Summer Thermal Comfort Conditions in University Classrooms
This paper provides some results on thermal comfort in classrooms through field experiments carried out from the end of June to the early of July 2006.Data were obtained by measurements of physical parameters and a questionnaire survey was conducted at the same time in 4 mechanically cooled classrooms and 2 hybrid cooling classrooms at Nanjing University of Science & Technology (NUST),Nanjing,China.Three thermal parameters (air temperature,relative humidity and air velocity) and two air parameters (carbon dioxide and formaldehyde) were collected during an objective investigation.With the assessed clothing insulation and metabolic rate,the predicted mean vote (PMV) was calculated.The subjective survey involved questions on the demographic information of students,health status,environment comfort conditions and acceptance.A total of 326 questionnaires were completed.The results show that the hybrid cooling classrooms are 5.4 ℃ warmer than mechanically cooled classrooms.All subjective and objective investigations show that the obvious advantage of mechanically cooled classrooms is to maintain temperate temperature,while the disadvantage of hybrid cooling classrooms is they can easily overheat.Students feel comfortable in a wide humidity zone.Although carbon dioxide concentration in mechanically cooled classrooms is much higher than the value prescribed in the standard and the concentration is below the standard thresholds in hybrid cooling classrooms,according to physical measurements data,the majority of occupants are satisfied with the air quality in all classrooms.The results suggest that occupants after spending long periods indoors cannot accurately perceive the indoor air quality.Most classrooms acoustic comfort conditions are beyond standard.Students prefer the hybrid cooling classrooms although the noise levels are higher than that in mechanically cooled classrooms.The main complaint in all classrooms is fatigue.No significant difference is found in relation to health complaints between mechanically cooled and hybrid cooling classrooms.The human ergonomics environment and learning achievements in hybrid cooling classrooms are similar to that in mechanically cooled classrooms.In general,the available data indicate that the occupants dissatisfaction mainly focuses on air temperature,humidity and air velocity in all classrooms.With the comparison of the subjective survey results to the PMV index from measured data,there is an apparent difference especially for the hybrid cooling classrooms.The PMV index should be amended with further research to accurately predict eastern students thermal sensation.
Classrooms Field experiment Questionnaire survey Physical measurement
Fang Wang Xiaosong Zhang
School of Energy and Environment,Southeast University,Nanjing,China School of Power Engineering,Nanj School of Energy and Environment,Southeast University,Nanjing,China
国际会议
The First International Conference on Building Energy and Environment(第一届建筑能源与环境国际会议)
大连
英文
654-661
2008-07-01（万方平台首次上网日期，不代表论文的发表时间）