A 7.5 ton rooftop AC unit is a large air conditioning system that is typically installed on the roof of a commercial building. It is designed to provide a large amount of cooling capacity for a large area, such as an office building or warehouse. This type of unit is typically used in areas that require a large amount of cooling, such as in a hot climate or in a large building with a lot of occupants. The unit is typically made up of several large components, including an evaporator coil, condenser coil, compressor, and fan. The evaporator coil is responsible for absorbing heat from the air, while the condenser coil releases the heat outside. The compressor then pumps the refrigerant between the two coils, and the fan helps to circulate the cooled air throughout the building. The size of the unit is determined by the amount of cooling capacity it provides, with 7.5 tons being the largest size available.