Here is a rack fan I made for that one open slot (it just bugged me) in my rack case. I don't have any temperature issues I just thought it would be cool to do & since I run a machine shop & have the means at my disposal I figured, why not. I machined the chassis out of a 1.75" wide aluminum channel & added the bent bracket for the power plug from a piece of flat stock. The fans are a surplus item we had around here, but I had to widen the inside channel width by .080" to accomodate them. Of all this stuff the only thing I needed to buy was a 12VDC power supply to get me up & running. It runs very quietly & I don't expect any EMI issues, but I'll find out for sure tonight when I run everything.
Here it is from the front:
A couple of views from the back:
And, installed in the rack:
The cords coming through the front are my effects send/return & tuner. I didn't have any other cool way to run them so I put them through the fan chassis. The diagonal layout of the cords is for style points only. Before anyone asks, I'm not looking to make more of these or sell them. I just thought it was a cool project & figured some of you might like to see it.