Volatile organic compounds (VOCs) emitted from indoor sources are primary contributors to odor nuisance and can affect indoor perceived air quality (PAQ) and occupant comfort. However, odor perception depends on multicomponent mixtures, and the relationship between indoor VOC concentrations and human olfactory perception remains unclear. In this study, we measured VOC emissions from nine typical odor sources, including occupants, pets, furniture, and building materials and assessed odor intensity (OI) by a trained sensory panel. A total of 31 odor-active VOCs were identified, with aldehydes and acids being the dominant odor contributors, accounting for 36%–100% and 1%–45% of the sum of odor activity value (OAV_sum), respectively. Across the nine source categories, odor-active VOC profiles differed markedly in composition and relative contribution patterns. Further, multivariable models linking odor profiles with perceived OI were developed, using Elastic Net Regression with variable selection (R² = 0.64), and partial least squares regression (PLSR) based on full VOC profiles, which showed improved performance (R² = 0.84). 2-butanone oxime, 2-butanone, 2,3-butanedione, m-xylene, acetaldehyde, and 6-methyl-5-hepten-2-one (6-MHO) were further identified to be closely related with OI perception. These findings support a shift from total-concentration metrics to profile-based odor assessment for indoor PAQ monitoring and evaluation.

Adsorption has been the most feasible and reliable technology to tackle indoor gaseous pollutants. Theoretical analysis is required for a better understanding of adsorption in addition to trial-and-error experiments. A systematic overview of the conventional mechanistic models for adsorption equilibrium (capacity) and kinetics (transport), which are the two key ingredients needed for a complete understanding of adsorption, was presented first. In spite of the valuable guidance those models have provided, their dependences on lumped or unsubstantiated parameters and deficiency in molecular-level information of adsorption processes have become bottlenecks of the adsorption research. Molecular simulation was then introduced as a powerful tool to overcome the limitations of the conventional models by providing the details at molecular level that are intractable for trial-and-error experiments or the conventional modeling to access. The bottom-up scheme of molecular simulation with minimal assumptions is particularly suitable for exploring the underlying mechanisms of adsorption. The basic principles and key procedures of molecular simulation were introduced, followed by the recent progress of molecular simulation study on indoor air pollutants and its comparison with the conventional models.