Research On Indoor Micro-Environment And Discussion On Improved Strategy Of Colleges' Microcomputer Laboratories

Building indoor micro-environment has been one of the outer environments people contact most frequently.So researches on indoor micro-environment quality have attracted more and more people's interest and the importance and necessity of the researches have been realized.The colleges' microcomputer laboratories are the main places where students accept computer knowledge and skills.Students spend almost 1/3 day in the computer room.To study the indoor micro-environment quality and improve indoor micro-environment of colleges' microcomputer laboratories has important significance in enhancing physically and mentally healthy of teachers and students.Field tests,questionnaires and numerical simulations were employed in this thesis to study the indoor micro-environment quality of colleges' microcomputer laboratories in Harbin. Main Works are as follows.Count the testing data which include the main parameters such as IAQ(indoor air quality),noise and electromagnetic radiation by mathematical statistic method. The objective factors of measured microcomputer laboratories were carried on investigation and statistics.And analyzed the relevance between the objective factors and various indoor environment parameters.Then the primary factors to influence indoor environment were determined.Make questionnaires of indoor micro-environment quality and perform, Subjective survey results were analyzed and evaluated.Distribution of temperature field and flow field in the microcomputer laboratories under natural ventilation in summer was simulated using CFD technology and FLOVENT6.1 software.The changing rules of indoor temperatures,airflow velocity in the circumstances of different computer and personnel density and the ventilated way differently were known from the analyse.Finally in experimental study foundation,the feasible countermeasure to improve the indoor micro-environment quality of colleges' microcomputer laboratories were discussed.Solutions in this thesis can be summarized as follows:(1) Objective and subjective investigations of the indoor micro-environment quality in colleges' microcomputer laboratories have demonstrated the basic condition of the indoor micro-environment quality in Harbin colleges' microcomputer laboratories.Objective Evaluation:The overall percentage of dissatisfied is 36.6%,which doesn't meet the criteria established in this paper.The cold or hot feeling percentage of dissatisfied is 63.4%,the dry or moist feeling percentage of dissatisfied is 65.9%.The thermal neutral temperature of students is 23.8℃(t_o) in Harbin colleges' microcomputer laboratories.The acceptable upper limit of the thermal environment is 27℃(t_o) higher than the comfort temperature(t_o=23～26℃).To indoor sound environment the overall rate of satisfied is 84.6%.Moreover,76.4%university students thought that they had already been influenced under the electromagnetic radiation in a certain extent.Subjective Evaluation:The ratio of the number of microcomputer laboratories,that its indoor air temperature doesn't meet the criteria established in this paper,is 71.4%.The ratio of the number of microcomputer laboratories,that its indoor air relative humidity doesn't meet the criteria established in this paper,is 42.9%.The ratio of the number of microcomputer laboratories,that its HCHO concentrations exceed the criteria established in this paper,is 64.3%.The ratio of the number of microcomputer laboratories,that its NH₃ concentrations and TVOC concentrations exceed the criteria established in this paper,is 29.6%and 14.3% respectively,but exceptional cases exceeding the criteria has reached above 3 times.The indoor noise has not exceeded the criteria established in this paper before the indoor microcomputer starting,and after starting,exceeded the highest upper limit(55dB) of the criteria.In electromagnetic radiation aspect:Using microcomputer has not had the remarkable influence to overall electromagnetic environment in the microcomputer room.Most of the investigated microcomputer laboratory is without effective measures to ventilate,absorb noise and prevent electromagnetic radiation.The comprehensive evaluation results combining both subjective and objective evaluation: The IAQ of the colleges' microcomputer laboratories is very bad.Indoor noise exceed the criteria established in this paper in normal computer starting situation.Because students stay for relatively long periods of time in the microcomputer laboratories,the accepted electromagnetic radiation dosage will accumulate in their bodies and threaten their health. Therefore,the health of students is under serious threat from several aspect factors.We must take the effective actions to improve the indoor micro environment quality.(2) Simulation analysis were carried on IAQ of colleges' microcomputer laboratories.The influence results from the indoor computer and the personnel density to the indoor airflow and the thermal environment have demonstrated:The radiation of the human bodies and the computer equipments have affect on the temperature distribution in the microcomputer laboratory greatly.After indoor starting-computer quantity and the population be a half,the indoor temperature may reduce obviously.To opens the door,the windowing and the windows and doors with opens under three natural ventilation ways the simulation results have indicated: In aspects of indoor temperature control and the distribution of the indoor temperature and the airflow,the ventilates way by both windows and doors is best,but the filthy air in the corridor is taked into indoor easily.The ventilates way by windowing for next,the ventilates way by door is worst.(3) Improvement MeasuresIn view of the present existing whole and partial questions in indoor micro-environment of colleges' microcomputer laboratories,the control and the improvement suggestions were proposed from two aspects of control pollution and enhanced the comfortable to guarantee the indoor micro environment quality and comfortableness could be enhanced,based on existing theories and the technologies factor fully.