Experimental study on the influence of human respiratory metabolic exposure on students'reading efficiency
College classrooms are the main places for students to study and live,and their indoor air quality is closely related to students'health and learning efficiency.Endogenous chemicals produced in densely populated classrooms are one of the major causes of indoor air quality problems.Exploring the effects of human metabolic pollutants on the health and work efficiency is the basis for optimizing indoor air quality and formulating relevant standards.As an important indicator for judging indoor air quality,existing studies have mostly explored the correlation of pure CO2 exposure on human health,which is quite different from the real indoor environment.At the same time,studies on indoor air quality problems on work and study efficiency are mostly qualitative.However,based on multifunctional classrooms in diverse teaching modes in college,the relationship between the quantitative effects of indoor metabolic pollutants on health and the efficiency of different tasks needs to be further investigated.In this paper,different CO2 concentrations(600 ppm,1 000 ppm,1 500 ppm,2 000 ppm,2 500 ppm,3 000 ppm,and 4 000 ppm)were used to characterize the concentration of pollutants produced by human metabolism.Statistical methods were used to analyze changes in subjective comfort ratings,physiological indicator surveys,and task performance at different CO2 concentration levels through subjective questionnaires,verification tests,and text reading tests,and thus exploring the relationship between human metabolism pollutants on physiological perceptions and various types of learning tasks.The subjective comfort questionnaire consisted of two parts:indoor thermal comfort evaluation and self-assessment of sick building syndrome(SBS).Thermal comfort was categorized into five rating levels based on the index of"uncomfortable-very comfortable",and the thermal sensation vote(TSV)was designed in according to the seven-level scale of ASHRAE.Sick Building Syndrome(SBS)was evaluated by a questionnaire based on the five categories of diagnostic criteria adopted by WHO,and the severity and frequency of SBS were judged by the indicators of"often","sometimes","rarely","never",and"never".The reading test included two parts:NVT experiment(Number Verification Test)and reading efficiency experiment.After adapting to different CO2 concentration conditions,the tester's task was to review the list and mark the errors encountered,and then to comprehend the text at a deeper level and answer the corresponding questions.The comprehensive reading efficiency index was calculated by weighting the test results and the finishing time.Nine students were selected from the pre-experiment to carry out the formal experiment,which was conducted from October 19,2022 to October 28,2022,from 15:00 to 17:00 for a total of seven times.The first 30 mins of the experiment was the stage of sedentary adaptation and carbon dioxide concentration regulation.The indoor CO2 concentration was monitored in real time by adjusting the fresh air system and the opening of doors and windows,while physical environment indicators such as light environment,sound environment,temperature and humidity were also monitored.After the indoor CO2 concentration level was stabilized at the preset conditions,the students filled in the subjective comfort questionnaire for about 20 mins and completed the corresponding reading task for about 40 mins.This study verifies that human respiratory metabolic pollution is a key element that affects students'health and learning efficiency.The results showed that:1)the thermal comfort of the subject students decreased by 22.2%as the indoor CO2 concentration increased,in which the human thermal sensation and each physiological feedback in the sick building syndrome(SBS)changed significantly when the indoor CO2 concentration exceeded 1 500 ppm;2)the effect of the elevated CO2 concentration on decreasing the speed of the proofreading task was more pronounced,whereas the effect on the reading task was mainly shown in the correctness;3)the overall reading efficiency of the subject students decreased by 14.1%at the high concentration(4 000 ppm)compared to the low concentration(1 000 ppm),while maintaining a lower CO2 concentration below 1 500 ppm did not result in significant gains in reading efficiency.Therefore,it can be observed that setting up monitoring and early warning devices for CO2 concentration in classrooms and timely adjusting the working conditions of indoor doors,windows and fresh air fans to maintain CO2 within the appropriate concentration will help to enhance students'learning performance.The experimental results provide a reference for different types of college classrooms to address the air quality regulation needs of students'thermal comfort and different reading tasks.
college classroommetabolic pollution exposureindoor CO2 concentrationreading efficiencythermal comfort
万方数据
维普
