Maybe Peter Halle can shed a little light on this,
[attachimg=1]
from:
http://festoolownersgroup.com/festool-tool-reviews/gary-katz-reviews-the-ct-wings/
He appears to know some one who knows all about it.
His statement got me thinking in the first place, btw thanks for that Peter.
Don't know about the construction of the CT 26 and family, but I replaced the motor of my old Festo SR151-AS once. (wasn't it originally a WAP?) It had a seperate fan on the back of the motor for cooling.
[attachimg=2]
But still; you can hear the rpm of the motor rise if you block the inlet completely. I wonder what effects that might have.
I usually let the vacuum-jigs bleed air with the aid of the Festool vacuum air bleeding valve:
[attachimg=3]
In this case the valve was closed (for 12 seconds only), but later on it became clear that this was not necessary at all.
To get lifting power you need maximum surface, thats's more important than suction power.
All you have to do is lower the air pressure inside the jig, than the atmospheric pressure provides the force.
When using vacuum jigs I open the bleeding valve as much as possible for the purpose at hand. It is amazing how little suction you need when the surface is big enough.