PB Pushing to Change Plumbing Design

[Glitterbub]

I am going to focus on the spa since that is really the problem with the setup. But do you know what the PB is planning for the pad pipe size? I will assume 2.5" unless stated otherwise.

3" suction, 2.5" return.

Also, how do you get 10 jets if you are using these:

It should be a multiple of 3 or are you counting this as one jet? How many manifolds are you planning to use? Was the 15 GPM for the 3 jet cluster or each jet? What source were you referencing for the 15 GPM?

Keep in mind those manifolds are for a single person so if you have 3 manifolds with 3 jets each, then only 3 people will get to use the jets. With standard venturi tees, you can position each jet for a single person. What is the size of your spa?

I am counting the manifold as three jets. There are two manifolds on the west side, each with three jets. I've planned for 15GPM for each of these jets (Source: https://www.waterwayplastics.com/manuals/810-0336.0512.pdf), for a total of 90GPM on the West. Two "normal" jets on the North. One "normal" jet on the East. One "normal" jet on the South. I've kept the "normal" ones at 15GPM as well for ease of calculation. I assume they will be some of the cheaper jets. 7 x 7 spa internal water width.

I wanted to get these answers to you. Will review what you posted in detail in a bit. Thank you for taking the time to respond.

 

[Glitterbub]

I am going to focus on the spa since that is really the problem with the setup. But do you know what the PB is planning for the pad pipe size? I will assume 2.5" unless stated otherwise.

Also, how do you get 10 jets if you are using these:

It should be a multiple of 3 or are you counting this as one jet? How many manifolds are you planning to use? Was the 15 GPM for the 3 jet cluster or each jet? What source were you referencing for the 15 GPM?

Keep in mind those manifolds are for a single person so if you have 3 manifolds with 3 jets each, then only 3 people will get to use the jets. With standard venturi tees, you can position each jet for a single person. What is the size of your spa?



That's correct. There is no difference to the pump. The only difference is water going through the filter (plus a bunch of other plumbing) and returning to the spa jets vs no filter. But it is very common to bypass the filter for spa jets. This is the way my spa is plumbed and 1000s of other pool/spas as well. Plus the pump has a basket to stop large debris.

So I put together a first cut at an analysis based upon what I think you were telling me but it might change depending your answer to the jet questions above:

Pool Pump Tools v027 - Glitterbub

docs.google.com

The first column shown (P), represents what the PB wants. The rest are variants of a separate loop for the spa jets:

P: PB Version, 10 jets, 3" plumbing - 105 GPM @ 64' of head

Q: Separate Loop, 10 jets, 3" plumbing - 137 GPM @ 51' of head

R: Separate Loop, 10 jets, 4" plumbing - 146 GPM @ 46' of head

Note that none of the scenarios reaches the 15 GPM per jet requirement but the one with 4" plumbing comes close.

These can easily be revised based upon any additional information you may have.

Also, if you are really set on 10 jets, then you might split them up between the two plumbing loops. I am still unclear if you are using the 3 jet manifold or not but you could put two manifolds on the separate loop and run one off the main pump through the filter/heater. This reduces the flow rate requirement through the filter and lifts some of the burden off the jet pump.

Thank you again for doing all of this work. Should line 116 change to 2.5" because all the returns are 2.5"? Unfortunately, I guess it looks like I'll only get 10GPM.

What happens if I close some of the other jets? We'll run the 6 and only turn on the other 4 if we have guests?