# Exploiting the Value of Active and Multifunctional Facade Technology through the IoT and AI
## 4 An IoT-Based Multifunction Facade Prototype
### Facade Control System  
The MF MEZeroE multifunctional facade is managed through a Modberry gateway that collects and analyzes sensors every 5 s and uses ruled-based decision-making AI to define input for the integrated technologies. Thus, environmental data feed energy and IEQ algorithms for adjusting actuation for the heat pump, mechanical ventilation, solar blinds, and opening of windows. These optimization rules also included aspects related to acoustic, perceptual, visual, and air quality to provide multidomain comfort for \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sensor Kit** & **Parameter** & **Units** & **Range Value** \\ \hline \multirow{3}{*}{\begin{tabular}{c} Master \\ (transom) \\ \end{tabular} } & Glass surface temperature & \({}^{\circ}\)C & \(-\)40 to 200 \({}^{\circ}\)C \\  & Transom surface temperature & \({}^{\circ}\)C & \(-\)10 to 50 \({}^{\circ}\)C \\  & Internal solar radiation & W/m\({}^{2}\) & 0 to 1500 W/m\({}^{2}\) \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} Slave 1 \\ (internal \\ \end{tabular} } & Internal air temperature & \({}^{\circ}\)C & \(-\)55 to 125 \({}^{\circ}\)C \\  & Internal relative humidity & \% & 0 to 100\% \\ \cline{1-1}  & Internal illuminance & lux & 0 to 100 klux \\ \cline{1-1}  & Internal CO\({}_{2}\) & ppm & 0 to 1000 ppm \\ \cline{1-1}  & Internal TVOC 1 & \(\mu\)g/m\({}^{3}\) & 0 to 110 kPa \\ \cline{1-1}  & PIR (presence) & - & 0/1 \\ \hline \multirow{4}{*}{
\begin{tabular}{c} Slave 2 \\ (external \\ \end{tabular} } & External air temperature & \({}^{\circ}\)C & \(-\)55 to 125 \({}^{\circ}\)C \\  & External relative humidity & \% & 0 to 100\% \\ \cline{1-1}  & External pressure & Pa & 0 to 110 kPa \\ \cline{1-1}  & External illuminance & lux & 0 to 100 klux \\ \cline{1-1}  & External solar radiation & W/m\({}^{2}\) & 0 to 1500 W/m\({}^{2}\) \\ \cline{1-1}  & External noise & dB & 0 to 130 dB \\ \hline \hline \end{tabular}  
* TVOC: total volatile organic compounds.  
\end{table} 
Table 2: List of sensors integrated in MEZeroE MF. Figure 5: MEZeroE IoT sensor positions outdoors (**left**) and indoors (**right**). users. The rules are managed and implemented in Node-RED, an open-source flow-based development tool designed for visual programming. It offers a user-friendly interface for connecting hardware devices, APIs, and online services to IoT sensors, automation workflows, and more. The main rules for energy and IEQ optimization can be summarized as follows (in order of prioritization of the algorithm functionality):  
* Energy and thermal comfort. Depending on the season, different temperature thresholds are set to ensure ideal thermal comfort. These rules provide operating ranges according to the predictive mean vote (PMV) and predicted percentage of dissatisfied (PPD) standards defined for office buildings [3,4]. Implementation of the different technologies will be achieved to enhance the energy performance of the system as much as possible. * Indoor air quality (IAQ). CO2, atmospheric particulate, and VOC values are monitored to adjust natural/mechanical ventilation in the room when strictly necessary. This approach drastically reduces heat loss and increases the well-being of users. * Acoustic comfort. Noise control is carried out externally to promote a healthier and more comfortable working environment. This implies a control on the opening of windows if noise pollution values are too high. * Visual comfort. Lighting and solar radiation are integrated to guarantee visual and perceptual comfort to allow aspects related to the quality of the working space to be included. For example, a view towards the outside of the building can be favored when there is no glare inside. These algorithms are designed to adapt dynamically the thresholds of the main comfort parameters (temperature and lighting) based on users' discomfort feedback. Thanks to the adoption of a web app, the users can interact with the algorithms, identifying a status of discomfort.