| Since the outbreak of SARS in 2003, the pollution caused by the air conditioning system has attracted more and more attention. With the wide application of central air conditioning system in public buildings, the research on the status of microbial contamination in air conditioning system has become an important research topic.This paper selected the air handling unit of a stadium in Dalian as the research object, microorganism associated with dusts, air and water were measured in two sets of air handling units in the air conditioning system. The study found that there are different levels of microorganism pollution on the surface of air inlet pipe, the filter, the surface cooler, cooling section ground and in the air, and in the condensate water. In the air handling unit, the distribution of the microorganism on filter is center<corner<bottom, the distribution of the microorganism on the surface cooler is center>by the wall>corner, and the total number of fungus and bacteria in the air inlet pipe are more than 100cfu/cm2, which are not up to the standard. Using Miseq fungal genome sequencing technology of molecular biology, this paper found that the detectable rate of Cladosporium spp. was 88.9%, and the detectable rate of Penicillium spp. and Rhodotorula spp. was 77.8%. Meanwhile, accompanied with Alternaria, Aspergillu, Verticillium, Candida, Trichoderma genera and so on.Based on the survey results, the paper selected Cladosporium spp. and Penicillium spp. as the dominant fungus used in the hygrothermal response experiment. When the temperature is 20?30?, and relative humidity is 45%?75% conditions, the study found that with the increase of temperature and the relative humidity, the same strain of colony growth showed a growth trend. When the relative humidity is higher than 75%, it played a significant role in promoting he growth of the colony; when the relative humidity is lower than 45%, the growth of the colony has a significant inhibitory effect. In contrast to the growth pattern of two fungus, it was found that the growth rate of the Cadosporium colony was faster than Penicillium colony, which could not be changed by the method of controlling the heat and humidity. Through orthogonal experiment design, using the method of variance analysis, the effect of temperature on the growth of experimental fungus is greater than the effect of relative humidity.Based on the data of Cladosporium in hygrothermal response experiment, this paper uses the logistic equation, the Gompertz equation and square root equation, fitting the growth predictive model of Cladosporium genera in different temperature, relative humidity conditions, and is earried on the analysis to verify the accuracy and feasibility of the established model equation. It is found that the Logistic equation is more suitable than the Gompertz equation in the first order model to predict the growth of the fungus. This paper uses logistic model as the foundation, and is combined with square root equation, discussed under the condition of single factor and two factor conditions, forecast the two-level model of growth trend. It is found that the square root equation can predict the growth of Cladosporium. The accuracy and feasibility of the application of all models are verified by the method of deviation factor and accuracy factor. The final parameters of square root equation b2=0.00521, Tmin=-4.89647, ?min=-0.60914, for providing a theoretical basis for the study of the growth/ growth-Inhibited of microorganisms in the air conditioning system under the conditions of hot and humid environment. |
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