A method of cooling a radiator in an internal combustion engine wherein a plurality of fan assemblies is provided. Specifically, each fan assembly has a housing with an interior containing a fan blade and an exterior having six sides to form a hexagonal perimeter. The fan assemblies are then arranged side by side to form a cluster of fan assemblies in order to maximize the amount of fan assemblies that may be provided on an enclosure. The cluster of fan assemblies is then placed adjacent to a radiator to control the air flow over the radiator in order to cool the engine.