Why is it important to control the suction force?
All Festool dust extractors feature a control that allows you to adjust the amount
of air flow, which is typically measured in cubic feet per minute (CFM). The higher
the CFM rating, the more air is being moved and the more suction is being created.
As a note, larger hoses generally produce higher CFM ratings, all things being equal.
So, why is variable suction control important? Different tools have different CFM
requirements. For instance, if you are removing larger chips generated by a router
or planer, you would want to use a higher CFM and larger hose to ensure that all
of the material is being captured.
On the other hand, when sanding, you want a lower CFM, and smaller diameter hose
to reduce the amount of pressure being created at the point of sanding. Fine dust
does not require a great deal of pressure to pick up, and using too high of a setting
will actually pull your sander down onto the work and increase the probability of
creating swirl marks in your finish.
Variable suction control is not a standard feature on most other brands of dust
extractors.
With a simple turn of the dial, CFM is regulated at the CT. This allows you to increase
or decrease suction to match the operation being performed. Use the high setting
to capture large chips when routing or planing; use the low setting to capture fine
dust when sanding. When using the low setting, you can reduce noise, vibration,
and power consumption, making this one of the Cleantex's most touted features.