All buildings need air conditioning in order to obtained a good indoor environmental quality (IEQ) essential for the proper execution of the tasks and to assure a healthy environment of the occupants. Generally speaking, in the case of smaller buildings this can be provided by A/C units of each room, but once the building reaches a certain size it becomes cost-effective and more energy efficient to use a centralized system. This configuration normally uses “chillers” which are basically giant A/C units, but they work slightly differently because of their size.