Replacing Pentair SuperFlo with VS help

[GaryT58]

Thanks all. I appreciate the different points of view. Will look closely at 2-speed versus VS. Our current adjusted electric cost is about 9.4 cents/kw. So every 100W is about $2.25 /day so about $400+ savings for 6 month season here. So even if squeeze only another 25W savings from a VS compared to 2 speed, that would be $100/year savings. The Autopilot can run the SWG at 20 GPM (have read of others running at 15 gpm), so hoping to dial in pretty low.

I found a VS replacement motor for my existing pump (AO Smith ECM16SQU - $399). Does require a couple additional parts, but still much less than full replacement. Some reviews say its a little loud. Thanks Mark for the link to the 2-speed replacement, as that lead me to find this one.

Gary

 

[barnnns1]

I thank you for the inputs. A Pentair SuperFlo VS 1.5HP (342001) is $683 and the Pentair SuperFlo 2 Speed (340043) is $479, so difference of $204. The VS can run from 300 - 3450 RPM. The dual speed runs at 1750 and 3450 rpm. So, I should be able to run lower than 1750 (i.e. 1400) and meet the flow rate needed for my purposes. Since I do not know specifically the rate, I would rather not risk it on a 2 speed.

I appreciate the concern for the cost difference, but I want the flexibility of the VS.

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Again, I do not want separate timers. I do not want to worry that the timers will always be in sync. The pool pilot has the control built in, so I want to use it.

I get what you are saying but keep in mind that the vs has an on board timer so it will still be like having 2 timers no mater what you do. Maybe the pentair controller is your best option. Pricy though.

 

[CJadamec]

If you are paying less than $0.18 /KW for electricity go with the new two speed motor for your wet end. The amount of power you will save being able to run at 1400 rpm vs 1750 is trivial. I have a very simple plumbing setup and my heater which requires 20gpm won't switch on if my pump is below 1400rpm. I'm paying around $0.24 / KW so those extra few watts add up quickly for me. Even still I won't recoup the price difference over the two speed option. One of the reasons I got the VS was so that I didn't have to get a mechanical timer which for me lowered the price gap between the two because I had no equipment to start with.

The superflow VS only displays current time, time remaining in the program cycle (duration), current wattage used, and pump rpm. It does not display flow rate or GPM information.

There is a catch to the superflo VS programing that might give you a wrinkle. The pump timer electronics are designed to only run for 23hrs and 59min. You have to program the pump to run on its own timer schedule even if you use the relay inputs. The relays only allow you to automate the speed settings while the pump is running its programed schedule. With the superflo electronics there no way to avoid using the onboard timing. If you aren't running a pump program every time you cycle the power to the pump you will have to manually start the pump.

Honestly you will probably be very happy with a new 2 speed motor over changing out the pump to a VS setup.

 

[mas985]

Our current adjusted electric cost is about 9.4 cents/kw. So every 100W is about $2.25 /day so about $400+ savings for 6 month season here.

I think your decimal point is off. I get only $.225 per day or $40/yr but that assumes you run for 24hrs/day. No reason to do that. I have a two speed and run on average about 4 hours per day (1 on high, 3 on low). So if you run at 6 hours per day, that is only $10/yr difference.

 

[GaryT58]

I think your decimal point is off. I get only $.225 per day or $40/yr but that assumes you run for 24hrs/day. No reason to do that. I have a two speed and run on average about 4 hours per day (1 on high, 3 on low). So if you run at 6 hours per day, that is only $10/yr difference.

Yes you are correct. But as I said, I will be running 24/7. Maybe not what others would do, but what I will do. And the cost is only part of the equation. I want to run 24/7 so looking for the most economical method. If $ was my only concern, I sure wouldn't have built a pool

 

[GaryT58]

My original goal with this thread was to look at VS pumps that would easily replace my existing single speed SuperFlo. For ease of DIY replacement I am looking at Pentair SuperFlo VS and Hayward SuperPump VS. Also, from discussions here, considering I 2-speed SuperFlo and 2-speed motor-only replacement. I looked at a VS motor replacement, but adding up cost for motor, and other parts, was to me not worth it. I want to run pump at about the lowest RPM to allow for SWG to work (20 GPM) and for 24/7 operation. I do not have automation, nor will.

While searching I found the thread on TFP that had a great set of excel worksheets available that had a pump database. I was able to use the "Energy Cost" worksheet to help me decide on my pump choice. I was able to edit it to put in my electric cost, cost to purchase new pumps, my run schedule, ... and compare cost of ownership for these options. I selected to run for a target of 25 GPM for VS pumps, and used the lower speed for the dual speed, for the calculations.

