Numerical Study On Microorganism Growth On Glass Fiber Filter Media Under Different Temperature And Relative Humidity Conditions

People has been inseparable from the air conditioning system to get healthy and comfortable living environment. Air conditioning system is widely used in all kinds of buildings.But the air conditioning system itself may cause environmental problems. If the people can not clean the air conditioning system regularly,the air conditioning system itself can be sources of pollution,which will make the indoor air quality worse. The study found that under the condition of suitable environment, the air filter in the system is hotbed of microorganisms grow, these microbes can produce volatile chemicals, which will cause the secondary pollution for indoor environment. Therefore,it is necessary to study the microorganisms grow on the air filter under the condition of different temperature and humidity environment.At first, our study analyses the temperature and humidity values of the air flow during air handling process on the basis of the actual running status of air conditioning unit. Then We select 15?, 22?, 30? and 15% RH, 60% RH, 90% RH to act as the temperature and relative humidity conditions in this study. Incubator shaker were used to control consist temperature conditions. Allochroic silicagel, saturated aqueous solution of NaBr and physiological saline were used to control relative humidity conditions.Then, select the F5, F8 and H13 three kinds of glass fiber filter material with different levels of filter as the research object..For the convenience of the experiment, the filter material samples are cutted into 8 cm diameter circles. The concentration of bacteria suspension was determined by using ultraviolet spectrophotometer to measure the OD value. 0.2 ml bacteria suspension of appropriate concentration was coated onto the filter materials with coating rod methods, thus could make the bacteria suspension uniformly distributed on the surface of the filter material. Afterwards, filter materials with bacteria were put into consist temperature and relative humidity conditions to culture for several days. Different humidity conditions need different cultural time.1 day, 7 days and 7 days were respectively selected as the cultural time of 15% 60% and 60% relative humidity condition. Take out the filter material after different cultivation time, then cut up and remove bacteria from the surface of the filter fibers. The plate count method is adopted to determine the concentration of eluent and corresponding diluents. Then we obtained the growth trend of Bacillus subtilis on filter materials under different temperature and humidity conditions.Finally, the Gompertz model and square root model are respectively used to build primary model and secondary model based on microbial growth. Gompertz model is a primary model, and the microbial growth dynamics parameters under different temperature and humidity can be got through the model. Square root model is a secondary model, with this model, the researchers can find the relationship between the square root of the maximum growth rate and the temperature.