Hey Dirk - I started reading your "getting ready for SWG" thread just now and came across the discussion of the speed to set a VS pump. The PB set ours at 2500 rpms. As I mentioned before they set it to go for 12 hours a day, Not sure what is "normal", and I don't what to open that door right now as that info will just get lost in my long list of notes of notes. BUT what I did want to mention is I did a test with running that pump for one hour between 3-4am, when there is little variation in our electric consumption. Consistently it uses 1kwh per hour.
Do you know how much energy your pump uses per hour? (what speed your pump is set to for general filtration)
Start
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ScreenLogic gives me power usage in watts for any given RPM. I presume that's data from the pump, but I don't know that for sure. I don't know how that's calculated: if it's actual watts, or based on some algorithm that is using RPMs.
I have speeds of 500, 900, 1500, 1900 and 2200, for different purposes. But I don't use any of those "for general filtration."
Besides, asking me about
my RPMs, and energy use, would be about as useful as asking me what RPM my engine was turning to get me up a hill in exactly 15 minutes, so that you could use the same throttle in your car, to achieve the same gas mileage. Well what kind of vehicle do we each have? Size of tires? What gear are we in? How many people are in the car and how many kegs of beer are in the trunk? Every pool is different and each has its own set of variables that affect optimum RPM setting(s).
You'll work it backwards, as I did. First off, I have a solar heater, an SWG and a cleaner. Each needs its own flow rate, and so their own RPM setting. I adjusted the RPMs as I watched my FlowVis until I got the proper flow for each device. So I don't start with RPM to see if that's going to work or not, I start with the device and it's actual flow need and then find the RPM that provides that flow. I don't expect most others do it that way, because most others can't determine flow on the fly like that. (And that's why I think a flow meter is as fundamental to running pool equipment properly as a filter's pressure valve is.)
I don't worry about "general filtration" because during swim season my solar runs the show. The panels need 40GPM of flow. That takes 2200RPM to achieve. The solar runs enough during the day to achieve the temp I want, so that more than covers sanitation and water filtering. When solar is not active (because there's not enough sun out), or not needed (because the pool is warm enough), then the SWG runs the show. Mine requires 21GPM to operate correctly (which takes 1500RPM in my pool), which is
also enough for sanitation and filtering. During the night, my vac runs, which needs its own unique amount of flow, or 1900RPM, and that is also providing circulation and filtration. See? So I don't have, or need any "general filtration" cycle and corresponding RPM setting, because that's already covered, in spades, by other cycles.
Until you need or want to heat your pool, your SWG will be running your show. Whatever minimum flow your SWG needs will determine the RPM you'll run, and that will be your pool's sanitation and water filtering cycle, so you won't have a need for a separate general filtering mode either. Once the SWG puts out enough chlorine, you'll just schedule your pump to shut down. That'll more than cover your sanitation needs.
If you find that's not enough for either the water clarity you want, or the skimming your surface needs, you'll then start ramping up the RPMs until those needs are met. Or you can do a combo: a medium speed to satisfy your SWG and the water clarity you want, and then maybe some short "high speed" skimmer cycles, hour, or half hour, once or twice a day, whatever, to "polish" the surface of whatever it collects. There are as many ways to set this up as there are pools. There is nothing "general" about it.
So again, you'll work backwards, with what you need the pool equipment to do (filter, skimmer, vac, SWG) and dial up the RPM until those systems are performing as you want. Some systems will need what they need to function, the rest are determined by your personal preference, for your particular pool. It's why I started you off with the pump runtime article, because runtime and pump speeds go hand in hand, in that it doesn't take a lot of either to achieve sanitation, the rest is just personal preference.
One thing to know about an SWG, that it took me a while to wrap my head around: once the SWG's minimum flow requirement is met, it doesn't matter the RPMs. It puts the same amount of chlorine into your pool at 25GPM as it would at 40GPM. Doesn't matter. The only reason the minimum flow exists, I think, is to keep too much super-chlorinated water from collecting in any one place.
One caution... which I learned from one of the TFP experts. It's common, and maybe desirable by some (you, maybe, based on your questions about energy) to dial a VS pump way down low, because you want to save money. I'll use an extreme example to prove a point. You could dial that pump down to 100 RPM and boy that'd be a low electric bill that month. But that pump has to move a lot of water through a lot of pipe to 3 or 4 returns. What do you think the force is going to be like at each return if you run that low? You'd be sacrificing circulation, filtration and sanitation (because your chlorine would never get mixed around) just to save on electricity. Not actually such a bargain. A higher RPM, which will provide more of all those things, will actually be the better "value" because your pool water will be cleaner and healthier. So lower is not always better. Cheaper is just, well, cheap.
Any help?
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what in the world?????????? Try to make sure the pump is on for about 30 mins before you pull any water for tests. It can make a difference.