yea, the computer fans are great, but not for replacing the way more powerful FF motor. Maybe using one to blow air in from a window would help move air out the roof vent and that could be a compromise solution.
I have a second vent that is not FF but also not covered bc the solar panels are right there and I cannot shade the panels and cannot really leave the vent open all day and be gone due to the constant haarp rains all the time getting inside.
I ordered that controller in the link and will drill out some vent holes to help cool it. Hopefully the ringing of this one is out of my hearing range too