Friendswood pool build - almost there......

[Guest]

Re: New build in Friendswood now with pics......

As for pumps, my thought was to use one pump for circulation, one for the spa, one for the water features/sheer descents (all three of them the Intelliflow 4x160) and then a smaller (0.75 HP I think) for the cleaner.
I just realized I had left out one pump in my signature...... .....

OK, now I feel better

 

[Pisces]

Re: New build in Friendswood now with pics......

Oh, my goodness gracious...be still my heart!! :bowdown: That is a FABULOUS design!! I love love it. If only I'd had that much room. This is going to be an awesome pool!! I can see the glass tile and limestone. Beautiful and classic. Talk to you guys this weekend about the Pebblesheen. It's going to be really exciting to see this build..love the originality of the design..now I see what you were talking about with the spa...great design.

 

[friendswoodnewbie]

Re: New build in Friendswood now with pics......

Thanks, Pisces. Let's hope the weather will behave.
Yes, we are really excited to get started. I am still struggling a bit with the plumbing decision. I definitely want to go big enough but having looked more at the numbers today, I cannot see anything larger than 2" making sense on the pool for circulation. For the spa and sheer descents, it is another matter.
For the pool circulation, I was told by an 'expert' (and he really did sound knowledgeable) that with a desired flow rate of 53 gpm and a total head loss of around 20 feet, anything more than 2" would simply be a waste. IF he is right on the head loss, it does seem that already at 2" the flow rate will be low enough that plumbing restriction will be negligible.
I will do some more digging....

 

[Guest]

Re: New build in Friendswood now with pics......

I am still struggling a bit with the plumbing decision. I definitely want to go big enough but having looked more at the numbers today, I cannot see anything larger than 2" making sense on the pool for circulation. For the spa and sheer descents, it is another matter.
For the pool circulation, I was told by an 'expert' (and he really did sound knowledgeable) that with a desired flow rate of 53 gpm and a total head loss of around 20 feet, anything more than 2" would simply be a waste. IF he is right on the head loss, it does seem that already at 2" the flow rate will be low enough that plumbing restriction will be negligible.
I will do some more digging....

Keep digging.......... Keep digging....... Keep digging.........

None of us giving you advice here have anything to gain, yet the "expert" may. What you are being told here is being told for a reason. You cannot change this later "if" the system does not work.

 

[friendswoodnewbie]

Re: New build in Friendswood now with pics......

Bruce,

Well, I would agree except the 'expert' recommended AGAINST upgrading. Normally, they would not be shy in upgrading if there was more money in it for them.
He said that with 31000 gallons and a 10 hour turn it corresponds to 52 gpm (i can't disagree there... :lol: ) That is still less than 6 ft/s even in a 2" pipe.
The big question is the head loss over the system. Is 20 or 50 feet of head more realistic?
According to mas985's post it seems that with a 'typical' pool using 2.5/2" piping the total head loss will be about 25 feet at 59 gpm with a filter psi of around 8 (which was actually also a number I heard today from the 'expert'.)
So if the 20-25 feet of head is correct, the pump will do that at less than 2000 rpm.

RPM 3450 2500 2000 1000
2.5"/2.0" Head Loss 74 39 25 7
2.5"/2.0" GPM 104 74 59 28
2.5"/2.0" Filter PSI 25.2 13.4 8.6 2.2

I will look at it again tomorrow - enough numbers for one day......

Thanks again for all your comments.

 

[mas985]

Re: New build in Friendswood now with pics......

One thing to keep in mind about plumbing sizes is that multiple runs of smaller pipe can often be better than a single run of a larger pipe. There is a table of equivalent runs in this post. Also, at some point increasing the pipe diameter doesn't help flow rates much because there are other components in the plumbing system which will not change with pipe size: skimmers, main drains, valves, filter, heater, etc.

3x2" pipes from the two skimmers and main drain will have the same head loss as one 3" pipe of the same length. 3x2.5" pipes will have the same head loss as a single 4" pipe. I don't think increasing the size of each suction line will help much beyond 2.5" but if you give me some more information, I can show you how the performance will change with pipe size. The important thing on the suction is to run each pipe all the way from the skimmer/main drain to a header next to the pump so you can isolate each of the suction ports should you need to in the future. Do not allow the PB to run the main drain through one of the skimmers.

