Pumps / Valves

Here's where I spent a lot of time.  Not that I had to, but I really wanted to learn how pool plumbing works.  The reason for this is because I wanted the waterfalls to work a certain way.  There were certain scenarios that I wanted to make sure would work.  Specifically:

1. The waterfall should have two independent paths - one to the pool and one into the spa.

2. When spa is NOT being used, the waterfall path that goes into the spa should overflow into the pool through the spa damwall.  This gives a nice cascading effect.

3. When spa IS being used, the waterfall should still be operational.  It should have the option of going EITHER into the pool ONLY (cold water) or the spa ONLY (heated water).  I don't think I can have have both on at the same time (heated waterfall into spa and cold waterfall into pool) without having a separate pump.

4. The waterfall into pool/spa should be able to still work while the pool filtration/VAC is working.

5. The waterfall, lights, spa control should be able to be operated via a remote control switch inside the house.  I would like a spa-side remote as well for the spa functions.

6. I would like to do this on a single powerful pump (not including blower pump) if possible.

So as a rough first cut, I envisioned this for my valve system:

 The circles with the letters in them denote Jandy 3-port NeverLube Valves.  Here is the schematic for them.  The way they work is that water comes through one of the ports and can be diverted to either of the remaining two ports.  It can be diverted to one or both of the other ports, or any combination thereof.

I should mention that typically the pool plumber handles all the details of planning out the valves.  As the GC, I didn't need to know how to design the valve scheme.  I don't need to know the details of how a Jandy valve works or what a Jandy Actuator does.  I should be able to just tell the plumber how I want things to work (like described in the scenarios on the top of the page), and they should be able to make a recommendation.   They should be able to tell me what I can and cannot do.  But me being an engineer and wanting to understand everything, I WANTED to take a first crack at it.  More the fool I.

Anyways, getting back to the story, there were a few problems with this setup:

1.  The plumber said that there's no way that one pump is powerful enough to drive all this stuff.  (NOTE:  see what I mean about not having to know everything.  You can be sure the subs will tell you how stupid you are.  And believe me, thats a GOOD thing.  When you are a GC, don't let pride get in the way of having something done right.  After all, you're going to have to live with the finished product when you're done.)

2. I forgot to include the Therapy jets for the spa.

3. I had the skimmer and drain on separate lines.  The plumber corrected me, saying that the drain is typically tied to the bottom of the skimmer.  He said he could plumb it so that the drain is totally separate from the skimmer line, but that its not necessary.  He said that the pool vac will be more than adequate to suck up all the debris on the bottom of the pool and that having a drain work independently from the skimmer cost more $$$ and doesn't really help you any.

So I asked him to send me over what he the revised valve schematic should look like.  This is what he sent me:

The plumber said that he understood my desire to minimize the number of pumps, but that one 2HP pump would not be sufficient to drive everything I wanted.  He said that there should be a separate booster pump to drive the waterfalls.  Notice that the waterfall booster pump allows water to go to either the spa or to the pool.  I can actually have heated water coming down into the waterfall while the spa is in use.  Or if I don't want that, and other people are in the pool, I could turn the valve so that the waterfall is working only on the pool side.  And when the spa is not in use, the Jandy valve can be turned 50% to each port so that the waterfall is nicely split in half (half of the water goes into the spa and half into the pool).

On the filtration pump side, he added the therapy jets.  While this was a better scenario, and would definitely would work, he mentioned that there were a few drawbacks to this scenario:

1. Spa jets typically blast water at a fairly high pressure in order to create the therapeutic action (blower pump not shown).  He said that with the sand filtration system in-line, I was not going to get the optimal amount of pressure coming out of the jets as I would if I had gone with a separate pump for the jets.

2. The 2.0HP pump is overkill for the filtration system and being that it runs 8 hours a day, it will waste electricity needlessly.  The need for the 2.0HP pump is really for the jets.  For the filtration part of the circuit, a 1.5HP pump is sufficient, but since I have the jets in the same circuit, I need to put a pump that will be strong enough for both functions.  In order to optimize it, I could get a separate pump just for the jets and put a 1.5HP pump in place for filtration.

After much thought, I decided to get the third pump.  My reasoning was simple.  I was already going to save $15,000 from doing the pool myself.  I could afford to splurge an extra $350 for a pump to optimize things.  I liked that tradeoff.  So at the end of it, this is what we agreed to:

Its interesting that what looks good on paper rarely works in the real world without being tweaked a little bit.  When the plumber finally arrived and started assembling the valves, he noticed there were a few more problems.  Not big problems - He was just trying to optimize things at that point.  Here's what he found:

1.  

   For the filtration pump/valve scheme, he noticed that on the return side, if I accidentally turned valve (C) to close off the Spa return and valve (D) to close off the Pool return, the only water that would be flowing would be to the aerator, which is a tiny 3/4" PVC pipe.  That would be a bad day for the 1.5HP Hayward pump.  He said that its not likely it would happen, but if it did, I would burn out my pump in no time.  I said Ok.  So he proceeded to get rid of valve (D) so that there was just a plain "T" directing water to the pool return and the aerator.  He put a small turn valve on the aerator side so that I could just walk over and turn the aerator on manually whenever I wanted to use it.  Pretty simple.
   

   For the waterfall pump/valve scheme, he said that he typically likes to put a bleeder valve on the return side so that the waterfall water volume can be adjusted.  If the waterfall is blasting too much water out to the pool/spa, I can slowly turn it down by adjusting the newly added valve (F) to bleed off some of the water pressure.  The bleeder valve just runs out to the pool like any other return.
   

2. For the therapy jet booster pump, he said that the blower is not attached like shown in the picture.  Its attached separately. 

So after all the tweaking and fiddling, here's how my FINAL pump/valve scheme looks:

So at the end of it, this is what my equipment looks like:                     

• 1.5 HP Hayward SuperII Pump (Filtration System)

• 2 HP Hayward SuperII (Therapy Jets)

• 2 HP Hayward SuperII (Waterfall booster pump)

• 2 HP Blower Pump (Spa Jets - air)

• Triton TR 100 4.9 Sand Filter

• Hayward H-Series Natural Draft 400,000 BTU natural gas heater

• Hayward Ultra Pool Vac

• Jandy Never-Lube 3-port valves (6)

• Jandy JVA 2440 Actuators (3)

• Clear Water Salt Chlorinator

• Auto Water-Leveler

• Aerator