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Well water pumps

user-2069108 | Posted in Mechanicals on

Is there any preferred efficient water delivery systems from a well? The constant pressure systems were mentioned sometime on this website, but I don’t know if that was for space or efficiency.
Grunfos was the brand mentioned.

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  1. Anon3 | | #1

    It really depends on how deep and what GPM you can get/want. But really the only thing that makes a difference in residential usage is the size of the pressure tank, or if you can go gravity that is the most efficient. As long as you don't do constant pressure and have a big tank, the kwh usage is nothing. Remember, the pump is rated at g/minute while kwh is per hour.

    (It's more important to focus on whole house filtering though)

  2. GBA Editor
    Martin Holladay | | #2

    As far as I know, drilled wells all require the same three components for water delivery: a submersible pump, a pressure switch, and a pressure tank. I don't think that there is a significant difference in electricity consumption between different brands of submersible pump.

  3. user-2069108 | | #3

    Thank you.
    I guess I will speak with my future neighbours and a few well drilling contractors in that area to see what they recommend. I have to admit, I like the idea of a small water tank. The Marathon water heater (Something that I learned about on this site) has a big enough footprint.
    As for filtering, I am hoping that I do not need that. The water that we had at our neighbour's place was very good.

  4. STEPHEN SHEEHY | | #4

    Steve Young: Don't assume you won't need a filter. Our water tastes great, and is free from any nasty chemicals. But we still need a filter for sediment. Make sure you leave room for one in case you need it.

  5. user-2069108 | | #5

    I planned my utility room to have a few tanks, and I will have the CERV above them. Once again, I will try to see what folks nearby have installed.

  6. Anon3 | | #6

    You want the biggest pressure tank 119 gallon to reduce pump cycling. Also check out

  7. Stockwell | | #7

    Two things---if you are in an area with Radon gas worries, then you may have radium in the water. You would want a water softener in that case. It will remove 90% of the radium.

    As for the constant pressure wells, also ask your neighbors about the quality of power in your area. I live in an area that is prone to voltage dips and spikes and loss of power. My well guy said he would not put the constant pressure unit in my house because he is constantly replacing the circuit boards in houses that don't have consistent power. Something to think about. The boards are expensive to replace.

  8. user-2310254 | | #8


    Could you use an uninterrupted power supply (UPS) to address the fluctuations?

  9. user-2069108 | | #9

    How much power does a well pump need? I suspect that the depth of well would greatly influence that figure.
    Even a shallower well would likely need a significant motor. This would likely require quite a large UPS.

    Is the idea of a personal water tower something to consider? Or does that then open up the need for chlorination?

  10. Stockwell | | #10

    Steve--Yes, I am sure it's possible though I don't know the cost for such a beast. I have them on every computer, router, modem, switches as well as in my home theater. They have to be the line conditioning variety or line interactive topology such as APC calls them, but they definitely work well here.

  11. Stockwell | | #11

    The constant pressure model would use a smaller pump, but we have a 5Hp pump, 740 foot well.

  12. user-2069108 | | #12

    That is bigger than my pool pump, and I know when that sucker is running. That is a lot of wattage - way more than your UPS for your electronics.
    I think that my well will be in the 200 -300 foot depth, thank goodness.

  13. GBA Editor
    Martin Holladay | | #13

    I have a 1/3 hp Grundfos submersible pump in my 200 foot well, and it easily keeps up with our family's water use, even when we are operating sprinklers in the summer (and taking a shower at the same time).

    The pump draws about 1,000 watts when it is running.

  14. user-2069108 | | #14

    Thank you for relating your experience, Martin.

  15. STEPHEN SHEEHY | | #15

    Not sure how much the draw is, but our submersible pump is on a separate 240 volt, 20 amp circuit. Well is almost 400 feet deep.

