For a cartridge filter, you don't need to backwash.
For sand, you don't need more than 105 gpm, which it could easily do.
For DE, you don't need more than 60 gpm.
Variable Speed Pumps Maximum Speed.
- Thread starter JamesW
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For sand, you don't need more than 105 gpm, which it could easily do.
For DE, you don't need more than 60 gpm.
- May 3, 2007
- 18,067
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- 20000
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Then you are basically talking about an Intelliflo with the original motor/drive. The smaller drive is not going to support 105 GPM even with a slight reduction in head loss due to backwash mode.
Below is the SuperFlo VST pump curve, which can do 105 at full speed.
If you took the SuperFlo motor and put it on an IntelliFlo VS or IntelliFlo XF, it would easily be able to do 105 GPM without overloading the motor.
In any case, if you need more flow, you can go to a bigger pump.
My main points are:
1) Upsize the impeller on the bigger VS pumps so that you can run at lower RPM for the same flow, which is much quieter.
Even getting down to 2,750 RPM significantly reduces the noise.
In other words, redesign the pumps around a maximum RPM of maybe 2,450 to 2,750 RPM instead of 3,450 RPM.
2) If you don't need high flow, use a smaller motor on the IntelliFlo or IntelliFloXF and just program the motor to limit the amps such that the motor is not overloaded.
3) The original IntelliFlo and IntelliFlo XF will still be available for the people who want that pump performance curve.
In my opinion, only poorly designed systems with excessive head loss will benefit from a 3,450 RPM design.
For a well designed, low head loss system, a pump designed around a max RPM of about 2,450 RPM to 2,750 RPM would be a better fit; it would be more efficient and it would be quieter.
www.pentair.com
If you took the SuperFlo motor and put it on an IntelliFlo VS or IntelliFlo XF, it would easily be able to do 105 GPM without overloading the motor.
In any case, if you need more flow, you can go to a bigger pump.
My main points are:
1) Upsize the impeller on the bigger VS pumps so that you can run at lower RPM for the same flow, which is much quieter.
Even getting down to 2,750 RPM significantly reduces the noise.
In other words, redesign the pumps around a maximum RPM of maybe 2,450 to 2,750 RPM instead of 3,450 RPM.
2) If you don't need high flow, use a smaller motor on the IntelliFlo or IntelliFloXF and just program the motor to limit the amps such that the motor is not overloaded.
3) The original IntelliFlo and IntelliFlo XF will still be available for the people who want that pump performance curve.
In my opinion, only poorly designed systems with excessive head loss will benefit from a 3,450 RPM design.
For a well designed, low head loss system, a pump designed around a max RPM of about 2,450 RPM to 2,750 RPM would be a better fit; it would be more efficient and it would be quieter.
SuperFlo® VST Pool Pump
Pentair SuperFlo VST Variable Speed Pool Pump for inground pools is for pools requiring up to a 1.5 HP pump. This pump is a TradeGrade product.
- Jul 21, 2013
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And thus is the market problem.
How many existing pools are poorly designed with excessive head loss and need the brute force?
And will Pool Builders stop building such poorly designed pools? I doubt it so equipment is sold to work with poorly designed pools. Otherwise the pump vendor will get the complaints that their pump is inadequate.
- May 3, 2007
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That is at very low head loss. In a typical pool, only about 10-15% of the total head is in the plumbing after the filter so the plumbing curve does not shift very much in backwash mode.
Pools don't need more than 40 gpm, so even if poorly designed, it does not make much difference.
You only need more than 40 gpm for things like water features like infinity edges, large sheers or multiple sheers, spa jets etc.
These are low head applications if the plumbing is designed correctly.
New hydraulic efficiency regulations require suction be kept below 6 feet per second and returns be kept below 8 feet per second and many building permits and inspections enforce these rules.
If a builder is incompetent, then their system is going to perform poorly in any case.
Also, the original 3,450 RPM pumps will be available to brute force water through inefficient systems if necessary.
You only need more than 40 gpm for things like water features like infinity edges, large sheers or multiple sheers, spa jets etc.
These are low head applications if the plumbing is designed correctly.
New hydraulic efficiency regulations require suction be kept below 6 feet per second and returns be kept below 8 feet per second and many building permits and inspections enforce these rules.
If a builder is incompetent, then their system is going to perform poorly in any case.
Also, the original 3,450 RPM pumps will be available to brute force water through inefficient systems if necessary.
