A fan cooling system has individual fan modules which are connected together in an end-to-end configuration, where one of the fan modules is connected to a mechanism which rotates the linear array of fan modules. The fan modules are substantially identical, which allows prefabrication of the fan modules prior to on-site installation of the system. Each fan module may contain water injection piping and nozzles, which allows the fan cooling system to dispense fog. The linear array of fan modules may be rotated along a longitudinal axis, such that the axial flow direction of the fans may be changed with respect to a vertical plane. A suggested use of the fan cooling system is for the cooling of livestock in large livestock structures.