A system for cooling components, comprising: an enclosure; an air cooling system configured to receive warm air from within the enclosure through a warm air port in an enclosure ceiling, cool the warm air to produce cooled air, and provide the cooled air into the enclosure through a cool air port in the enclosure ceiling; a cool air duct attached to the cool air port within the enclosure and extending from the cool air port toward an enclosure floor, the cool air duct having an outlet disposed above the floor of the enclosure to isolate the cooled air flowing in the cool air duct from the warm air located at the ceiling portion of the enclosure; and one or more racks (106a-106f) disposed within the enclosure, for each rack: i) a stacked arrangement of heat dissipating components mounted to the rack; ii) an air plenum disposed on a rear side of the rack and covering a rear opening of the rack, thereby forming an air channel along a rear portion of each heat dissipating component of the stacked arrangement of heat dissipating components mounted to the rack, wherein the air plenum is dimensioned such that a pressure drop along the air channel of the air plenum is low relative to the pressure drop across each heat dissipating component; and iii) an air mover disposed at a bottom of the rack, the air mover configured to pull the cool air from the floor portion of the enclosure, and to force the air into the air plenum to pressurize the air plenum, wherein the stacked arrangement of heat dissipating components are configured to facilitate a flow of air from the pressurized air plenum at the rear portion of each heat dissipating component, to a front portion of each heat dissipating component. an enclosure; an air cooling system configured to receive warm air from within the enclosure through a warm air port in an enclosure ceiling, cool the warm air to produce cooled air, and provide the cooled air into the enclosure through a cool air port in the enclosure ceiling; a cool air duct attached to the cool air port within the enclosure and extending from the cool air port toward an enclosure floor, the cool air duct having an outlet disposed above the floor of the enclosure to isolate the cooled air flowing in the cool air duct from the warm air located at the ceiling portion of the enclosure; and one or more racks (106a-106f) disposed within the enclosure, for each rack: i) a stacked arrangement of heat dissipating components mounted to the rack; ii) an air plenum disposed on a rear side of the rack and covering a rear opening of the rack, thereby forming an air channel along a rear portion of each heat dissipating component of the stacked arrangement of heat dissipating components mounted to the rack, wherein the air plenum is dimensioned such that a pressure drop along the air channel of the air plenum is low relative to the pressure drop across each heat dissipating component; and iii) an air mover disposed at a bottom of the rack, the air mover configured to pull the cool air from the floor portion of the enclosure, and to force the air into the air plenum to pressurize the air plenum, i) a stacked arrangement of heat dissipating components mounted to the rack; ii) an air plenum disposed on a rear side of the rack and covering a rear opening of the rack, thereby forming an air channel along a rear portion of each heat dissipating component of the stacked arrangement of heat dissipating components mounted to the rack, wherein the air plenum is dimensioned such that a pressure drop along the air channel of the air plenum is low relative to the pressure drop across each heat dissipating component; and iii) an air mover disposed at a bottom of the rack, the air mover configured to pull the cool air from the floor portion of the enclosure, and to force the air into the air plenum to pressurize the air plenum, wherein the stacked arrangement of heat dissipating components are configured to facilitate a flow of air from the pressurized air plenum at the rear portion of each heat dissipating component, to a front portion of each heat dissipating component.