1963 pool resurection

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Awesome mark. You're the man when it comes to this stuff.
I think his reasoning is closer to what melt is saying about a separate spa loop for the jets because he is concerned about 3" of water being forced through the heater coils. Are we talking about 2 different methods here?
Does the 3" actually feed into filter and heater and then return to spa or are we talking about a loop separate from filter and heater? Now I'm starting to get confused as to whether or not we are picturing the same thing.
I'm gonna have to draw out what I think and compare with his drawing to be sure.
Although adding a separate pump might really crank out the spa it just doesn't seem energy/cost efficient if not necessary.
Thanks guys.
 
There are two ways to plumb a spa, single pump or dual pump. With a dual pump, a jet pump is dedicated to only the spa jets with no other plumbing. The spa heating and filter is accomplished by the primary pump on a completely separate loop with separate returns. This allows you to run the jets completely separate from the heater/filter. So once the spa is heated, you could switch the primary pump back to pool mode or a waterfall while the spa jet pump runs on it's own for just the jets. The advantage to this is that the spa pump can be sized for just the jets and the extra head loss of the heater and filter do not come into play so the spa jet pump can be a little smaller. Also, the disadvantage of a single pump setup is that you will be sending high flow rates through the filter so filter will either need to be super sized, which isn't a bad idea either, or you will need to put in a bypass around the filter and heater to minimize head loss as well as prevent filter damage. Of course the disadvantage of a dual pump system is extra cost and when you use a VS pump, you won't be able to adjust the strength of the VS pump. So there are trade-offs either way.
 
ok. so let me see if i get this, if we use 1 3hp vsp for pool and spa 8 jets, we should have a bypass around filter and heater with the 3" pipe to avoid the high pressure in each causing problems.
that seems to be what he is thinking about having 3" pipe to and from spa.
maybe he is not thinking about bypass.
maybe it will help to list equipment again;
Pentair easy touch 4 w/ic40, screenlogic 2 wired and wireless, intelliflo vs 3hp, ccp 420 cartridge filter and raypak 400k natural gas heater. possible intelliph system as well and will plumb for future solar. spaside remote.
7' round spa raised 18" attached to approx. 20k gallon pool. one skimmer, split main drain, 3 returns all 2" except spa plumbing which will be 3" suction and return for 8 jets.
is this a reasonable set up? would i need to bypass for this set up or would it best to add a jet pump to the equipment now while we still have the opportunity? spa has 24"spillover into pool with no waterfalls or any other water features other than future solar.
thanks for clearing this up for me before i meet with pb again so i can understand both options. we are overkilling this install because we can now not later. that's just how i roll. overkill.lol
 
just got off the phone with him, he wants to order plumbing supplies tonight and is trying to talk me into 2 1/2" pipe for spa. reasoning is that filter and heater size down and even the pump has just 2" fittings so it is going to be reduced there and when it hits the manifold at the spa itself. also that having to encase pipe in concrete a minimum of 3" on each side will make the spa walls huge and just not recommended for residential spa.
after a little conversation he has agreed to run a bypass to eliminate the need to push through filter and heater just so i wont be upset later that we didn't. he states that i probably wont feel the difference but to avoid problems down the road with my being unhappy will comply.
he also uses the 1/4hp method of calculation.
question; in doing so, wont i lose the ability to push heated water through my jets? if so wouldn't it better to let him down size to 2 1/2" pipe so i could have the jets heated?:confused:
 
According to basic flow rates , 15 gpm x 8= 120. For the spa jets.
3" pipe should have a flow rate of 140 at 6 ft/s.
Ccp420 can handle a flow rate of 150 gpm.
Why bypass at all?
Won't the reduction in the filter be enough to protect the heater?
Am I missing something?
 
ust got off the phone with him, he wants to order plumbing supplies tonight and is trying to talk me into 2 1/2" pipe for spa. reasoning is that filter and heater size down and even the pump has just 2" fittings so it is going to be reduced there and when it hits the manifold at the spa itself. also that having to encase pipe in concrete a minimum of 3" on each side will make the spa walls huge and just not recommended for residential spa.
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Again, your PB does not understand hydraulics. Everything adds head loss. When you go to 3" pipe, it reduces the head loss of those components. But if 3" is given him heartache. Suggest two loops of 2 1/2" pipe with 4 jets each that will work fine too. For the MD, you can also bring both drains back to the pad individually with 2 1/2" pipe. You are really going to have to trust me on this, it will be worth it. You just need to search the forum and there are many posts about poorly designed spas with weak jets.


