Dynamic Use-Phase Variability In IoT-Enabled Systems: A Simulation-Based Case Study Of Smart Thermostats

In this study, we demonstrate that static estimates are inadequate for characterizing the use-phase performance of IoT-enabled systems. We present a case study based on a simulation that evaluates the thermal behavior of a room over one year using real 2023 outdoor temperature data from Konstanz (Germany). The simulation integrates a conventional heating source with a smart thermostat that adjusts the heating based on occupancy and time of day preferences. By varying key parameters such as wall thickness and temperature setpoints, we reveal significant variations in predicted energy savings. The savings distributions are irregular, often fat-tailed or multi-modal. This shows the complexity of the use phase and the need for dynamic modeling when assessing the environmental impact of such systems.