- May 3, 2007
- 18,067
- Pool Size
- 20000
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- Hayward Aqua Rite (T-15)
Most of the time this is true but as I said before, it is nice to have the higher flow rates when needed and I need it many times a year. I would never consider purchasing a handicapped pump just to reduce noise a tiny bit when my pump already very quite. It just doesn't make a lot of sense to me.
105 gpm is based on backwashing the TR-140, which is the biggest residential sand filter available.
Most sand filters are smaller then the TR-140 at 7 square feet.
The SuperFlo VS motor should easily be able to do well over 105 gpm if paired with the IntelliFlo front end on backwash.
In any case, a larger pump can be chosen if it is a better fit for the system.
My point is that there are probably tens of thousands of pools where a pump designed around about 2,450 RPM to about 2,750 RPM would be a better choice.
Most sand filters are smaller then the TR-140 at 7 square feet.
The SuperFlo VS motor should easily be able to do well over 105 gpm if paired with the IntelliFlo front end on backwash.
In any case, a larger pump can be chosen if it is a better fit for the system.
My point is that there are probably tens of thousands of pools where a pump designed around about 2,450 RPM to about 2,750 RPM would be a better choice.
Ultimately, the only way to really prove if it is a good idea or not would be to make some to see if anyone wants them and if the people who buy them feel like they are a good choice.
If you see one of those companies suddenly announce such a pump design, you know where they got the idea.
If I was running Pentair, Hayward or Jandy, I would choose to make some.
If you see one of those companies suddenly announce such a pump design, you know where they got the idea.
If I was running Pentair, Hayward or Jandy, I would choose to make some.
The pump will be able to do as much flow or more than your current pump if your system is well designed.
So, you are not losing any flow, you are getting more flow.
The only way you would get less flow is if your system is poorly designed and if it has extremely high head loss.
What speed and flow are you talking about?
What is the filter PSI on high speed.
You're talking about two different pump performance curves.
One pump will produce more flow on a high head loss system curve and one pump will produce more flow on a low head loss system curve.
If Pentair came out with two variable speed pumps designed around a top speed of 2,450 RPM and using the same variable speed motors as the SuperFlo VST (2.2 THP) and the IntelliFlo VSF (3.95 THP) using a larger impeller such that the motors would be identically loaded at 2,450 RPM with the bigger impeller as they would be at 3,450 RPM with the smaller impeller, I think that at least half of all systems would do better with the lower RPM pumps in energy use and noise levels.
Also, for low head applications like an infinity edge, the lower RPM design would be able to produce more flow as long as the system was designed and installed correctly.
In my opinion most pools would be better off using a pump designed around a 2,450 RPM pump design.
Also, for low head applications like an infinity edge, the lower RPM design would be able to produce more flow as long as the system was designed and installed correctly.
In my opinion most pools would be better off using a pump designed around a 2,450 RPM pump design.
- May 3, 2007
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- Pool Size
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- Hayward Aqua Rite (T-15)
I was referring to the 40 GPM cap you mentioned and that for me is way too low and I think it would be too low for most people. My pump peaks at about 70 GPM and my plumbing has a plumbing curve that is slightly better than Curve-C (0.0078). However, there are times where I wish I had more than 70 GPM. The Intelliflo at 2450 RPM would have a flow rate of 70 GPM on Curve-C which is still not unreasonable so similar performance as what I get at full speed. And yes, I am sure it is quieter but I run at full speed only occasionally so not big deal for me.
But if a SuperFlo motor is used on an Intelliflo wet end, then yes the cap would be much higher than 40 GPM. How much depends on how high you can cap the RPM without exceeding the power limits. Given the Intelliflo power usage peaks near the right side of head curve, it would need to be at that same location. The other factor to consider is that the SuperFlo motor/drive is more than likely less efficient because of the lower motor rating. Lower THP motors generally use thinner winding wires which is what make them cheaper to build and also less efficient. If you set the maximum RPM near the right side of the head curve, that means everything to the left will have less flow rate than the standard SuperFlo.
So I am still trying understand what the benefit would be. A standard Intelliflo operating at the same flow rate/RPM will have better efficiency and a lower noise level than the hybrid Intelliflo/SuperFlo due to the cheaper motor in the SuperFlo.
Also, a point that I don't think has not been brought up, the more you run a motor closer to full load, the lower the life span of the motor. So the Intelliflo would be operating at a much lower relative load that the SuperFlo hybrid would be over the life of the motor.
