Plumbing Schematic Review - Help?

[Brant]

Here is the flow rate and impact force for each of the configurations assuming a separate spa jet pump and separate plumbing:

6 Jets 3" pipe: 17.8 GPM & 1.99 lbf
8 Jets 3" pipe: 16.0 GPM & 1.60 lbf (25% reduction from 6 jets, 3)

6 Jets 2.5" pipe: 16.9 GPM & 1.79 lbf (5% reduction from 6 jets, 3") Out of APSP compliance for suction side velocity (6.79 ft/sec)
8 Jets 2.5" pipe: 14.8 GPM & 1.38 lbf (9% reduction from 8 jets, 3") Out of APSP compliance for suction side velocity (7.95 ft/sec)

For 6 jets, 2.5" or 3" is ok but for 8 jets, you definitely need 3" to maintain less than 6 ft/sec in the suction line.

Also, sheer descents require high flow rates and low head loss so a waterfall pump is really more appropriate for that and doesn't cost as much as a VS. The bubblers could then be run off the main pump.

OR, you could run all the water features off the main pump because they are usually much lower head loss than a spa jet so running all 5 features should not be an issue.

i guess im leaning towards 2 VS pumps. one for pool/heater and one for jets/features. unless you see a major issue with this. Or add a feature only pump for the waterfalls is an option. what pump would you recommend if i went this route?

there are too many options. this is harder than i thought it would be.

edit- im just going to go with 3 VS pumps. bite the bullet on cost. it gives me a backup pump if one fails.

 

[mas985]

i guess im leaning towards 2 VS pumps. one for pool/heater and one for jets/features. unless you see a major issue with this.

The sheer descents requires a filter which will reduce flow rate for the jets as well unless you put in a bypass when using the jets. But it also prevents you from using the water features when in the spa.

Or add a feature only pump for the waterfalls is an option. what pump would you recommend if i went this route?

there are too many options. this is harder than i thought it would be.

The AFP-120 should produce around 80 GPM on simplified plumbing, filter with 2.5" suction and 2" return.

 

[ajw22]

i guess im leaning towards 2 VS pumps. one for pool/heater and one for jets/features. unless you see a major issue with this. Or add a feature only pump for the waterfalls is an option. what pump would you recommend if i went this route?

there are too many options. this is harder than i thought it would be.

Three pumps using a waterfall pump will make the IntelliCenter programming and controls straightforward.

Looking at the diagram telling the IntelliCenter to turn two valves and turn on the pump could get awkward. I have not seen anyone doing that. The IntelliCenter should be able to do it but we have seen other things that it should be able to do and it can’t.

I would keep things simple and go with 3 pumps.

 

[Brant]

The sheer descents requires a filter which will reduce flow rate for the jets as well unless you put in a bypass when using the jets. But it also prevents you from using the water features when in the spa.


The AFP-120 should produce around 80 GPM on simplified plumbing, filter with 2.5" suction and 2" return.

yeah, i edited my other posts and removed the schematics. im going to 3 pumps- all the same variable speed. that way i have a spare. if something goes out.

on the filter... i considered a cyclone as they supposedly do have a lot of flow restriction. do they only catch sediment? do you have something else in mind- like a strainer basket?

 

[Brant]

Three pumps using a waterfall pump will make the IntelliCenter programming and controls straightforward.

Looking at the diagram telling the IntelliCenter to turn two valves and turn on the pump could get awkward. I have not seen anyone doing that. The IntelliCenter should be able to do it but we have seen other things that it should be able to do and it can’t.

I would keep things simple and go with 3 pumps.

will do!

 

[mas985]

The spa jet loop doesn't really require a filter. Mine does not have one. A filter is really only necessary for the sheer descents and general water filtering. For the spa, there is a separate loop for filtering through the main pump.

 

[mas985]

Also, note that with a Hartford loop, a blower should not be necessary. My spa does not have/need one. I get plenty of bubbles without the blower. Blowers are mainly used for air lines that do not have a Hartford loop so the blower is necessary to blow out the air lines before the venturis can work properly. With a Hartford loop, the air line does not fill up with water so it is easier for the venturis to clear the line. I would use a 2.5" air line as well.

 

[Brant]

The spa jet loop doesn't really require a filter. Mine does not have one. A filter is really only necessary for the sheer descents and general water filtering. For the spa, there is a separate loop for filtering through the main pump.

