**7. Conclusions**

In order to solve the problem of time delay in the control process of the air conditioning system, the LFF control strategy was developed. In this control strategy, the cooling load forecast is used as an input parameter to regulate and control the air conditioning system in advance and ignore the problem of parameter variation caused by time delay in the control process.

The energy performance under the LFF control strategy has been validated based on the actual case built TRNSYS simulation platform. The results show that compared with the commonly used feedback control strategy, the proposed e ffective control concept ensures indoor comfort and reduces system energy consumption. Under the LFF control, the indoor temperature fluctuations are minimal and the energy consumption under this control strategy is the lowest. Compared with the SWT and RTF controls, the total energy consumption of the LFF control at full-time simulation was reduced by 13.4% and 7.8%, respectively.

However, the simulation analysis results of the energy-saving rate have some limitations. By changing the simulation parameters, it can be found that the system energy-saving rate obtained by the TRNSYS simulation platform is mainly a ffected by outdoor meteorological parameters and thermal performance parameters of the building envelope. For di fferent types of buildings and di fferent outdoor meteorological parameters, the system energy-saving rates simulated by the LFF control strategy are often di fferent.

**Author Contributions:** Methodology, J.Z.; software, R.G.; Y.S.; validation, Y.S. formal analysis, J.Z.; investigation, J.Z.; R.G.; resources, J.Z.; writing—original draft preparation, Y.S.; writing—review and editing, Y.S.; R.G. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported by the Natural Science Foundation of China, Project No. 51678398 and the Natural Science Foundation of Tianjin, Project No.18JCQNJC08400. "The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results".

**Conflicts of Interest:** The authors declare no conflict of interest.
