8 if you include the air duct. Stock included fans: 2x230mm at top exhaust, 1x120mm rear exhaust, 1x230mm front intake. The stock fans aren't loud. The 230mm are only 800rpm, not sure what the rear 120mm is but I swapped it out for a Slipstream.
Then you can add bottom 120mm intake, 2x120mm by the 3.5" drive cage (behind the front 230mm) to help with airflow and pulling in air from the front 230mm.
And the air duct adds another slot for a fan, I don't use it myself tho.