Abstract : This paper discusses the principles, methods, and effects of energy saving in central air conditioning, focusing on the application of frequency converters in energy saving. The amount of energy saved is calculated using the formula relating motor power and speed. The feasibility of different energy-saving schemes is studied, and the effects of energy saving are demonstrated through application examples, aiming to raise awareness and motivation for energy conservation. Keywords : Energy saving; Frequency converter; Central air conditioning 0 Introduction Energy is indispensable for national construction and people's lives, and energy utilization efficiency is a symbol of a country's technological level. Developing new energy sources and improving energy utilization efficiency are primary tasks to ensure economic development. Central air conditioning uses electricity to provide a comfortable working and living environment. However, central air conditioning accounts for more than 40% of the total electricity consumption of an entire unit. Therefore, energy-saving design and renovation of central air conditioning systems are crucial for energy conservation. 1 Working Principle of Central Air Conditioning Central air conditioning consists of several parts, including a refrigeration unit, a cooling water pump unit, and a chilled water pump unit. Its function is to provide cool and fresh air to the air-conditioned room through cooling and heat exchange. Figure 1 shows a traditional central air conditioning system. Temperature regulation is achieved by adjusting the opening of indoor air dampers. When the temperature is high, the damper opening increases, accelerating heat exchange and lowering the indoor temperature. When the indoor temperature decreases, the damper opening decreases, slowing down heat exchange and thus raising the indoor temperature. During normal operation, the cooling, heat exchange, and damper controls of a central air conditioning system are manually set and remain unchanged. While this method is simple and easy to implement, it comes at the cost of consuming a large amount of energy. Therefore, it is necessary to change this approach and implement energy-saving operation. [b][align=center]For more details, please click: Research on Countermeasures for Energy Saving in Central Air Conditioning[/align][/b]