Yeah, I understand no filter on the jets. What do you recommend for a sheer filter? Something that can flow at least 80 gpm?

 

[ajw22]

Yeah, I understand no filter on the jets. What do you recommend for a sheer filter? Something that can flow at least 80 gpm?

This is the Jandy recommended filter…

Filter/Strainer, Zodiac/Jandy Sheer Descent, 60Gpm

Zodiac Pool Systems Filter/Strainer, Zodiac/Jandy Sheer Descent, 60Gpm - Item 43-100-1002. Save on this and other Zodiac Pool Systems replacement pool & spa parts from Hydropool.com.

www.hydropool.com

 

[ajw22]

 

[Brant]

View attachment 553053

Thanks for the info.
I have a question about the 3-way valve and pool return they state is needed for balancing. Is this also required in my situation if I use a VS pump? If I install a variable speed pump and separate diverter valves upstream of the sheers, wouldn't I be able to dial in the pump speed and throttle the valves to balance the sheers and achieve the correct flow/pattern? Seems like this would be the case. The only reason I see a need for a 3-way valve returning to the pool would be to bypass any excessive pump discharge back to the pool if the pump was constant speed.

Thoughts? Or am I misunderstanding the reason for this 3-way valve and return line?

Also, do you think I could use this RTL50 Pentair filter instead of running two parallel smaller filters? It's a Pentair filter with a max flowrate listed at 100 GPM and my sheers will need approximately 72 GPM total.

Dynamic RTL50 Cartridge Filter II Top Load 50 Square Feet

Pentair Dynamic RTL50 Cartridge Filter II 50 SF - R172504B

The Pentair Dynamic II Model RTL50 Cartridge Filter is a top load high flow filter and is sized at 50 square feet with a max flow rate of 100 GPM and features 2 inch socket plumbing size. The Dynamic Cartridge Filters are designed for spas, hot tubs and small swimming pools. They include a 3...

www.poolweb.com

 

[ajw22]

Thanks for the info.
I have a question about the 3-way valve and pool return they state is needed for balancing. Is this also required in my situation if I use a VS pump? If I install a variable speed pump and separate diverter valves upstream of the sheers, wouldn't I be able to dial in the pump speed and throttle the valves to balance the sheers and achieve the correct flow/pattern? Seems like this would be the case. The only reason I see a need for a 3-way valve returning to the pool would be to bypass any excessive pump discharge back to the pool if the pump was constant speed.

Thoughts? Or am I misunderstanding the reason for this 3-way valve and return line?

I think the manual reflects the use of a single speed pump. Manufactuers often don’t go back and update their manuals for every new device.

Varying the pump speed will accomplish the same thing as that diverter overflow dump valve.

Also, do you think I could use this RTL50 Pentair filter instead of running two parallel smaller filters? It's a Pentair filter with a max flowrate listed at 100 GPM and my sheers will need approximately 72 GPM total.

Dynamic RTL50 Cartridge Filter II Top Load 50 Square Feet​

Pentair Dynamic RTL50 Cartridge Filter II 50 SF - R172504B

The Pentair Dynamic II Model RTL50 Cartridge Filter is a top load high flow filter and is sized at 50 square feet with a max flow rate of 100 GPM and features 2 inch socket plumbing size. The Dynamic Cartridge Filters are designed for spas, hot tubs and small swimming pools. They include a 3...

www.poolweb.com

I think so. But this is an example of leaving room in the actual plumbing so if some of these decision’s don’t work as you expected you know where you can remove this filter and install parallel Jandy filters in the pipes.

 

[Brant]

@ajw22
A friend is also building a pool at this time and he just sent me an email from a professional in the pool building industry. This is related to a question about his pool build and pumps for his spa and water features.

Here is the email he received...

Thanks for the email.
I would have a dedicated pump for the jets - Variable speed are not the best option for jets though as you want it running on the max that it can and VS are not designed to do this. Look for a large single speed pump instead.
.......

What are your thoughts on what he is saying about using a VS pump for a spa jets?

 

[mas985]

There is nothing wrong with running a VS on full speed all the time. In fact, it is slightly (~10%) more efficient than a single speed pump. Plus a VS allows you to adjust the strength of the jets which to me is a big plus. Sometimes you want jets very strong and sometimes not.

