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Thread: Does Watt Usage Variance Make Sense on This Pump?

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    Does Watt Usage Variance Make Sense on This Pump?

    I have a Hayward EcoStar Variable Speed Programmable pump, pool only set up for 2 months. PB set pump up to run at 2750 RPM (12 hours). The unit displayed it was using 1243 watts. I throttled it down to 2500 RPM, it was much quieter but also noticed that it reported using 950 watts. The lower watts really threw me. The change from 2500 to 2750 RPM is 10%, however the wattage difference is 30%. Slightly lower water circulation, however the descents and bubbler seem to be moving more than enough water, but pretty significant reduction in watts (and therefore my electric bill). That doesn't seem to make sense for that large of a drop in watts. Does that make sense to anyone else? Is there perhaps something that I'm not understanding with the higher RPM and wattage increase?
    Free Form 13K IG (Quartz) w/Screen Enclosure - 2 Sheer Descents, 1 Bubbler - Hayward 60 SF DE Sta-Rite - Hayward SP3400VSP EcoStar - Hayward Aqua Rite AQR9 (T-Cell-9) SWG - Zodiac MX6 - July 2016 - Taylor K-2006 - Taylor K-1766 Salt Test

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    Mod Squad Jimrahbe's Avatar
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    Re: Does Watt Usage Variance Make Sense on This Pump?

    Bob,

    Sounds about right to me.. In my case..

    1200 RPM = 172 watts (where I run most of the time)
    1500 RPM = 288 watts
    2400 RPM = 1014 watts.

    Jim R.
    Finished in 2015 - 17K Gal, IG, 20' x 25' Almost Rectangular Pool, Pebble finish, three rockport water falls. Pentair Equipment: EasyTouch 4, IC40 SWG, 3 HP VS Pump, CCP520 Cartridge Filter.
    TF100 with SpeedStir and SampleSizer, ColorQ Pro 7, Dolphin Premier Robot Cleaner, added Screen Logic 2, added small 3 person Calder Spa.

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    mas985's Avatar
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    Re: Does Watt Usage Variance Make Sense on This Pump?

    Energy use for a VS pump is roughly proportional to RPM^3.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Re: Does Watt Usage Variance Make Sense on This Pump?

    That’s how VSPs work. The power usage is exponential. At 2x the RPM, you get 2x the flow, 4 x the pressure and 8 times the power usage (Theoretical. Real world power change is about 6 x). 3x the rpm, you get 3 x the flow, you get 9 times the pressure and 27 x the power.

    (2500 /2750)^3 x 1243 = 934

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    Divin Dave's Avatar
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    Re: Does Watt Usage Variance Make Sense on This Pump?

    And this is why TFP regularly recommends that pool owners at least, have 2 speed pumps instead of single speed ones.
    The energy savings can be substantial.
    Divin Dave,
    IG Vinyl, 15' x 30', 3 1/2' - 6' deep, Oval, ~15K gal, Intelliclor IC40, Intelliflo VS pump, Clean and Clear 420 Filter, auto-fill-disabled, Retrofit LED Color Light, Dolphin Nautilus Robot, TF100 Test Kit, Taylor K1766 Salt Test Kit, Tftestkit Pressure Gauge.
    www.tftestkits.net Experience- it's what's learned just after you needed it most !!

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    Re: Does Watt Usage Variance Make Sense on This Pump?

    All - thanks for the responses.


    Jimrahbe - With your slower speed and given the size of your pool and features, is that enough to run the vacuum? Or do you kick the pump speed up for that? My PB is saying he can probably run at 1750, but the descents and bubbler would lose their effects due to the lower pressure.
    Free Form 13K IG (Quartz) w/Screen Enclosure - 2 Sheer Descents, 1 Bubbler - Hayward 60 SF DE Sta-Rite - Hayward SP3400VSP EcoStar - Hayward Aqua Rite AQR9 (T-Cell-9) SWG - Zodiac MX6 - July 2016 - Taylor K-2006 - Taylor K-1766 Salt Test

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    Re: Does Watt Usage Variance Make Sense on This Pump?

    If you want to operate the water features (sheer descents and bubblers) at lower rpm, close off other returns so that all water goes to the features.

    If you have a heater, always make sure that it has enough flow while heating.

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    Mod Squad Jimrahbe's Avatar
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    Re: Does Watt Usage Variance Make Sense on This Pump?

    Quote Originally Posted by bobandsherry View Post
    Jimrahbe - With your slower speed and given the size of your pool and features, is that enough to run the vacuum? Or do you kick the pump speed up for that? My PB is saying he can probably run at 1750, but the descents and bubbler would lose their effects due to the lower pressure.
    Bob,

    I am not a fan of water powered cleaners. I have a robot so I don't worry about pump speeds.

    I have to increase the speed to 2500 RPM to make my water fall wall look good, but I only turn it on when I want to aerate, or when I have guests and I want to show off...

