## 5 Conclusions  
This paper firstly proposes a wireless DYU Air Box in which a TTGO ESP32 Wi-Fi device was adopted to aggregate heterogeneous devices of a BME680 air quality index (AQI) sensor, PMS7003T PM\({}_{1.0}\)/PM\({}_{2.5}\) sensor, SCD30 carbon dioxide (CO\({}_{2}\)) sensor, and BH1750 light sensor to acquire the data of AQI value and level, PM\({}_{1.0}\) and PM\({}_{2.5}\) concentrations, CO\({}_{2}\) concentration, brightness, ambient temperature, and relative humidity (RH). The acquired data were forwarded to the public Thing5 peak IoT platform through the existing DYU-802.1X Wi-Fi network with Wi-Fi Protected Access 2 (WPA2) Enterprise security based on the Hypertext Transfer Protocol (HTTP). With the help of the existing DYU-802.1X network and the public Thing5 peak IoT platform, the implementation and evaluation of the DYU Air Box for the environment-monitoring IoT system are completely conducted with sufficient accuracy. The acquired data of the DYU Air Box were evaluated with the following commercially available measurement instruments: a TES-1337B light intensity meter, a TES-1364 temperature and humidity meter, a TES-1370H CO\({}_{2}\) meter, a TES-5110 particle counter, and a TES-5322A IAQ meter. The results reveal that the mean absolute percentage error (MAPE) values between the sensing data and the readings of the instruments were less than 0.5% which reveals that the proposed DYU Air Box has a close agreement with the above instruments of over 99.5%. As compared to the two commercialized devices of Enviro+ Raspberry Pi HAT and Verkada SV11-HW, the DYU Air Box is more cost-effective than them. Therefore, the proposed DYU Air Box features cost-effectiveness and sufficient accuracy and confidence. Due to the visualization limits of the public Thing5 peak IoT platform, further work will be aimed to development a private DYU EMIoT system which will allow the observation of multiple DYU Air Box devices through the DYU-802.1X Wi-Fi network with WPA2 Enterprise security on campus. Furthermore, the planned DYU EMIoT system will feature simultaneous observations for the public Thing5 peak IoT platform and a customized, private environment-monitoring IoT one only using the proposed sensing device. This DYU Air Box with the public Thing5 peak IoT platform is the first step to offer organizational environmental, social, and corporate governance (ESG) value for all stakeholders including the students, faculty, and staff on campus as well as other stakeholders such as the alumni and students' parents. Furthermore, both the public Thing5 peak IoT platform and private EMIoT system will provide data on the environmental conditions for all stakeholders according to their interests.  
Conceptualization, L.-M.S. and H.-L.T.; methodology, H.-L.T. and L.-M.S.; software, H.-L.T. and C.-Y.T.; validation, L.-M.S., H.-L.T. and C.-Y.T.; formal analysis, H.-L.T. and C.-Y.T.; investigation, H.-L.T.; writing--original draft preparation, H.-L.T.; visualization, L.-M.S. and C.-Y.T.; supervision, H.-L.T.; project administration, L.-M.S.; funding acquisition, L.-M.S. and H.-L.T. All authors have read and agreed to the published version of the manuscript.  
**Funding:** The authors gratefully acknowledge the financial support by the project 112-2813-C-212-015-E from the National Science and Technology Council of the Republic of China.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Available online: [[https://thingspeak.com/channels/1408273](https://thingspeak.com/channels/1408273)]([https://thingspeak.com/channels/1408273](https://thingspeak.com/channels/1408273)), accessed on 15 December 2023.  
**Acknowledgments:** The authors gratefully acknowledge the administrative and technical support from the Computer Center of Da-Yeh University (DYU) for in situ measurement through DYU-802.1X communication network on DYU campus, Taiwan.  
**Conflicts of Interest:** The authors declare no conflicts of interest.