Tale of two pumps- compare and contrast

Rangeball

Well-known member
May 25, 2007
785
#1
I'm finally looking to upgrade my pump to a 2 speed model. I was pretty settled on the whisperflow 3/4 hp, but now the 3/4hp 2 speed from electricmotorwarehouse.com has caught my eye. Here's the specs of each, the pentair is first:

Model Voltage Full Load Amps HP SF Price
WFDS-3 115V 14.6/4.7 3/4 1.67 $540
EMW 115V 11.2/5.0 3/4 1.50 $358

I have emailed the company for the flow chart for the second. I assume the pentair is a bit more energy efficient, but is it enough so to offset the almost $200 more price tag? I plan to run the pump on low speed 24/7 during season, with bursts at high for vacuuming, etc.

Thoughts?
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,181
Pleasanton, CA
#2
You really need to compare the pump head curves to determine the overall efficiency. My guess is that the GPM/Watt will be 5-10% higher for the Whisperflo.

Note too that you have to use the same plumbing system curve on top of each pump head curve to compare them fairly. Each pump will have a different operating point for a given plumbing system.
 

Rangeball

Well-known member
May 25, 2007
785
#3
Thanks Mark. I was getting serious de ja vu when I typed that, but search yielded nothing. I then spent a good bit of time being stubborn hunting and pecking through my old posts from last year and found where we had discussed these two pumps, you even provided a link to the flow chart for the cheaper pump, and I thought I updated this thread with a link to it, but apparently I only hit preview and not submit :(

Thanks again, and sorry for being redundant :)