pumps, like any new tech they are priced high to start, then as they become the pump of choice by the pro's = down goes the price.

Really when you think of all the zone pumping math that you can just forget about, your going to see more & more of these pumps as now you just need to do total system pumping at max demand & let these pumps handle everything in between by speeding up or slowing down.

Real bonus for all the DIY types like on this board as many of them would struggle with the math involved in pumping for all the zones. Now they too can just forget about it & choose a pump that will handle the whole system & let the pump do the math for how much pumping to do for each zone.


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## nate379 (Nov 11, 2011)

Sure but if the pump is $300 vs $100 for a regular pump and the pumps have a 10-15 year life span, it would not pay itself off.  Don't get me wrong, I think it's a great idea.

BUT it's going to be spend a dollar to save a dime for a while... be working like the .gov then!




			
				PassionForFire&Water; said:
			
		

> NATE379 said:
> 
> 
> 
> ...


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## weiland13 (Nov 11, 2011)

They are not $300.  They are $148.00.


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## Pat53 (Nov 11, 2011)

weiland13 said:
			
		

> They are not $300.  They are $148.00.



And with electric rates skyrocketing, I would not be surprised if the payback for the Alpha is less than 5-6 years


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## nate379 (Nov 12, 2011)

Point I was making is they cost more.  I'm not saying it's a bad idea by any means, but sometimes it's not worth spending the money is my point.... again this is just my opinion and I'm not posting to say don't buy it... just do the math before you do.

I didn't know they were that cheap though (someone said they were $$).  For the $70-80 extra, I don't think it'd break the bank for too many people.


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## Lapeer20m (Apr 27, 2014)

I spend approximately $30/month to power my heating system. This includes 2 circulators.  One that runs 24x7 during the below freezing weather, and the other that runs when the house calls for heat.  I have a simple single loop system with about 75k btu worth of cast iron radiators.  

If I could power the system for $3/month a pair of new pumps would pay for themselves in 2 heating seasons.


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## DaveBP (Apr 27, 2014)

I would like to see an ECM draft fan for the boiler. Then the total power to run the entire system would be covered by a large but affordable UPS in the event of a power cut.


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## JMac23 (Apr 27, 2014)

Hi everyone, long time lurker/first time poster. I'm not sure about other states, but CT it offering a $100 rebate on these pumps (bumble bee also). I am installing 5 of them on a job right now & they were under $80 from one of our suppliers. 

I work for a small oil company (know your enemy!!), but I'm trying to talk my boss into getting into wood boilers & I WILL have one when I get my own house!!


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## CTFIRE (Apr 29, 2014)

Thanks Jmac. Bought one in January, going to get my $100


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## heaterman (Apr 30, 2014)

The other side of the coin which is often overlooked when considering a VS pump is what they can do for your system efficiency. 
Any boiler, be it fired with gas, pellets, wood or oil is going to generate higher efficiency with a nice big Delta T. Over the long run this is probably worth more savings than the reduced KW consumption. In nearly all typical installations we see, the supply/return differential is less than 10 degrees and sometimes even less than 5. 
A VS pump can solve that problem. .... and in my book, low delta T is a problem or at least a sign of an installation that was not well thought out.

I have a Taco BumbleBee running the iron radiation in my shop office and it's dialed in to maintain a 30* temp drop. The display routinely shows 11 watts with the Delta T at or near that 30* target.


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