But if a SuperFlo motor is used on an Intelliflo wet end, then yes the cap would be much higher than 40 GPM. How much depends on how high you can cap the RPM without exceeding the power limits. Given the Intelliflo power usage peaks near the right side of head curve, it would need to be at that same location. The other factor to consider is that the SuperFlo motor/drive is more than likely less efficient because of the lower motor rating. Lower THP motors generally use thinner winding wires which is what make them cheaper to build and also less efficient. If you set the maximum RPM near the right side of the head curve, that means everything to the left will have less flow rate than the standard SuperFlo.
So I am still trying understand what the benefit would be. A standard Intelliflo operating at the same flow rate/RPM will have better efficiency and a lower noise level than the hybrid Intelliflo/SuperFlo due to the cheaper motor in the SuperFlo.
Also, a point that I don't think has not been brought up, the more you run a motor closer to full load, the lower the life span of the motor. So the Intelliflo would be operating at a much lower relative load that the SuperFlo hybrid would be over the life of the motor.
- May 3, 2007
- 18,067
- Pool Size
- 20000
- Surface
- Plaster
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- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
If you truly believe in the viability of this solution, take a SuperFlo motor/drive and put it on an Intelliflo wet end and compare the energy use and noise levels to that of the original Intelliflo. It would be fairly straight forward to test the premise albeit a little expensive.
That's not the point.
The point is, would you rather have the SuperFlo VST as it comes with a top speed of 3,450 RPM or the SuperFlo VST motor on a pump designed to have a top speed of 2,450 RPM or maybe 2,750 RPM with a larger impeller?
My main point is design the pump around a lower top speed and a larger impeller so that you get a quieter pump, better efficiency and better flow for low head applications.
In my opinion, 1,725 RPM is too low and 3,450 RPM is too high.
I don't know the ideal top speed, but I think that it is below 3,000 RPM.
Maybe 2,750 RPM would be a good choice with a larger impeller.
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I wasn't saying that the pump could not do more than 40 gpm, I was saying that there are many people who never run the pump over 40 gpm.
Many people have the IntelliFlo and run it 24/7 at maybe 200 to 300 watts and they almost never go more than that.
If you never run the pump at more than 320 watts and the motor is rated at 3,200 watts, then it is 10 times to big.
If you use the SuperFlo vs motor, it has 2.2 hp so still plenty of power if someone want to ramp it up for whatever reason.
It's like if you buy a car and get an 800 hp engine and then just drive it at normal speed limits.
Is it really worth the extra cost to have the big engine if you will never use it?
- Jul 21, 2013
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Detroit Marketing 101 - race it on Sunday, sell it on Monday.
Almost every car has more HP than necessary to go at the national speed limit.
American consumers like power in their cars and pools and will pay for it.
- May 3, 2007
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HP in automobiles isn't as much for top speed as it is for acceleration. That is much more important for times such as getting on the freeway.
But even for pumps, in some cases it is worth the larger HP if it lasts longer plus gives you more head room for faster cleanups.
I don't know if you own a pool since your sig doesn't contain one but having the ability to run at higher flow rates is definitely a plus for some pool owners.
Also we really don't know what the price point would be. Part of the Intelliflo premium might be in the wet end in addition to the motor. So it isn't clear there is a cost benefit given all of the factors.
But even for pumps, in some cases it is worth the larger HP if it lasts longer plus gives you more head room for faster cleanups.
I don't know if you own a pool since your sig doesn't contain one but having the ability to run at higher flow rates is definitely a plus for some pool owners.
Also we really don't know what the price point would be. Part of the Intelliflo premium might be in the wet end in addition to the motor. So it isn't clear there is a cost benefit given all of the factors.
- Jul 21, 2013
- 65,062
- Pool Size
- 35000
- Surface
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- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
That is because we have poorly designed entrance ramps with inadequate acceleration lanes. If road engineers needed to design entrance ramps for slow acceleration they could.
It’s the same argument as pools having poorly designed systems with excessive head loss.
The cars and the pumps are built to match the roads and pools that are built.
- May 3, 2007
- 18,067
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
If you change the top speed to 2,750 RPM and increased the impeller accordingly, then that would still give you more than enough power to achieve any flow rate you want.
You're not compromising at all unless you need 115 gpm at 80 feet of head.
In that case, get the 3,450 RPM model.
With the 2,750 RPM model, you can still get well over 100 gpm.
In fact, the 2,750 RPM model with a larger impeller will outperform the 3,450 RPM model for systems with lower system curves.
As long as the required flow rate does create more head loss than the maximum head loss capability of the larger impeller, then the larger impeller will outperform the smaller impeller or it can be run at a slower speed.
So, the main question is what is the maximum head loss that you will get at top speed.
