Which VS pump? (SuperFlo vs IntelliFlo) Move 3-Way valve to intake line on solar?

[mbeames]

May I get your advice on two questions? Thanks!
1. If I have a 1.5HP pump now, can I get away with the 1.5HP SuperFlo VS or do I need to increase my HP, for example to the 3HP Pentair IntelliFlo? I have solar panels on a 2-story which work fine now, but I want to drop my electricity bill and still keep the panels working. Additional pool details are below.
2. Is it better to move my solar panel 3-way valve control from the return line (from panels to pool) to the intake line (from filter going to panels)? Not sure of the rationale nor if it was installed incorrectly on the return line. I may want to have it changed when I change the pump if it is necessary.

If my head calculations and methodology below are OK, with both the SuperFlo and IntelliFlo, I will be able to turn on both pumps at max speed and operate my solar panels, etc. I just don’t know how low in RPMs I can go. It appears to me that with both pumps, at a head of 70, I may not be able to lower the RPMs below ~3000 RPM. I am sure I don’t understand something here. Thanks for your advice! Electricity is expensive in SoCal!

Pentair head and GPM curves:
SuperFlo: https://www.pentairpool.com/~/media..._vs_variable_speed_pump_brouchure_english.pdf
IntelliFlo: https://www.pentairpool.com/~/media...es/intelliflo_variable_speed_pump_english.pdf

Additional Pool Details:
Pool Size: 18,500 gallons
Hayward Super II pump (1.5HP, 3450 rpm single speed)…it works now with my setup!
Filter: Pentair CCP320 (120gpm, 50 psi max)
Distance, pump from pool: suction side 66' from skimmer (closest) to roughly 100' from vents
Height, pump to solar panels: ~30' (2 stories)
Height, pump above pool: <1’ (same as deck level but across a lawn)
Cleaner: Polaris 360 (pressure side)
Power: 240V

Pump/Head testing and calculations (on drain ports of pump):
Vacuum, no solar panels (inHg): Max 15, Steady State 11
Vacuum, solar panels (inHg): Max 13, Steady State 8 (Not sure why this is less than with solar panels shut off)
Pressure, no solar panels (psi): 22.5
Pressure, solar panels (psi): 27
With a 1.13 for the vacuum and a 2.31 factor for the pressure readings, this indicates a steady state head of 64-71' and a maximum head of 69-77' for when the pump just comes on.

 

[jblizzle]

Welcome to TFP!!!

1. The Hayward Super II would be similar to the Pentair Whisperflo (Intelliflo). The Harward Super Pump would be similar to the Pentair Superflo.
Switching from a 1.5HP Super II to the 1.5HP Superflo VS would be a reduction in flow rate at full speed. It is possible that the SuperFlo would still run the solar panels just fine, although you may need to be running near 100%. How many sqft of panels do you have?

2. The typical solar setup goes as follows: Pool -> Pump -> Filter -> check valve -> solar 3-way valve -> check valve on the solar return -> Tee back into the main line -> Normal heater -> Chlorine source -> pool

 

[mbeames]

Thanks Jason. I have about 440 sq ft of panels. Thanks for your comments and advice.

-Mike

 

[jblizzle]

So you would want around 44 GPM of flow through your solar.
I think the 1.5HP Superflo could likely do that at full speed and should be able to pump up to the roof without issue. Where is your VRV for the solar?

mas985 might be able to help a bit with some of the calculations.

 

[mas985]

Which Super II do you have? The uprated Super II SP3010X152AZ or the full rated Super II SP3015EEAZ?

The SuperFlo VS is a bit more powerful than the up rated and little less powerful than the full rated. But I think it should work fine either way.

But one thing to keep in mind is that if you have a VRV on the roof, you will probably need to run at close to full speed when solar is running so you will not get much of a benefit from a VS although it does allow to you fine tune the flow rates and pressure for the lowest possible energy use.

But once I know which pump model you have I can give you some more definitive answers.

Vacuum, solar panels (inHg): Max 13, Steady State 8 (Not sure why this is less than with solar panels shut off)

Total head loss increases with solar so flow rates decrease which means suction head decreases.

 

[mbeames]

My VRV for my solar is on the top left corner of the panel array. The top pipe of the panels then goes to the far right, then the pipe goes up the roof a foot, and then snakes back to the left until passing all the panels again and then descends.

 

[mbeames]

Hi Mark,

My pump label is worn off. How do you figure out which type of pump you have? Thanks. I am a new owner of this home as of 5 years ago.

