Abstract : This paper introduces the energy-saving principle of variable speed regulation of air conditioning fans. Based on data measured on actual ships, the dynamic heat load changes of air conditioning are analyzed for different sea areas and times. Numerical calculations of energy-saving indicators are then performed, concluding that variable frequency regulation of air conditioning fans has a high energy-saving rate. Keywords : Air conditioning system; Partial heat load; Fan; Inverter 1 Introduction To ensure safe navigation and crew comfort, more than 2,500 ocean-going vessels in China are equipped with centralized central air conditioning systems. The power consumption of air conditioning fans on ocean-going vessels of 10,000 tons or more generally accounts for (8-13)% of the ship's electrical grid capacity, making it a major energy-consuming device. However, when ocean-going vessels cross the equator from the Northern Hemisphere to the Southern Hemisphere, the outside temperature may vary within a wide range (+50 to -30)℃, and the air conditioning load and the required air volume of the air conditioning fans will also change drastically. Traditional ship air conditioning system design is based on meeting the maximum load, adopting a constant speed and constant power operation mode. However, the air conditioning system operates under partial heat load for more than 85% of the time, leading to a significant loss of effective energy. Variable frequency speed control of air conditioning compressors can match the cooling capacity of the air conditioner with the load. However, after the compressor is variable frequency speed controlled, if the air conditioner fan speed is not adjusted, the evaporation pressure will decrease when the compressor speed increases, and the energy efficiency ratio of the air conditioning system will decrease. When sailing in high-latitude sea areas, the room temperature is low and the air volume is large, which leads to an increase in the back pressure of the air conditioner fan, fan surge, and increased airflow noise. Therefore, adjusting the fan air volume is an important way to save energy in air conditioning. [b]2 Air Volume Adjustment Methods and Energy Consumption of Ship Air Conditioning 2.1 Air Volume Adjustment Methods[/b] Currently, cargo ships generally use fixed-speed fan centralized mixing single-duct air conditioning systems. All air handling equipment, including fans, surface coolers, humidifiers, and filters, are concentrated in one air handling box, and then the treated air is distributed to each air conditioning compartment through several channels. [b][align=center]For details, please click: Research on Energy Saving of Marine Air Conditioning Fan Variable Frequency Adjustment[/align][/b]