Active Thermal Managment.

Look at the system 3 fan kits. They are fairly inexpensive, and easy to install. They have a thermostat so they wont run all the time, but they are quiet. You have to have a place for intake and exhaust. Remember that equipment is suposed to cool via convection so the cool air comes in the bottom, and hot air exhausts out the top. I usually use both fans as exhaust and let them pull cool air through the cabinet. I've been to a ATM training, and the interesting thing to me was that they said to remember that there was no perfect way to accompish cooling, but anything you do will help!