Prediction of Mould Growth by Hygrothermal Calculation

Abstract

In buildings growing conditions for mould fungi can occur and cause fungus infestation. The danger for the occupants of dwellings lies in the production and spreading of pathogens (disease causing agents). Therefore, consequent measures have to be taken to avoid health dangers that come from mould fungi in buildings. In order to avoid the mould fungus formation, a strategy has to be set up that focuses on the growth conditions for mould fungi and also considers the complex transient processes of building physics. The boundary conditions for the growth of fungi are temperature, humidity and substrate conditions which have to be simultaneously available over a certain period of time. In [15] a biohygrothermal procedure is developed, which allows the prediction of mould growth under transient boundary conditions. The assessment results from a comparison of the water content in a modelled mould spore determined by transient calculations, with the critical water content, above which the spore germinates and grows. This means that long-term humidity values exceeding this critical water content indicate mould growth. This new method is described in this article and the functions are shown within an example.