Application of a new 13-value thermal comfort scale to moderate environments

A new 13-value thermal comfort scale is adopted in the present study, in order to evaluate the thermal comfort sensation within non-residential buildings with the adaptive approach. 18 classrooms located both in Pavia and Perugia, the Fraschini Theatre, and one auditorium located in Pavia were investigated from October 2014 to October 2015 collecting about 1600 questionnaires. All the information reported in the questionnaires was correlated by defining several indexes and a comparative analysis was carried out between the two comfort scales (13-value and 7-value scale). Results showed that using the new 13-value scale the percentage of people who declared a thermal sensation equal to 0 greatly decreased: from 66% to 41% for the classrooms and from 47% to 36% for the theatre-auditorium. The percentage of occupants who considered the environments not thermally comfortable, although they declared a thermal sensation equal to 0, also decreased, from a mean value of 10.4% to 2.7% for the classrooms and from 6.0% to 2.6% for the theatre-auditorium. Considering the 7-value scale, although a thermal sensation equal to 0 was declared, a higher percentage of people who would feel a little bit cooler or a little bit warmer was found. Instead using the 13- value scale, this percentage significantly decreased, because people declared a thermal sensation equal to ±0.5 (more than 50% of cases) instead of 0. In agreement with these results, the new scale seems to be more accurate than the traditional one, allowing a better correlation among all the data reported in the questionnaires.