This Hyperdrive fan photo shows how GCC mounted a cooling fan in one of the diagonal vents at the top-back of the Mac case (inside, of course).
As much as I know you love to brag about your Hyperdrive :beige: –
He has a Classic. It
already has a fan, a very good fan. There are no other vents to blow out of. He seems to be overly concerned where there is no cause for it: This is the final design of the compact Mac. Apple's engineers had perfected the art of cooling it by then. Adding another fan internally is likely only going to increase the load on the PSU making it run even hotter and possibly defeat the engineer's design by recirculating hot air back onto the PSU. The caps are going to eventually leak, if they are not already, regardless of how many fans you have running inside the unit and that will cause the Classic to eventually die, even if you only run it inside a refrigerator. Adding more fans or running an AC duct directly into it will not help. Electronics get hot. The components inside are rated for the heat. Your best bet would be to drop this exercise in futility and learn to replace the vintage caps with modern equivalents that will run cooler and last decades longer.
If you really, really , really, really want to install another fan, you can squeeze one into the handle to pull air out the top, you can put another one over the back vent that will force even more air out of it and you can put little micro fans pointed at every warm component on the PSU. Plug them all into the power connector and turn up the voltage. I bet if you tried you could get maybe another 5 fans in there. More if you drill a new vent on the right side of the cabinet. There's a template for adding a speaker grille in Larry Pina's book (Apple manufactured them that way later), you could put another fan over it, bringing the total to six! Possibly even squeeze some into the bottom side vents as well – I'm thinking 8 fans now. Actually, as long as we are modifying the case, you could take JDW's advice and cut those vents back into the chamfers and install 2 more fans there. The one on the left rear will be right above the flyback transformer which gets the warmest, so I don't know why I didn't suggest it sooner. Just cut more holes in the case! But make sure you operate it only in a clean-room environment, because all of those fans are going to pull an awful lot of dust and debris into it. In fact if your floppy drive does not have the dust shield, you should probably make one for it – oh and put a micro-fan inside it to keep it cool since it will be sealed inside a heat trapping insulator.
Pfffffft! On second thought, what were those engineers thinking putting just one fan in the Classic!?
