*2.4. Questionnaires*

Two questionnaires were given to students, with scaled answers for a better understanding and evaluation on their part, as well as to collect aggregated data.

Firstly, they were asked to fill in the questionnaire on user comfort perception, aligned with ISO 7730, with questions about comfort perception, which included environmental issues such as classroom location, lighting perception [52], indoor air quality and possible inconveniences linked to the pupil's position in the classroom. The survey was used to establish the boundary conditions of the classrooms, but its results are not discussed in this article in depth. However, the results of those surveys and the internal measurements of humidity and temperature and the quantitative indices such as PMV and

Predicted Percentage of Dissatisfied (PPD) in classrooms for the same typology have been discussed in [14]. The CO2 concentration and symptomatology of the students in [15] have also been analyzed for the same climate and typology. A version of this questionnaire adapted to schools has been adapted in [53].

Secondly, the facilitator distributed to the students the questionnaire on what conditions influence their comfort in the classroom. It also contained scaled-answers and included a wide variety of issues that potentially could affect to the environmental conditions of the classroom, as well as to their hypothetical improvement according to the students' own perspectives. In this questionnaire, the main questions use language aimed at obtaining an impulsive response, without prior reflection or necessary observation. The objective of this method is to extract the unconscious information that influences the state of thermal comfort. The surveys distributed to the students in their original version in Spanish are found in Appendix A.
