I have one on my Diesel and run it continuously when the key is on. It is fused and runs off of one of the switched terminals I have on a Painless fuse block I installed.
The fan is a bilge fan that looks like the one used in the post you reference. I was able to take the factory CVT exhaust outlet and heat it just enough to soften it so I could get the fan slipped into the outlet. I then added band clamps to hold everything together.
I also masked everything off and painted the exterior of the fan housing so everything matched.
As far as noise, I can barely hear it when the engine isn't running.