Analysis About The Influence Of Thermal And Humidity Environment On Mold Growth In Multi-layer Wall

Indoor environment is the most significant place for people production and living, it’s greatly affects the quality of life, health and productivity. Because the indoor mold growth with suitable conditions, and provide exposure for their disease conditions and susceptible hosts, the problem of indoor mold contamination is growing. There is great harm to human health for long-term exposure and inhalation of mold; it also can cause respiratory and allergic symptoms.The main factors which affect the mold growths are temperature, humidity, nutrients, exposure time, pH, oxygen, light, surface roughness and so on. The first four are the main factors; the latter four are secondary factors. The biohygrothermal model took into account the growth of mold four main factors: temperature, humidity, nutrients, time. The measured or simulated climate data for the boundary conditions can be calculated to the actual water content of mold spores and mold spore germination critical water content. When the actual water content of the mold spores is greater than critical water content, assuming that germinated spores, mycelium began to grow; when the actual water content less than the critical water content is not germination of spores.Base on the biohygrothermal model, and this paper will simulation analysis of 7 types composite wall of heat and moisture transfer and the growth of mold. The Chinese Standard Weather Data will be used with outdoor weather border. Respectively, indoor climate will be in natural conditions, heating, and air conditioning for the three conditions. It’s also considered building orientation, building materials and nutritional media level, the initial water content of mold spores and other factors change to the impact of mold germination time. The main conclusions include:(1) Indoor climate under natural conditions, the germination time of mold may be short duration in the wall with internal thermal insulation, within which the structure of aerated concrete are least likely to moldy. To the external insulation wall, the outermost layer of wall is in a long period of high temperature and humidity condition, and will be likely to cause mold growth.(2) In the heating conditions, the accumulation of wet inside wall is severe for the indoor temperature and relative humidity at a higher level of long-term, and mold spore germination time scope is extended. In the air conditioning conditions, although it’s able to control the indoor temperature and humidity, there is still a big range of internal walls of fungal spore germination in low humidity conditions.(3) There will be a certain extent to internal mold spore germination if change the building orientation. Compared with the nightside, the time and scope of mold spores germination inside building wall of sunward side is reduced.The impact of initial moisture content for mold spore germination is less than ambient humidity changes. In the context of increasing the nutrients, the mold spores will be germination early and the extended duration.(4) The experiment showed that the internal wall of bamboo combined changes in temperature and humidity is relatively stable, there is a low probability of germination of mold spores. In the absence of proofing, in the experimental room bamboo surface relative humidity significantly affected by the outdoor climate and it’s relatively large. It’s most likely to be moldy on bamboo surface in a long state of high humidity.