Air conditioning systems are the primary energy consumers in the service industry, mainly because of their high electricity consumption. The chilled-water system, which includes the chiller, water pump, and cooling tower, is responsible for the majority of electricity consumption. Therefore, improving the efficiency of the chilled-water system often has a greater impact than improving the air distribution system. The efficiency of centralized chilled-water systems is typically expressed in kW/RT. This metric considers factors such as water volume, water temperature, and the coordinated operation of components like chillers, water pumps, and cooling towers. It assesses the overall energy efficiency of the system. This study aims to gather energy efficiency management measures for air conditioning systems, both domestically and internationally. The study will sample and measure the efficiency of centralized chilled-water systems. The objective is to help users understand the trends in energy efficiency management of air conditioning systems, assess the efficiency of their own system, implement energy-saving measures, and identify potential energy savings. The study aims to enhance the efficiency of air conditioning systems and decrease operating costs.