3" pipe should have a flow rate of 140 at 6 ft/s.
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This is one of the reasons why you want 3" pipe or at least 2x2 1/2" pipe. VGBA regulations require that the suction velocity not exceed 6 ft/sec. Otherwise the spa may not pass inspection.


Why bypass at all?
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To increase the life of your filter. Pounding it with 140 GPM may not damage the filter right away, but it will shorten the life of the filter. One of the reasons my filters have lasted 9 years is because I have a 1/2 HP low flow rate pump. My filter is rated at 150 GPM but if you read some posts, not everyone that has that filter has cartridges that last that long. Peak rate is one of the reasons.
 
I do trust you on this. That's why we're communicating. I'm trying to be able to fully understand what it is I'm trying to explain to him so it gets installed properly.
So to be clear we still want the bypass even if we go 2 loops of 2 1/2"?
Will this affect hot water in the jets?
He is willing to do whatever I want as long as he doesn't smell damage to equipment down the road from it.
Thanks again
 
Ok, so I ran some quick head calcs and flow rates. If you design the spa like the PB wants, you will end up with a flow rate of 94 GPM. Well below the 120 GPM required. Those will definitely be weak jets.

Adding dual suction and dual return lines at 2.5" brings the flow rate to, 100 GPM. Still not good enough.

With a bypass in, the peak flow rate is 122 GPM. So you can see there is a big difference when adding the bypass. It will also increase the life of the filter.

This is one of the reasons people go with a separate pump. It is easier to get the flow rates.

But if you have automation, you will want the bypass valve to be automated so when put into spa mode, the valve is set for bypass. When in pool mode, the bypass is not used. Also, I forgot to mention that you don't need to bypass all the water so that the heater can continue to work.
 
Jim, you probably don't want the jets to actually be heated...in my parents spa, when the heater kicks on, the water coming out is HOT! We all shimmy away from it until the heat kicks off again.

edit for clarification: they have a two pump system. Jets are unheated (drains -> big pump -> jets), the heated water comes in through the other loop (separate drain -> pump-filt-heat -> floor return. when the heat kicks on the water coming out by our feet is almost too hot to touch.
 

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Sorry for the confusion but you don't need 3" on the pad. 2 1/2" is fine. Head loss is proportional to the pipe length and lengths are very short on the pad so not so much real benefit there. Standard Jandy 3-way valves with an actuator are fine. Just like the one used for the pool to spa switch over.
 
No 3" at all. The PB wants 2 1/2" pipe so just use that up to the pad and including the pad itself. The two suction suction lines will be teed together and the two jet lines will be teed together at the pad in a header configuration. Your PB should know how to do that.

Similar to this but not so many lines:

cache_2664431.jpg
 
I must have missed the switch.
We are now talking about 2 loops of 2 1/2" pipe bypassing instead of 1 3". Which in turn means double drains as well? Total of 4?
Then the 2 loops T together at the pad into one 2 1/2" pipe? Bypassing or no?
I think I might be getting more confused. :confused:
Ok, reading back now I see you were talking about 2 loops of 2 1/2". But my question about drains remains, does that also mean 2 sets of split drains in the spa?
He may have already bought and possibly installed the 3" if so, then wouldn't I need a 3" automated bypass valve?
I'll be home in a couple hours and hopefully he will be there to clear this issue up.
 
dumbcluck said:
I must have missed the switch.
We are now talking about 2 loops of 2 1/2" pipe bypassing instead of 1 3". Which in turn means double drains as well? Total of 4?
Click to expand...
No

So starting at the MD. There are two. For each MD, run a separate 2 1/2" pipes to the pad. If they have separate pipes, they don't need to be teed at the spa.

Once at the pad, the two suction pipes are then combined via a tee header.

That pipe will then be valved with the pool suction pipe in a 3-Way valve.

After the 3-way a single pipe goes directly into the pump.

After the pump comes the bypass 3-way valve which spilts the flow and one port goes to the filter. The second port will reconnect with the spa return lines but before they are split into two for the two loops.

After the heater, there is a 3-way valve which splits the return to either the pool or spa.

The spa return line then has the bypass connection.

After than, the spa line is split into two lines which go to the two sets of spa jets.

All plumbing is still 2 1/2" and there is only one bypass line around the filter and heater and pool/spa valve.
 
No, all jets are heated. The bypass is a partial bypass. Some of the water goes through the heater and to BOTH sets of jets. Look at the drawing again.
 

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