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Energy Efficient Circulators

van_5
van_5 Member Posts: 6
in THE MAIN WALL
A typical Taco 007 uses about 75 watts of electricity. With system pumps and low temp radiant zones in nearly constant circulation, this adds up quickly. Does anyone make a much more energy efficient circ that could replace the 007?

Comments

  • ALH_4
    ALH_4 Member Posts: 1,790
    efficiency

    Correct sizing is the biggest factor in pump efficiency. If a 007 is oversized, use a smaller pump and save the electricity. There is really no way around the amount of energy it takes to provide the flow you need. All brands I know of have similar electricity usage for similar pump curves.

    -Andrew
  • hr
    hr Member Posts: 6,106
    zone valves

    are another option. Typically a single circ like that can move 100,000 btu or more. Zone valves use a lot less power than a wall full of 75watt circs running at 20% efficiencies. Divide the amount of BTU's moved by the power consumption and oversized circs look pretty bad, often dropping below 20% wire to water efficiencies.


    Wilo is about to un-veil a 1 watt, 1 gpm mini circ for zone applications!

    hot rod

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • BC
    BC Member Posts: 28
    Armstrong e-series

    These have much better efficiencies than wet-rotor designs, but they are probably higher flow than you need. I am considering them for my geo system - when you're moving that much water, the pumping power becomes significant.

    http://www.armstrongpumps.com/Data/otherinfos/Links/01_05_008/E Series White Paper.pdf
  • Joe Mattiello
    Joe Mattiello Member Posts: 740
    slightly more then a 25 watt light bulb

    How did you determine 75 watts? The 007 has a 1/25 hp motor. The conversion from from hp to watts multiply by 746.0, 1/25x746.0=29.84 bhp watts/.4eff=74.6 watts That’s not bad because the pump does not run that often, compared to a higher cost pump.
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
  • D107
    D107 Member Posts: 1,908
    so if my math is right that's 14¢ a 24-hr day constant circ

    30watts x 24 hrs = 720 watts. In westchester total cost of electric including adjustments, delivery, taxes = 19¢ KW. .72KW = 14¢. Per month about $4.20 each circ

    Still if you can use one circ with TRVs you'd be ahead of the game. But different temp zones makes that hard to do.
  • Floyd
    Floyd Member Posts: 429
    Wilo...

    is supposed to getting to our shores a varispeed circ. based on delta P... runs on just a couple of watts at low loads. Would be great if we could actually get it once.... something about gov. approvals or UL listing.... go figure.

    Floyd
  • Uni R_2
    Uni R_2 Member Posts: 589
    Hey Joe

    The 007 is rated at 0.7 amps. So 0.7A x 115V = a lot more than 29.84W. ;-)
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    Power Factor

    You are forgetting the power factor which optimistically can be a 0.85 or 0.90 divisor. In smaller circulators this can be a smaller (less efficient) number, in the 0.70's on occasion.

    Also the "1/25 HP" rating is really nominal if not bogus.

    Grundfos and others use that across a number of their small circulator lines regardless of actual amperage which will vary in that range. They are all close within that range but generally are 1/25 as a minimum then go to 1/12, 1/6 and up.

    They do this because they have to list some horsepower because some expect it expressed as such.

    David and UniR have it right, Amps x volts = Watts in single-phase power and that is where it counts.
  • jp_2
    jp_2 Member Posts: 1,935
    one more

    isn't the .7 amp under full or maxium capable load?

    so in fairness I think you need to measure the current on the motors when thinking about actual cost of operation.
  • Constantin
    Constantin Member Posts: 3,796
    Power Factor is important...

    ... as is the nominal power rating and the motor construction itself. There is a world of difference efficiency-wise between shaded pole, PSC, and permanent magnet motors, for example. Where a small shaded pole motor may be in the 20%'s (i.e. 80% of the energy goes to heat, not motion), a permanent-magnet motor with the same ability to do work might be 70-80% efficient.

    Presumably, this is one of the reasons why the Grundfos alpha plus and other such drives are far ahead of their competition when it comes to real-life performance, i.e. the combination of an intelligent variable-speed drive with a high inherent motor efficiency. Such ΔP-sensing pumps combined with reliable zone valves could make microzoning very cost and energy efficient.
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    Rated for NEC purposes

    for every motor has to have a wiring size basis and it tends to be the worst case. But you are correct, JP, the load (draw) will vary. My Grundfos runs about 60% of nameplate but when I open the balancing valve and let it run out, this increases. With no resistance (maximum flow) it runs out on it's curve toward maximum draw.

    Still, as a nation, we do over-pump. We just crossed the 300 million population mark so the nation at least is pumping away.

    :)
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