Variable Speed Pumps

jordangregory

Well-known member
Jul 12, 2010
145
Anyone out there with a variable speed pump?
I was thinking of getting one but was not sure of the advantages/disadvantages
 

Davegvg

LifeTime Supporter
Nov 30, 2008
337
jordangregory said:
Anyone out there with a variable speed pump?
I was thinking of getting one but was not sure of the advantages/disadvantages
I have one.

To my mind the only real disadvantages are the price compared to a 2 speed unit, and perhaps the need for a real controller/complexity of programming the unit.

The advantage over a 2 speed is the ability to define exactly what is "high" "low" and, or anything in between.

At times "low" on a 2 speed pump may be just shy of what you actually need, or a bit too much for optimum efficiency and savings.

Depending on your pools complexity a 2 speed may pay back faster than a variable.


Uncle Dave
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
I replaced a 1 HP Jandy HHP (1.65 SF) and a 3/4 HP booster pump with a Pentair IntelliFlo VF and absolutely love it. It has saved me 50% on pump electricity costs and that's with a solar system. If I didn't have solar, I would have saved close to 80%. It's not a cheap pump, but my marginal electricity rates are around 40 cents per kilowatt-hour so the payback time wasn't too long.

As was noted by Uncle Dave, a 2-speed usually gets you a good part of the savings at lower cost, but doesn't save as much nor let you tune in to specific speeds if that's what you want to do. The variable speed pump is not as efficient at high speed / high head but is more efficient that a 2-speed pump at its lowest speed (even with the variable speed set for that same low speed).
 

Laker4ever

Well-known member
Jul 17, 2009
61
I have a similar issue of selection....
If my difference between a 2 speed whisperflow and ePump (1.5HP) is $300. What would you choose?
I also have solar, so seems like the high head will cut in the possible savings...
I tend toward the variable ePump ust because it gives you the options to fine tune. With the 2 speed you need to hit the numbers exactly to make it work otherwise, either too much flow/pressure or too little.
 

jordangregory

Well-known member
Jul 12, 2010
145
Is there going to be any problem with getting a variable speed pump and keeping my current sand filter. I know my sand filter is rated for 60 gallons per minute. If I run a variable speed pump at a low rate that allows all the water in my pool to turn over 3 times per day, and this is less than 60 gallons per minute, will my filter work correctly?
Also, just to check, what is the proper amount of water to push through the filter each day? Do I want to put my entire pool volume through 2 or 3 or 4 times per day?
 

Davegvg

LifeTime Supporter
Nov 30, 2008
337
jordangregory said:
Is there going to be any problem with getting a variable speed pump and keeping my current sand filter. I know my sand filter is rated for 60 gallons per minute. If I run a variable speed pump at a low rate that allows all the water in my pool to turn over 3 times per day, and this is less than 60 gallons per minute, will my filter work correctly?
Also, just to check, what is the proper amount of water to push through the filter each day? Do I want to put my entire pool volume through 2 or 3 or 4 times per day?


Yes it will work fine- the current theory of filtration is that to be efficient - you move the water slower- less overall pressure. Low slow and long is best. You'll find even though its slower the extra run time does wonders to keep the pool clean and be amazed at what sits on a gets through the top layer while that pump is off.

2-3 times a day a lot - more than most run. 1 full turnover is fine for me.
You compensate by running a longer cycle.

The are ways to start calculatiing GPM, but the short aswer is you run it as long as it takes.
If I have a heavy bather load I just RPM up the pump for half a day.

Just filtering (no solar) I can keep a 20K gallon 80 degree pool clear and clean using 200 watts of power running the pump 13 hours a day.
2.6 KW hours a day of power use at 15cents per. 39 cents day. Thats pretty cheap in my opinion.










Uncle Dave
 

lbridges

LifeTime Supporter
Nov 12, 2009
323
Indialantic, FL
I have a variable speed pump and some automation. The setup provides me the three speeds I wanted - "low" (900 rpm) for normal flow, "high" (1750 rpm) for extra skimming action, and "solar" (1450 rpm) for the flow I need for the panels. If I ever get around to water features (for which I pre-plumbed) I might add in a 4th speed to the mix.
 

Coinman

Member
May 22, 2010
14
Hi all, I installed a Hayward echo star pump about two weeks ago, it mates with a pro logic 8 controller with Hayward swg and the sense and dispense system for ph and chlorine control. The Hayward guy said to program the speed just fast enough to keep the swg flow switch open which is at 35% 135watts. But when I run that low the swg does not read right also the sense and dispense does not monitor correctly. I turned off the swg 5 days ago because the chlorine test looked almost red, I tested again today and it's still almost red. I run the pump 11 hrs. At 35% and at 80% for 1 hr for skimming and 1 hr for the the suction cleaner. I'm wondering if the swg and the sense and dispense will work with a variable speed pump running that slow. Thanks for your help.
 

bk406

Well-known member
Dec 3, 2009
2,690
Central Massachusetts
A lot of the savings numbers you see are based on higher electric rates than the norm (i.e. california). It really depends on what you electric rates are. I'll say upfront i have a 3/4 HP single speeed that's pretty economical. I probably will get a 2 speed when this one goes, but a variable speed is pump is pretty expensive. And unless your electric rates are pretty high, then I really dont think a VS pump is all that good of a buy. It would take a long time to pay off if you pay 10-20 cents a kW hr for power. And in all practicality, 2 speeds is really all you would ever want anyway, IMO.
 

Laker4ever

Well-known member
Jul 17, 2009
61
I bought a variable speed (Jandy ePump 1.5HP), and i love the way you can tweak the exact speed/flow that you need. I could probably do what i need with 2 speed, but it would be much harder to "hit" the exact HP that I really need. I have Solar, and suction cleaner.
In california some utility companies rebate up to $500...So getting a VS pump can pay off much quicker even with rates $0.10 -0.20 per KWH
 

Coinman

Member
May 22, 2010
14
Thank you for the help, but I was mainly concerned if my existing equipment, like the sense and dispense and the swg would work ok at the lower rpm. Right now it does not seem to be working correctly. Thanks
 

Ranger987

In The Industry
Nov 3, 2010
152
Coinman, make sure you have good water flow thru the clear flow cell that the sensing probes are in, then clean the probes. It should still work at a lower rpm/gpm, assuming you're still getting good flow thru the sensing cell. Verify that your pH is being maintained at the proper level and then if your CL is still high, lower your set ORP value.
 

Other Threads of Interest