The spa however, will definitely benefit from larger suction pipe since there is only one port there and on the jets side, you may even want to run 3 separate loops for the jets with each running 4 jets. One of the most critical elements and the one that seems to be screwed up the most by PBs are spas. Nothing is worse than having a really nice spa with extremely weak jets so plumbing sizing is critical. Also, I think it is much better to have the spa jets on a separate pump from the spa circulation so the jet flow does not have to go through the filter and heater but it sounds like you were planning on that anyway.

So if you would like me to run some simulations, I will need some additional information:

Run lengths from pool to equipment.
Number of pool returns and eyeball size (3/4", 1")
What is the flow rate requirement for the spa jets and the orifice size for each type of jet?

On the spa jets, you may actually need a second pump depeding on the flow rate requirements of the jets. 12 jets at 25 GPM each would require 300 GPM and not even two Intelliflos can really accomplish that well.

 

[friendswoodnewbie]

Re: New build in Friendswood now with pics......

Mark,
Thank you for looking into this.
From the drawing I measure the following:
About 68 ft from main drain to pool pump
About 32 ft from one skimmer to pool pump
About 96 ft from the other skimmer to the pool pump
About 40 ft from the spa to the pool pump

There should be 5 pool returns. I don't know about the eyeball size. What would you recommend? I understand the plan is to run one 2" line from the pump to a 'ring' around the pool and from that ring feed into 5 returns - everything in 2". Just intuitively that 2" pipe sounds a little small to feed those 5 returns but the flow may be low enough to justify it (from one of your tables it looks like less than 6 ft/s). Running dedicated 2" piping to all 5 returns all the way from the equipment sounds a little excessive but let me have your thoughts.
We have not selected spa jets yet but of course it would be great to be able to select some nice ones and not be limited by the equipment. Recommendations are welcome :-D

For the spa I was thinking that perhaps it would make sense to have the 8 jets on one dedicated Intelliflow pump (no filter=very little restriction=high flow rate). Then the 4 leg jets could be hooked up to the main circulation pump, filter and heater (and SWG). That flow rate would not need to be so high. Does that make sense?
The third Intelliflow would then just take care of sheer descents but with the two 6' sheers that may even be a tall order.
With the Quad DE 100 filter and 2.5/2" piping, do you think a reasonable expected head loss is around 20-25 feet at 52 gpm?

 

[mas985]

Re: New build in Friendswood now with pics......

With five returns, it make sense to feed them with a loop so that is ok. The main choice is what size pipe to use. I would still recommend having separate runs on the suction side but you don't need them on the return side. So I looked at three separate scenarios for the pool with 3 separate suction lines and a single return line with 1" eyeballs. These numbers should be representative but will depend some on how the plumber actually configures the plumbing.

2" Plumbing
2000 RPM, 66 GPM, 23.5' of head, 6.24 gallons/watt-hr
1000 RPM, 33 GPM, 6' of head, 13.53 gallons/watt-hr

2.5" Plumbing
2000 RPM, 72 GPM, 21.7' of head, 6.54 gallons/watt-hr
1000 RPM, 36 GPM, 5.5' of head, 14.51 gallons/watt-hr

3" Plumbing
2000 RPM, 75 GPM, 21' of head, 6.65 gallons/watt-hr
1000 RPM, 37 GPM, 5.3' of head, 14.89 gallons/watt-hr

As you can see, every time you step up to the next size, the improvement is less. You have to decide what works for you but they are all viable designs.

As for the spa, if I assume that you have 7/16" nozzles which are typical and 3" plumbing, the maximum flow rate for the Intelliflo would be about 142 GPM @ 55' of head or about 18 GPM/jet @ 10 PSI which are fairly weak jets. If you step down to 3/8" nozzles, flow rate will drop to 15 GPM/jet but @ 13 PSI each, they would feel stronger. 10 PSI is considered a weak jet, 15 PSI a moderate jet and 20 PSI a strong jet. So you need to figure out the jets that you want and what they will require in terms of flow rate. Then you can decide how to power them. Also, the Intelliflo is an expensive jet pump. Unless you need to have multiple speeds, you might be better off with two jet pumps but again it depends on the type of jets you choose. But remember, the higher the flow rate per jet, the larger the pump(s) are required. But on the other hand, lower flow jets are not as nice as the higher flow jets although they may feel stronger. This is one of those personal preference things that nobody can really tell you what to do, you will need to make those decisions yourself.

BTW, this is one of the reasons that some people have chosen to go with a stand alone spa because they will simply work much better than an attached spa plus you can wet test one. But again, it is personal preference and some like the look of an attached spa.