But this so called "pool professional" should know there is no choice in the matter anymore. DOE regulations mandate VS pumps for anything less than 5 THP.

 

[Brant]

@mas985
Had another thought/question...

If I'm now going to use a dedicated spa pump, could I get away with not installing the spring loaded bypass on the heater? The VS pumps provide a GPM flow rate reading, right? So in theory, I would know my flow rate through the heater when in spa mode. If I set the pump below the heater max allowable GPM flow, I wouldn't need to protect it. Additionally, any higher flow rate would just be wasting electricity anyway as the bypass would just be circulating the excess water and the heater wouldn't heat it.

Thoughts? Or should I leave it as a layer of protection for the heater?

 

[ajw22]

@ajw22
A friend is also building a pool at this time and he just sent me an email from a professional in the pool building industry. This is related to a question about his pool build and pumps for his spa and water features.

Here is the email he received...

Thanks for the email.
I would have a dedicated pump for the jets - Variable speed are not the best option for jets though as you want it running on the max that it can and VS are not designed to do this. Look for a large single speed pump instead.
.......

What are your thoughts on what he is saying about using a VS pump for a spa jets?

Mark had you covered.

And your prissy wife may want you to turn down the jets that only a VS pump can do.

Understand there is nothing that makes a Pool Professional special. There is no certification or training for construction or equipment.

 

[ajw22]

@mas985
Had another thought/question...

If I'm now going to use a dedicated spa pump, could I get away with not installing the spring loaded bypass on the heater? The VS pumps provide a GPM flow rate reading, right? So in theory, I would know my flow rate through the heater when in spa mode. If I set the pump below the heater max allowable GPM flow, I wouldn't need to protect it.

Since you are no longer running your high flow items through the main pool pump there is no reason to run that pump at high flow rates.

Additionally, any higher flow rate would just be wasting electricity anyway as the bypass would just be circulating the excess water and the heater wouldn't heat it.

That is incorrect. The heater puts out a fixed amount of BTUs regardless of flow rate. The bypassed water will get heated when it is combined with the heated water.

Thoughts? Or should I leave it as a layer of protection for the heater?

You can delete the flow bypass if you are going with three pumps.

 

[mas985]

@mas985
Had another thought/question...

If I'm now going to use a dedicated spa pump, could I get away with not installing the spring loaded bypass on the heater? The VS pumps provide a GPM flow rate reading, right? So in theory, I would know my flow rate through the heater when in spa mode. If I set the pump below the heater max allowable GPM flow, I wouldn't need to protect it. Additionally, any higher flow rate would just be wasting electricity anyway as the bypass would just be circulating the excess water and the heater wouldn't heat it.

Thoughts? Or should I leave it as a layer of protection for the heater?

There are several reasons for a bypass.

1) Flow rate protection of the heater but most NG heaters have fairly high max flow rates so that usually isn't an issue and it probably would not have been and issue for your heater as well given the flow rates with the heater in the loop is going to be limited to well below the maximum.

2) Head loss reduction. I think this is the real reason the bypass was suggested to increase the flow rate to the jets. But that has since gone away.

3) Heater isolation. There will be times where you might want to remove the heater from the circulation loop. Low PH treatment is one reason. So this is always a good reason to have a bypass although not mandatory.

 

[ajw22]

There are several reasons for a bypass.

1) Flow rate protection of the heater but most NG heaters have fairly high max flow rates so that usually isn't an issue and it probably would not have been and issue for your heater as well given the flow rates with the heater in the loop is going to be limited to well below the maximum.

2) Head loss reduction. I think this is the real reason the bypass was suggested to increase the flow rate to the jets. But that has since gone away.

3) Heater isolation. There will be times where you might want to remove the heater from the circulation loop. Low PH treatment is one reason. So this is always a good reason to have a bypass although not mandatory.

Mark, he has two bypasses in his drawing.

An Aquacal flow bypass and a diverter heater bypass.

Brant should delete the Aquacal flow bypass and keep the diverter bypass.

 

[mas985]

I don't think the heater would have exceeded the flow rate rating even without the AquaCal so I don't it was necessary to begin with.

In pool mode with 6x1" returns at full speed, flow rate would be less than 110 GPM even if all the flow rate when through the heater and I believe the requirement is 120 GPM.