When I Googled those two pumps, I likely have the full rated Super II. My pump is a single speed (AO Smith ST1152 motor). It appears that the SP3010X152AZ is a Dual Speed and the SP3015EEAZ is a Single Speed.

Thanks to you and everyone for your feedback on pumps you recommend!

Side note: I am guessing my pump is a Super II because of strainer lid part lookup match. The strainer and general pump features seem to match. My pump is older but does not have the horizontal external ribs on the housing like in current models.

 

[mbeames]

Another question...It appears that a pump like the SuperFlo has a 1.5" inlet/outlet; how much of an impact will this make to my current 2" system? Not sure if this is significant enough that I should be looking at a pump with 2" ports. Thank you.

 

[jblizzle]

No real impact. But it is an indicator of the amount of flow the pump will produce.

 

[mas985]

Hi Mark,

My pump label is worn off. How do you figure out which type of pump you have? Thanks. I am a new owner of this home as of 5 years ago.

When I Googled those two pumps, I likely have the full rated Super II. My pump is a single speed (AO Smith ST1152 motor). It appears that the SP3010X152AZ is a Dual Speed and the SP3015EEAZ is a Single Speed.

Thanks to you and everyone for your feedback on pumps you recommend!

Side note: I am guessing my pump is a Super II because of strainer lid part lookup match. The strainer and general pump features seem to match. My pump is older but does not have the horizontal external ribs on the housing like in current models.

The SuperFlo VS at full speed would only have about 3 GPM less than the Super II so not even worth worrying about.

But since the panels are 30' high, you are going to need at least 16 PSI at the filter to keep the VRV closed. So the minimum you would be able to run the pump's RPM is around 2800 RPM. At that speed, the pump would produce about 53 GPM through the panels.

 

[mbeames]

Thanks for the insight. Do you think there is some margin with this 16 PSI hurdle figure at the filter? If I understand correctly, a 1.5 HP VS pump will probably work at a minimum RPM 2800 RPM, but given that I would think that pressure will likely drop with lower RPM, the worst case scenario is that I may need to increase RPM until I have 16 PSI.

Also, is it normal to have a drop in pressure of 6-7 psi at the filter? I expected less than 2 given the Pentair CCP chart. While I am changing the pump, it looks like I need to change my system plumbing configuration. Could I have an issue with my setup? (I want to get rid of a Fiberstar Catalyst water conditioner and move a check filter that are prior to the filter, for example.) I registered a filter PSI of 15.5 without Solar (drop of 7 from pump) and 21 with Solar (drop of 6). Cartridges are recently cleaned.

 

[mas985]

The 16 PSI is based upon the static + dynamic head loss from the filter to the VRV. It is an estimate so you may need more than that or even less. I just depends on the plumbing and how dirty the filter is. But you should never need to run at full speed (24 PSI). If you clean the filter at a 25% PSI rise, you should be fine but you may need to up RPM a little to get there.

Also, is it normal to have a drop in pressure of 6-7 psi at the filter?

If you wait to clean the filter too long, you can get very large PSI rises. Again, TFP recommends cleaning the filter at a 25% rise. If you are talking about a clean filter PSI loss, the base head loss of the filter is dependent on the flow rate through it so you can go by the loss curves in the manual. But that is only for a clean filter.

While I am changing the pump, it looks like I need to change my system plumbing configuration. Could I have an issue with my setup? (I want to get rid of a Fiberstar Catalyst water conditioner and move a check filter that are prior to the filter, for example.) I registered a filter PSI of 15.5 without Solar (drop of 7 from pump) and 21 with Solar (drop of 6). Cartridges are recently cleaned.

I am not sure what you are getting at here. By check filter, do you mean check valve? I would always put the check valve after the filter to prevent debris from keeping it open.

 

[Joshii]

I would absolutely get the Intelliflo not the Superflo. My reasoning:

* You won't be running it full strength even with your solar. This will prolong the life of your pump and it will also run very quiet since you will never be running it full speed.
* You can run the pumps with very low RPM (in the low hundreds, so you the Intelliflo won't cost you more to run than the SuperFlo

And, just a note, be careful with head calculations. They can make your brain hurt. And then, once you figure out all the "feet of head" calculations are based on a specified flow rate through your pipes and they are not valid at low speed operation, it is enough to make you throw up your hands. Which brings me to the final point:

* Between the 2 pumps, you are guaranteed "enough pump" with the IntelliFlo.