The Research On Aerosol Particle Pollution And Deposition Characteristics In HVAC Ducts

Based on the review and analysis of existing research, home and abroad, on the effects of HVAC on IAQ, this paper pointed out the exiting problem and scheduled the methods and contents of this research. Although considerable numbers of academic analysis and numerical simulation have been executed by many experts and scholars so far, little definite and reliable in-site tests data is available on the influence of the deposition and dispersion of aerosol particles in HVAC ducts on IAQ. Imbursed by natural science fund item in Hunan province, the research of deposition mechanism and flow characteristics of aerosol particles in HVAC systems, in-site tests have been carried out in a hotel building in Changsha city, Hunan province throughout the entire air-condition period, including summer and winter (Jul. ~ sep. 2003 and Dec. 2003~Mar. 2004) to investigate the influence of the deposition and dispersion of aerosol particles on IAQ. The in-site tests include the contents as followings: firstly, aerosol particles deposited in the HVAC ducts during summer and winter operation periods were collected and weighed respectively in the library. Secondly, the concentrations of aerosol particles in the ducts were measured by PM10 microcomputer powder analysis instrument. Thirdly, microorganisms in the ducts were sampled, classified and counted. Fourthly, relevant circumstance parameters, such as air temperature, relative humidity, air velocity and so on, were measured. Lastly, questionnaires were given out to the operators and maintenance men to investigate the operation and maintenance rule of the HVAC system and the cleaning periods of the filters and HVAC ducts.By comparing and analyzing the in-site tests data, this paper investigated deeply the status of aerosols particles in HVAC ducts, discussed the deposition mechanism and effect factors of aerosol particles, and analyzed the distribution rule of aerosol particles deposition in different sites of the ducts. Based on the analysis and simulation of tests data by using aerosol particles deposition mechanism and the accomplishment of scholars, home and abroad, this paper brought forward some empirical formula.This paper also analyzed the growth and dispersion rule of microorganism in the ducts by analyzing the influence factors of the growth and propagation of microorganism, such as environmental factors and the form and structure of bacteria...