Building and Environment 42 (2007) 951–959 Perception of the thermal environment in high school and university classrooms: Subjective preferences and thermal comfort Stefano Paolo Corgnati à , Marco Filippi, Sara Viazzo Department of Energy (DENER), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy Received 4 May 2005; received in revised form 5 October 2005; accepted 21 October 2005 Abstract This work shows some of the results of a field study about environmental comfort investigations in classrooms. In this project thermal, acoustic, visual and air quality aspects were analysed in a number of classrooms—13 classrooms at four different high schools of the Provincia di Torino and four typical medium-sized university classrooms of the Politecnico di Torino, Italy. The investigations were carried out during the heating period. Both field measurements and subjective surveys were performed at the same time during the regular lesson periods. This paper focuses on thermal comfort, which may have a significant effect on the students’ performance, in terms of attention, comprehension and learning levels. The measurement campaign consisted in measuring the thermal environment parameters—air temperature, mean radiant temperatures, air relative humidity and air velocity. Through these data, the thermal comfort Fanger’s indices (predicted mean vote (PMV), and predicted percentage of dissatisfied (PPD)people) were calculated, the actual people clothing and metabolic rate being known. The subjective survey involved questions on the thermal environmental perception. They basically investigated the thermal environment acceptability and preference. Moreover, a judgement based on the typical seven point thermal sensation scale (Fanger 7- points scale) was also asked. Through the elaboration of the questionnaire data, the actual percentage of dissatisfied (PD) people of the felt thermal environment was evaluated. The judgements about the thermal environment were compared with the results of the field measurements. Moreover, the subjective mean votes were compared with the thermal environment perceptions in terms of acceptability and preference. r 2005 Elsevier Ltd. All rights reserved. Keywords: Indoor environmental quality; Thermal comfort; Classrooms; Objective approach; Subjective approach 1. Introduction Healthy and comfortable microclimate conditions are essential for any type of environment but, in particular, schools are a category of buildings in which a high level of environmental quality may considerably improve occu- pants’ attention, concentration, learning, hearing and performances [1,2]. The first scientific studies about the effects of the thermal environment quality in classrooms on the students’ performances began around the middle of 1950. An interesting review of the results of these first studies, lots of them performed as field studies, is gives in the work of Pepler and Warner [3]. After this period, the birth of the Fanger theory about thermal comfort based on the results from a fully controlled climate chamber [4], broke the developing of new field researches on thermal comfort. But the growing interest in the last years about the adaptive theory of thermal comfort [5,6] has again stimulated researches by field studies aimed at qualifying the thermal environment both objectively (by measurements) and subjectively (by occupants judgments). The base of the adaptive approach is the conviction that a person, consciously or unconsciously, plays an active role in creating the thermal environment conditions that he ARTICLE IN PRESS www.elsevier.com/locate/buildenv 0360-1323/$ - see front matter r 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.buildenv.2005.10.027 à Corresponding author. Tel.: +39 011 5644507; fax: +39 011 5644499. E-mail address: stefano.corgnati@polito.it (S.P. Corgnati).