Fan trays offer intelligent cooling in tight spaces

For one particular project, the requirement was to modify a standard unit so that it would fit into the top of a 19” rack to extract the heat from the cabinet. The rack design provided four 166x440mm slots in the top cover; the challenge was to reconfigure the unit so that it would fit into one of two standard central apertures so that the rack did not need to be modified.

The solution was to reconfigure the mechanical layout of the unit so that it could be slid at an angle through the aperture into the unused space above the topmost rack slot; once in position the unit is then secured to the top cover using a custom designed escutcheon plate.

The intelligent fan trays have a maximum operating temperature of 70°C. The 170m³/h DC fans are managed by a controller that, as standard, restricts the fans at half speed up to 35°C; the speed then linearly increases to maximum at 55°C. The upper and lower limits can be adjusted as required to suit the specific application. If the temperature exceeds 71°C the fans all increase to full speed and an alarm is generated. If one fan fails, the remaining fans increase to full speed and an alarm is generated; if the thermal sensor fails open or short circuit or power fail is detected, again an alarm is generated.

In addition to providing local audible and visible warnings, the fan tray can interface with rack management monitoring through rear mounted connections. A computer-optimised aperture pattern retains mechanical protection, maximises airflow and reduces noise as the air passes through it.