SUBJECTIVE AND MEASURED THERMAL COMFORT IN ITALIAN UNIVERSITY CLASSROOMS IN HEATED AND FREE RUNNING CONDITIONS

This work examines the applicability of comfort criteria, based on a heat balance model and on an adaptive model, in naturally ventilated classrooms. The adaptive opportunity of students are limited during the lesson time, while they are free during the lesson breaks. The field study was conducted by physical observations, survey questionnaires and behavioral observations. Both field measurements and subjective surveys were performed at the same time during the regular lesson period. Thermal environment parameters were measured: indoor air temperature, mean radiant temperature, air relative humidity, air velocity and outdoor air temperature. Through these data, Fanger’s comfort indices were calculated (predicted mean vote and predicted percentage of dissatisfied people), the actual people clothing and metabolic rate being known; furthermore the indoor operative comfort temperatures were obtained from the adaptive model. The subjective survey basically investigated the thermal acceptability, the thermal preference and the thermal sensation, asking students to assess their comfort on subjective scales. The judgments 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. The monitoring campaig