These huge commercial and industrial fans distribute large amounts of air throughout the building which cools people up to 7 degrees celcius.  The most economical form of cooling; both for capital expenditure and operational costs. 

When combined with a cooling system, these fans assist the system by circulating the air which then provides a wind chill factor to increase the cooling capability - this equates to you adjusting the temperature gauge which reduces the load on your cooling system and saves a huge amount of money - they literally pay themselves off.