replace Jandy JHPU 2 circulation pump help?

[wadewood]

My Jandy JHPU2 2 HP circulation pump is making a lot of noise. Somewhat goes loud then softer every 45-60 seconds. I want to replace it with something more energy efficient and less noisy. I also think it is over sized for my application.

Pool is 25,000 gallons. This pump is for circulation only. There are 2 more Jandy pumps same model for waterfall and effects. And another Jandy 2.5HP for the spa. Polaris also with it's own booster pump. Note - I bought the house and pool was already installed and I'm guessing # of pumps and HP was the pool builders selling point. Pool and equipment about 6.5 years old.

So the circulation pump feeds a Jandy CL580 cartridge filter and AquaPure chlorine generator and then to pool. All lines are 2".

Since I don't need this pump to run at a higher speed to power anything else, I'm thinking I should buy a much lower horsepower pump that will turn water over once every 24 hours. Is one turnover per 24 hours the correct guideline? Looks to me a 1/2 HP pump would need to run 14 hours a day for 1 turn?

What advantages would a larger pump with 2 speeds and run on low speed offer?

My electricity is right now .12/kwh, but likely to be .15 this summer. I would consider VFD style pumps, but just do not see the cost justification. Unless payback period is under 5 years, then it's not for me.

Based on the above, I would appreciate any feedback with suggestions or pump brand/model recommendations.

I bought house 2 years ago and struggled with pool the first year. I found this site last spring, became a BBB convert and pool has looked great since!

 

[JasonLion]

A pump like the Pentair WhisperFlo WFE-2, 1/2 HP full rated, would be fine in that application. If you are looking at other brands/models of pump, keep in mind that there are different ways of rating HP and thus not all 1/2 HP pumps are the same.

The advantage of a two speed pump is that it's low speed can be even lower than full speed on a 1/2 HP pump, which saves electricity, yet high speed is available for special situations. For example, a pump smaller than 1/2 HP is unlikely to be able to prime properly and may not work well when trying to vacuum. A two speed pump has the energy saving of a pump smaller than 1/2 HP, but has high speed available for priming, vacuuming, and running solar panels (if you ever get them).

The exact time a turnover will take is a little difficult to estimate precisely. Your guess is in the right range, but there are plenty of details that can affect the actual time.

 

[wadewood]

Jason - thanks for the response.

In looking at 2 speed models, at what point does the low speed on pump not overcome head loss and filter backpressure? My cartridge filter has a PSI fitting on top and it's reading 21psi. How does 21psi equate to ft of head height?

For a 2 speed model, I was looking at Pentair Whisper WFDS-4 or Hayward Tristar SP32152EE. Any thoughts on these 2 pumps or differences between them. I was looking at Pentair website and I can't tell the ratings at low speed in their performance curves. Their charts are not labeled very well.

 

[mas985]

The only concern for low speed of a two speed pump is static head (i.e. elevation lift) such as to solar panels on a two storry roof. The dynamic head which is caused by pipes, fittings and filters is a function of flow rate so half speed has half the flow rate and 1/4 the head loss as does full speed. A lower HP pump will also produce lower flow rates and head loss.

21 PSI is 48.51 feet of head (2.31 * 21) but that is only the return side head loss. The suction side will also produce head loss.

 

[wadewood]

Ok - bought a 2 speed pump and will hook it tomorrow. Since I plan on running it in low speed 99% of time (maybe high speed to prime pump), I thought I would install a low tech toggle switch in electrical box on wall near pump. I know I can install 2 speed pump relay in Jandy AquaLink panel, but that is spendy. Looking at Lowes, I can buy a weatherproof electrical box with toggle that switches a normal light switch. I'm thinking any normal light switch would work; they are rated for 15 amps 120/277 volts. Pump is 230 volt and my existing wiring and pump were 230volts. Will this work?

 

[JasonLion]

You need a 3-way switch with an amp rating at least as high as the motors, normally very easy to find.

 

[wadewood]

I got it installed and working with the 3 way switch. Thanks for your help.

At first could not get it to prime. After shutting off pump, I saw it leaking at union at front of pump. Not priming because drawing in air. Tightening this up solved this.

One downside, at low speed pump does not overflow hot tub into pool to circulate hot tub water. At high speed, it does this. Hot top lip of spillover is about 28" above pool water level. Low speed can not overcome this. I do have another pump that floods this spillover for effect, so I programmed this pump to run for 15 minutes twice a day.