Can I use a rheostat or fan speed control with an In-Line Duct Fan?
No. A rheostat lowers the voltage supplied to the fan motor. This will cause the motor to overheat and the Thermal Protector will open, destroying the motor. A solid-state fan speed control could be used. The problem is that such a control allows the fan to be adjusted to very low RPM’s. Since the electric motor needs air flowing over it for cooling, adjusting to too low a RPM will cause the motor to overheat. That will cause the Thermal Protector to open, destroying the motor and voiding the Warranty. Since the speed the motor is adjusted by the user and is not under the control of Suncourt, we advise against using a solid-state motor speed control.
