Integrated Numerical Simulation with Fungal Spore Deposition and Subsequent Fungal Growth on Bathroom Wall Surface

Abstract

Fungal contaminations in indoor environment are recognized as one of the serious problem in terms of health and aesthetic impact. Large numbers of studies have shown an association between the health risk of fungal contamination. Residence in houses and fungal growth is well known to be strongly related to various indoor environmental parameters and hence the development of a comprehensive prediction method for fungal contamination is needed for healthy indoor environmental design. This research focused on the fungal growth problems in residential bathroom where the temperature and humidity can become relatively high. This paper reports the procedure and results of numerical simulations of fungal contamination. The simulation was incorporated with flow field, temperature/humidity distribution, which was used to predict fungal spore dispersion/deposition in bathroom space and subsequent non-uniform distribution of fungal growth on wall surfaces. Fungal spores transportation was analyzed by Lagrangean approach. For fungal growth phenomenon, the reaction-diffusion model that reproduces morphological colony formation of fungi was adopted. By continuously executing these numerical analyses, fungal spore deposition and subsequent fungal growth on wall surfaces was demonstrated for two targeted representative ventilation rate in normal bathroom condition.

Improvement of ventilation efficiency by changing the shape of glass partition in bathroom of apartment house

“…This hot water would produce temperature and humidity differences between the floor and ambient air, causing buoyancy effects to occur and making variation in the water vapour and air temperature. Ito 8 reported that the buoyancy effects caused by the humidity differences are small compared to the buoyancy effects caused by the temperature difference. Droplets would be generated during a shower in general.…”

“…[4][5][6][7] On the other hand, there have only been a very small number of research studies aimed at improving the ventilation performance of the bathroom and its IEQ. Ito 8 proposed an analysis model that can predict fungal contaminants and fungal growth problems in a bathroom. Tung et al 9 examined experimentally the effects of the toilet location and ventilation rate on the ventilation efficiency.…”

Ecological Modelling Applied to Entomology

“…Conventionally, problems emphasising biological diffusion are frequently studied or solved based on examples of animal movement (Benhamou 2014), diffusion of plants or seeds (Coulson et al 2014) and spores (Ito 2013). However, there are situations in which spreading particles are not living organisms, despite being associated with them.…”