On the right side of the casing we see a front-panel to connect USB 2.0, Microphone, FireWire, headphone.
On both the right and lower left side at HD level we see air intakes. There's a lot of ventilation going on in the Lexa. Let me show you.
Left side windows, you can see the humongous 120mm fan there. With dust filter I might add.
Easy to clean and remove, or vice versa ;)