electrical question

[whytepizza]

Okay, so i want to put a fan system in one ofmy racks that i have. It's made of all solid wood, but there is a space behine the bins that traps all the hot air waaaay on the top shelf, and not enough on the bottom. I wanted to take two old computer fans and use those to blow the air back down to the bootom shelf, but i'm assuming the fan motors run on dc current, are probably around 12v, have four freaking wires coming out of them, and i wanted to wire it to work with a dimmer switch.
Any suggestions/ideas? I know how to get it in there, and where, i just don't know how to wire the thing. I'm at a total loss and i'm by no means the most electrically gifted.
Thanks guys!

[PythonWallace]

You only need the red and black wires from the fans. Cut the other two off, and wire it up to a 12v DC wall adapter. Just test the polarity if the adapter only has black wires before you make perminant connections. They should work with a lower mA rating adapter, but aim for around 1700mA if you can. A dimmer switch won't work, it will break the fan motors. Most computer fans are brushless motors, so to control the speed you need a speed controller like the ones used in R/C airplanes. If you run both fans on a single, lower amperage adapter they will run slower while still getting 12v, but I don't know if that will cause any problems to the motor. Good luck.

Check out electronic Goldmine or allelectric.com for really cheap fans and adapters. They might even have speed controllers for brushless motors.

[whytepizza]

You only need the red and black wires from the fans. Cut the other two off, and wire it up to a 12v DC wall adapter. Just test the polarity if the adapter only has black wires before you make perminant connections. They should work with a lower mA rating adapter, but aim for around 1700mA if you can. A dimmer switch won't work, it will break the fan motors. Most computer fans are brushless motors, so to control the speed you need a speed controller like the ones used in R/C airplanes. If you run both fans on a single, lower amperage adapter they will run slower while still getting 12v, but I don't know if that will cause any problems to the motor. Good luck.

Check out electronic Goldmine or allelectric.com for really cheap fans and adapters. They might even have speed controllers for brushless motors.

You are a god! The electronic goldmine site is awesome! Thanks for all the advice!
So, now that i think about it, and like you said i would need a speed control like in an r/c plane... would a potentiometer work? I know they are good for low voltage computer or robotic equipment. I'm no good at anything with a board unless it is already made so i figured i would ask about potentiometers.
Anything else you might think i should take into concideration wiring a fan system into a reptile rack?