The design is well thought out and I have no doubt the gadget works as described, but it's a lot of labor to build. There are cheap commercial radio-controlled (300 MHz) appliance switches on the market that would at least turn the fan on and off. There are also 3-speed models using phase angle controllers for ceiling fans. I have one that cost <$20 and works just fine. There's no reason it wouldn't control a table fan just as well. All one would have to do is install it in a suitable box.
I also like to build stuff but generally do so when there is no economical solution already available.
A new service lets engineers and orthopedic surgeons design and 3D print highly accurate, patient-specific, orthopedic medical implants made of metal -- without owning a 3D printer. Using free, downloadable software, users can import ASCII and binary .STL files, design the implant, and send an encrypted design file to a third-party manufacturer.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.