# Research on Real-Time Control Strategy for HVAC Systems in University Libraries
## 5 Conclusions  
In this study, the LM-UGO was used to investigate the energy-saving potential of a real-time control strategy for HVAC systems in library buildings using an algorithmic control model. The results and contributions are summarized as follows.  
The HVAC system in an existing campus building was transformed and upgraded, and the control and operation platform of the HVAC system was established and implementedin the library. This initiative aims to give building managers a better understanding of the operation of HVAC system equipment while providing a convenient means to adjust its operating status to significantly improve efficiency.  
The proposed HVAC system control scheme was implemented in a real project and evaluated in several ways. 1. In the experimental project, the energy saving results show that the energy saving rate of the project is more than 35%. 2. In terms of long-term return on investment, the calculated investment reporting ratio for a 10-year service life is 97%. 3. In terms of user comfort, the temperature and relative humidity are compared with the values in the standard specification (GB 55016-2021) for comparison. After using the energy saving strategy, the comfortable values of humidity (60%) and temperature (26 \({}^{\circ}\)C) were reached on average 1.2 h earlier.  
In future work, we plan to use more advanced intelligent algorithms and simulation techniques to improve the accuracy of HVAC system control. The objective is to study intelligent maintenance solutions for HVAC systems in different types of buildings.  
Conceptualization, investigation: Y.Z.; writing--review and editing: W.Z.; project administration, methodology: H.C.; data curation, supervision: X.D.; formal analysis, validation: L.Z.; software, visualization: H.S. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Major Research Project of Department of Science and Technology of Hubei Province in (JD) 2023 BAA007.  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
Author [PERSON] was employed by the company Central-South Architectural Design Institute Co., Ltd. Authors [PERSON] and [PERSON] were employed by the company Wuhan Ruqing Technology Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.  
The following abbreviations and variables are used in this manuscript:  
\begin{tabular}{l l} HVAC & Heating, ventilation, and air conditioning \\ LM & Levenberg-Marquardt \\ LM-UGO & Levenberg-Marquardt algorithm combined with universal global \\  & optimization algorithm \\ COP & Coefficient of performance \\ t & Temperature \\ t\({}_{0}\) & Condensation temperature (\({}^{\circ}\)C) \\ t\({}_{v}\) & Evaporation temperature (\({}^{\circ}\)C) \\ z\({}_{1}\) & Parameter \\ z\({}_{2}\) & Parameter \\ r & Load rate of the chiller \\ t\({}_{w,0,E}\) & Outlet temperature of cooling water (\({}^{\circ}\)C) \\ t\({}_{w,v,E}\) & Outlet temperature of the chilled water (\({}^{\circ}\)C) \\ t\({}_{w,0,L}\) & Inlet temperature of the cooling water (\({}^{\circ}\)C) \\ t\({}_{w,v,L}\) & Inlet temperature of the chilled water (\({}^{\circ}\)C) \\ G\({}_{w,0}\) & Cooling water flow rate (kg/s) \\ G\({}_{w,v}\) & Chilled water flow rate (kg/s) \\ \end{tabular}