Modeling and estimation of the humans´ effect on the CO2 dynamics inside a conference room

We develop a data-driven, Partial Differential Equation-Ordinary Differential Equation (PDE-ODE) model that describes the response of the Carbon Dioxide (CO₂) dynamics inside a conference room, due to the presence of humans, or of a user-controlled exogenous source of CO₂. We conduct two controlled experiments in order to develop and tune a model whose output matches the measured output concentration of CO₂ inside the room, when known inputs are applied to the model. In the first experiment, a controlled amount of CO₂ gas is released inside the room from a regulated supply, and in the second, a known number of humans produce a certain amount of CO₂ inside the room. For the estimation of the exogenous inputs, we design an observer, based on our model, using measurements of CO₂ concentrations at two locations inside the room. We perform several simulation studies for the illustration of our design.