VOC emissions from two-layer building and vehicle cabin materials: Measurements and independent validation

Most indoor building materials and vehicle cabin materials consist of multiple layers which can emit volatile organic compounds (VOCs), and these adversely affect indoor and in-cabin air quality. Previous studies have generally targeted VOC emissions from single-layer materials, while only a few look at emissions from multi-layer products, with experimental studies being very rare. This paper uses a two-layer emission model to predict the emission characteristics of VOCs from both indoor building materials and vehicle cabin materials. A hybrid optimization approach (ant colony optimization (ACO) coupled particle swarm optimization (PSO)) is presented to determine the three key parameters for each layer of material in the model, i.e., the initial emittable concentration, the diffusion coefficient, and the partition coefficient. The results indicate that this method has significant advantages compared with previous fitting methods. In addition, independent experiments for formaldehyde emission from a variety of two-layer building materials, and acetaldehyde emission from car seat materials, were performed to validate the two-layer emission model. The good agreement between model predictions and experimental results implies that the key parameters derived for each layer of material can be applied in two-layer emission scenarios. Furthermore, we explore the influence of the three key parameters on VOC emission behaviors, which is helpful for achieving effective source control.