This study presents a system dynamic model of mould growth on wood by taking into account of the physiological properties of mould and the material properties of wood. Mould growth on wood was first analyzed by systems thinking with a causal loop diagram. The system is then simulated by computer software. The moisture exchange between the wood and air by desorption and adsorption processes are simulated by calculating the moisture diffusion and absorption over relative humidity differences, which is also influenced by temperature and pressure. The model also simulates the mould growth, which is influenced by moisture, temperature, nutrient, oxygen availabilities etc. This conceptual simulation model of was made by STELLA® to show the correlation of the factors for mould growth and the influences by the physical parameters.
Three samples of the model simulation results are shown: one is wood was wet and the air is relatively drier. Second one is when wood was dry and the air was wet. The third one was with the temperature variation between day and night.
This interdisciplinary study shows how the knowledge of building physics and biological aspects can be combined in construction a system model and used to predict the biological growth on materials.
Keywords: mould, system analysis, modeling, wood
Authors
Li Y.
Division of Building Materials, Lund University, Lund, Sweden
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