Monitoring Multi-Domain Occupant Comfort in Living Labs Using IoT devices

Indoor Environmental Quality (IEQ) has become a growing area of research as people spend an increasing share of their time indoors. In workspaces especially, poor IEQ can negatively impact health, efficiency, and productivity. IEQ and occupant comfort are shaped by four main domains: thermal, visual, acoustic, and air quality. Among these, thermal comfort remains a major focus of investigation. Current methods often rely on continuous subjective feedback, which can be inconvenient, or direct body-attached sensors, which are intrusive. This has motivated exploration of standalone, non-intrusive solutions. Within this scope, this thesis presents the development of a novel approach for monitoring occupants’ thermal comfort through facial temperature analysis. The work centers on implementing a firmware solution for the MLX90640 thermal imaging sensor paired with the ESP32-S3 microcontroller, creating a low-cost IoT-based acquisition unit designed for workspace comfort monitoring. This was developed within the broader MIRABLE project, a living lab initiative at DENERG, Politecnico di Torino, aimed at advancing both energy efficiency and well-being in indoor environments. The thesis discusses the design alternatives considered for frame processing (local vs. remote) and communication protocols (BLE vs. Wi-Fi/MQTT), highlighting how decisions were shaped by constraints in processing power, memory, scalability, and privacy. The firmware was iteratively developed with lightweight image processing algorithms, modular code structure, and real-time scheduling mechanisms. Experimental validation was carried out through progressive testing: from debugging iterations, to short standalone sessions, to controlled trials in the living lab, and finally to systematic climate chamber experiments against reference instruments. This work demonstrates the feasibility and potential of thermal imaging as a non-intrusive method for comfort monitoring in workspace IEQ devices, and points toward future opportunities for integrating such approaches into next-generation indoor comfort and energy management systems.