On Tue, 13 Jul 2010 11:46:11 -0700 (PDT), keith
wrote:

On Jul 13, 1:04*pm, mm wrote:
On Sat, 10 Jul 2010 23:18:19 -0400, "Ed Pawlowski"

wrote:

"Jon Danniken" wrote

It is a function of the motor, which will be a split-phase induction
motor. You either have a motor designed with multiple windings for
multiple speeds, or you don't. *If you don't, the only practical way would
be to replace the motor with one designed with multiple windings, or get a
new unit.

Not quite true. *Mine works with a simple dimmer switch of proper capacity.
Multiple windings not needed.

It's said that motors won't run off of light dimmers, but of the 6 or
so table fans I've used over the years, all but one worked fine. *The
other one required a fan speed control, usually used for ceiling fans.
I got one at a surplus store.

*Induction* motors won't run off light dimmers. Universal motors will
(off dimmers rated for inductive loads). Small motors are almost
always universal motors. Whole house fans are likely a mix, with the
better ones being induction motors. Generally a belt is the tell
(belt = induction motor). I would guess the crossover is about
1/4HP.

And of course, back to the oP's question, they sell fan speed controls
that mount like wall switches. Often there's a switch there for the
light that often comes with a ceiling fan. I presume whole-house fans
use more current than ceiling fans, but would the speed control be big
enough?

He could use teh toggle swtich for any old thing, including perhaps
turning off the fan without changing the speed setting.

I wouldnt' let the fan get so slow it stopped, althoughif the dimmer
is at the very bottom when this happens, maybe it's okay.. * Depending
on the fan, it might well overheat if it did that, and burn out the
fuse (or worse?). *Also if a whole house fan gets too slow, it won't
open the louvers I think, which are just sucked open.