 

[friendswoodnewbie]

Re: New build in Friendswood now with pics......

Mark,

Thank you very much for looking into my numbers. When you say 2.5" and 3" plumbing I assume that is both suction and return?

It sounds like it will be OK to stick with 2.5" suction and 2" returns for the main pool/circulation. My hope is to be able to run the pump at the lower flow to get e.g. 1.5 turns a day while only having around 6' of head (@ 1000 rpm)

For the spa, I will have to talk to the PB about jets/nozzles. I think I will go with the 3" pipe. Would that be both for suction and return?

I will also have to see if it makes sense to put the 4 leg jets on the main pool pump. We have a meeting with him scheduled tonight.

I really appreciate this input. Now I feel I can have a more intelligent discussion with the PB tonight and hopefully arrive at a very good solution for our pool.

 

[Guest]

Re: New build in Friendswood now with pics......

I'm just going to ask the question: Why would you come in from the pool in 2 1/2" and go out with 2"? If you put 1,000 cars on a one lane highway and 1,000 cars on a 4 lane highway, which highway do you think would flow best? Now, take the 4 lane highway and skinny it down to the one lane highway; does traffic flow the same or does it slow down?

I can't understand the rationale of changing pipe sizes, so I am just curios as to what the train of thought is here.

 

[mas985]

Re: New build in Friendswood now with pics......

Thank you very much for looking into my numbers. When you say 2.5" and 3" plumbing I assume that is both suction and return?

Yes, I did it that way just to make things simple.

It sounds like it will be OK to stick with 2.5" suction and 2" returns for the main pool/circulation. My hope is to be able to run the pump at the lower flow to get e.g. 1.5 turns a day while only having around 6' of head (@ 1000 rpm)

Yes, it isn't going to make that much difference but the reason that the PB chose 2.5" for the suction could be because he was planing to tie the three suction ports together at the pool and send only one pipe back to the pad. I would not recommend this and in fact I would choose 3 - 2" separate runs over a single 2.5" run. So find out what he had in mind.

For the spa, I will have to talk to the PB about jets/nozzles. I think I will go with the 3" pipe. Would that be both for suction and return?

Yes


Also, to address Bruce's question regarding pipe size and why not go with both 2.5" pipe, for comparison, I added the 2"/2.5" scenario to the list:

return/suction size

2"/2" Plumbing
2000 RPM, 66 GPM, 23.5' of head, 6.24 gallons/watt-hr
1000 RPM, 33 GPM, 6' of head, 13.53 gallons/watt-hr

2"/2.5" Plumbing
2000 RPM, 67 GPM, 23.2' of head, 6.28 gallons/watt-hr
1000 RPM, 33 GPM, 5.9' of head, 13.66 gallons/watt-hr

2.5"/2.5" Plumbing
2000 RPM, 72 GPM, 21.7' of head, 6.54 gallons/watt-hr
1000 RPM, 36 GPM, 5.5' of head, 14.51 gallons/watt-hr

3"/3" Plumbing
2000 RPM, 75 GPM, 21' of head, 6.65 gallons/watt-hr
1000 RPM, 37 GPM, 5.3' of head, 14.89 gallons/watt-hr

As you can see there is very little difference between 2"/2" and 2"/2.5". Increasing the size on the suction doesn't do much because the head loss is already very low due to the multiple suction runs. However, the 2.5"/2.5" is a big jump from the 2"/2.5" so it is worth it to upgrade to all 2.5" as long as the PB doesn't charge you too much more. If he is going to charge you a lot then counter that you would now like all 2" and save the differential he gave you for the all 2.5".

 

[friendswoodnewbie]

Re: New build in Friendswood now with pics......

Well, we signed the contract

I was promised a complete plumbing layout suggestion soon so I will return with more details but for the main pool, the current set-up is 2.5/2". Yes, it may not make a lot of sense with different suction and returns but that seems to be their standard and for the small differences I did not see a big reason to argue that point. I guess the one suction (+2 skimmers) vs. 5 returns does make it somewhat justifiable? I will make sure they don't combine suction and skimmers at the pool.
For the spa, the current set-up is 3" suction/2.5" returns leading into jets. The jets are apparently a special upgrade jet assembly - either rotating or pulsating but we could also choose one or several just be an open pipe which will most likely give more flow. We kind of left that open until we have seen examples of both in some of their other builds.

I will be back with more.......

 

[Guest]

Re: New build in Friendswood now with pics......

