Currently a lot of research is being conducted on the air filtering capabilities of moss. Some claim it filters the air quite effectively and thus diminishes the amount of particulate matter in the urban environment. Certain research institutes and manufacturers express rather impressive claims, but BESIX needs some additional unbiased information, such as: how much of these moss walls are needed to generate a substantial impact, at what distance is the impact still noticeable, does it work in a dense urban environment, etc.
BESIX asked Actiflow to answer these questions. To make this possible a relatively simple model was made using a road with moss screens on both sides or a tunnel entrance with the walls covered in moss. Some additional variances were made in empty surrounding, low rise buildings and high rise buildings. Simulations were carried out using different wind directions and wind speeds to establish a correlation (if present) between these boundary conditions and the dispersion of particulate matter. These results were transferred to BESIX to be used in future projects.