Front: 140 x 25mm blue LED fan x 1 / 1200RPM / 19dBA
Rear: 120mm fan x 1 / 1200 RPM / 17dBA
Top: 140 x 25mm fanx1/1200RPM/19dBA(supports120/140mm fan x 2)
Bottom: 120mm fan x 2 (optional)
Left side: 120/140mm fan x 2 (optional)
Right side: 80 x 15mm x 1 (optional)
HDD cage: 120mm fan x 1 (optional)
likely you are completely fine but if you wanted to add a fan i'd fill one of the side panel spots with a 140.
then just take a look at your temperatures idle and in game and see what they look like. i dont see a problem for a non o/c system though.