Rack for cooling computing devices in a cylindrical configuration

A system for cooling a plurality of computing devices in a data center, the system comprising:

• a controller;
• a cylindrical rack comprising a plurality of annular shelves and vertical supports, wherein each of the annular shelves has a plurality of positions for holding one of the computing devices;
• the plurality of vertical supports configured to hold the annular shelves in a vertically spaced arrangement;
• and
• a smooth cylindrical air barrier affixed to the rack and having an opening for each of the computing devices on the annular shelves;
• wherein the computing devices have cooling fans and exhaust air to the outside of the rack;
• wherein the computing devices are positioned to exhaust air away from a centerline of the rack;
• wherein the controller is configured to instruct the plurality of computing devices to operate with cooling fan speeds according to a pattern;
• and
• wherein the pattern varies vertically relative to the computing device's position on the cylindrical rack.