## 3 Case Study  
This study executed the proposed HVAC system optimization control strategy involving FCU temperature control in a university in Taipei City, Taiwan. The study focused on energy conservation optimization control for an HVAC system in the university to meet the required levels of indoor thermal comfort. The HVAC system was installed in the teaching and administration building of the university. This HVAC system was determined to comprise a chilled water system, a chilled water pump, a cooling water pump, and two cooling towers. The teaching and administration building was observed to be four stories high, with the HVAC system being operated from 08:00 to 18:00 from Mondays to Fridays; 42 FCUs supply cold air. This study used a Gateway communication system to monitor the water system operation status of the HVAC in the building. In addition, supervisory  
Figure 5: Mutation process of a child. Figure 6: Genetic algorithm flowchart. control and data acquisition (SCADA) was used for energy conservation control in the centralized HVAC system. The SCADA functions are outlined as follows:  
1. FCU data collection  
Data, such as _Ti, Ts_, and wind speed of the 42 FCUs in the teaching and administration building, were stored in a back-end server using the Modbus transmission method. 2. Chilled water system power consumption monitoring  
Digital electricity meters were installed on the chilled water system, chilled water pump, cooling pump, and cooling towers of the HVAC system. Power consumption data were wirelessly transmitted to the SCADA database. 3. Chilled water system flow and temperature monitoring  
Flow meters were installed on the piping system of the chilled water system and cooling machine, and thermometers were installed on the outlet and return pipes of the chilled water system. Therefore, data concerning the flow of chilled and cooling water and the temperatures of chilled and cooling water in the outlet and return pipes of the HVAC system were transmitted to the PLC controller. Finally, the entire sensor-driven data of the HVAC system were obtained through SCADA using the Modbus transmission method. 4. Chilled water system ON/OFF and frequency change control  
Frequency converters were installed on the chilled water pump, cooling water pump, and cooling tower fans of the chilled water system. Such converters can adjust the frequencies of the chilled water pump, cooling water pump, and cooling tower fans in the event of changes in heat load. Moreover, they can turn the setups on and off through automatic scheduling. 5. FCU temperature control  
The FCU temperature control point in the teaching and administration building enabled automatically setting the indoor temperature according to dynamic FCU temperature settings. Such control was achieved by transmitting temperature settings through SCADA. The HVAC system in the aforementioned building was operated at full load (i.e., 60 Hz) in 2016. The annual mean power consumption of the chilled water system was 33.1 kWh. During the summer (i.e., June, July, and August) of that year--characterized by high power consumption--the monthly mean power consumption of the chilled water system was 62.7 kWh. Figure 7 shows statistics of the annual outdoor temperature distribution and power consumption of the HVAC system. Figure 7: Outdoor temperature and HVAC system power consumption. In general, outdoor temperature is a crucial factor affecting the power consumption of an HVAC system in a building. Figure 8 illustrates a regression model of the outdoor temperature and power consumption of the chilled water system in 2016. The reliability of this regression model was determined to be 90.9%. As shown in this figure, the power consumption of the chilled water system increased as the outdoor temperature increased. The regression equation for power consumption is presented as follows:  
\[kWh=4.56x-76.179, \tag{9}\]  
where the regression coefficient \(x=To\).