# Thermal Comfort and Sustainability in University Classrooms: A Study in Mediterranean Climate Zones
## 3 Results
### Subjective Thermal Responses
Similar trends were observed in the work of [PERSON] et al., who found patterns consistent with the aforementioned results, also reflecting a relationship between the type of ventilation and the thermal sensations reported by the students [47]. These differences can be explained by the higher heat tolerance of people living in hot and humid climatic zones, who tend to adapt more effectively to the usual thermal conditions of their environment, even when these exceed the established standards [54; 61]. On the other hand, [PERSON] and [PERSON] carried out an investigation in an Italian university in the same climatic zone as the present study and obtained similar results in terms of thermal sensation for classrooms with NV (TSV = \(1.49\)) and with AC (TSV = \(-0.46\)) [62]. Finally, the work of [PERSON] et al., carried out in southern Spain with primary school students, showed that most children felt comfortable and preferred cooler environments for both modes of operation studied [33]. This preference for cooler environments in children living in temperate climate zones has been reported by other authors [60; 61; 63]. To continue, Figure 4 compares the thermal comfort ratings (TCV) as a function of perceived thermal sensations in the two modes of operation. In AC mode (Figure 4a), the average TCV was \(2.55\), indicating that the majority of students were positioned between the \"Comfortable\" and \"Slightly uncomfortable\" categories. The results show that \(53.85\%\) of the students who experienced neutral thermal sensations (0) felt comfortable, while \(38.46\%\) reported being very comfortable. In addition, \(18.52\%\) of students reported comfort under slightly cool sensations (\(-1\)). However, more extreme sensations, such as cold (\(-2\)), registered an increase in discomfort levels, with \(33.33\%\) of the votes placed in the uncomfortable category. When students voted cold thermal sensations (\(-2\)), they presented the highest levels of discomfort (\(33.33\%\)). In contrast, the NV mode of operation (Figure 4b) had an average TCV of \(3.45\), indicating that students felt slightly uncomfortable to mostly uncomfortable. Thermal comfort was mainly concentrated in neutral thermal sensations (0), while as thermal sensations became warmer, the level of discomfort increased significantly. In particular, warm thermal sensations (3) reached \(100\%\) of votes in the very uncomfortable category. These results are consistent with those reported by [PERSON] et al. for NV classrooms in a tropical climate zone [43]. Similarly, [PERSON] et al. showed that the majority of students who voted a TSV of \"Warm\" (approximately \(90\%\)) felt very uncomfortable [22]. The results indicate that the AC mode offers better performance in maintaining acceptable thermal comfort over a wider range of thermal sensations, although it does not always guarantee comfort, especially if students feel cold. On the other hand, the NV mode showshigher acceptance in neutral thermal conditions, but its effectiveness decreases significantly as thermal sensations become warmer [62; 64]. In this case, Figure 5 presents the cross-tabulation of the thermal preference votes about the perceived thermal sensations in both modes of operation. In AC mode (Figure 5a), the mean TPV was 0.19. In neutral thermal sensations (0), most students voted for \"No change\", indicating satisfaction with the perceived temperature. However, in slightly cool thermal sensations (\(-1\)), a little more than half of the students (51.85%) preferred a \"Warmer\" environment. For cold thermal sensations, this percentage rises to 100%. For slightly warm thermal sensations (1), a significant percentage expressed a preference for a \"Cooler\" environment. For the NV mode (Figure 5b), the average TCV was \(-0.76\), indicating that, in general, students preferred a \"Cooler\" thermal environment. For neutral thermal sensations (0), most students preferred \"No change\", indicating that these conditions are perceived as adequate.