Juniper EX4550 - Back-To-Front Airflow; Figure 22: Back-To-Front Airflow through the EX4550 Switch Chassis

Table 18: Airflow Direction in EX4550 Switches (continued)
Direction of AirflowFan Modules and Power SupplyModel Number
Front-to-back—air intake to cool the chassis
is through the vents on the front panel of the
chassis, and hot air exhausts through the
vents on the rear panel of the chassis.
The switch ships with three fan modules, each
bearing a label AIR OUT (AFO), and an AC
power supply bearing a label AFO.
•
EX4550-32F-AFO
•
EX4550–32T-AFO
Back-to-front—air intake to cool the chassis
is through the vents on the rear panel of the
chassis, and hot air exhausts through the
vents on the front panel of the chassis.
The switch ships with three fan modules, each
bearing a label AIR IN (AFI) and a DC power
supply bearing a label AFI.
•
EX4550-32F-DC-AFI
•
EX4550–32T-DC-AFI
Front-to-back—air intake to cool the chassis
is through the vents on the front panel of the
chassis, and hot air exhausts through the
vents on the rear panel of the chassis.
The switch ships with three fan modules, each
bearing a label AIR OUT (AFO) and a DC power
supply bearing a label AFO.
•
EX4550-32F-DC-AFO
•
EX4550–32T-DC-AFO
CAUTION:
Do not mix:
•
AC and DC power supplies in the same chassis.
•
Power supplies (AFI or AFO) and fan modules (AIR IN (AFI) or AIR OUT
(AFO)) with different airflow labels in the same chassis.
Back-to-Front Airflow
In the EX4550 switches that have back-to-front airflow, the air intake to cool the chassis
is through the vents on the rear panel, and hot air exhausts through the vents on the front
panel of the switch. See Figure 22 on page 37.
Figure 22: Back-to-Front Airflow Through the EX4550 Switch Chassis
g021408
Front
Rear
37Copyright © 2015, Juniper Networks, Inc.
Chapter 3: Cooling System and Airflow