Cisco GoQAM Installation And Operation Manual page 38

Chapter 2 Installing the GoQAM
The 4 RU space at the top is covered with a closed panel. This option uses an exhaust
fan located on top of the rack to draw the heated air upward and out of the rack. The
4 RU space at the top allows the ventilation space needed for the exhaust fan to
operate efficiently. The exhaust fan should be chosen so that a minimum of 600 cubic
feet per minute (cfm) flows through the rack with 2000 cfm being the ideal amount.
Example:
22 4004834 Rev D