The Air Microbes Transmit And Disinfection Control Method In VAC System

In building environment, VAC system is to provide a healthy and comfortable indoor environment for people. Due to microbe is aviable on everywhere, however, if the design, operation and maintance of VAC system are not correct, there will be growth of microbe in VAC system. It would be to pollute the air and have adverse effect on human health. Therefore, aim to the VAC system, this dissertation investigates the the problems of microbial ecology, transmit of microbial particles which are the basic theory. Based on of that, the research of precaution, control and disinfection technology used in VAC system is conducted. It has important theotical value and social significance to protect microbial safe of building environment, promote the capability of VAC system to deal with microbial diseases.The work of microbial contaminates in VAC system were profermed by many people and this is the basis of the microbial pollution research. This paper investigated the microbial ecological property of common air microbe and the pollution of VAC system by it. Two large public buildings with VAC system were measured and the species, distribution, relationship to particle and control efficiency were researched.Fungi spore is the most microbial contaminates in VAC system. The fungi spore resuspention is mainly acted under the parallel airflow in VAC system. So the parallel airflow fungi spore source strength tester (PAFST) was developed and the meathod of developing that device was presented. The spore spot inoculation and full-sample meathod were used to shorten the researching period. Four speices of fungi release were measured on three material surfaces. It is founded that PAFST can test the fungi spore release strength effectively under the action of the parallel airflow and the results are less than the data under action of air jet. The spore release strength changes with airflow velocity as power function. The statistic model of fungi spore release was established.In VAC system, microbes attach to the dust particle mostly and formed microbial particle is adhered to the surface of duct. The paper analysis the forces and resuspension mode of polydisperse microbial particle in laminar sublayer and the resuspension model of polydisperse microbial particle was established based on the force/moment balance. The fraction of poludisperse microbial particle on the surface of duct and cooling coil was calculated. The CFD technology was used to simulate the movement of particle on duct surface and analysis the effect on the supply air particle concentration.The objective of research on the microbial contaminates and transmit is to control pollution and decrease the adverse effect on people. Two disfection meathods of far-infrared and microwave irradiation were used to develop the Air disinfector and air disinfecous device. The temperature-rise and disfection characteristic of far-infrared irradiating on the surface of HEPA filter were investigated and clean experiments of Air disinfector on the microbes and particles inside room were conducted. The microwave disfection mechanism was investigated and the power design, leakproof design of microwave device was put forward to and disfection effect factors were analysised. The kill ratio experiments of four bacteria were conducted.