    Continually running my waterfall (just like your descents and bubblers) causes my pH to rapidly increase, so I only do it when necessary.

    Jim R.
    Finished in 2015 - 17K Gal, IG, 20' x 25' Almost Rectangular Pool, Pebble finish, three rockport water falls. Pentair Equipment: EasyTouch 4, IC40 SWG, 3 HP VS Pump, CCP520 Cartridge Filter.
    TF100 with SpeedStir and SampleSizer, ColorQ Pro 7, Dolphin Premier Robot Cleaner, added Screen Logic 2, added small 3 person Calder Spa.

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    Re: Does Watt Usage Variance Make Sense on This Pump?

    If you can get the rpm down to 1750, you should see the power drop to about 350 watts.

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    Re: Does Watt Usage Variance Make Sense on This Pump?

    Quote Originally Posted by Jimrahbe View Post
    Bob,

    I am not a fan of water powered cleaners. I have a robot so I don't worry about pump speeds.

    I have to increase the speed to 2500 RPM to make my water fall wall look good, but I only turn it on when I want to aerate, or when I have guests and I want to show off...

    Continually running my waterfall (just like your descents and bubblers) causes my pH to rapidly increase, so I only do it when necessary.

    Jim R.
    I'm learning about the impact of the descents and bubblers on my PH. I'd lower it and within a few days see it increase, read that aeration raises PH, but they are so peaceful sounding when sitting on the deck or lanai. PB provided the vacuum (Zodiac MX6) and it seems to be doing a good job. I'll look up the details on your vac if/when it's time to replace my current vac.

    - - - Updated - - -

    Quote Originally Posted by JamesW View Post
    If you can get the rpm down to 1750, you should see the power drop to about 350 watts.
    Thanks James. PB was suggesting dropping to 1250, but then have descents and bubbler off. Ramping up speed during the time of day when we are around the pool and want the descents and bubbler effects. I'll have to try out 1750 and see how that looks and ensure enough water circulation (still learning the finer parts of owning the pool).
    Free Form 13K IG (Quartz) w/Screen Enclosure - 2 Sheer Descents, 1 Bubbler - Hayward 60 SF DE Sta-Rite - Hayward SP3400VSP EcoStar - Hayward Aqua Rite AQR9 (T-Cell-9) SWG - Zodiac MX6 - July 2016 - Taylor K-2006 - Taylor K-1766 Salt Test

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    Re: Does Watt Usage Variance Make Sense on This Pump?

    When you have the sheer descents and bubblers on, is there also water going to other returns (floor, wall etc)?

    If you have all water going to the sheers, I think that 1,750 might be enough.

    What are the specifics of the sheers (length, height)?

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    Re: Does Watt Usage Variance Make Sense on This Pump?

    Quote Originally Posted by JamesW View Post
    When you have the sheer descents and bubblers on, is there also water going to other returns (floor, wall etc)?

    If you have all water going to the sheers, I think that 1,750 might be enough.

    What are the specifics of the sheers (length, height)?
    I have 2 descents of 24" each, 18" drop. The returns (3 on the walls) are always on when descents and bubbler is on. For proper circulation wouldn't I want the wall returns always on? I was thinking to just turn off the bubbler and that should improve the flow to keep the descents looking good.
    Free Form 13K IG (Quartz) w/Screen Enclosure - 2 Sheer Descents, 1 Bubbler - Hayward 60 SF DE Sta-Rite - Hayward SP3400VSP EcoStar - Hayward Aqua Rite AQR9 (T-Cell-9) SWG - Zodiac MX6 - July 2016 - Taylor K-2006 - Taylor K-1766 Salt Test

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    Re: Does Watt Usage Variance Make Sense on This Pump?

    There is no reason that the wall returns need to be on. The sheers and bubbler can function as the only returns as long as the total system GPM is sufficient for your pool.

    2 descents of 24" each with an 18" drop shouldn’t require high RPM if the wall returns are closed.

    However, as noted, aeration can be an issue from a pH rise point of view.

    There are multiple options that you can choose for the best combination of cost vs. performance.

    Perhaps run all wall returns at 1750 RPM until you want the sheers and then open the sheers and bubbler and close the wall returns (completely or partially). Even closing the wall returns 1/2 way will allow you to run at a much lower RPM while maintaining good Sheer action.

    As long as water is returning to the pool, it doesn’t matter if it comes from the wall, floor or fountains (other than aeration).

    Note: Always be careful not to close all returns at the same time.

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    Re: Does Watt Usage Variance Make Sense on This Pump?

    Vs pumps are most energy efficient at lower rpms so in my case I only run at a high enough rpm to run vacuum for 2 hr then goes to 800 rpm for 22 hr. I think by even running at the rpms for 8hr that you are running you aren't getting the benefits of a VS pump
    aprox 18k in ground

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