## 5 Conclusions and Discussions
### Limitation of Research and Future Work  
This study emphasized that, the ability of technology to save energy in buildings is affected by the climate. Thus, it is necessary to use efficient technology that is suited to the specific climate regime. Implementing the energy saving technologies, while un derstanding the energy conservation principles underpinning each system under certain climate conditions, is important for energy efficiency considerations when designing high-performance buildings in the future. However, a building's energy performance can be driven by other factors additional to technology and climatic conditions, such as operating hours and occupant behavior. Unfortunately, this information is predicted based on the assumptions adopted by the programmer at the simulation stage and, because real life data can only be obtained from existing buildings measured in real time, an impact analysis of these factors was not possible in this study. However, this is an appropriate topic for future building performance studies.  
Our conclusion that no single technology factor determines building energy performance means that the precise nature of the factors driving building energy use, in addition to the climate, remain unclear. Therefore, an energy saving strategy must consider all factors that can affect the actual energy use of a building. Building use and occupant behavior can influence a building's operating schedule and energy usage. An integrated design approach that considers all factors offers the greatest potential for planning and building energy-efficient buildings informed by real world data.  
In this study, representative ASHRAE international climate zones were selected and simulations were carried out, but data reflecting all of the global climate zones was unavailable. To address this, in the \"Supplementary Materials\" we present a reference list of the potential energy saving rates suggested in various papers. In addition, it is necessary to propose a more realistic solution for energy performance information by region and system in connection with the optimization process of passive, active, and renewable energy systems. In a future study, we will conduct research to identify the optimal cost-effective combination by region, by undertaking an economic analysis of each type of technology. Therefore, the future research will analyze and discuss the results of the actual system operation through an experimental study.  
The following are available online at [[https://www.mdpi.com/article/10.3390/app11157115/s1](https://www.mdpi.com/article/10.3390/app11157115/s1)]([https://www.mdpi.com/article/10.3390/app11157115/s1](https://www.mdpi.com/article/10.3390/app11157115/s1)), Table S1: Review of researches on energy saving potential of energy saving technologies for simulation verification (Passive systems), Table S2: Review of researches on energy saving potential of energy saving technologies for simulation verification (Active and renewable energy systems).  
[PERSON]-H.K. performed the simulation and data analysis, and wrote this paper based on the obtained results with the help of [PERSON]-K.P. and [PERSON]-H.K.; [PERSON]-H.K. led and supervised this study. All of the authors contributed to collecting ideas and concepts presented in the paper. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea), grant number 20014154.  
Not applicable.  
This work was supported by the Technology Innovation Program (or Industrial Strategic Technology Development Program-Advanced Technology Center Plus) (20014154, Development of EMS with Optimal Control Algorithm for Energy Efficiency Improvement in Commercial Buildings Using AI and Digital Twin Technology) funded By the Ministry of Trade, Industry & Energy (MOTIE, Korea).  
The authors declare no conflict of interest.  
The following abbreviations are used in this manuscript: