Help with Spa Blower

[Lves2raft]

How can I fix this pressure situation?

So I had a brand new hot tub installed this year. Long story but installer was horrible. There was so much done wrong. I have had most of it fixed correctly but I don’t know how to fix this one since the right way to fix it (change the pipe size) is impossible without removing the hot tub and breaking concrete etc.

Basically the pipe should have been two inch most of the way and instead he changed to 1 inch pretty close the blower. The blower fried itself after just a few months and maybe 15x using the hot tub with this set up.

Open to creative solutions!

 

[JamesW]

It is probably not fixable without replacing the line.

Check the pressure during operation with a water tube manometer.

 

[ajw22]

You can try venting some air by the blower to lower the pressure on the blower. Read Spa Air Blower - Further Reading

 

[Lves2raft]

It is probably not fixable without replacing the line.

Check the pressure during operation with a water tube manometer.

If I can replace the line to two inch about 90% of the way will that solve the issue? Basically I can change the line about 12 feet before I get to the outer wall of the hot tub and then it would involve destroying the hot tub to change for further

 

[JamesW]

If I can replace the line to two inch about 90% of the way will that solve the issue?

Probably not.

Check the pressure with a manometer or a gauge.

Disconnect the line as close as possible to the spa, connect the blower there and check the pressure to see if the pressure is low enough for the blower.

What is the blower model number?

Spa Blower Help needed -pics attached!

First of all, thanks again to all in this invaluable forum. We're over a year into our build, and have water in the pool, and nearly everything complete. However, I cannot get attention from my pool builder and am past the point of frustration. I got a verbal agreement from her to have the...

www.troublefreepool.com

 

[Lves2raft]

Probably not.

Check the pressure with a manometer or a gauge.

Disconnect the line as close as possible to the spa, connect the blower there and check the pressure to see if the pressure is low enough for the blower.

What is the blower model number?

View attachment 615681

Spa Blower Help needed -pics attached!

First of all, thanks again to all in this invaluable forum. We're over a year into our build, and have water in the pool, and nearly everything complete. However, I cannot get attention from my pool builder and am past the point of frustration. I got a verbal agreement from her to have the...

www.troublefreepool.com

This is the model number. I can’t really do a test because the blower is dead and have to buy a new one. Hayward 2-HP Spa Air Blower SPB201 | 115V

 

[JamesW]

https://hayward.com/media/akeneo_connector/asset_files/I/S/ISSPB_RevA_d907.pdf

 

[JamesW]

I can’t really do a test because the blower is dead and have to buy a new one.

Without a test, we are just guessing about the expected back pressure.

It might work and it might not work.

65" of pressure means an airflow of 60 SCFM.

You need to know the head loss of 60 SCFM going through 12 feet of 1" line plus however many feet of 2" line.

Maybe ask Hayward if they know the expected head loss and if it will work.

 

[JamesW]

This shows 31.3 inches for the 12 feet of 1" pipe and 8.04 inches for the 2" pipe, which is 39.34 total.

So, it might work if the calculator is accurate.

You also have back pressure from a check valve and any water level, so you might exceed the 65" limit.

Increasing the main line to 2.5" will help reduce pressure.
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Air Duct Friction Loss: Pressure Drop Calculator & Chart

Head loss or major loss in air ducts - equations and online calculator for rectangular and circular ducts - Imperial and SI units.

www.engineeringtoolbox.com

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[Lves2raft]

This shows 31.3 inches for the 12 feet of 1" pipe and 8.04 inches for the 2" pipe, which is 39.34 total.

So, it might work if the calculator is accurate.

You also have back pressure from a check valve and any water level, so you might exceed the 65" limit.

Increasing the main line to 2.5" will help reduce pressure.
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View attachment 615695

Air Duct Friction Loss: Pressure Drop Calculator & Chart

Head loss or major loss in air ducts - equations and online calculator for rectangular and circular ducts - Imperial and SI units.

www.engineeringtoolbox.com

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View attachment 615696

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View attachment 615697

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Thank you! That may work - change to 2.5 from 2. Also there doesn’t seem to even be a check valve. I assume I should install that !

 

[Lves2raft]

This shows 31.3 inches for the 12 feet of 1" pipe and 8.04 inches for the 2" pipe, which is 39.34 total.

So, it might work if the calculator is accurate.

You also have back pressure from a check valve and any water level, so you might exceed the 65" limit.

Increasing the main line to 2.5" will help reduce pressure.
_________________________________________________________________________________________________________________

View attachment 615695

Air Duct Friction Loss: Pressure Drop Calculator & Chart

Head loss or major loss in air ducts - equations and online calculator for rectangular and circular ducts - Imperial and SI units.

www.engineeringtoolbox.com

_________________________________________________________________________________________________________________
View attachment 615696

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View attachment 615697

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Would this check valve work if I plan to change to the 2.5 pipe? Waterway 600-7010 2"-2.5" Straight CPVC Truseal Check Valve

 

[JamesW]

Maybe get a spa blower check valve to minimize head loss.

Below is a water check valve and the associated head loss for water.

 

[JamesW]

Air blower check valves usually have a 1/4 psi spring tension, which is about 7" w.c.

That brings the total to about 47".

65" - 47" = 18", so you are cutting it close.

You also have the water depth and any pump backpressure.

Most spa jets should pull in air, which actually removes head loss.

Properly designed jets can even work without an air blower.

Once you get the new blower and new plumbing, test the backpressure with a tube manometer, pressure gauge or digital manometer.

If the pressure is more than 65", the blower will probably overheat.






Super-Pro; SP0830-15C Check Valves; Slip x Slip; Clear; 1/4 Lb. Spring; 2"

 

[Lves2raft]

Sorry so the air one is better to get or the jandy one? I’ll get whatever is the right one. I think you are saying the air check valve is better

 

[JamesW]

I think that the air one will probably be better.

 

[Lves2raft]

I think that the air one will probably be better.

Thank you. Do you by any chance know how I would use the 2 inch air check valve since I plan to use 2.5 inch pvc pipe? I am not finding a 2.5 air valve version anywhere online . Thank you

 

[JamesW]

2-1/2" x 2" Schedule 40 (S x S) 429-292 | Sch 40 Couplings

2-1/2" x 1-1/2" Schedule 40 (S x S) 429-291 PVC Reducing Coupling at PVC Fittings Online and receive huge savings on all Schedule 80 CPVC, Schedule 80 PVC and Schedule 40 PVC fittings

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The valve will usually take 1.5" pipe inside and a 2" fitting outside.

Use 2 of the reducer couplings to go from 2.5" pipe to the 2" check valve and then back to 2.5" on the other side.