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The air conditioning and refrigeration system in the process workshop of a pharmaceutical company consists of 4 York centrifugal chiller units and 2 LG dual-mode units. Due to the long operating time of the system and poor quality of the cooling water, scaling tended to occur severely within the system. After about three months of operation, the temperature of the condensers rose above 8°C, which triggered alarms and caused the main units to shut down. The engineering department of the pharmaceutical company regularly uses chemical agents to clean the copper tubes of the condensers by removing bubbles, in order to restore the temperature difference within the system. After cleaning, the temperature difference increases rapidly in a short period of time; repeated cleaning increases the costs associated with the system, shortens the lifespan of the main equipment, and results in unnecessary waste of energy, posing a significant problem for the company’s management. In response to the need for **energy conservation and emission reduction as well as to address issues related to system operation, the pharmaceutical group began implementing energy-saving upgrades to the air conditioning systems in its refrigeration facilities in March 2016. In the system energy-saving renovation plan, to address the issue of a rapid increase in the temperature difference across the condenser, an online cleaning solution was adopted. The online cleaning system is used to remove dirt from within the copper tubes of the condenser, thereby maintaining a small temperature difference across it. Through investigations into market applications, it was found that both ball-type and brush-type online cleaning systems are widely used. The company decided to employ ball-type online cleaning for the 6 York centrifugal chiller units in its office facilities, while using Qin Yuan brush-type online cleaning for the 6 units in the air conditioning systems of its production workshops. By comparing the performance of these two types of online cleaning, the company aims to develop solutions for energy-saving design of other cooling systems within the group. After the system renovation was completed, within one year of the data center’s operation starting in May 2016, the facility managers regularly monitored the approaching temperature of each unit on a daily basis and kept records. In February 2017, the end caps of the condensers were opened to check the condition of the inner walls of the copper tubes. The air conditioning and cooling system in the production workshops is in operation from May to November, while that in the office areas is in operation from June to September. After the computer room staff analyzed the operational data, it was found that the approximate temperature of the main condenser in the processing workshop remained at 1.7–2.2°C, which is similar to the approximate temperature achieved after cleaning the condenser by removing bubbles during the renovation process ； The temperature of the condenser of the main unit in the air conditioning system in the office area is maintained at 3.0–5.0°C. In February 2017, the front and rear end caps of the main unit in the process workshop’s refrigeration system were removed to inspect the inner walls of the copper tubes. It was found that the inner walls of the condenser copper tubes were clean and smooth, with the metallic luster of the copper tubes visible. Two hosts were randomly selected from the office area, their covers were removed to inspect the copper tubes. It was found that the inner walls of the copper tubes in the middle part of the condenser were relatively clean, with only minor deposits of dirt in some areas; the copper tubes further toward the periphery had more dirt buildup, and in some cases the color of the copper tube interior could no longer be seen at all. It can be concluded that the online brushing cleaning system in the processing workshop provides good cleaning results, allowing the main machine to operate for longer periods of time ； The cleaning efficiency of the online gel ball cleaning system for the refrigeration system in the office area is relatively poor, and the operating time of the main unit is short. However, compared with the operating data from previous years before the renovation, the average temperature at the end of September each year ranges from 4.8 to 6.8°C, indicating that the online gel ball cleaning method also brings about significant improvements. For the routine maintenance of online cleaning equipment, the Qinyuan brush online cleaning system requires a continuous power supply. When the power to the equipment is lost and then restored, it is necessary to reset the equipment parameters, as well as to regularly check and record the number of times cleaning has been performed using this online cleaning system ； In the online cleaning system for rubber balls, it is necessary to regularly check the wear level of these balls using the eyepiece of the launcher; those that are severely worn need to be replaced. When replacing the balls, they should be soaked in water and squeezed with the fingers. It is also necessary to monitor the recovery of the balls on a regular basis. After power is restored, the device parameters must be set again, making maintenance and management relatively complicated. Every month, the rubber balls must be removed and manually squeezed to expel the sediment inside them; otherwise, if there is too much sediment, the elasticity of the rubber balls will decrease significantly, preventing them from passing through the condensation tubes and leading to numerous blockages. By comparing the operational data, it can be determined that the Qinyuan brush online cleaning system achieves a much better cleaning effect on the copper tubes of condensers compared to the rubber ball online cleaning method. Taking into account the effectiveness of online cleaning as well as routine maintenance, other newly built workshops in this group have adopted the Qinyuan brush online cleaning system during subsequent technical upgrades; to date, they have been operating well, achieving significant energy savings.