There is space for up to three 120mm fans or two 140mm fans. The rear and the base have a single 120mm fan mounting option with the right side panel allowing airflow for three 120mm fans.

The aforementioned fan mount, for example, can actually support a 120mm or 140mm fan, and it has mounting points so you can hang it wherever you want. The other premade kit is the NV-FS2 ...