Dry-cooling unit with gravity-assisted coolant flow

A cooling unit comprising:

• at least one heat rejection unit configured to reject heat from coolant passing through a coolant loop to air passing across the at least one heat rejection unit, the at least one heat rejection unit comprising at least one heat exchange assembly coupled to the coolant loop for at least a portion of the coolant to pass therethrough;
• an elevated coolant tank coupled in fluid communication with the at least one heat exchange assembly of the at least one heat rejection unit, the elevated coolant tank facilitating return of coolant to the coolant loop at a substantially constant pressure, wherein the elevated coolant tank is elevated above at least a portion of the coolant loop;
• and
• wherein one heat exchange assembly of the at least one heat exchange assembly of the at least one heat rejection unit is rotatably mounted to a support structure, and wherein the cooling unit further comprises a controller coupled to automatically rotate at least a portion of the one heat exchange assembly responsive to a change in direction of ambient airflow at the one heat exchange assembly to facilitate rejection of heat to air passing across the one heat exchange assembly.

A data center comprising:

• a plurality of electronics racks;
• a cooling apparatus facilitating extraction of heat from at least one electronics rack of the plurality of electronics racks, the cooling apparatus comprising at least one coolant loop;
• and
• a cooling unit comprising:
• at least one outdoor heat rejection unit, the at least one outdoor rejection unit being a dry heat rejection unit configured to reject heat from coolant passing through one coolant loop of the at least one coolant loop of the cooling apparatus to air passing across the at least one outdoor heat rejection unit without water evaporation, and the at least one outdoor heat rejection unit comprising at least one heat exchange assembly coupled to the one coolant loop for at least a portion of the coolant to pass therethrough;
• and
• an elevated outdoor coolant tank coupled in fluid communication with the at least one heat exchange assembly of the at least one outdoor heat rejection unit, the elevated outdoor coolant tank facilitating return of coolant to the coolant loop at a substantially constant pressure, wherein the elevated outdoor coolant tank is fixedly elevated above at least a portion of the one coolant loop and fixedly elevated at least partially above the at least one heat exchange assembley of the at least one outdoor heat rejection unit.