minimum speed of exhause fan

I am pretty sure I have read somewhere that you should not run your exhaust fan at less then 50 percent of its max speed or it will cause it to heat up and could cause fire. I do not know where I have seen that, and cannot find anything on it again. Is this true? I am about to run a 6" can fan with speed controller and want to be safe. thanks for any replies.

I am using mine @ 10%, the controller is not warm. Hope this helps.

I ran my 4" fan at less then 25% speed for most of its life, no problems so far. Just adjust your fan speed to the level you need it at to properly cool your grow room and you should be fine.

Yes I have heard of this before but never encounter it and have been using a fsc the last 7 months at 5-10%..Ive been told this a few times before and Was told at a hydro shop by the owner that he doesn't stock fan speed controllers as they can cause fires or burn out your fan but I think those things happen to the older fans on their last legs not new gear.

thanks for the responses.