Calibrating pump speeds after upgrade to variable speed pump

[rosensama]

My 2.4 total HP single speed pump is dying and I'm replacing it with a Pentair IntelliFlo VS. The single speed runs at 3450 RPM.

Short of flowmeters before and after is there a way for me to get an idea of what RPM on the Pentair gets as much circulation as my old pump?
* My pump directly proceeds my sand filter, so is PSI there an indicator of flow rate?
* The Pentair is listed at 3.95 total HP, so can I expect that 3450 RPM * 2.4 / 3.95 on the Pentair is equivalent flow?

I hope to run most of the time at much lower RPMs, but like how the skimmers, spa, etc. work now and would like to replicate that.

Thanks,
Rob

 

[rolo918]

Get this !!

http://h2flow.net/h2flow/index.cfm/products/flowvis-flow-meter/

 

[pooldv]

You just need to do a little experimenting. Here is where I ended up with mine.

1100rpm for skimming and making chlorine, draws 150 watts and gives good skimming action. I started at 900 and ended up at 1100.
1950 RPM for running solar panels, draws 550 watts and gives good flow through the panels and isn't too warm in the returns indicating pretty good solar efficiency.
2500 rpm for solar and waterfall
1500 skimming, filter, waterfall and no solar

I would guess that about 2000 rpm will be close to where you were.

 

[rosensama]

Thanks. That fits with what I was guessing.

@rolo918, that flow meter looks great, but pricey. Maybe I should have received one for Father's Day