Please review my plumbing schematic

[JoyfulNoise]

Also, not sure if you're married to the idea of having a blower on the spa but many of the expert builders here will say that, if the spa plumbing is done right, a blower is unnecessary. Could save you a small bit of money to do away with it (and they are noisy!)

Also, have you considered running the waterfall using an entirely separate pump?

I only ask because water features like waterfalls are low head / high flow features. Unlike bubblers and returns, waterfalls and scuppers work best when the pressure is low but the flow rates are high. And open pipe water feature like that on a high head pool pump can cause the return side head loss to be so low that you can actually cause the pump to cavitate. I know because my pool was designed and built with a 3HP WhisperFlo pump to drive a waterfall and it is total overkill. I had to add a shutoff valve to restrict the flow and increase the back pressure on the pump return or else it sounds like a giant bag of marbles rattling around inside the wet end. Pentair makes waterfall pumps specifically designed to move lots of water at low pressure.

 

[Foosman]

Yeah, you don't want a bubbler running all the time. It will drive your pH up. Put a valve on it and only turn it on for parties or if you want to show off to the neighbor's.

I should have been a little more clear, I have a manual valve on the bubbler...I'm just planning to not have it automated. I suppose if it becomes an issue I can add an actuator later.

Also, not sure if you're married to the idea of having a blower on the spa but many of the expert builders here will say that, if the spa plumbing is done right, a blower is unnecessary. Could save you a small bit of money to do away with it (and they are noisy!)

Also, have you considered running the waterfall using an entirely separate pump?

I only ask because water features like waterfalls are low head / high flow features. Unlike bubblers and returns, waterfalls and scuppers work best when the pressure is low but the flow rates are high. And open pipe water feature like that on a high head pool pump can cause the return side head loss to be so low that you can actually cause the pump to cavitate. I know because my pool was designed and built with a 3HP WhisperFlo pump to drive a waterfall and it is total overkill. I had to add a shutoff valve to restrict the flow and increase the back pressure on the pump return or else it sounds like a giant bag of marbles rattling around inside the wet end. Pentair makes waterfall pumps specifically designed to move lots of water at low pressure.

Both great points that I am wrestling with. I have gotten similar feedback on the blower from at least one other PB, but noticed the majority recommend a blower. They are under $200 and supposedly the newer one's aren't so loud. I think it really came down to avoiding an air inlet on the spa (more a cosmetic concern, but also I've been in spas where water gets in the vent and you hear a constant gurgle sound). I may flip my decision on the blower after talking more with experts. As for the dedicated waterfall pump, not having one is simply a cost savings move. We are still finalizing the design and it's possible we end up with a dedicated pump. I was over checking out and5555's pool and he's using the same pump I'm planning to use (Intelliflo VS) and it did pretty well on a 3' sheer, but he had to run at a pretty high speed to get ideal results and it was very quiet. I'm not sure if a waterfall pump could run at a lower rate and produce better results. I'll look into the cost more on a waterfall pump.

 

[JoyfulNoise]

Just for reference, my spa air intake is way over at the equipment pad, not located on the spa. It's about 30ft away around a corner. You can't hear the air intake at all. And, if you have a properly laid out Hartford loop, you should never get water in the intake air line. Mine has never had water in it.

What you use for a waterfall pump all comes down to proper head loss calculations. PBs have a tendency to just use a pool pump for everything even when it's not the correct choice from a hydraulic standpoint. They really just don't know any better. Waterfalls need volume flow rate to look and sound good; using a pool pump is typically not optimal for that as you'll run into cavitation issues or you'll have to use a restriction to create back pressure on the pump which then does the opposite - it reduces flow.

You'll also save operational costs as a typical waterfall pump can supply high flow rates at low power whereas a pool pump has to be run at higher power to get higher flow rates.

 

[Foosman]

Just for reference, my spa air intake is way over at the equipment pad, not located on the spa. It's about 30ft away around a corner. You can't hear the air intake at all. And, if you have a properly laid out Hartford loop, you should never get water in the intake air line. Mine has never had water in it.

Interesting...I was thinking the air intake would be mounted on the top of the spa. I'm thinking I can run the air intake to the equipment pad (as in your case) and then worst case I can add a blower in the future if needed.

 

[JoyfulNoise]

Interesting...I was thinking the air intake would be mounted on the top of the spa. I'm thinking I can run the air intake to the equipment pad (as in your case) and then worst case I can add a blower in the future if needed.

The rotating spa jets will screw into pipes in the spa wall. Each of those return pipes is plumbed with a Venturi tee where one port is for the water return to the jet and the other port is for the air line to attach to. The venturi air lines are then all connected together and run to a Hartford loop which is set to the highest point in the spa just beneath the coping (you will see a loop of pipe in the steel rebar cage that goes all the way up to the bond beam). Since the top hartford loop is higher than the water level, water will never get into the full run of the air line. You can kind of think of it like an upside version of the P-trap that's under your sink. After the hartford loop, the air intake pipe simply runs back to the equipment pad. It can remain open ended or have a blower attached to it or some people put a valve on it. If you are standing at the equipment pad and you stand near the air intake pipe, you can hear it make a rhythmic thump, thump, thump sucking noise.

 

[CCCentralFL]

Matt, great insight into spa design! Is there a difference in jet performance with a valve added to the end of the air intake pipe? Curious if there was any advantages to added a valve vs leaving it open.

thanks!

 

[JoyfulNoise]

Matt, great insight into spa design! Is there a difference in jet performance with a valve added to the end of the air intake pipe? Curious if there was any advantages to added a valve vs leaving it open.

thanks!

Pentair automation systems have a built in water feature circuit called "SPILLOVER". It allows the owner to create the spillway waterfall by using the existing spa jets instead of having to plumb a single dedicated return to the bottom wall of the spa. It does this by setting the intake actuator to the pool side (skimmers and main drain) and the return to the spa side jets. So water flows from the pool to the spa. However, in order to make it so that the jets don't produce a lot of aeration, you can either cap off or valve off the air intake. If you add automation to that valve then you can simply program the system to actuate that air intake valve (close it) when the "SPILLWAY" feature is running. Some people also prefer less air in their therapy jets and more water; partially obstructing the air intake allows you to achieve that.

Someone much smarter than me figured this all out (he's a regular expert in the build sub-forum)...I'm just relaying second hand info.

 

[Foosman]

Pentair automation systems have a built in water feature circuit called "SPILLOVER". It allows the owner to create the spillway waterfall by using the existing spa jets instead of having to plumb a single dedicated return to the bottom wall of the spa. It does this by setting the intake actuator to the pool side (skimmers and main drain) and the return to the spa side jets. So water flows from the pool to the spa. However, in order to make it so that the jets don't produce a lot of aeration, you can either cap off or valve off the air intake. If you add automation to that valve then you can simply program the system to actuate that air intake valve (close it) when the "SPILLWAY" feature is running. Some people also prefer less air in their therapy jets and more water; partially obstructing the air intake allows you to achieve that.

Someone much smarter than me figured this all out (he's a regular expert in the build sub-forum)...I'm just relaying second hand info.

Hmm...wouldn't it be easier and probably the same cost to use a blower? I'm assuming when the blower is off it acts similar to a closed valve.