A cooling approach is provided for one or more subsystems of an electronics rack.
The cooling approach employs a coolant distribution unit and a thermal dissipation
unit. The coolant distribution unit has a first heat exchanger, a first cooling
loop and a second cooling loop. The first cooling loop passes facility coolant
through the first heat exchanger, and the second cooling loop provides system coolant
to an electronics subsystem, and expels heat in the first heat exchanger from the
subsystem to the facility coolant. The thermal dissipation unit is associated with
the electronics subsystem and includes a second heat exchanger, the second cooling
loop, and a third cooling loop. The second cooling loop provides system coolant
to the second heat exchanger, and the third cooling loop circulates conditioned
coolant within the electronics subsystem and expels heat in the second heat exchanger
from the electronics subsystem to the system coolant.