Congrats on signing the contract!!

 

[friendswoodnewbie]

Re: New build in Friendswood now with pics......

We have finally nailed down all the plumbing details (I think.....)

Please let me know if this sounds reasonable:

All pumps are the Intelliflow 4 x 160
Pump 1 (main circulation):
Suction piping:
2.5" from main drain and
2" from each of the two skimmers
2" suction from spa
All suction piping goes all the way to the pad
Returns:
2.5" to loop around pool (which will be 2") - 5 returns from that loop into the pool
2" spa return which will feed 4 leg jets and will also be used when we want to heat the spa
2" for bubbler on tanning shelf (will probably be throttled way back most of the time)

All flow coming through pump 1 will go through the filter (Quad 100 DE), through the heater and the salt cell (IC60).
I did, however, think that 90+% of the time we will not be using the heater so it seemed wasteful to go through the heater all that time and paying for that head loss. The PB agreed to put in a manual valve to bypass the heater. Does that sound reasonable?

Pump 2 (spa pump): 2.5" suction from spa and 2" return to the 2" loop around the spa feeding the 8 jets (not going through filter or heater or anything else)

Pump 3 (water features): 3" suction from closest place in pool
Returns:
One 2.5" return to each of the two 6' rainwalls (separate runs all the way)
One 2.5" return feeding the two 2' sheer descents (splitting off near the pool)

PB also agreed to make all 45 Deg bends - no 90's. I think that is a very good detail.

There will also be an air pump (I think they said 2 HP) and the cleaner booster pump (0.75 HP, I believe)

My main concern is the manual bypass of the heater. Have you heard of that before? Should I have a little flow though the heater to avoid stagnant water?
Obviously, it is critical to remember to turn the valve to allow all flow through the heater when we want to heat spa and/or pool.

If the weather behaves we should start digging this week. We can't wait......
I will start taking pictures when there is something to look at........

 

[mas985]

Re: New build in Friendswood now with pics......

Pump 2 (spa pump): 2.5" suction from spa and 2" return to the 2" loop around the spa feeding the 8 jets (not going through filter or heater or anything else)

With 8 jets, I would go with at least 2.5" on the return. 2" is too small and may result in weak jets.

Also, I am a bit confused on the spa plumbing. In one part you mention that the jets will be used for heating? Normally with a separate jet pump, the jets are run off of one pump and the circulation is run through a separate spa return eyeball. Otherwise you will be mixing the plumbing and require a lot of valves.

My main concern is the manual bypass of the heater. Have you heard of that before? Should I have a little flow though the heater to avoid stagnant water?
Obviously, it is critical to remember to turn the valve to allow all flow through the heater when we want to heat spa and/or pool.

Since this will be on the circulation loop for both the spa and pool, it will normally be run at lower RPMs so the extra head loss of the heater will not be a big impact. It doesn't hurt anything to have a bypass but you will probably end up leaving it closed most of the time.

Note too that with some heaters, if water is not flowing through the heater at all tiimes, a safety blower will kick on. So if you plan to bypass the heater, you might also have to turn it off. Another thing to consider is that some heaters have a built in bypass so when water flow gets too high, it will automatically bypass water around the heat exchanger.

 

[friendswoodnewbie]

Re: New build in Friendswood now with pics......

Mark,

Thanks for looking into this again.

I will get them to change to 2.5" for the spa return. It will go into a 2" loop around the spa but that seems OK to me (it is essentially 2 x 2" piping once you enter the loop, right?)

The spa will have 8 (back) jets purely for circulation with suction from the spa. (Pump 2)

Then there will also be a separate suction from the spa going to the main circulation pump, through the filter and heater and back to the spa (through 4 jets/pipes down low in the spa/calf height). When we heat the spa only the 4 leg jets will bring in the warm water but getting the warm water down low should also minimize the heat loss. Does that make sense?

Maybe, I am overthinking this pressure drop over the heater. I just want to have the minimum pressure drop for 'normal' operation and a bypass valve seemed to make sense for the vast majority of time we don't use the heater. I will check if the heater itself has any sort of bypass built-in.

I am certainly aware that the heater will not work without flow (I would hope it kicks off automatically, otherwise it could get really ugly....)

When we are talking running the main circulation on low flow, I guess the bottleneck will really be the skimmers, right? The minimum flow that will allow skimmer action (and still achieve the say 2 turns a day) is the optimum, it seems. I may end up with e.g. 20 hours on very low flow (1000 rpm) and 2 hours on high/medium flow (2500 rpm) to have the skimmers work.

