Split off this thread since it's a different topic than the poster is asking about.
I can see how using one 1.5 H.P pump for twice as long as a single 3 H.P pump would be more efficient, but I don't see how using two 1.5 H.P pumps for the same amount of time as a single 3 H.P pump would be more efficient. If you're generating the same flow rate, then the dynamic head should be the same.Originally Posted by JasonLion
How much more efficient do you think it is?
Perhaps they are using the setup as a type of variable speed pump? They could run both pumps when they need full flow and they could run just one when they want to save electricity. It seems like a single variable speed pump would be a better choice.