16 July 2024 Finishing Up my OB Pool

[JoyfulNoise]

What’s the infinity edge trough going to be filled with? Stone? Smooth pebbles? Recycled glass beads in mermaid colors?? Alligators?

 

[setsailsoon]

What’s the infinity edge trough going to be filled with? Stone? Smooth pebbles? Recycled glass beads in mermaid colors?? Alligators?

Hopefully, just pool water. But will clearly also be a collection point for anything that floats in the pool thus the need for an access door just above the basin. Also, this will house the level sensors that control pump speed. I plan to use a simple home-made stand pipe with 3 level switches mounted inside. Goal is to maintain pretty low level to provide plenty of surge for multiple large bodies entering simultaneously. I originally used 18 gal per adult. @JamesW pointed out 20+ was more representative... sadly I think we're heading closer to 25 but I hope Ozempic may help reverse this trend!

Chris

 

[setsailsoon]

01 March 2024 update

Couple of interesting cost data points:

Screen enclosures went through the roof after covid. Mine would have been unaffordium to me approaching $50K. Entire pools used to cost that! But now aluminum prices, screen material, and labor is much closer to normal. We paid $13.40 per sq ft back in 2014. Current cost are about $16.90 per sq ft. This is very consistent with the national home builders cost factors that were published last year. This for an enclosure that meets Florida storm code including site-specific stamped drawing, alloy fasteners, and picture window, It can probably be done cheaper than this in other southern US locations.

Next cost item to mention is one that I had left out of my estimate. I had money included for final site grading but no money for back-fill and compaction around the pool shell. Don't know how I missed this but I did. Fortunately it's only a couple thousand $. I'll do it at the same time as we trench from the pool to the equipment pad for plumbing and electrical. Won't have any impact on schedule since there's a LOT of float on this due to the 28 day wait time for concrete cure.

Right now I'm working on equipment orders. Trying to get pricing from my subcontractor that will add 10% to his price. I'm hopeful this will be close to the internet pricing and it will have the benefit of better warranties that justifies some added cost. I'll provide a complete update on this next week.

Chris

 

[setsailsoon]

02 Mar 2024 Update - Comments/Suggestions on Pool Control Logic

I'm often surprised at how much a pool build is similar to building a chemical plant. When designing the process we have a control philosophy and logic document that describes how the plant will be controlled. This is important since it affects what piping, valves, instrumentation, controls need to be designed and included in the estimate. So I'm thinking through this now for the pool. It's important now because next week if all goes well I'll have concrete in the pool and adding pipe or anything that penetrates the pool will be extremely costly and risky. So below are my thoughts on control logic, what do you all think?

Chris

Pool Control Logic

• Main Pump Run and Speed Control: I'd like to do this with the Pentair RS 485 protocol if possible. Otherwise we can rig up to do it with digital inputs. The intent for this pool is that the pump runs at min speed 24/7. It will increase speed as needed for other operations such as spa mode, clean mode, max flow infinity wall mode.
• Max flow infinity mode is unique to this pool design. Normally circulation water flows over the infinity wall in the back and to the gutter surrounding the pool. The gutter is a 2" wide channel that goes completely around the outside of the pool. Water drops into the gutter and dumps at each end into the basin below grade via a short 2" pipe. The pipe on each end can be closed. This causes the gutter to fill up and the level to raise slightly in the pool which forces all the water over the infinity wall. The tiles just outside the gutter drain slope up about 5% to accommodate the increased water level without spilling out all over the pool surround pavers. These two actuated valves are opened or closed together and controlled by one relay to invoke "infinity mode". The water level on this pool is always right up to the top. So essentially the entire pool is a skimmer and no separate skimmers are used.
• Gas Heater On Mode: Normal fireman's switch to turn on heater and control spa as well as pool temp. I expect to use the pool water return temp sensor for both cases.
• Switch the pool suction and return valves to switch between pool mode and spa mode.
• There will be a 3-position level switch in a stand-pipe located in the basin. This will sense levels in the basin and switch between low, med, high speed on the Pentair commercial 5 hp main pool pump. We can control the pump with digital inputs or the pentair RS 485 protocol.
• SWG On Mode: Turn on the swg that is powered from an output on the main pump and controlled by either the Pentair RS 485 or a separate relay powered from the main pump breaker load side. I will need to be able to adjust the duration for SWG mode
• Air Blower ON: Control the air blower for the spa as a separate control... I may not want it to turn on every time we are in spa mode.
• Solar Heat Mode: There will be a temp sensor to sense surface temp on the solar heater panels. I'd like to control this similar to the way I did with my Intellicenter previously:
  • There is a bypass valve that is normally closed to prevent return water from going up to the panel.
  • The bypass valve opens when pool temp is below set point.
  • If it rains during the day and the panels are below a tube surface set point this over-rides the previous signal to prevent accidentally cooling the pool during an afternoon shower or dark cloud passing by.
  • A "would like" is an option that starts the gas powered pool heater when the solar is not able to raise pool to set temp.
• Bubbler flow On Mode: We have 3 LED bubblers on the sun deck end of the pool. I'd like to have a separate valve actuator on the flow to these.
• Bubbler LED On Mode: The bubbler 3 LED's will be switched separately from the pool/spa LED's.
• Pool/Spa LED Control: The Pool LED switches all use a very simple protocol to change color. It's an on-off count system or pulse system. One switch on and off within 1 second sets the lights to white. Switch on and off twice is blue and so on. So I'd like to set up a pulse count from 1 to 8 pulses to the LED on-off switch to accommodate this. Different brands use different numbers of pulses to get a different color but they all work the same way. Looks like I'll be using J&J Electronics so we can set up for them.
• My pool robot will be controlled separately using a smart outlet. So nothing needed there.
• I will have a separate suction port mounted in the pool wall but will manually switch it initially and only add control later if for some reason I can't use my robot.
• Filter mode: There is a separate filter pump that will be run for the filter system. This will take water through the filter for a period of time each day. This will take water directly from the basin through the filter and dump back into the pool via the return line for the main pump.

