Data centre cooling system

26) An indirect air cooler for cooling a data centre, wherein the indirect air cooler defines:

• i) an internal air flow path configured to receive interior air from an interior of the data centre and to return the interior air to the interior of the data centre, and
• ii) an external air flow path configured to receive external air from an exterior of the data centre and to return the external air to the exterior of the data centre,
• wherein the indirect air cooler comprises a plurality heat tube heat exchangers for exchanging heat between the interior air and the exterior air, wherein at least one of the plurality of heat tube heat exchangers is removable, and wherein the indirect air cooler comprises a baffle configured to maintain separation between the internal air flow path and the external air flow path when the at least one removable heat tube heat exchanger is removed from the indirect air cooler.

An indirect air cooling unit for cooling a data centre, wherein the indirect air cooling unit comprises a first air flow path, a second air flow path, and a plurality of heat tubes for transferring heat from air flowing along the first air flow path to air flowing along the second air flow path;

• wherein at least one of heat tubes is removable from the indirect air cooling unit, the at least one removable heat tube extending through an opening between the first air flow path and the second air flow path when present in the indirect air cooling unit;
• and wherein the indirect air cooling unit comprises an adjustable baffle for closing the opening when the at least one removable heat tube is removed from the indirect air cooling unit.

A method of operating an indirect air cooling unit for a data centre, wherein the indirect air cooling unit comprises a first air flow path, a second air flow path, and a plurality of heat tubes for transferring heat from air flowing along the first air flow path to air flowing along the second air flow path,

• wherein at least one of heat tubes is removable from the indirect air cooling unit, the at least one removable heat tube extending through an opening between the first air flow path and the second air flow path when present in the indirect air cooling unit;
• and wherein the indirect air cooling unit comprises an adjustable baffle for closing the opening when the at least one removable heat tube is removed from the indirect air cooling unit;
• wherein the method comprises removing a removable heat tube from the indirect air cooler and operating the baffle to close the opening.