This dual 3stage CFX has the same CFMs (230) as a #3 blower TM
Well, not really - due to the way cfm is measured for a centrifugal fan vs. PD blower.....
This comes up a lot, and I'm not sure I've ever seen a comparison graphed out - so here goes. I picked a 33 blower (wimpy) and a pair of fancy new 8.4 Ameteks in parallel (super powerful!) to give the electric vac's the best chance of showing up that poor PD blower. Using the numbers the Ameteks (280 cfm) appear to handily beat the #33 (195 cfm). Here's what it looks like:
The two are equal only if you limit lift to 2"hg - after that the electric vacs are toast. The Ameteks only beat the PD under basically free flow conditions - no wand, no hose, just an open inlet......
Under actual use conditions PD blowers are still king and will be for the forseeable future.