# System for Indoor Comfort and Health Monitoring Tested in Office Building Environment
## 1 Introduction  
Nowadays, reducing energy consumption in the context of an increasing need for comfort is a global trend that can improve the performance of buildings. Residential or office building users can adapt their own routines in order to maintain indoor air quality at a desired level by using a continuous monitoring device. In this way, they are able to understand the impact of their behaviour on the quality of the indoor environment and can undertake appropriate measures. In recent years, global population growth has led to increased housing and job needs, which has made it imperative to adopt innovative solutions embedded in the built space of residential and office buildings. It is well known that buildings significantly contribute toglobal energy consumption due to their heating, ventilation and air-conditioning (HVAC) systems, having a major impact in terms of greenhouse gas emissions [1]. Even though energy efficiency is a key element in the process, occupants' health and comfort must also be considered, with the aim of finding an optimum between the two. A perfectly insulated house is, of course, optimal in terms of energy needs, but from the occupants' point of view, it can prove unhealthy, presenting the so-called Sick Building Syndrome [2]. The evolution of smart technologies and the Internet of Things (IoT) has set a path for improving energy efficiency, energy savings, and occupants' comfort and health in the built environment, as well as for enhancing the overall building performance [3]. Thus, [PERSON] et al. showed that [3] by controlling specific parameters like lighting, HVAC, switches and blinds in a test lab of the University of Murcia, energy savings from 14% to 30% can be achieved. According to [PERSON] et al. [4], as well as [PERSON] et al. [5], a deterioration in occupants' health is associated with exposure to high levels of indoor pollutants and compounds emitted by building materials. In order to prevent the harmful effects of exposure, it is important to correlate energy efficiency actions with adequate ventilation rates. Air tightening and inadequate ventilation might affect indoor air quality and raise radon (\({}^{222}\)Rn), total volatile organic compound (TVOC) and formaldehyde (HCHO) concentrations. [PERSON] et al. [4] performed extensive research on indoor air pollutants by analysing 226 articles and revealed that the most monitored parameters are suspended particulate matter (PM), nitrogen dioxide, TVOCs including formaldehyde, polycyclic aromatic hydrocarbons and carbon monoxide. [PERSON] et al. [6] analysed indoor air quality in several spaces in a hotel in Turin. The results of PM2.5 monitoring showed that mean values from 4.09 to 9.33 \(\mu\)g/m\({}^{3}\) were registered; TVOCs varied from 108.4 to 162.41 ppb, while CO\({}_{2}\) values from 457.1 to 463.44 ppm were registered. Smart IoT systems represent promising solutions that, through the integration of various sensors, devices and data analysis algorithms, offer the possibility of integrated control, automated diagnostics and users' proactive control. Interest in the development of local or remote comfort-monitoring and control systems in residential or office buildings underwent an increased trend after the 2000s [7; 8; 9; 10]. If the energy efficiency of a residential area is the objective, then consumption monitoring must be carried out for the entire building [9], as well as its surroundings (for example, public lighting). Systems dedicated to monitoring and analysing environmental parameters and consumption in residential and office spaces mainly consist of the following [8]: a hardware module for data acquisition, a software module for collecting and processing the measured data and a storage module (cloud--repository). When monitoring environmental parameters in residential and office buildings, challenges are often encountered regarding the communication of the sensors (wired or wireless), the sampling rate and/or data storage, as well as cybersecurity aspects.