Air flow is impressive, even out the top. The front and rear panels are mostly stamped mesh and the left side panel is about 25% mesh. There is a 120mm fan in lower front (intake), a 120mm fan in upper rear (output), and a 140mm fan directly above CPU on top of case (output). The power supply fan pulls from bottom rear through a filter. There are 2 spots on left panel for additional 120mm fans, but if you use a big ass CPU heat sink (like me) you intrude on the available space for one of them, effectively eliminating it.
Those who hammer their guns into plows will plow for those who do not. ~ Thomas Jefferson