Juniper MX2020 Hardware Manual page 157

For the cooling system to function properly, the airflow around the chassis must be unrestricted.
For service personnel to remove and install hardware components, there must be adequate space at the
front and back of the router. At least 36 in. (91.44 cm) is required both in front of and behind the router.
Airflow must always be from front to back with respect to the rack to ensure that fresh air from the
front of the rack is supplied to the inlets, and exhaust exits the rear of the rack. Care must also be taken
around cables to ensure that no leakage of air in situations where recirculation may result.
NOTE: There are no additional clearance requirements to accommodate the depth of the
MX2020 Power Distribution Modules (PDMs), and Power Supply Modules (PSMs); they are
within specification.
An MX2020 router with an extended cable manager requires extra clearance to accommodate the depth
of 37.46 in. (95.1 cm).
Figure 55: Chassis Dimensions and Clearance Requirements for the MX2020 Router with the Standard
Cable Manager
134