When mounting the router vertically, ensure that the fan tray is at the bottom to ensure bottom-to-top air
flow.
Caution
Figure 30: Cisco ASR 902 Router Chassis Air Flow - Vertical Mounting
•
If airflow through the equipment rack and the routers that occupy it is blocked or restricted, or if the
ambient air being drawn into the rack is too warm, an overtemperature condition may occur within the
rack and the routers that occupy it.
•
The site should also be as dust-free as possible. Dust tends to clog the router fans, reducing the flow of
cooling air through the equipment rack and the routers that occupy it, thus increasing the risk of an
overtemperature condition.
•
Enclosed racks must have adequate ventilation. Ensure that the rack is not congested because each router
generates heat. An enclosed rack should have louvered sides and a fan to provide cooling air. Heat that
is generated by the equipment near the bottom of the rack can be drawn upward into the intake ports of
the equipment above.
Cisco ASR 902 and ASR 902U Aggregation Services Router Hardware Installation Guide
51
Preparing for Installation
Air Flow Guidelines
