Re: Optimize Your In-Floor Cleaning System's Energy Efficiency
Here is one issue (of two) that I am thinking about for my in-floor cleaning and may apply directly to some other systems (gvc). These are more “technical challenges” than issues…I am actually very satisfied with my system’s performance.
Issue 1 (Are there advantages to increasing cGPM?)
I haven’t had time to run more experiments on my in-floor cleaning system. But last night, I woke up and started thinking again (this is what usually gets me into trouble)... my new revelation is that “what I have been thinking about” the last few days might NOT be so pool-specific (at minimum, as Dodger once indicated, it might apply to 1000’s of Phoenix area Shasta pools with in-floor cleaning…I may be forced to change the thread title again, haha). In any case, I think there is some value in me throwing it out so that others can think about how it might apply to their situation.
Here are some entries from the data I posted:
Config | Pump Speed % | RPM | Watts | GPM | Filter PSI | Manifold PSI | G/kWh |
| | | | | | | |
A-50/50 | 85 | 2933 | 1342 | 86 | 19 | 12 | 3845 |
A-100 | 65 | 2243 | 473 | 31 | 14.5 | 12 | 3932 |
| | | | | | | |
B-50/50 | 80 | 2760 | 1126 | 80 | 16.5 | 10.5 | 4263 |
B-100 | 60 | 2070 | 391 | 29 | 12 | 10 | 4450 |
First, some definitions:
a) oPSI = optimum manifold PSI is the minimum required PSI at the manifold that still cleans your pool, it is the most energy efficient point at which the cleaning system can be operated
b) cGPM = cleaning GPM, this is the cumulative flow (in GPM) through the system while running your in-floor cleaning system...for the current use model and for most systems today, cGPM is equal to the flow through popups. This is because when the cleaning system is in use, most users return 100% of the system water flow back through their popups
c) ocGPM = optimized cleaning GPM, this is the cumulative flow through the cleaning system when the manifold is at the system's optimized PSI (@ oPSI)
For me, here are two of the important takeaways from the experiments we have done
1) for optimum energy efficiency, run your pool’s in-floor cleaning system at oPSI using the minimum water flow through the system; in other words, all water flow is being directed back to the pool through its in-floor cleaning system manifold.
2)
once oPSI is found It is possible to increase “cleaning GPM” (cGPM) in a system through a “parallel path” in the system (maintaining oPSI) and STILL be close to optimum energy efficiency. For my pool, the data above indicates that my system can almost triple cGPM without “significantly reducing” energy efficiency. The above two cases are not run at oPSI, but similar results should apply. Based on my numbers, I imagine that most systems have “some” room to increase their cGPM at oPSI; successfully finding those points would result in an optimization of that specific flow through your system, an optimized, cleaning GPM (ocGPM)
The question:
Is increased cGPM at oPSI useful for anything other than faster cleaning (Case 1 is simply cleaning faster)? I can think of more cases where it might, all triggered by discussions on this thread.
CASE 2 of Issue 1 (using increased cGPM to make in-floor cleaning more effective)
I have definitely overplayed the monsoon argument. I initially thought that if I solved that issue, I might solve all the issues for my system. Truthfully, after trying out my improved in-floor cleaning system on one monsoon, I probably will still be vacuuming, mostly because monsoon season IS swim season. Why take a chance on algae growth, and other problems with something that only happens a few times a year?
Also, I am NOT going to continue running my system at 80gpm, which is the maximum recommended RPM for my pump given that I have 2” pipes (I found this out when Mark asked me about RPM adjustment and I went back to look at my pump documentation). When I redid my equipment pad a few years ago, I replaced all pipe that I could with 2” and larger valves; and luckily for me, back in 1993, Shasta had run 2” on the suction side. If the suction side had been done with 1 ½” pipe, like all the rest of the pipes, the recommended max pump RPM is 45GPM, a number suspiciously close to the MAX GPM I can push through my 1 ½” returns to the popups when I send 100% of the water back through the cleaning system (from my tables 50GPM).
