Diffusion Of Air Pollutants Classrooms Spread Of Their Properties

The psychological and physical health and learning efficiency of the staff in classrooms are related to indoor air quality. People have realized the importance and urgency to improve indoor air quality in classrooms. The structure of most classroom buildings in our country is similar. The high density of classroom staff and simple modes of ventilation may lead to the bad indoor air quality if people pay no attention to the enough ventilation.The indoor air quality in classrooms is very important for the teachers and students’physiological and psychological health.Live tests, questionnaires and numerical simulations were employed in this thesis to study the indoor air quality of university’s classroom in Nanjing. Main works are as follows. The indoor air quality were continuously detected by the methods of live tests and questionnaires.Analyze the affecting factors such as the classroom position, the gallery window, the students’s attendance and the opening of the doors and windows. The countermeasures and suggestions may be proposed to improve the indoor air quality. This experiment used CO2as the tracer gas which comes from human breathing to examine indoor air quality under different ventilation conditions during different periods. The air change flow was calculated by using analytic solution from box model. Flow field in the classroom under natural ventilation in winter was simulated using Fluent software.The changing rules of indoor temperatures, velocities and CO2concentration in the circumstances of different attendance (person density), ventilation condition (number and position of windows) were known from the analyse.The results indicate that the CO2average concentration of classroom in autumn and winter was more than the concentration in summer due to insufficient ventilation. The opening of gallery window was not effective to reduce CO2concentration and improve the indoor air quality. Different outside window may affect the CO2concentration. The over indoor person density and insufficient ventilation are the factors for high CO2concentration.Different ventilation conditions have great impact on the ventilation rate.The results showed that formaldehyde and TVOC were the main indoor pollutants at Kindergartens after decoration in Nanjing. Different attendance (person density) and ventilation condition (number and position of windows) affected the changing rules of indoor temperatures, velocities and CO2concentration.People could have preliminary understanding of the indoor air quality in Nanjing university classroom by the results in this thesis. At the same time, it can be a reference to know and improve the indoor air quaiity in university classroom.