What good are PSI measurements?

[jonpcar]

I’m thinking about adding some monitoring gadgets to my pool equipment pad and am considering some PSI transducers so that PSI related events can be monitored and/or triggered (notifications). It seems a filter PSI transducer would be useful to monitor filter pressure and tell you if it’s dirty.

Would a pump suction side monitor (basket) let me know if the pump basket and/or skimmer basket is full/impeded? What kind of pressures are there at the pump basket? I have found only one example that indicated about -15psi for a pump running at its particular full speed.

Are there any other psi measurements/monitoring within a system that might provide some value?

 

[Dirk]

I see you already have a FlowVis, that's what I would have recommended.

I suppose it would be nice to be able to monitor your filter pressure from afar, but I'll only caution you this: if you get that working, don't let that be the reason you don't monitor your equipment pad, in person, while the pump is running, every day. You should get into the habit of walking past your pad daily. In about 15 seconds you can check for leaks, check the filter pressure, check the flow rate, check the contents of the pump basket, and listen for any abnormal sounds. This on your way to your pool where you check the bottom and surface and walls and water for anything that's not supposed to be there, check the water level, and a quick peek in the skimmer(s) to make sure they're clear and not full of something bad (like a dead animal). 45-60 seconds a day, which you can call "pool enjoyment time," to ensure you don't let a little problem get by you that can turn to a much larger, more expensive one, if you ignore your pool for days or weeks at a time.

A pressure sender won't give you the full picture... One or two on your system might be a type of "early warning" system, for some problems, which would be cool, I suppose. Personally, I wouldn't go punching holes into my PVC or pump to add one. The one I have on my filter is one too many potential leak points as it is...

I know you only need one FLowVis, a second one wouldn't give you any additional data, flow is constant throughout the system, and two would always read the same. Pressure would be different, I suppose, depending on where you installed them, but I'm not sure you'd get any useful additional data from a second one. If something was to affect your flow (like a clogged up pump basket), then I would think all pressure gauges would move. Not in the same direction or by the same amount, necessarily, but enough to let you know something wasn't normal, and requiring your attention. I don't think you can have a spike in pressure at the pump, and not have that change the pressure everywhere else. Which would mean you'd really only need the one for the filter. Granted, pressure sensors throughout your plumbing could help you quickly pinpoint the area of a problem, but I'm not sure the effort to install them, and record their data for comparison, and then to track them constantly, is going to give you any great ROI.

 

[jonpcar]

Dirk, I love the FlowVis! I have discerned a lot of information about my system using it. Actually, what I would really like is a gpm meter that can be monitored through an electronic method. I have rpm & watts which could give me a rough one using Mark’s tables. PSI readings (suction & return) can give me that as well, but not sure how accurate those are either.

As as far as monitoring my pool, I agree, a walkthrough is best but not only am I lazy about this, but I also travel a lot which means that I am not really able to do that sometimes. I can’t rely on my neighbor either (my sister’s family, haha).

You our are right, the ROI (time not money...it actually is cheap) is probably not worth the PSI gauges but I love data, and I also like the challenges in gathering it. Pool data and automation is my latest hobby.

 

[Dirk]

Then go with cams. One on the pool, to observe level and color and clarity, and a couple on the pad. Is there a position or two where a remote-pan-tilt-zoom cam could keep an eye on the pump basket, and the FlowVis? You could even listen in to the pump motor, check for leaks, double-check the filter pressure, etc.

 

[jonpcar]

Dirk, I am considering cams for a number of reasons...but until now not to monitor my pool equipment pad...nice suggestion if/when I ever get around to doing it, haha.

The measurements and checks I have in mind are going to be more real time...I will be sent emails/texts if I run into issues. I get it that I still need to check my pool, but I don't do that consistently (especially off-season) and this will be the next best thing. I'm not afraid of changing my pool plumbing, but actually, these psi transducers will fit into existing plumbing quite easily and at $10 a pop, they are essentially free for the purposes I have in mind. I was hoping that there might be some other ideas that people might have for effectively using them as monitoring devices.