  16. user-2310254 | | #16

    FWIW. A few years ago I was able to buy a new but obsolete Axxium (now Eaton) data center 1000 VA UPS for about $100. While it did not have batteries, it was till a great deal. Axxium also made 2000VA and 3000VA model with versions for 80 to 138 VAC and 160 to 276 VAC. This unit was well over a $1,000 on the regular market.

  17. Jon_R | | #17

    Pump selection is critical to kwh/gal efficiency - check the curves. A pump designed for 65% more head than you use can be 1/2 as efficient.

  18. user-2069108 | | #18

    So, Jon, you are saying that the pump should be matched to the head for a particular flow rate to be most efficient? Attached is the plot that one would consult?

  19. Anon3 | | #19

    Not just that, it needs to be able to produce 40-50psi at the ground so you'd actually have pressure going into the pressure tanks, unless you are going with an extra booster pump.

    Edit: the SmartFlo system sounds interesting, you should try it and let us know.

  20. Jon_R | | #20

    Steve, you want a performance curve showing head and efficiency (eta) for specific models. Say page 40 here:

  21. SwitchgrassFarmer | | #21

    With regard to the question about electrical usage for a well pump, attached are March and April Sense charts for my home.

    March total well pump usage was 24.7 kWh

    April total well pump usage was 27.1 kWh.

    Sense picked up the VFD coming alive as a separate device, so I called the two values "Stage 1" and "Stage 2", although that isn't quite accurate.

    About 1 person here on average in March, 1.25 in April.

    Run the dishwasher and take a shower every day. Generally a load of laundry about every 2 days, slightly more often in April as it's my busiest farming month.

    This is a 1 HP 230V submersible pump on a variable frequency drive.

    The well is 6.25" bore hole, 298' deep, with water bearing zone at 200 to 210', i.e. we drilled deeper for reserve. Somewhere I have a record of where we put the pump, it's towards, but not at, the very bottom.

    We do have a quite beefy sediment filter on this system, that has a manual wash down feature. However about twice a year I still end up taking it apart to scrub the screen by hand.

    I did not select this Pentek VFD and pump; it was actually a leftover from a different job our contractor had where they lucked into a well with enough total capacity to do a "pump and dump" geothermal system. However I did double-check the engineering before it went in, which was a good thing, as the original supplier had mated the wrong pump motor. So that part ended up being brand new. Oh and yes it has its own surge suppressor, we have a master surge suppressor for the house, etc.

    You can also notice: Water heater electrical usage climbing in April because the geo unit runs less as it warms up outside, so there is less desuperheater availability. Tend to use the oven more in the winter, etc.

    Someone will likely ask about the "Always On" percentage. A significant component of that is the aerator on our septic system, which is oversized for my actual usage since I am not a "typical" family of four. Someday I would like to control that via IFTTT based on actual water consumption. Part of it is also routers, computers, etc, so I can write this note!

  22. ranson | | #22

    I would consider a cycle stop valve instead of a variable speed pump. They both achieve the same end, which is matching pump flow to the demand. The CSV is essentially a pressure regulating valve installed between the pump and the tank. Both will result in energy savings. Which will have greater energy savings depends on the nature of the load.

    The big saving on a CSV is upfront cost, long term reliability, and repair costs. A CSV can work with a standard pump, standard controls, and a minuscule pressure tank. The pump will turn on once, and then operate continuously, for loads above the minimum flow of the CSV. This means your pump reliability will be improved over a standard system. And should something break, everything is less expensive. The CSV itself is probably only $100ish. A variable speed system is more expensive and more complex.

  23. user-2069108 | | #23

    This is very interesting. I looked up CSV and came across this very good explanation.

  24. Anon3 | | #24

    Actually, looks like for constant pressure Goulds Pumps ProPak is a much better deal compared to the SmartFlo. Same price as a normal system, in fact, it might be cheaper... Converts 230v to 3 phase. You get a bunch of protection features for free too.

  25. user-2069108 | | #25

    Anon3. I looked that up and yes, you are correct, a $300 to $400 savings.
    But I am intrigued by the CSV for its simplicity and lower cost.

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