Here's a diagram of the flow.
The blue arrows show the water flow (Pump -> Rad -> Maze 4 GPU -> MCW-6002 -> Rad -> Pump)
The red arrows show air. There's holes in the bottom of the case, and in the stand the right rad is sitting on, below the PSU, which has a fan in the bottom to suck air through the rad as well as the fan on it.
