Actually I was looking at this build for some other cooling needs myself. Not so much a computer rack. I have lots of “fans” around from PC’s I have stripped over the years from the side of the road. Always wanted to do something with them.
http://www.instructables.com/id/Temperature-Control-With-Arduino-and-PWM-Fans/?ALLSTEPS
3 Responses to Arduino Controlled PWM fans to cool a PC rack