Need help ASAP please——-spa blower size

[Ramdough]

I might have a problem.

My spa was plumbed with 1.5” air line to 6 jets. The line has only sweep 90’s or 45’s.

5ea 90’s and 1ea 45

the spa Jets are probably 12” below water.

The total run is probably about 39 feet.

All of the calculators seam to use 2” air line.

There is no changing out the pipes at this point.

What do you think? I think my back pressure is going to be too high, so I want the biggest blower that won’t die early and get me as close to 60 cfm as I can.

Thoughts. Would like to buy the blower today if I can do I can install over the weekend.

Thanks in advance.

 

[mas985]

Much like putting a large pump on smallish plumbing, it creates more pressure at the pump but not much more flow rate so I suspect the same will happen with putting a large blower on such a small air pipe. The risk is that without a lot of air flow, the blower could overheat and shut down.

Is the spa running now and have you tried running it without a blower?

But just curious as to what is magical about 60 cfm?

You might try and find a place that has a good return policy and willing to work with you.

 

[Ramdough]

6 Jets = 60 cfm. Jandy recommendation. Nothing magical. I could miss that number and not care probably.

Pool was filled yesterday. Jets are not yet installed.

My cousin, Who builds crazy pools for himself, said his spa uses a 2 hp and it was similar to mine. Don’t have any other data.

I think older spas spas used to use more 1.5” air and 2” water.


Any opinions on my setup?

 

[mas985]

For 6 spa jets, the water and air line plumbing should be at least 2.5". I don't know what your PB was thinking but that size pipe is not really sufficient for decent jet action.

Do you know what size jet nozzle is going to be used in the spa? About the only size that makes sense for that size plumbing is 1/4" which has a recommended flow rate of 10 GPM per jet. This keeps the total flow rate and velocity for at least the water pipes to a reasonable level.

As for the blower, trial error might be your only solution. It is hard to say what will or won't work with that setup. My feeling is that you won't be able to use a large blower because of the restriction but you can try it and see if it works.