# System for Indoor Comfort and Health Monitoring Tested in Office Building Environment
## 1 Introduction
The proposed system includes sensors for the continuous, real-time monitoring of the concentrations of various parameters, pollutants like radon, CO\({}_{2}\), suspended particulate matter, formaldehyde and TVOCs, as well as meteorological factors like temperature and relative humidity. To test and validate the system, preliminary experiments were conducted in an office building with specific settings. The data provided by the new modular, custom-made and replicable system for the monitoring of indoor comfort and health set the path for the end-user to control and adjust its parameters. Although the experimental model of the system was used to monitor comfort in an office building, this can be easily applied or adjusted to end-user needs in residential or other types of buildings as well by adding or removing specific sensors. While most existing solutions focus on monitoring common parameters related to either health or comfort [27], the innovative character of the proposed system allows it to provide accurate measurements of a multitude of parameters related to both health and comfort. Moreover, apart from the frequently measured health parameters [27], the current research also includes \({}^{222}\)Rn monitoring. A recent literature review of 163 papers performed by [PERSON] et al. [27] showed that radon is not monitored by current IoT systems. The current research also addresses the new legislation requirements in Romania published on 27 July 2023 [28]. The regulation states the obligation to determine the indoor radon concentration in public and office buildings. Thus, the system provides users with access to real-time data on potentially harmful pollutants in order to undertake appropriate control and reduction measures. Not only are users able to protect their health, but, at the same time, they can also control and improve comfort in living and working spaces. In this regard, one of the novelties of the proposed monitoring system consists of implementing an Arduino microcontroller with a unique code written using a specific programming language tailor-made for this specific application. This code enables data acquisition from multiple sensors and devices, making it suitable for subsequent integration with an energy management system. This facilitates the automation of HVAC systems, contributing to the improvement of the energy efficiency of the building. The conducted tests are considered preliminary since only health and comfort parameters were monitored in a short time period. The researchers aim to extend the measurements to long time periods and to add a dedicated energy efficiency module based on smart plugs and switches, as well as indoor occupancy sensors. This paper is structured in six chapters. Section 1 reviews the current state of the research field and presents the main achievements in IoT monitoring system development. Section 2 highlights the main definitions and standards related to indoor comfort parameters. While Section 3 proposes a methodology for IoT system development, Section 4 provides the description, analysis and interpretation of the experimental results following the system testing in an office building. Section 5 points out the limitations of this article. Section 6 concludes the main findings of the paper.