Adaptive analysis of thermal comfort in university classrooms: Correlation between experimental data and mathematical models

Numerous studies are in progress to support adaptive models in indoor thermal comfort evaluation and to establish quantitative indexes to allow the subject to optimize his/her comfort conditions. A wide experimental campaign was carried out in moderate environments, such as university classrooms, and a multiple choice questionnaire was elaborated, comprehensive of information for the static and adaptive model proposed by UNI EN ISO 10551, in order to find a correlation between experimental data measured by the instruments and subjective responses given by the occupants. The questionnaire was applied in autumn, winter and spring in classrooms of the University of Perugia, Terni and Pavia. During the campaign, all data needed to calculate both Fanger and Wray comfort indices were acquired by instrumental surveys and questionnaire compilation. By means of results' analysis of both questionnaires and measurements, the following couple of parameters (derived from Fanger and Wray) were correlated: Predicted Mean Vote (PMV) versus the difference between the Equivalent Uniform Temperature and the Comfort Uniform Temperature (T-eu-T-u) and the Predicted Percentage of Dissatisfied (PPD) versus the absolute value of the same difference between temperatures (vertical bar T-eu-T-u vertical bar). For the first couple of parameters, a linear correlation was found while for the second one a second-degree polynomial relation was obtained. Better correlation was found for measurement data rather than questionnaire results. Finally values of Operative Temperature T-0 and Equivalent Uniform Temperature T, obtained for each single experimental survey, were compared, observing a very good agreement between the two quantities, with differences that exceed 0.1 K only for a few number of values. Questionnaire and experimental PMV data were also correlated to T-0: higher values of questionnaire than instrumental PMV were obtained for the same value of T-0. (c) 2008 Elsevier Ltd. All rights reserved.