Development of environmental chamber NUAGE and its digital twin for holistic indoor air quality studies in French dwellings

Bad indoor air quality (IAQ) plays an important role in people's lives as it has adverse health effects particularly in urban environment, making ventilation essential to the built environment. Studying ventilation strategies as a function of building permeability and its outdoor conditions is challenging, as in situ experiments offer limited control over environmental factors. This demands the development of experimental and numerical setups capable of reproducing well-controlled yet representative real-world conditions. The objective is therefore to create an environmental chamber that enables testing of these strategies under various controlled scenarios, along with the development of a digital twin using CONTAM. This allows studying the impact of ventilation strategies on IAQ parameters (i.e., pollutant concentrations). The comparison with experimental findings for CO 2 and PM levels showed that the model was capable of predicting the transport dynamics with an error for CO 2 below 10 % under carefully monitored conditions. The error rose to about 16 % when operating parameter deviations took place. The dynamic buildup and decay patterns for PM were realistically modeled; however, calibration was necessary to bring experimental data closer to numerical results. The discretization of the particle size distribution within the model was identified as the cause of the disparity in PM levels. The combined experimental–numerical framework offers a strong foundation for researching the dynamics of pollutants in ventilated spaces and facilitates the creation and assessment of sophisticated ventilation control techniques, especially demand-controlled ventilation, which are intended to enhance IAQ in residential buildings while reducing their energy footprint.