Variable speed pump

[skydude]

I am thinking about replacing our single speed pump with a variable speed one. I run the pump from 6am to 2pm, 7 days a week.

The price plan I am on is this one: EZ-3 Price Plans for SRP residential electric customers


My price per kilowatt hour is between 7.58 cents and 8.64 cents for the hours I run the pump.

Does this investment make sense? My current single stage pump is in good condition and the noise does not bother us.

 

[pooldv]

Not really. I run my VS pump at 1100 rpm to skim, filter and make chlorine with the SWG. It uses 150 wqtts. At 10.25c/kWh I can run my pump 24x7 for less than 12 bucks per month. It is nearly silent, even at the pad.

The Pentair 342001 1-1/2hp Superflo VS pump would be your best option if you want to.

A 2 speed pump will use less than 1/4 the electricity to move 1/2 the water on low as it does on high. And it will be much quieter.

 

[GaryT58]

I replaced my 1hp Pentair SuperFlo with the 1.5HP Pentair SuperFlow VS.

Here is link to thread (see 2nd post) that shows a great table that compares cost of ownership for various pumps. You can download the excel spreadsheet from the 3rd posting, with link next to "Pool Pump Tools*". You can edit this worksheet (must enable macros) to change the various things to your case, like electric power cost, run times, product cost, run speeds, ....

There are other spreadsheets included which can provide some great info.

I used the "Energy Cost" sheer to verify in my case that the 5-year cost of ownership of the Pentair SuperFlo VS was much better than a 2-speed pump for how I plan to run (low speed 24/7). Also, with the "Energy Cost" worksheet, you can select the pumps you want to compare by entering the "Pump Model" value for the column and it will fill in the data for the pump from the "PumpData" sheet (where you can get the Pump Model values. I edited sheet with my local power $, run times, rates, current pump costs, and compared the couple models I was looking at (couple VS, one 2-speed) and compared to my original pump. Very helpful in selecting my new pump.

As for power, the 2 speed SuperFlo (SF-N2-1A) uses 1276 W at 3450RPM, and 312W at 1725RPM, so you can see the major power savings. With the VS (342001), if you would use 130W at 1100 RPM, or 95W at 850RPM. So for me, these savings made sense for me to go with the VS.

 

[GaryT58]

I used the worksheet I linked to in previous mail. I plugged in the electric cost of $0.0811, which is the average cost of the two # you listed. I entered an 8 hour run time.

You did not list your existing pump model, so can not give you estimates based upon you exact model. For simplicity I limited comparison to just 3 pumps - the single speed 1HP Pentair SuperFlo, the 2-speed 1HP Pentair SuperFlo and the 1.5HP Pentair SuperFlo VS. I entered a $0 cost for the single speed since it represents the pump you already own.

You can download the work sheet and select the specific models you want to get a comparison, but this shows that a VS can make sense depending upon how you run it.



So assuming you would run the 2 speed at the lower speed (1725 RPM) and the VS at 1300 RPM, you would see a cost savings of about $25/month with the VS and $22/month with the 2 speed. This shows a break-even (when pump savings have equaled the cost of new pump) of just over 24 months. And the VS becomes the better choice after 66 months.

Saving can increase if you run the pump at lower speeds or longer periods of time.

There are some other advantages to a VS. For example, the Pentair SuperFlo VS you can program up to 3 time/speeds a day. So could come on initially at higher rpm to make sure skimmer pulls off surface debris, then go to lower speed for period to keep water flow (and meet SWG flow if you have one), then at maybe other speed for running vac. Can override these as well at any time. Also, has a "quick clean" button which will run a programmed speed to perform clean cycle, after which it returns to the programmed speed. I've used if I come out and we're going to swim soon and there are a lot of pine needles floating around - goes up to higher speed and sucks them out more quickly than when running at my lower rate. Some (not this one) have a freeze-protect mode, which will run pump when temperature gets near freezing - good for those that leave pool open all year.

Can't really lose with the upgrade to either. Just will say, that if you plan to ever go to a SWG, the VS may be a better choice, as there have been those that could not run their 2 speed at the lower speed when running the SWG because the flow rate was not sufficient. Would not have been an issue for me, but chose VS as I want to run longer (24/7 during peak season - use water jets at night to cool pool for example).

 

[pooldv]

 

[mas985]

$650 for the SuperFlo VS? Did that include the surge protection too or is that because of a rebate? The up front cost plays a big part in that analysis. Also, if you just replace the motor with a two speed, that can drastically change the results because of the lower cost.

 

[GaryT58]

$650 for the SuperFlo VS? Did that include the surge protection too or is that because of a rebate? The up front cost plays a big part in that analysis. Also, if you just replace the motor with a two speed, that can drastically change the results because of the lower cost.

That is lowest price found online for that model. No it does not include any extras (wiring, surge, plumbing, ....). Comparing costs of pumps. I added a surge protection that covers my subpanel, and would recommend all would, regardless of pump type, even if staying with single speed.

 

[CJadamec]

The super Flo vs will run-on your existing wire it accepts 110 or 220 voltage. If you add a surge protector and additional breaker for it add about 100 to upfront cost for the VS pump. Surge protector pays for itself 6 times over if it saves your pump once. That's good odds in my book. For the cost everyone should have a whole house surge protector.... But I digress. The 2 speed pump or motor replacement is your most economical upgrade. The VS pump gives you the added cool factor and is fun to tinker with. And if the VS pumps lasts 10 years or so, and I hope mine does, you will defiantly have saved you money at that point.