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Off Grid

Jed_2 Member Posts: 781
I had a question asked the other day about 25W circs that would handle 7gpm@20' head. Is there such an animal?



  • [Deleted User]

    Look at the Stratos From Wilo. It is a variable speed circ that uses little power. The smallest one available is from 0 to 30 gallons per minute.
  • scott markle_2
    scott markle_2 Member Posts: 611
    no such animal

    That's quite a bit of head and flow for that level of power consumption. Grundfos makes a 25 watt circ. up15-10 but @ 7 gpm it barley does 1 ft. of head. while ecm motor technology and advanced impeller designs may boost water to wire efficiencies I think the beast your after may defy of conservation of energy laws.

    If your really interested in saving energy in pumping costs the first step is reducing required head thru system design. If you ask me 20ft of head is indicative of a not conservation minded design.
  • Joe Billow_6
    Joe Billow_6 Member Posts: 69

    I to have had problems with off grid stuff. I am starting to think that gravity is the way to go if you do not want generator time.
  • Kevin_21
    Kevin_21 Member Posts: 10
    off-grid vitodens

    I installed a Vitodens 200 in my off grid cabin this summer. Have only used it for DHW so far but so far am happy with the draw on my battery bank. I know when I switch it over to heat i will have to run the generator more to charge the batteries. Will get a good idea of the draw on the batteries this winter as I won't have time to get my wood boiler installed this year as I have to build a separate building for it. Will let you know more in the future.
  • Jamie Hall
    Jamie Hall Member Posts: 23,324
    Well, no

    a 25 Watt circulator can't do the combination of head and flow; you're asking for more power out than you are putting in.

    On another aspect of off-grid; if you have a fuel powered generator, be certain that you are using it's cooling system heat! Great for domestic HW and radiant, and boosts your overall efficiencies something terrific.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • hot_rod
    hot_rod Member Posts: 22,158
    Maybe a pair of 25W in series

    might get you thers. cost you more PV panel, but that what it takes to move that flow at that head.

    El Sid has some fairly high head circs in the 4-5 GPM range. www.dankoff.com

    hot rod
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
This discussion has been closed.