The Test And Analysis Of Analysis Of Indoor Air Quality Of Student Dormitories In Severe Cold Area

As expanding enrollment and the increasing number of students in China’s colleges, indoor air quality in students’ dormitories is worth worrying about. Because of the large temperature between indoor and outdoor in severe cold areas,in order to reduce energy consumption and maintain temperature, good building air tightness, the short time to open the window and severe haze outdoor make the fresh air in the students’ dormitorys only relys on penetration from the windows. The inadequate ventilation leads to poor indoor air quality.Firstly the sources of common several pollutants and their harm in the students’ dormitories in severe cold areas is analyzed and the PM_2.5 concentration limitation is seted reference to domestic and international standards, which is 0.075 mg / m3. In order to analysis the variation of pollutants concentrations in dormitories in severe cold areas, some dormitorys are selected from a college in the city of Harbin and the field testing was done. The main pollutants as CO₂, CO, PM_2.5, TVOC were selected and were tested continutinuously and these pollutants concentrations values in 76 dormitories were selected for samples before doing to sleep at night.CO₂ was selected as trace gas, using Matlab programming to calculate ventilation rate and the fresh air flow affected by the hot pressure and wind pressure through windows and doors to penetrate into the interior under the conditions of closing the window Affected by the hot pressure, the low-floor ventilation time is greater than the high floor and affected by wind pressure and the local prevailing wind in winter, the ventilation rate in rooms with the outside windows which face south and west is larger than the north and east. By calculation, even if there is only one person in the dormitory, lowering the concentrations of CO₂ to the outdoor concentrations 400 ppm before falling asleep the flow of fresh air by penetration into the interior through the window can not dilute indoor CO₂ concentration and the CO₂ concentration will exceed upper the limitation 1000 ppm of national standard.Without PM_2.5 emission from the indoor air in dormitory in severe cold area the concentration of PM_2.5 primarily affected by dust bring by staff activities and the outdoor air haze. The indoor staff activities, ventilation by opening the windows, the condition of the outdoor concentration greater than the indoor concentration variation of indoor PM_2.5 concentration on the indoor concentration variation with the degree of impact varies.The indoor air quality of sampling room were evaluated by fuzzy evaluation and gray relational evaluation, which were found that the higher the outdoor PM_2.5 concentration, the indoor air pollution levels will be higher. Due to the impact of lifestyle, such as smoking, the large amount of CO₂ sporadic at the same time and single room occupancy rate and so on, Pollution grade of boys’ dormitory will higher than girls.Toward has little effect on the distribution of indoor air cleanliness level.By the wind pressure, the indoor air quality of the north and east room is slightly worse than the west and south room.The analysis of a variety of contaminants and their variation of concentration on indoor air quality Natural ventilation of indoor air quality can not meet the the need of cleanliness, so some measures need to be taken, such as mechanical ventilation to improve indoor air quality.