I bought a small HEPA air filter fan that was advertised as being a quiet model. But it's not quiet enough for me. I bought another "quiet" fan, but the new one is also too loud for my liking.
Could just I buy one of those extension cords with a dimmer switch (designed for use with room lamps), plug in my air filter, and safely use the dimmer to control the fan speed (and therefore volume) of the air filter?
Safety is my priority. I don't want to start an electrical fire. If it's not safe, I'll buy a different fan.
Best Answer
Light dimmers are designed to drive loads that are largely resistive in nature like light bulbs. They are generally not compatible with loads that are inductive. Most, if not all, AC motors are inductive type loads.
That said, whether a dimmer switch will work safely with your fan or not depends entirely upon the type of motor on the fan.
There are some types of AC motors that can work to gain speed control via a dimmer switch type of circuit. These motors are often found in AC corded power tools such as electric drills and jig saws. Just as often these tools come with a variable speed capability via a proportional squeeze trigger. These tool speed controls work just like a common lamp dimmer. The motor type involved is generally the type with brushes.
Common low cost fans do not use brushed type motors. The usage life time would be just too short and non-brushed low power motors are often way cheaper to manufacture.
With this information in hand you may be able to evaluate your fan and decide if it is suitable for use with a dimmer. I suspect that it is likely not compatible.