Is the very low flow a problem for the salt cell? I found out that our pool may only be ~25,000 gallons so the IC60 will need to be run on a very low setting (hopefully lasting a very long time.... )

Does this sound reasonable?

 

[friendswoodnewbie]

Re: New build in Friendswood now with pics......

After the freeze (yes, even in Houston!) we finally got started.

The excavation, rebar and stub-outs was all done in 3 days. Those guys are amazing at doing their jobs.

I have posted some pictures below.

Gunite will be tomorrow - we can't wait.

Bobcat arrived

Just getting started

Grass removed

Lots of dirt to move.....

What a mess - soil was wetter than we thought....

Getting deeper....

Main drain

Column - amazing how they can bend the rebar. I wouldn't want to arm-wrestle those guys!

Spa rebar

I will post a few more with the skimmers and spa plumbing in place......

 

[friendswoodnewbie]

Re: New build in Friendswood now with pics......

Last pictures before gunite....

Spa plumbing seen from house

Picture taken towards the deep end

Spa plumbing - you will notice the 8 back jets coming from the spa pump (including the air piping) and the 4 bottom/leg jets coming from the main circulation pump/heater. You can also see the 2 suction pipes in the bottom.

Skimmers and pool lights (we decided to move one pool light further over toward the deep end

Big gunite day tomorrow.....

 

[JasonLion]

Re: New build in Friendswood now with pics......

When we heat the spa only the 4 leg jets will bring in the warm water but getting the warm water down low should also minimize the heat loss. Does that make sense?

Low or high inlets for heat doesn't make all that much difference. You will have enough water movement in there that the water will be throughly mixed in either case, even when the pump is on low.

Maybe, I am overthinking this pressure drop over the heater. I just want to have the minimum pressure drop for 'normal' operation and a bypass valve seemed to make sense for the vast majority of time we don't use the heater. I will check if the heater itself has any sort of bypass built-in.

Most heaters have a built-in bypass, which usually maxes out around 100 GPM. Adding an external heater bypass does help a little, but you have to remember to use it, and most people would rather not be bothered for the small difference it makes.

I am certainly aware that the heater will not work without flow (I would hope it kicks off automatically, otherwise it could get really ugly....)

All heaters will turn off if there is neither flow nor pressure. Some will stay on when there is pressure but not flow. As long as the bypass closes off both the inlet and the outlet the heater should turn off. However, those flow sensors can fail, so there is some risk in the unlikely event of a flow sensor failure.

When we are talking running the main circulation on low flow, I guess the bottleneck will really be the skimmers, right? The minimum flow that will allow skimmer action (and still achieve the say 2 turns a day) is the optimum, it seems. I may end up with e.g. 20 hours on very low flow (1000 rpm) and 2 hours on high/medium flow (2500 rpm) to have the skimmers work.

Some people get perfectly fine skimmer action even on low, others have problems. Generally the variable speed pumps are not most efficient on their very lowest speed. By the time you turn them up to their most efficient speed there is often enough flow to take care of the skimmers.

If you don't have enough flow, the ideal thing to do is to turn up the pump speed three or four times a day for about 15 to 30 minutes, but not all the way to high, just enough to work. Of course not all automation systems/timers allow that many speed changes to be configured.

Is the very low flow a problem for the salt cell? I found out that our pool may only be ~25,000 gallons so the IC60 will need to be run on a very low setting (hopefully lasting a very long time....

The SWG needs a certain minimum flow to work. Usually they require something around 15 to 25 GPM to work. Again, most pumps actually put out that much flow when on their ideal speed, so it is rarely a problem.

 

[friendswoodnewbie]

Re: New pool build - now with real construction pics......

Jason,
Thanks for commenting.

I think I may waive that heater bypass anyway. I will see if I can find the actual heater head loss anywhere. The small improvement may not be worth the hassle of manually turning the bypass valve when we want to heat the spa. Also, the risk of a sensor failure is not nice to consider :?

For the 4 leg jets, you are probably right the difference in heat loss is marginal but the main point was to use the 8 back jets on a dedicated pump with no filter, heater etc restricting the flow to get maximum spa jet action.

For the skimmer minimum necessary flow, I really hope we will be able to run as you describe - low flow most of the time and just higher flow for several shorter periods during the day. I guess I will know a lot more a few months from now..... :-D