Intelliflo VF Power Consumption

[sbe]

I've been working for some time on a pool that was designed from the beginning with low power consumption in mind. The pool is about 30,000 gallons and has 4 floor returns, a main drain, suction from the skimmers and return to the skimmers (for venturi). The Intellflo pump handles all the pumping needs eliminating the need for a boost pump for a pressure cleaner.

Today I powered it up and I thought there might be some interest in how much energy it is using running the basic functions.

gpm watts pressure

15 133 2.0
20 145 2.0
25 165 2.5
30 191 3.0
35 240 3.5
40 295 5.0
45 370 6.0
50 500 7.0

First off I wouldn't put too much faith in the back pressure numbers. The reading are such a small percentage of full scale that they could easily be off substantially particularly at the low end. Second the power numbers are from the unit itself not from a calibrated watt-meter. Still the data gives a good idea of how the system is performing which appears to be quite efficiently. Assuming 1 turn/day and $0.10/kwh this setup would consume less than $10/mo in electricity.

What these number don't include would be the cost of running any water fixtures, pressure cleaners or the venturi skimmers. I'll be testing the last of those next, then the pressure cleaner and will post the results as soon as I have them.

 

[chem geek]

Wow, that's great. What kind of piping is being used in this situation? Is it 2.5" or 3" for the pressure side and 2" or 2.5" for suction?

In my pool with 1.5" suction lines split to two lines (one for two floor drains and the other to one skimmer) and one 2" pressure line that splits to 3 1.5" returns, I get the following with solar off:

15 GPM, 1185 RPM, 155 W, 3 PSI
18 GPM, 1325 RPM, 195 W, 4 PSI
24 GPM, 1460 RPM, 255 W, 4 PSI
30 GPM, 1805 RPM, 420 W, 6.5 PSI
36 GPM, 1975 RPM, 535 W, 8 PSI
42 GPM, 2160 RPM, 685 W, 9.5 PSI
48 GPM, 2310 RPM, 835 W, 10.5 PSI
54 GPM, 2490 RPM, 1030 W, 12 PSI

 

[sbe]

I plumbed it so long ago I've forgotten, but its large enough that the back pressure is insignificant at these flow rates. I'd suspect that the difference between our systems is the MPV and jetting.

Multiport Valves often are the largest single contributor to an otherwise low head system so I choose a filter with a side mounted valve which is upsized from top mounted designs. Also my returns are floor mounted which have significantly more face area than your typical eyeball.

That's the good news. The bad news is that the venturi skimmers work by creating a strong jet of return water to the pool that draws in water to the skimmer and creating that strong jet requires the pump to do more work, even though the flow rate per skimmer is only around 6-8 gpm. As of this morning I partially closed the valve regulating flow to the floor returns until the flow to the skimmer returns looked about right (the best I can do until I hook up something to measure it) and the power consumption at 25 gpm hopped up to about 290 w. Not unexpected.

Hopefully I be learning a lot more about how to set up the system as I play around but this initial information has made me aware of something I hadn't focused on before...that skimming consumes significant power. Given that its yet another reason for an automatic pool cover and to keep it closed when the pool isn't in use. One not only keeps dirt out and heat in but there is no reason to run the skimmers when the pool is covered.

It looks like I'll have to consider adding a "pool open/closed" sensor so that I can automatically have the skimmers go on and off depending on if the pool is open or not.

 

[geekgranny]

With clean filter mine are closer to sbe's than chem geek's. When I open and clean the filter (my quad DE, using Fiber Clear, and my loads of sticky clay powder aren't successfully clearing off the Quad cartridges with backwashing. ) I'll get numbers and stats on plumbing. When filter is not clean, as it is now, the wattage and rpm go way up. When filter clean, turning on booster, numbers don't change significantly.

gg=alice

 

[mas985]

sbe,

Do you have the RPM numbers to go along with the others?

 

[sbe]

I'll rerun the test tonight and post them.

 

[tsunami]

my returns are floor mounted which have significantly more face area than your typical eyeball.

Do they have regular drain covers over them?

 

[sbe]

No they are designed especially as in floor returns. Round, about 6" in diameter with a solid center and a wide slot so there is a ring shaped area where the water exits. Fairly standard part. With 4 of these in place the face area is probably as large as the cross section of my piping so there almost no additional head loss.

Normally the pool runs around 18 gpm total so each skimmer runs at 9 gpm and flows 50+ gpm through each basket. When the heat kicks in the pump gets upped to either 25 or 40 gpm and a valve partially opens so that the additional flow goes to the floor. This keeps the head loss to an absolute minimum plus I like the idea of directing heated water to the bottom of the pool.