不同LED照度水平对设计类教室学习效率和舒适度的影响研究

Study of the Effect of Different LED Illumination Levels on Students’Learning Efficiency and Comfort in Design Classrooms

设计类教室对照明环境的要求不同于传统教室。但是,目前设计类教室还基本按照普通教室的光环境进行设计,同时存在学生对照度水平设计满意度低的问题。为提高设计类教室学生的学习效率和舒适度,确定设计类教室适宜的照度水平,本研究在重庆大学B区第二综合楼建筑学专业教室中安装LED灯具,并在不同照度水平条件下(125 lx、300 lx、500 lx、750 lx、1000 lx)进行视觉作业实验。每组实验过程中被试需完成一系列纸质作业量表,实验后被试填写主观舒适度评价量表,实验前后采集被试的血压、心率和体温三项生理指标,并全程记录被试的面部表情视频。通过分析不同照度水平条件下被试的主观舒适度评价、作业绩效、生理指数变化率和面部情绪,结果表明:750 lx照度水平下,被试的视觉作业准确率最高,500 lx照度水平下,完成视觉作业速度最快,综合绩效最高;750 lx照度水平下,实验前后被试的生理指数变化率最低,学习状态最轻松;1000 lx照度水平下,被试面部愉悦情绪值占比最高,750 lx照度水平下,面部厌恶情绪值占比最低;主观舒适度评价随着照度升高而增加,750 lx照度水平下,学习状态主观评价得分最高。因此,综合学习效率和舒适度,对于设计类教室而言,750 lx是较为适宜的照度水平。本文的研究能为设计类教室光环境的相关研究提供参考。

Design classrooms have different requirements for lighting environments than traditional classrooms.Compared with traditional classrooms,students in design classrooms have more fixed seats,longer learning periods,and more diverse learning behavior patterns.This means that in design classrooms,where students are required to perform close,long-term,high-intensity visual assignment activities,the visual tasks are complex and heavily loaded,and they face a greater risk of visual fatigue.However,at present,design classrooms are still fundamentally designed based on the light environment of the average classroom,and students have low satisfaction with the design of illumination levels.This shows that the illumination level of 300 lx in ordinary classrooms cannot meet the visual requirements of students.Therefore,additional in-depth research is needed to determine the appropriate illumination level for design classrooms.To improve the learning efficiency and comfort in design classrooms,this study sets up LED lighting conditions with different illumination levels(125 lx,300 lx,500 lx,750 lx,1000 lx)in the architecture design classroom on the 17th floor of the second comprehensive building in B District of Chongqing University,and conductes visual work experiments under different illumination levels.The experiment uses the measurement of objective physiological index,subjective psychological sensation questionnaire,visual task test and facial expression video collection,analyze the change rate of physiological index,subjective comfort evaluation,job performance and facial emotion of subjects under different illumination levels,and discusses the relationship between different illumination levels,comfort level and learning efficiency of design classrooms.The subjective psychological sensation questionnaire consists of three parts:basic information,subjective comfort evaluation,and learning status evaluation.The evaluation of subjective comfort uses the five measures of brightness,fatigue,color rendering,relaxation,and pleasure,and the self-evaluation of learning status uses seven-level Likert scale.The objective physiological indexes include blood pressure,body temperature and heart rate.The PG-800A3 is an automatic wrist blood pressure monitor that measures changes in heart rate and blood pressure,and a non-contact thermometer that measures changes in body temperature.The visual task test consists of three paper task scales:pointer recognition test,general attention test,and Stroop color-word test.The facial emotion test is performed by collecting the entire facial video data of the subject using a camera,and then using FaceReader to analyze the psychological state of the facial expression video images to capture the subject’s emotional changes.Based on the completeness of the experimental data and taking into account the maleto-female ratio,data from 12 subjects is selected for analysis,including six males and six females.The experiment is conducted in March 2022 and lasted for 20 days,from 7:00 to 9:00 p.m.every day.During the experiment,try to ensure that the lighting conditions in the classroom are uniform.The illuminance is adjusted through the mobile APP,and the real-time illuminance is measured with the XYI-III full digital illumination meter to ensure the stability of the experimental illuminance.Before and after each experiment,three physiological indexes of subjects are collected.In each group of experiments,subjects need to complete the paper task scale.After the experiment,subjects fill in subjective comfort evaluation scales.Video of subjects’facial expressions is recorded throughout the experiment.The total duration of a single experiment is about 20 mins.In this study,60 valid data groups are collected.Each group of data includes physiological index change data twice,job performance data once,subjective comfort evaluation data once,and facial expression data once.By analyzing the physiological index change rate,job performance,subjective comfort evaluation and facial emotion of subjects under different illumination conditions,the results show that:the subjects’job performance is the highest under 500 lx illumination level,followed by 750 lx illumination level,and the lowest is under 125 lx illumination level;the subjects’physiological index change rate is the weakest before and after the experiment under 750 lx illumination level that means the learning state is the most relaxed,the highest rate of change in physiological indexes is at the 300lx illumination level;subjective comfort scores increase with the increasing illumination level,the highest personal evaluation score of learning state is at the 750 lx illumination level;subjects have the highest values of facial pleasure emotion at the 1000 lx illumination level and the lowest values of facial disgust emotion at the 750 lx illumination level.Therefore,for design classrooms,750 lx is an appropriate illumination level for comprehensive learning efficiency and comfort.This study conducts a preliminary experiment on the learning status of students during paperwork and design specialty classrooms with the same orientation layout in terms of illumination changes.However,the space layout of the design classroom and the students’learning mode are diverse,and further research should be conducted from the aspects of space layout,light source illumination direction,color temperature and so on.The relevant research in this paper can provide reference for the research of design classroom light environment.