Air Blower for Whirlpool

[JamesW]

Why is this Teed in like this?

Maybe this is an air line designed to inject air?

I would use a 3" suction and then either a 3" return with a hydraulically balanced design and replace the wall fittings and install a blower line.

Alternatively, you can run each return separately using a 1.5" line from a 3" manifold at the pad and use individual valves on each line so that you can choose which jets to concentrate the flow on.

You would also need a separate 1.5" air line for each return with individual valves so that you can select which returns to send air to.

That is 16 individual 1.5" PVC lines, which is a lot of plumbing, but 1.5" PVC pipe is pretty cheap.

For example, you might choose to only use 4 jets, which will only require about 60 GPM.

Core drill out the existing returns and install venturi jets.

 

[AquaPNC]

This was never designed correctly from the beginning.

What main drains are available and what size is the main drain line?

If you do not have enough main drain surface area and a 3" suction, it will probably not work unless you do some serious modification.

This wasn't designed to have air inlets just 6 high pressured and heated returns. So this is an after the fact attempt on our end to appease the customers new request.

So core drill and use the venturi extension would be a potential solution? Also we have 2" suction lines.

Thanks!

 

[JamesW]

So core drill and use the venturi extension would be a potential solution?

Possibly yes, if the suction and plumbing will support it.

Maybe see what CMP recommends for a retrofit.

Are you doing a separate Jet pump just for the jets?

What suction is available?

 

[AquaPNC]

Possibly yes, if the suction and plumbing will support it.

Maybe see what CMP recommends for a retrofit.

Are you doing a separate Jet pump just for the jets?

What suction is available?

We do have an air blower and if we need to add another pump we certainly can. The only suction will be from the MD/(1) skimmer. 2.5HP VSP.

 

[JamesW]

The only suction will be from the MD/(1) skimmer.

What make and model are the main drain fixtures?

What is the main drain line size?

You can add main drains to the walls if you want to add a second pump.

I would want plenty of surface area.

I would have a total main drain rating of at least 240 GPM, which might require 4 regular main drains.

Maybe do 2 sets of wall mounted main drains with 2" pipe from each drain to a 2.5" T and then (2) 2.5" lines to a 3" manifold at the pump.

You will need to core drill out the holes to add the main drains.

Pipe Size and Flow Rates.​

You want to keep the water velocity below 6 ft/sec on the suction and below 8 ft/sec on the pressure side of the pump.[7]

Pipe Size	6 ft/sec	8 ft/sec
1.5"	38 GPM	51 GPM
2"	63 GPM	84 GPM
2.5	90 GPM	119 GPM
3.0"	138 GPM	184 GPM
4.0"	235 GPM	312 GPM

Equipment Pad Best Practices - Further Reading

www.troublefreepool.com

 

[JamesW]

https://www.pentair.com/content/dam/extranet/nam/pentair-pool/residential/white-goods/starguard/starguard-8-inch-main-drain-installation-guide-english.pdf

https://www.pentair.com/content/dam/extranet/nam/pentair-pool/residential/white-goods/starguard/starguard-main-drain-brochure-english.pdf

StarGuard® Main Drains

The StarGuard Main Drains are available in many different colors & configurations to fit any residential inground pool or spa. See our selection of pool drains.

www.pentair.com

 

[JamesW]

With a wall rating of 88 GPM, I would use 4 main drains to keep the suction on each drain at safe levels.

This also provides safety if one or more get blocked by a person.

 

[AquaPNC]

Wow this is good stuff.

I'll present this option to the homeowner and go from there. Thanks again!

 

[1poolman1]

No air valves around the return, we do have access to the plumbing which is about 6ft from the hot tub, but it is just the return line. I read previously it could be accomplished with a check valve and a blower addition 4ft above the waterline but the feedback has of sure varied and I don't want to even try if it isn't possible.

My biggest fear is having significantly more pressure on the nearest jet/return than the farthest. I don't have the knowledge of the hydraulics, I am a commercial pool remodel company who has built a handful of concrete pools locally, all be it successfully but for me this situation is unprecedented.

I appreciate the feedback.

If all you have are returns (basically open pipes with or without directional fittings to the body of water), all you will get by plumbing in a blower is a lot of bubbles that immediately rise to the surface as fast as they exit the return. The air could interfere with the flow through the return line as well. You will not get "jet" action as you would from a true venturi jet fitting.
True jet fittings will pull their own air through a separate line to the jet body. A blower can be added to that air line if needed, and is done often.