1 or 2 pumps?

[dubele]

Hi,

Still at the drawing board here on the new pool. I asked for a 3rd sheer descent from 2. The builder is now saying I need to go from a single 2 HP (which would have powered everything from the filter, vacuum, and 2 descents) to another pump. I would have a 1 1/2 HP to filter and vacuum my 400 s.f. pool. I would have another 1 1/2 HP to power 3 18" sheer descents (may go to 3 24" descents). I talked to the project manager and he suggested I go to a 2 HP pump for the 3 descents as he thinks the 1 1/2 HP for the falls may not be enough and it's good to have more pumping power and the cost of the pump is only $100 more and power consumption won't be much more since I am not going to be running all that much in reality.

Any thoughts?

Thanks,
Doug

 

[jblizzle]

Electricity wise, you are always going to be better off with a single pump. For simple filtration / vacuuming, a 1.5HP is way bigger than you need as a 3/4-1HP would be fine (cheaper to buy and run). But, then you will still have 2 pumps to worry about.

You could consider a single 2.5HP 2-speed pump which is run on low for filtration and only on high for vac/shears.

Or maybe a better option would be to get a single large VS pump (Ecostar or Intelliflo) that could run all the shears on a high speed (which you could dial in for adequate flow) and run on very low speeds for vacuuming.

 

[mas985]

I agree with Jason. When you have water features and are uncertain as to the size of pump you may need, the best option is to go with a VS so you can adjust for the lowest flow rate possible and the lowest energy use possible.

 

[dubele]

Thanks guys.....that sounds great and I agree, but my pool builder is saying a 2 HP will not be enough power for three falls, filter, and vacuum.....he was fine with 2 falls. So, it seems I am stuck with getting two separate pumps if I add the third fall. And again, the filter pump will run about 6-8 hours a day at 1 1/2 hp.....about 60-75 dollars a month. The falls will only run when I am out there.....about 6 hours a week....at most! I did like the vs option as I could dial it down......oh, here's another wrinkle.....I am probably going with salt.....my understand is you can't benefit from a vs pump because the salt won't generate chlorine at a lower setting.

 

[mas985]

SWGs can operate down to 15-20 GPM so low flow rate is not an issue. There are plenty of people operating a SWG with a VS pump so I am not sure where you heard that but it isn't true. I use a SWG on low speed of a 1/2 HP pump.

But if you do go with two pumps, I would go with a low HP two speed (3/4 HP) for just the pool and a higher HP for just the water features. There is no sense in having a high HP pump for pool circulation.

 

[jblizzle]

You know there are pumps bigger than 2hp right? The intelliflo is 3hp so should be able to run everything just fine if the plumbing is done correctly.