A 15 ton AC unit is a type of air conditioning system that is designed to cool large spaces. It is capable of cooling an area of up to 45,000 square feet, making it an ideal choice for large commercial buildings, warehouses, and other large spaces. The unit is composed of two components: an outdoor condenser and an indoor evaporator. The condenser is responsible for removing heat from the air, while the evaporator cools the air and circulates it throughout the space. The unit is powered by electricity and is typically connected to a dedicated power source. The size of the unit is determined by the amount of cooling capacity it can provide, with 15 tons being the largest size available. This size of unit is capable of cooling a large area quickly and efficiently, making it an ideal choice for businesses and other large spaces.