Pump Help

[nickpool]

Just purchased a house with an old single speed pump and I'm distraught at the electricity bills. I'm considering a VS replacement and have some newbie questions.

Setup: 5000 gal, 50ft of head, cartridge filter, 1.5hp single speed pump

So I'm looking at variable speed pool performance curves and the low speeds of the VS pumps don't look to operate at 50 feet of head. Take for example the Pentair Superflo VS

http://www.pentairpool.com/pdfs/superflovsDS.pdf

My newbie question: does this mean that the lower speeds won't work for me and I'll be using the higher speed of the pump at all times?

Thanks for the help!

 

[jblizzle]

Welcome to TFP!!!

You can not know the feet of head without a flow rate.
At lower flow rates, the feet of head is also lower.

Just forget about the feet of head. You can certainly run a VS pump on lower speeds.

With a small pool like that, the Superflo VS or Maxflo VS would be good choices ... I would not go with the bigger VS pumps unless you need high flow rates.

Please add your pool details to your signature as described HERE as it will help us help you.

 

[nickpool]

Thanks for the quick response! Signature updated!

So follow-up newbie questions.

1) assuming the pool is balanced, and my current setup, how many hours should I run my pump per day?
2) given the above, does it make economic sense to upgrade to a VS pump?

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test

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5k IG cement? pool, Flotec 1.5HP single-speed pump and Hayward Star Clear Cartridge Filter

 

[Richard320]

Are you sure about the pool volume? 5000 gallons is pretty small for an inground pool. I can't imagine someone installing a motor that big on a pool that small, unless it's one of those treadmill pools and you need the current to swim against.

Just for comparison, I have 16000 gallons and a 1 hp single speed motor and the pool stays clear on just 3 hours a day. Sometimes less, if I happen to go by and there is no more debris to skim. More if I'm vacuuming that day.

 

[jblizzle]

Check out: Determine Pump Run Time and see if that answers your questions.

 

[nickpool]

Thanks for the help. As for my other question on whether to upgrade to a VS pump from a single speed. Is it a no-brainer upgrade because they're THAT much more efficient even for a pool as small as mine?

And yes, my pool is 5000gal. And the pump is ~50ft away from the pool

 

[mas985]

With CA energy costs, a VS will usually have a lower lifetime cost over a two speed. The biggest downside of a VS is that the drive is very expensive to replace should it fail. Drives rarely fail but it does happen and usually because of power surges so it is probably a good idea to install a surge protector with the VS to protect your investment.

A few other more cost effective solutions:

1) Reduce run time. Most pool owners run their pumps way too much.

2) Replace the impeller of your current pump will a smaller one. Replacing a 1.5 HP impeller with a 1/2 HP impeller will reduce energy costs by about 50% and it usually costs less than $50 to replace an impeller.

3) If you want to save even more on energy costs, you could replace your current motor with a two speed motor. This can usually be done for less than $300 but it depends on the motor. Low speed will use about 75% less energy than full speed.

 

[nickpool]

Thanks for the suggestions. Super helpful.

After calculating appropriate flow rates for my pump, it looks like I've been running my pump FAR too long. And using an Energy Star worksheet, the electricity savings from moving to a Superflo VS amount to just 40% which is significant but not nearly as much as I expected.

Thanks again!

 

[mas985]

Actually flow rates have very little to do with run time. Did you read the pool school article?

Also you might want to read the run time study in my sig.