I am going to continue to do some experiments to find my oPSI (which I currently believe is between 10 & 12 PSI at the manifold). I will then increase my cGPM to a number TBD, but probably around 50GPM. I will do this by adjusting flow through my wall returns (“parallel path”) and adjustments to my pump RPM. Currently, the granularity of my Jandy Valve actuator is not sufficient to allow me to find this spot (I only could run the 85/15 case and the 50/50 case, known now that both are inappropriately named); that is why I previously said I am going to run some experiments with the actuator taken off (I will have "infinite" cases to explore, haha).
That’s my plan, and here is why I’m pursuing this: for once my wife is right (now I am in real trouble)!
During the past week, my system HAS been clearer and cleaner. I suspect it’s clearer (clarity is better) because of over-running my pump and possibly because my chlorine levels have never been more consistent than with my new Stenner pump setup. But, it is cleaner because
my in-floor cleaning “dead spots” are gone.
With my system, probably because I have been overdriving well above my oPSI , I’ve never had dead spots that aren’t actually “swept” by the cleaning heads (unless one of them is stuck and not rotating). My dead spots all result from areas where pebbles/seeds/heavier material is swept from the floor, up the wall, and then falls back down into the same place. I have 2 bigger spots and 1 little spot where this occurs.
There have been quite a few comments on this thread regarding “skimming time” and the use of wall returns. Truthfully, my wall returns never moved from where the installers put them until about a week and a half ago where I started playing with them. In those early posts I mentioned that my pool (for the 50/50 case) looked like a spa now (an exaggeration of course), and that got Rob talking about his pool swirl.
Looking at Configuration B 50/50 case above (this is the spot I am actually running my system right now, it has 80 cGPM), we can determine that of that, there is about 50 GPM shooting out of my wall returns, and the remaining 30 GPM out of the popups (as shown by Config B 100 case which has "similar" manifold pressure). My theory is that this pool swirl is pushing that heavier debris around the pool walls as it gets shot up the wall…it no longer falls down in the same place and so eventually makes its way to the drain. I have also seen larger debris (leaves) actually go into the skimmer as the cleaning system is running. 50 GPM is clearly overkill to start a swirling motion in a pool.
NOTE: technically we know real numbers for these test cases and those entries should not be called 50/50 case, but for now, I will leave it
I believe that increasing the cGPM using the wall returns (via the “swirl”, patent goes to Rob, haha) has made my pool cleaning more effective. I am pretty confident that I will still get this same effect as I scale back the cGPM from 80gpm towards my target of approximately 50gpm.
So Dodger, I think you summarized Rob’s and my comments very well when you listed the 3 types of things that we needed here in Arizona. But I suspect they might apply to pools with in-floor cleaning systems elsewhere as well.
Note: I hadn't really given much thought to the fact that my "dead spots were gone", because I am currently running my cleaning system twice as long as I think I will eventually and attributed it to that...but, I am considering ordering a different type of wall return nozzle and was examining the threads on my existing one (I have a problem with them, but that is a different issue). I placed the nozzle on the deck where it has remained. Over the next day or two, the dead spot near that nozzle has reappeared (little twigs, heavier type sand, some seeds). There is still this unknown with the "swirl" theory, was the local wall return fixing it for that particular dead spot (my pool specific), or was the wall return contributing to an overall pool swirl to eliminate all dead spots? Unfortunately my 2nd larger "dead spot" is also right near where my other wall return is pointed. An experiment that reverses the swirl in my pool could resolve this...but I am running out of time for experiments right now because we are going on an Alaskan cruise.
Here is a photo of the area I have talked about. Not sure if you can see the little material on the bottom of the pool, but this "dead zone" is mostly along the wall from approximately where the wall return is seen on the left (with its fitting currently removed and on top of the wall), to the step on the right. So the wall return is exactly where it needed to be to fix my problem...was it the swirl...not sure, but with 50gpm, there is a LOT of swirl.
Anyway, that is Case 1. The 2
nd case is not as advantageous but still might be useful to some. It will take me some time to get to it as we have the grandkids today.