 

[JamesW]

Do you have an actuator for this valve (Red Arrow)?



Blue = Main Drains.
Green = 2" or 2.5" PVC pipe.
Red = 3" PVC pipe.
Black dot = Check Valve.
Purple dot = Jandy NeverLube 2.5" (Inside) x 3" (Fitting Outside) two-way valve or 2" x 2.5" Jandy NeverLube two-way valves for skimmers and pool main drain.
There will be (2) 2.5" (Inside) x 3" (Fitting Outside) Jandy NeverLube Check valves after the Infinity Pump and (2) 3" Jandy NeverLube Check valves before the Filter Pump Suction Manifold.

This will allow you to adjust the edge flow and filter flow independently.

 

[JamesW]

When designing the process we have a control philosophy and logic document that describes how the plant will be controlled. This is important since it affects what piping, valves, instrumentation, controls need to be designed and included in the estimate.

Do you use specific BIM (Building information modeling) and/or Digital Twin Programs?

 

[setsailsoon]

James,

Thanks for the quick reply and yes. Can you please tell me what the other 3 green lines are for outside the basin?

Chris

 

[JamesW]

The other 3 lines are for skimmers and main drain in the pool.

However, it looks like you won't have skimmers?

Will you have a main drain in the pool?

 

[JamesW]

Normally circulation water flows over the infinity wall in the back and to the gutter surrounding the pool.
The gutter is a 2" wide channel that goes completely around the outside of the pool.
Water drops into the gutter and dumps at each end into the basin below grade via a short 2" pipe.
The pipe on each end can be closed.
This causes the gutter to fill up and the level to raise slightly in the pool which forces all the water over the infinity wall.
The tiles just outside the gutter drain slope up about 5% to accommodate the increased water level without spilling out all over the pool surround pavers.
These two actuated valves are opened or closed together and controlled by one relay to invoke "infinity mode".
The water level on this pool is always right up to the top.
So essentially the entire pool is a skimmer and no separate skimmers are used.

Ok, I understand now.

I will be very impressed if the builder gets this correct as it will require extreme precision in leveling to millimeter accuracy.

 

[setsailsoon]

Do you use specific BIM (Building information modeling) and/or Digital Twin Programs?

Digital Twin is getting to be pretty big for offshore oil and gas. Some are starting to use it in chemicals but many haven't yet bought into the cost effectiveness. I think it's pretty short-sighted because the long term savings are huge. Some of this is complicated when private equity is involved since their time horizon to exit is often very short term. Most common process simulation and design software has been Aspen for a long time and most 3d modeling is Autocad 3D or a 3rd party add on.

Chris

 

[setsailsoon]

Ok, I understand now.

