Replace Single Speed pumps with Variable?

[belowry]

I recently completed an upgrade to my automation controls and conversion to salt chlorine generator. It was a big electrical job but it all went smoothly. Now I am thinking about upgrading my pumps. I bought the house 2 years ago but the pool was installed in 2003 so I am assuming the pumps are 12 years old and may be nearing end of life. I know that variable speed pumps offer significant energy savings.

I currently have 3 pumps - Pentair WhisperFlo 1HP for pool filer, 3/4HP for cleaner, and 2HP for spa.
It seems like a no brainer to replace the filter pump with a variable speed pump to gain energy savings.

A few questions:
1. By adding a variable speed filter pump can I also completely eliminate the 3/4 booster pump for the cleaner too?
2. I assume that there's no benefit to replacing the 2HP spa pump until it dies?
3. When would I consider variable flow vs. variable speed?

 

[mas985]

First, welcome to the forum!

Now the questions:

1) No, you still need a booster if you have one now. You can only eliminate a booster if you get a cleaner that does not require a booster.

2) Not really because you will need to replace it with the same size or suffer weaker jets.

3) I would not consider a VF because it tends to overdrive the filter when the filter gets dirty. You actually want the flow rate to decrease when the filter gets dirty so it doesn't damage the filter.

Also, a VS pump does save energy but so does a two speed and depending on your electrical costs a two speed can be more cost effective over the life of the pump. So a VS pump is not always a slam dunk.

 

[JasonLion]

Welcome to TFP!

1) No, a variable speed pump will not work with a pool cleaner designed to use a booster pump.
2) If you are happy with the current strength of your spa jets, there would only be a tiny (10-15%) savings, at best, by replacing the spa pump. Unless your electric rates are really high that would not pay back quickly enough.
3) I am not at all a fan of the variable flow feature. Simple variable speed is a better choice. A variable speed can save you just as much money, is simpler to setup, and tends to be less trouble prone.

 

[belowry]

Thanks for the quick replies. I definitely need to do the math on energy savings.

I Forgot to ask if I makes sense switch the cleaner booster to variable speed too?

 

[mas985]

No because first they don't make a VS booster and even if they did, there is no point because the booster requires full speed to achieve the pressure the cleaner requires.