PMV-PPD and acceptability in naturally ventilated schools

In this paper an expectancy factor value for the Mediterranean climate is proposed. This value has been obtained by carrying out a combined subjective and objective investigation on about 200 Italian classrooms and more than 4000 students both in winter and in summer season. All investigated school buildings were non-air conditioned and ventilated by operable windows. The subjective investigation has been carried out by means of a special questionnaire also containing a direct question on the acceptability to verify the agreement between the percentages of dissatisfied consistent with the votes assigned to the thermal environment and the acceptability. Obtained results seem to show similar distributions with only a slight overestimation (15% about) of the percentage of dissatisfied under neutrality conditions.