Ventilation

At first I just wanted to install one fan located in the top cover, as you can see in the next picture.

But later I decided to add another fan on the back cover, in order to improve ventilation.

Two fans can make much noise, so I decided to build a simple circuit working as a thermostat.

In the next picture you can see the typical 12V fan for PC, the control circuit wrapped in black heat-shrink plastic, the temperature sensor (NTC resistor) wrapped in red heat-shrink plastic, and the power connector.

These components are installed in the top, which is the hottest area.

And this is the result: an upper fan that will activate gradually when heat increases at the top; a fan at the back, also controlled by temperature (by the motherboard's BIOS). The power supply has its own fan, which is very quiet.