Will a VS pump work ?

[waterl0gged]

Hi all, just looking for some expert opinions on a new pump option ......
Our current pump motor seems to be showing signs of failing soon . Starting to run louder, Starting to run hot . Too hot to keep my hand on it for long if its running for more than a hour or two. Seems like a new pump may be in the cards soon . Pump in question is an 1.5hp old school single speed energy hog .
I can go with just a new motor, the cheapest option . Or maybe upgrade to a VS pump .

Here is my dilemma .....
I would really like to go with a quieter VS pump . Looking at the Pentair Superflow VS . https://www.pentair.com/content/pentair/en/applications/enjoying-water/pool-spa-equipment/pool-pumps/superflo_vs_variablespeedpump.html 1.5hp , 110v or 220v (I have 220v) variable speed with programming right on the unit. Approx $700.
Want a quieter pump that will save some $$$ on electric. My problem is I am not sure if it will work for our pool application .
Pool in question is a 18x36 , approx 25,000 gals . Very simple set-up . No water features, no floor drain . Just a single skimmer to pump , that splits into 3 returns back to the pool after the pump, filter and ........... heat pump heater . NO SWG , running a nice Stenner system for chlorine delivery , so not stuck on long run times for that , but I need to run the pump for the heat pump heater a few hours a day .

My question before I shell out the bucks for a VS pump , is if the heat pump heater can handle the slower flow without shutting down ?
Heat pump in question requires 25GPM for a low , and 80GPM for a high . works perfect now with a single speed 1.5 . Putting out tons of flow out of 3 returns to the pool .
Is 25 GPM still achievable with a VS pump at the lower RPM speeds ? I would be happy, if even half speed would be workable.

Anyone have any advise on this ? I am thinking 25GPM is really low and I should have no problems, just want to be a little surer about it before I make the leap .
The flow chart is in this link .......... https://www.pentair.com/content/dam/extranet/product-related/product-brochures/pool-and-spa-equipment/SuperFlo_VS_Variable_Speed_Pump_Brouchure_English.pdf

Thanks for any guidance !

 

[mknauss]

You would program a higher RPM time for your heat pump to operate. You would do that with the internal timer/scheduler within the VS pump.

You would have to test various RPM's to see what is needed to satisfy the heat pump.

 

[sktn77a]

Heaters have a flow sensor which cuts off heat when the flow is too low. As above, just experiement with flow rates to see when you heater kicks off and use a flow rate above that value. You can program the higher flow rate for a few hours before your expected swim times and have the lower flow rates for the rest of the day.

 

[CJadamec]

Heaters have a flow sensor which cuts off heat when the flow is too low. As above, just experiement with flow rates to see when you heater kicks off and use a flow rate above that value. You can program the higher flow rate for a few hours before your expected swim times and have the lower flow rates for the rest of the day.

Actually most heaters have pressure sensors not flow sensors to recognize if water is flowing or not. I figured this out one day when I took the eyeball out of my return fitting and the filter pressure dropped to about 2psi even with my pump running at 2000rpm which is quite a bit of water flow and the heatpump still said low flow. The heater wouldn't turn on until I got my pressure up to 4psi. I put the eyeball back in and run the pump at 1300 rpm and the heater works just fine.

As for weather the Superflo VS will work for this pool I would say it would. As was mentioned you will need to run the pump at a higher RPM to get your heat pump to work on high but I'm going to guess that will be in the 2000-2500 rpm range which still uses less than half the electricity that your single speed pump uses.

If you aren't running the heater or are using the heater on the low setting you will be running the pump down around 1300-1500rpm which uses very little power. Probably about 1/10th the power of your current single speed pump.

The superflo pump is very quiet when running at rpms below 3000. Its starts to sound more like a quiet single speed pump above 3000 rpm.

At full speed the superflo pump should be close to the same if not more water flow than the pump you currently have.

 

[waterl0gged]

Thanks for all the info ! Most helpful in my decision.
I am hopeful the heater pressure switch will still let the heater run at about half speed of a Pentair Superflow VS . Half speed is 2200 rpm . I have some doubt that the heater will still run at low speed which is 1400 rpm. I am hopeful it might, but not counting on it.

I am confused if this model is really a variable speed , or just has 3 speeds plus the high quick clean speed of 3450 . Its listed as having a quick clean high speed of 3450, then 3000, 2200 and 1400 as a low. Is it more adjustable than that or is it just truly 4 speeds , and not Variable ? Anyone know ?
Would just like to have an option to dial it in somewhere between 1400 and 2200 if my heat pump pressure cut off switch is somewhere in the middle of one of the listed speeds.

Thanks again .

 

[mknauss]

Those are the speeds that are pre-set at the factory. You can change them to anything you want between 0 and 3450. We do recommend not going below 1000 rpm on VS pumps as they lose efficiency.

 

[waterl0gged]

Those are the speeds that are pre-set at the factory. You can change them to anything you want between 0 and 3450. We do recommend not going below 1000 rpm on VS pumps as they lose efficiency.

Thanks you for the quick reply . So it looks like there are 3 different speeds "buttons" for setting up the programing, BUT each one of those speeds is user adjustable . Excellent , that will work just fine.

Thanks again !