I will be very impressed if the builder gets this correct as it will require extreme precision in leveling to millimeter accuracy.

Yep,
He's a little puckered about this (he is me). The final level will be controlled by the tiles on top. Plaster and tile guy says he's done this before and it's very difficult to get right. I have a zip level that's accuracy is about 1 mm in 100'. But this will be a challenge to get +/- 1/16". I suspect getting uniform flow will only occur at medium or high flow an I'll just have to live with what I get for the lower rates.

Chris

 

[JamesW]

So, the filter pump will only pull water from the trough and nothing from the pool?

 

[JamesW]

If you will not have any suction lines from the pool, you can put the check valves after the filter pump.

It is always best to avoid adding head loss on the suction side wherever possible.

Also, the water is cleaner at the discharge because the pump basket catches debris.

You can just use the Jandy 3” two-way valve to close the suction for servicing the pump basket (Cleaning etc.).

What will be the elevation of the pump suction relative to the trough water level?

 

[setsailsoon]

So, the filter pump will only pull water from the trough and nothing from the pool?

I can tie in to the drain line if you think that's needed but plan was to take only from the basin. That seems to be typical for infinity wall pools.

 

[JamesW]

Is there going to be a main drain?

If yes, what does it connect to?

 

[ajw22]

Pentair gas and HP heaters now all have RS-485 controls that let the heater do the temperature control instead of the automation. The automation sends the heater the desired setpoint to maintain. And diagnostics and messages are sent back to the automation through RS-485.

That is the preferred control rather then the fireman’s switch.

 

[setsailsoon]

If you will not have any suction lines from the pool, you can put the check valves after the filter pump.

It is always best to avoid adding head loss on the suction side wherever possible.

Also, the water is cleaner at the discharge because the pump basket catches debris.

You can just use the Jandy 3” two-way valve to close the suction for servicing the pump basket (Cleaning etc.).

What will be the elevation of the pump suction relative to the trough water level?

I just went out with my zip level to check elevations. The zip level is a fantastic tool that I used a lot on the house slab forms and during the concrete pour. It's sort of like a tap and die set. Almost never use it but when it's needed it's invaluable. The ZL is a fancy manometer with electronic pressure sensors, special manometer fluid, and can self calibrate for 5 years before it needs to be rebuilt. During that time I can measure accurately mm in 100'. I just checked and assuming 30% as normal level it's about -70" elevation below pump suction on the pad. Photo's of zip level below.

I could actually take suction off the inlet or outlet from the main pump but I will have a separate parallel 3" line down to the trough for the filter pump. I think this is a good idea anyway so I can independently circulate the pool all the way back from the basin even if normal flow is from the 3" main pump plumbing.

Chris

 

[setsailsoon]

Is there going to be a main drain?

If yes, what does it connect to?

Yes, I was thinking to tie it into the filter pump suction and/or the main pump and those valves would normally be closed. I actually considered not even using a main drain but the stamped drawings show it and cycling back for a change or deviation approval just led me to keep it. What do you think? Seems to me I could very easily siphon over the wall to almost completely empty the pool pretty easily empty it if I ever needed to. Or use my very old but handy submersible pump.

Chris

 

[JamesW]

it's about -70" elevation below pump suction on the pad.

Ok, that gives you about 5.8 feet of static suction head, which has to be added to the dynamic suction head loss.

As long as the total suction head loss is always below 17 feet, you should be fine.

Ideally, I would try to stay below about 12 feet of total head loss at full flow.

So, that gives you about 6 feet static and 6 feet dynamic.

The lines are sized to allow up to a total of about 378 GPM without getting above 6 feet per second in any line.

The manifold for the 5 HP Infinity Edge Pump can be 4" to reduce the head loss.

Pipe Size and Flow Rates.​

You want to keep the water velocity below 6 ft/sec on the suction and below 8 ft/sec on the pressure side of the pump.

Pipe Size	6 ft/sec	8 ft/sec
1.5"	38 GPM	51 GPM
2"	63 GPM	84 GPM
2.5	90 GPM	119 GPM
3.0"	138 GPM	184 GPM
4.0"	235 GPM	312 GPM

 

[JamesW]

You can tie in the pool main drain to the filter pump, but you would need to have one check valve before the filter pump suction manifold so that water cannot go from the pool main drain to the trough main drains.

I would be 50/50 on keeping or eliminating it.

It can be useful, but also not that useful.