 

[Dodger]

Hi jonpcar, this may just expand on what your are suggesting, but I would personally like to record and monitor psi curves for all my pump speed and valve position combinations.

The basic TFPC advice says clean at 20% increase on filter pressure, but this is more complicated the more valves you have, not to mention the huge number of permutations when combining valve configurations with variations in pump speed (if you have a VSP). In my case, I have at least 6 valve configurations on the pressure side, so I have to remind myself what the baseline pressure was in each valve configuration+speed combination before I think about if/how much my filter pressure has increased.

I can't store all those baseline numbers in my head, so I have sticky labels on my filter that show a handful of the datapoints. I would much rather have some curves than a few datapoints.

 

[jonpcar]

dodger...I have the same problem. The last time I cleaned my filter was the FIRST time that I dialed the little pressure gauge marker to indicate "cleaned pressure" so I would have it as a reference...previously I have just cleaned my filter every 6 months or so without regard to pressure. After a few days, I realized I did not know what setup (valves, rpm) I had "dialed in" the pressure marker to. So I still haven't successfully used that little marker on the pump filter yet, haha. Stickies might solve that for me.

I plan on using the PSI transducers and recording/monitoring pressures in various parts of my system to see if I get anything useful from it. The obvious one is the one we both realize would be useful: recording base pressure for various valve configurations with a clean filter and then monitoring those to determine when the filter must be cleaned.

A pump basket transducer won't tell us if OUR skimmers are blocked (we have that crazy spaceship configuration that would simply then switch to drain suction) but I believe it can tell us when the pump basket is impeded by debris. It may be possible to use pump basket pressure in combination with filter pressure to figure out a dynamic gpm flow through the system (some of Mark's curves), similar to using watts/rpm measurement to figure out gpm flow. I haven't looked at that in detail yet but it seems that I remember something to that effect.

Finally, if/when I go through with this, I might as well stick one on my popup manifold as well to record how pressure changes as it cycles through the cleaning zones AND to see how dirtying the filter impacts it.

This isn't going to happen immediately, I am working on a new controller/monitor for my pool system that will have a lot more flexibility than my current setup. Its slow going but a fun project.

 

[superray]

I used the Fibaro Zwave module on mine and used my home automation to graph the pressure (VeraLite), but the cheap pressure sensor didn't last (or I still need to work on the electronics). I'll try something different later this winter when I get some time

RGBW Controller - Z-wave controller | FIBARO Manuals


Also, there's this:
Wireless Pressure Sensor - Pool Pump Application - YouTube

 

[Dirk]

Well, in light of my, well, let's just say "lack of enthusiasm" for this effort, if ever there was a case to support your scheme, this new thread would be it, I gotta admit.

Swollen massive PVC pipe out from pump, into sand filter

 

[jonpcar]

Dirk, I can't believe that pipe didn't blow...wow! I get your lack of enthusiasm, haha, but I am pretty excited about this. I have some plans to do some other experiments with these transducers besides "sensing for problems" like that picture but that will come a bit later.

I used the Fibaro Zwave module on mine and used my home automation to graph the pressure (VeraLite), but the cheap pressure sensor didn't last (or I still need to work on the electronics). I'll try something different later this winter when I get some time

superray, after reading some reviews, I decided against the $10 cheaper transducers and found some industrial ones on ebay that were stripped from a job site somewhere. They all tested out good (and accurate as well) so I am proceeding. But I had to splurge, $17 each.

 

[Dirk]

Dirk, I can't believe that pipe didn't blow...wow!

Right?

And I'm not discouraging your efforts and experiments. Just spitballin' with ya. I'm no one to talk. Yours pale in comparison to the antics I've documented here! Automation, dosing gizmos, inventions, chemical balancing methods and experiments, etc, etc. A lot of them worked out great, and have made life with my pool easier, safer and more enjoyable. You go for it!