# Thermal Comfort and Sustainability in University Classrooms: A Study in Mediterranean Climate Zones
## 3 Results
### A Case Study on the Spatial Distribution of Students and Associated Factors  
The results of the analysis of the TSV distribution and thermal insulation levels of clothing, measured in clo, in the four classrooms studied at the Higher School of Health (ESS) of Beja (Portugal), are shown below, with an evaluation focused on the influence of the occupants' positions within the space. The study highlights how spatial distribution, in terms of proximity to windows, doors and air-conditioning vents, significantly affects the thermal perception of students, generating spatial gradients of thermal comfort. In addition, patterns associated with classroom modes of operation, AC (Figure 12) and NV (Figure 13), as well as interactions between positions and individual characteristics, such as clothing levels, are observed. This approach allows us to identify how architectural factors and operational conditions contribute to differences in occupants' thermal experience. Figure 11: Students’ communicative actions in response to thermal discomfort in AC and NV modes of operation. Figure 10: Effect of thermal discomfort on class performance in AC and NV modes of operation. The classrooms with AC (ESS01 and ESS02) had a mean \(T_{op}\) of 24.46 \({}^{\circ}\)C. In these classrooms, most students reported thermal sensations within the range of \"Neutral\" to \"Slightly cool\", reflecting an overall distribution of adequate thermal comfort. However, occupants located closer to the air-conditioning vents (area highlighted in light blue) experienced predominantly cooler sensations than the rest, which is evidence of a localised effect of the system. This pattern can be explained by the higher intensity of the cold airflow in the vicinity of the outlets, which generates a more direct and perceptible cooling in these positions [84; 85; 86]. In contrast, the cases where students reported thermal sensations of \"Slightly warm\" were mainly concentrated in positions close to closed windows with  
Figure 12: Distribution of TSVs according to position and level of clothing in classrooms with AC. Figure 13: Distribution of TSVs according to position and level of clothing in classrooms with NV. south-east orientation. These areas are more exposed to direct solar radiation, which probably increases the surface temperature of the glass and surrounding areas, contributing to a localised increase in thermal perception. The outside temperature, which reached approximately 32 \({}^{\circ}\)C during the measurements, may also have intensified heat transfer through the windows, despite being closed, negatively affecting the thermal comfort of students in these areas [87; 88]. This phenomenon is consistent with the limited ability of air-conditioning systems to counteract the heat generated by solar radiation in specific areas [89]. One particular case is that of a student who reported a thermal sensation of \"Slightly warm\" despite not being in the area of influence of the windows. This case could be related to individual factors, such as physiological differences in thermal perception. Specifically, previous research has indicated that males tend to report greater thermal discomfort due to a higher basal metabolic rate compared to females [67; 90]. In the NV classrooms (ESS03 and ESS04), whose mean \(T_{op}\) was 30.48 \({}^{\circ}\)C, the influence of position on thermal perception was even more significant than in the AC tests [32]. Natural ventilation, dependent on proximity to open windows and doors, generated an uneven distribution of thermal comfort, creating a marked thermal gradient in the classroom. Students near the openings (light blue area) tended to experience thermal sensations closer to neutral or \"Slightly warm\". This can be attributed to the more constant airflow in these areas, which facilitates the dissipation of body heat and reduces the feeling of thermal discomfort [91; 92].