Methods and apparatus for temperature control of computer racks and computer data centres

A computer data centre, comprising:

• a multiplicity of open computer hardware storage racks that are not hermetically sealed, each rack of the multiplicity of open computer hardware storage racks comprising:
• a plurality of individual computer hardware each horizontally rack mounted in a front side of the rack;
• and
• a heat exchanging unit vertically mounted to a back side of the rack;
• and
• a first cooling circuit, interconnecting in parallel heat exchanging units of at least some of the multiplicity of open computer hardware storage racks, the first cooling circuit configured to dissipate heat generated by first computer hardware in the at least some of the multiplicity of open computer hardware storage racks, supply the heat exchanging units of the at least some of the multiplicity of open computer hardware storage racks with a coolant, and convey the coolant heated by the first computer hardware away from the at least some of the multiplicity of open computer hardware storage racks,
• wherein:
• the multiplicity of open computer hardware storage racks are arranged such that at least a first rack and a second rack of the multiplicity of open computer hardware storage racks are back to back with a first heat exchanger unit of the first rack facing a second heat exchanger unit of the second rack;
• a first air temperature in the first rack of the multiplicity of open computer hardware storage racks, arising from the heat generated by the plurality of individual computer hardware mounted in the first rack, is up to 40 degrees Celsius during operation;
• the first heat exchanger unit for the first rack is configured to operates at an operating temperature that effectively absorbs essentially all of the heat generated by the plurality of individual computer hardware mounted in the first rack;
• and
• the data center further comprises a second cooling circuit, wherein the first cooling circuit interconnects first heat exchanging units of a first number of the multiplicity of open computer hardware storage racks, and the second cooling circuit interconnects second heat exchanging units of a second number of the multiplicity of open computer hardware storage racks.

A method of cooling a computer data centre, the computer data centre comprising a multiplicity of open computer hardware storage racks that are not hermetically sealed, each rack of the multiplicity of open computer hardware storage racks comprising a plurality of individual computer hardware each horizontally rack mounted in a front side of the rack, and a heat exchanging unit vertically mounted to a back side of the rack, the method comprising:

• using a first cooling circuit, interconnecting in parallel heat exchanging units of at least some of the multiplicity of open computer hardware storage racks, to:
• dissipate heat generated by first computer hardware in the at least some of the multiplicity of open computer hardware storage racks;
• supply the heat exchanging units of the at least some of the multiplicity of open computer hardware storage racks with a first coolant;
• and
• convey the first coolant heated by the first computer hardware away from the at least some of the multiplicity of open computer hardware storage racks,
• conveying a second coolant to at least some of the multiplicity of open computer hardware storage racks by a second cooling circuit,
• wherein the first cooling circuit interconnects first heat exchanging units of a first number of the multiplicity of open computer hardware storage racks, and the second cooling circuit interconnects second heat exchanging units of a second number of the multiplicity of open computer hardware storage racks,
• wherein the multiplicity of open computer hardware storage racks are arranged such that at least a first rack and a second rack of the multiplicity of open computer hardware storage racks are back to back with a first heat exchanger unit of the first rack facing a second heat exchanger unit of the second rack.