In terms of how long it would take for new pump to break-even (savings exceeding purchase price, electricity, versus just running old pump).

AO Smith 2 speed motor - 4 months.
Pentair SuperFlo SF-N2-1A (2-speed) - 7 months.
Hayward SuperPump SP2300VSP - 8 months
Pentair SuperFlo VS 342001 - 8 months.

Notes - Since the AO Smith motor wasn't in the PumpData database, I just used the same performance values as the SF-N1-1A, but entered lower purchase price.

So next compared Hayward SuperPump to others to see when it surpassed them in savings - that is at which month of ownership was this VS cost of ownership less than other pumps in my list.

AO Smith 2 speed motor - 28 months.
Pentair SuperFlo SF-N2-1A (2-speed) - 20 months.
Pentair SuperFlo VS 342001 - 18 months.

My pool will probably be open April - October (7 months) per year. So I would see that a VS will exceed a dual speed in 3-4 years ( a little less, as I will be running pump some even in other months to keep water moving and maintaining CL.

So for me it comes down to SuperFlo VS versus SuperPump VS. I would love any comments on why one may be better than the other. Hope to purchase this week so I can install and start saving $.

Thanks

 

[mas985]

Notes - Since the AO Smith motor wasn't in the PumpData database, I just used the same performance values as the SF-N1-1A, but entered lower purchase price.

That is because A.O. Smith is a motor manufacture, not a pump manufacture. You need to input the model number of the pump used, not the motor.

Just an FYI, you can get a two speed motor with a built in timer so there really is no need to run 24/7. With shorter run times, you will find more energy savings for both types of pumps but it also takes the VS pumps more time to be more cost effective than the two speed.

Also, did you include the cost of surge protection for the VS when calculating the lifetime costs?

However, if you decide on a VS, the Hayward MaxFlo VS is a more efficient pump over both the SuperFlo and SuperPump.

 

[GaryT58]

That is because A.O. Smith is a motor manufacture, not a pump manufacture. You need to input the model number of the pump used, not the motor.

I would have assumed it would be a combination of the motor and wet pump that determines power and efficiency. For simplicity used the 2-speed pentair in calcs. Figure it would be close.

Just an FYI, you can get a two speed motor with a built in timer so there really is no need to run 24/7. With shorter run times, you will find more energy savings for both types of pumps but it also takes the VS pumps more time to be more cost effective than the two speed.

Really do not need timer during "in-season" as I will dial the VS to produce flow needed for SWG and run 24/7, which is what I want. [/QUOTE]

Also, did you include the cost of surge protection for the VS when calculating the lifetime costs?

No I didn't as I am adding this regardless of pump purchased, so ROI would be identical for that portion.

However, if you decide on a VS, the Hayward MaxFlo VS is a more efficient pump over both the SuperFlo and SuperPump.

Thanks. I see that in the charts. Would need to do some plumbing, but the savings would make up for that. They haywards must run at a higher RPM to get same GPM, but do so with less power than the Pentair does with the lower RPM.

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Correction - I meant I used the same performance as the SF-N2-1A when replacing the existing motor with the AO Smith 2-speed

 

[mas985]

Actually the pump has a bigger effect on energy use than does the motor. Nearly all two speed motors of the same HP rating have similar efficiency so the motor really doesn't matter than much.

No I didn't as I am adding this regardless of pump purchased, so ROI would be identical for that portion.

Two speed does not require surge protection (no electronics).

 

[GaryT58]

Two speed does not require surge protection (no electronics).

Thanks, but doesn't matter, as I am adding to protect the power to not only the pump, but my new SWG, so again, was getting it anyway. Both are on the same circuit in my remote panel.

 

[CJadamec]

Since you are dead set on a VS pump, you have your reasons and that's good enough. I have a VS pump and I probably really don't need one either. I'm very happy with the superflo VS pump I have. Since you already have a superflo single speed stick with the Pentair pump so you don't have to change any of your plumbing. It should be as simple as take the old pump out and slip the new pump right in its place.

 

[GaryT58]

Thanks for the input. Was thinking that way too. Would like to replace pump and install my new SWG at same time, so the less additional stuff like plumbing the better.

 

[GaryT58]

Since you are dead set on a VS pump, you have your reasons and that's good enough. I have a VS pump and I probably really don't need one either. I'm very happy with the superflo VS pump I have. Since you already have a superflo single speed stick with the Pentair pump so you don't have to change any of your plumbing. It should be as simple as take the old pump out and slip the new pump right in its place.

Replaced SuperFlo with the SuperFlo VS and it was simple. Total less than an hour. No plumbing changes. Thanks for the input.