Liquid-air hybrid cooling in electronics equipment

An electronics chassis system comprising:

• a housing defining an interior area, said housing having four vertical walls including a front wall, a back wall, and two sidewalls, said housing further including an upper plenum having a upper air inlet opening in said front wall and a lower plenum having a lower air inlet opening in said front wall;
• a fluid cooling system disposed within said housing, said fluid cooling system including:
• a heat exchanger mounted in said upper plenum of the housing proximate to an outlet opening through said back wall of said housing;
• a fluid supply conduit leading from the heat exchanger to a backplane;
• a fluid return conduit leading from the backplane to the heat exchanger;
• and
• a pump for circulating cooling fluid through said conduits and said heat exchanger;
• a plurality of slots disposed below the upper plenum and above said lower plenum of said housing for selectably receiving a plurality of individual electronics modules in vertical alignment between the two sidewalls, wherein said slots are spaced to provide vertical airflow channels between said lower plenum and said upper plenum, each said slot including:
• a first fluid connector located at the backplane for fluidly connecting a fluid inlet of a received electronics module with said fluid supply conduit;
• a second fluid connector located at the backplane for fluidly connecting a fluid outlet of a received electronics module with said fluid return conduit, wherein said pump is operative to circulate cooling fluid through an electronics modules when the electronics module is engaged with the first and second fluid connectors;
• and
• a fan disposed within the upper plenum of said housing proximate to said back wall and said heat exchanger for displacing air through said interior area, wherein said fan is operative to:
• draw a first airstream into said lower air inlet opening in said lower plenum below said slots, through said vertical airflow channels, across electronics modules disposed in said slots and into said upper plenum;
• draw a second airstream into said upper air inlet opening into said upper plenum, wherein said first and second airstreams combine in said upper plenum to form a combined airstream;
• and
• draw the combined airstream across said fan and displace said combined airstream across said heat exchanger and out said outlet opening.