Looped Return

[luna31d]

How important is looped returns?

Some builders are quoting looped returns others are not.

Pool with be inground gunite, 22,000 gal, 115 ft perimeter. Equpment pad will be 50-70 ft from pool.

I have asked for 2" minimum suction with (3) direct runs to the equipment pad. (1) from each skimmer and (1) from the main drains.

I am not sure on the looped returns. My goal is to have energy efficient plumbing

Thanks

 

[PoolGuyNJ]

Looping is more important in a spa to equalize the return flow to each jet. It doesn't do much to reduce head loss.

Scott

 

[Bama Rambler]

Depending on where your returns are located in relation to the equipment it may be better to run individual lines to each rather than a loop to all.

 

[Guest]

Loop 'em! I loop all the pools that I build, and not only does it equalize the flow of all of the returns, the pumps run way quieter. You are right on with your larger diameter plumbing as well (I like to have the same size coming and going), and you may even consider going up to 2 1/2", depending on your pump size.

The little amount of extra pipe to create a balanced. equalized system is, in my opinion, well worth the minimal added expense.

 

[New2Me]

Some builders are quoting looped returns others are not.

Ask them to quote it both ways, and then tell you which way they think is better, and why.
You don't mention it, but are they using rigid or flexible pipe? PVC or Poly? There can be BIG differences in costs.
IMHO. Looped will be cheaper, as there is less pipe going to the pad, and may not cause you any problems. BUT, (and that is a big but.) individually piped returns allow you much more flexibility in the future, especially if valves are put on each line, so that you can equalize flow. You don't say anything about wanting a pressure side cleaner now , but with looped you will need to run a new line later; with separate lines, you can just dedicate one existing line to cleaner use, valving down the flow to the other lines if need be to run it. Or, Swimming Gods forbid, you get a leak in a line ( what, termites eat flexible PVC but not rigid???); with a looped line you are out of circulation as you plug all of your returns to stop the leak, with separate lines you can isolate the leaking line and use the others while you rally the repair team. For a truly balanced loop system, I would think that it would need to have the loop supplied at several locations evenly spaced around it, or it is no different then a common header with separated runs( and no way to isolate them.) A hydraulic engineer could tell you if the length of runs, and the number of turns, valves, etc.. for your pool would make any performance difference, one way or the other, as I am no expert. Unless you want higher head pressures, I've heard that bigger pool piping is always better, though!
Pipe is rather inexpensive to put in the ground now, especially compared to trying to do it later!
Good Luck, and Best Wishes!!!

 

[mas985]

Looped returns may help a bit to equalize flow between returns but the only way to guarentee equal flow rates in all returns is to use binary splits with equal lengths. A loop will still have some unequal path lengths and head loss while a binary split always has equal head loss between the returns. However, plumbers prefer loops because they are easier and take less time to do. Theoretically, you could design a serial feed line which would have equal head loss to all returns but that would require a bit of math to work out. But even without doing the math, a serial feed of returns is not all that bad in terms of flow rates between the returns but it does depend upon how it is done and how many returns you will have. If a large enough diameter pipe is used with tees to feed the returns, then the head loss in the header pipe will be insignificant compared to the smaller runs to the return. So bottom line is that there are a lot of ways to equalize the flow rates.

 

[Guest]

( what, termites eat flexible PVC but not rigid???)

I have heard this before (a couple of times). Is that a fact or an urban myth?

 

[bk406]

I vote myth

 

[PoolGuyNJ]

Fact. I've had to replace quite a few over the years. The little buggers hear/feel the water, want the moisture and chew to get at it. White flex and Tiger Pipe are susceptible. Black poly and hard pipe are not.

Scott

 

[lbridges]

Re: termites.

Here's a link to place that sells the stuff (see their name) that has a warning): http://flexpvc.com/application-guidelines.shtml

 

[Bama Rambler]

Not sure about termites but I've seen plenty of black poly eaten into by ants. I don't ever remember seeing hard PVC eaten by them.

 

[Guest]

I found it interesting that the link states that they are not responsible for rocks rubbing through flex pipe. I absolutely do not allow flex in any of my projects, and that is one of the reasons why. Tie wire, rebar, nails, etc. are all other reasons why I firmly believe flex has no place in a swimming pool. I'm sure it has its uses elsewhere, but I don't work on those kinds of projects

Interesting about the termites. Someone once told me they think it is "candy"! Not sure where they learned that from

 

[Guest]

I have a 8' attached spa that has ten jets. 4 returns from the filter pump and 6 returns from the booster pump. For whatever reason the plumber looped the 6 booster returns and NOT the 4 filter returns. The 6 booster returns have equal pressure on all six, but the 4 returns from the filter side do not. #1 has high pressure, #2 little less, #3 even less and #4 has very little. So, just from my experience... I would loop! As for running individual lines with a manifold type return, this would also work, but I think your chances of having a leak is much greater. More pipe... more fittings... greater the odds!

 

[luna31d]

Thanks for all the responses.

I will be using sch40 PVC. No flex. And I do plan to have a pressure type cleaner independant return(polaris 280).

 

[Guest]

Thanks for all the responses.

I will be using sch40 PVC. No flex. And I do plan to have a pressure type cleaner independant return(polaris 280).