Ruijie Networks RG-N18014 Hardware Installation And Reference Manual page 18

Note: 
Exhaust vents for power modules

Exhaust vents for service and supervisor
modules

Exhaust vents for switch fabric modules
For supervisor and service modules, air flows in from the front intakes and out from the upper vents.

 For the switch fabric modules, air flows in from the front intakes and out from the back vents.
 For the power supply modules, air flows in from the front intakes and out from the back vents.

The chassis should be mounted in a place with sufficient space for air circulation. Sufficient space (10 cm at
least) must be reserved at the air intakes and exhaust vents for ventilation.
If any module slot is unoccupied, install a filler panel to enable proper airflow.