Numerical prediction model for fungal growth coupled with hygrothermal transfer in building materials

A mathematical model that reproduces fungal proliferation and morphological colony formation was developed on the basis of a reaction diffusion modelling approach. In this modelling, fungal life stage was separated into two, active and inactive stage, and it was assumed that active fungus moves by diffusion and reaction while generating and producing inactive fungus. The effects of temperature and humidity on fungal growth were explicitly incorporated in the reaction term of nutrient consumption/production of active fungus in this governing equation. The damping function, which reproduces the effects of temperature and humidity on fungal growth, was developed and explicitly based on the fungal index proposed by K. Abe. In order to estimate the sensitivity of the proposed numerical fungal growth model, fungal growth on the surface of building materials was analysed for four types of building materials, and the prediction results were compared with the results of WUFI-Bio and the fungal index.