Intermittent Filter Cycles Save Energy?

[SebringDon]

I just watched this video, where they claim that running your pump for three one-hour cycles a day is as effective as running 8 hours. They say this is according to a study conducted by the Florida Atlantic University. Does anybody know the particulars?

It makes sense to me that intermittent cycles might allow reducing total filter time, since it takes some time for the water's movement to die down, but I'm not sure I buy the two-thirds reduction. Does anybody use a similar method? Is anybody experimenting?

[youtube:cb38w4vu]ujK5fcAdVY0[/youtube:cb38w4vu]

 

[UnderWaterVanya]

That is how mine is setup RIGHT NOW - but mine is set that way while I wait for the water temp to drop and my pool is covered at the moment. I just figured it would reduce concerns over stagnant water causing chlorine depletion in a particular area and as an added benefit reduce the chance that a freak drop in temps would freeze something.

I would like to see the data that backs up this claim. I do know that our resident pump expert has said before that the standard number of turns is not needed - and that many people can get by on four hours of pumping - 3 may not be a far stretch.

 

[Mike_W]

Interesting question. I tracked down the paper from Florida Atlantic University. Short version of what they are saying is:

1. Buy a smaller pump - as they use a lot less electricity to move the same amount of water (of course it takes longer). Substantial operating costs savings.

2. If you are running your pump to get one or more "turn overs" a day, that is likely too long and you can probably run your pump for less time than you do now. Try cutting back time and see if you still get satisfactory performance. Find the shortest time that works well for your pool. Reducing the pump "on time" is where the rest of money savings comes from.

3. So now you have a smaller pump and/or don't run it as long as before - you have saved money.

Why run it intermittently? Running the pump for three hours straight daily cost almost exactly the same as running it for 1 hour for three times a day and has no real effect on the cost of operation. Here’s the reason they give for intermittent operation:

"Programmable timers can be set to control the pump’s cycling. If debris is a problem, use a timer that can activate the pump for many short periods each day. Running the pump continuously for—say—3 hours leaves the other 21 hours a day for the pool to collect debris, whereas several short cycles can keep the pool clean all day. Check with the local utility company as to what times they suggest are the best off-peak hours in your area."

Here is a link to the paper.

http://www.floridaenergy.ufl.edu/wp-content/uploads/swimming-pools.pdf
Mike

 

[Bama Rambler]

The reasoning behind running it in several short periods rather than one longer period is for surface cleaning. Since the debris falls in the pool all during the day, with several short periods it's not sitting there most of the day, and possibly sinking, and while waiting on the next pump cycle.

 

[SebringDon]

So with a solar cover on, it wouldn't make much difference. But the article also says that people who run three hours intermittent are as pleased with their water as people who run 8 continuous. Does that just translate that most people are running their pumps too much? I'd love to have a three-hour-a-day electric bill.

 

[jblizzle]

Yes, I think generally people run their pumps more than is necessary. Really depends on the debris load though.

 

[SebringDon]

Yes, I think generally people run their pumps more than is necessary. Really depends on the debris load though.

I've wondered about calculating my turnover time, but from what I've read estimating flow is problematic, so I haven't tackled it yet. Right now I'm running 12 hours and the water looks great so I'm about to go to 10.

 

[mas985]

Worst case is probably around 55 GPM or a 4.5 hour turnover. I would try that and see how goes.

 

[personalpoolsandspas]

i have been doing this with pools i service, setting up 2 4 hour run cycles at different times of the day instead of running the pool 12 hours a day. like someone said, depends on the debris load, i don't do this on all pools. furthermore they are in the 25k to 40k gallon range, so 3 hours won't cut it.

point is that this does help save energy. figuring out how little you can run your pool is a different story. you have to do some math (55 gpm is accurate) and experimentation.

 

[Durk]

I ran my 28k pool for four hours a day when I had a single speed. This year I went to a two speed and ran eight hours a day on low in three cycles. This is substantially under the "approved" one turnover and pool is crystal. I will bump it up for rain, parties, pollen attacks and other adverse events. I have long felt that the suggested run times were excessive.