## 4 Results
### Air Temperature Distribution
#### 4.2.2 Asymmetry of Air Temperature  
Another analysis concerns the comparison between vertical temperature difference with data of sensors in the same sectors and air temperature difference with data recorded in the room center. The temperature difference between data at 1.1 m and 0.1 m was calculated; it should be always lower than 3.0 \({}^{\circ}\)C, as previously explained with reference to local discomfort phenomena. Figure 13, in the case of baseboards, shows the maximum, minimum, and mean values of the calculated temperature differences. The discrete evaluation of \(\Delta\)T\({}_{\text{P,WC}}\), assumed as the difference T\({}_{\text{a,31}}\)-T\({}_{\text{a,0,1}}\), highlights that in all sectors, the threshold value was exceeded; for instance, in the first sector, during the 30 th of December, from 10:00 to 11:30 this values was higher than 6 \({}^{\circ}\)C, while in the other sectors it varied from 1.0 \({}^{\circ}\)C to 4.5 \({}^{\circ}\)C on the same day. However, for S4, the maximum difference (7.4 \({}^{\circ}\)C) was recorded at 13:30 during the same day. Considering the average value for all monitoring periods, it seems that a sensible thermal stratification occurred mainly in S1 and S4. The temperature difference between the room center and the other sensor allowed us to estimate horizontal non-uniformity inside the room. Considering the difference with the values monitored at 1.1 m and 2.1 m, both the average and extreme values were very limited. More in detail, T\({}_{\text{a,c}}\)-T\({}_{\text{a,1}}\) was always lower than 3 \({}^{\circ}\)C with a maximum value of 1.1 \({}^{\circ}\)C, which usually occurred after midday, and thus it was also influenced by the external conditions. Instead, the maximum difference T\({}_{\text{a,c}}\)-T\({}_{\text{a,31}}\) varied between \(-\)3.2 \({}^{\circ}\)C (S3) and \(-\)4.1 \({}^{\circ}\)C (S1). The negative values confirmed the phenomenon of thermal stratification also when the reference was the central sensor. Finally, according to the average value, the difference T\({}_{\text{a,1}}\)-T\({}_{\text{a,0,1}}\) was lower than 3 \({}^{\circ}\)C, and thus the discomfort phenomenon was usually avoided. However, the extreme value of 4.9 \({}^{\circ}\)C could be reached in the first and fourth sectors in both cases on 30 December, which was a sunny day. In the case of fan-coils, Figure 14 shows that in the fourth sector, where the fan-coil was located, the vertical temperature difference was very considerable; indeed, for the calculation of T\({}_{\text{a,31}}\) - T\({}_{\text{a,0,1}}\), the maximum recorded value could reach 10 \({}^{\circ}\)C, and the maximum value was 8.3 \({}^{\circ}\)C for S1 and S2. These values indicate a possible thermal stratification phenomenon in the ceiling. Indeed, the average values, mainly in the sectors where the units were located, were also high, and this indicates that usually in the room there was a vertical temperature difference that was on the verge of overcoming the prescribed threshold. Analyzing temperature differences between the sensor in the room center and sensors at other heights (horizontal asymmetry), it can be seen that lower values were obtained, for each sector, with the sensor at 2.1 m. The mean values, considering data for the entire monitoring period, suggested good results also for sensors at 3.1 and 1.1 m, also if, with several external conditions, very extreme temperature differences could be recorded; for instance, T\({}_{\rm c}\) could be also 17.1% (S4) or 19.9% (S2) higher than values recorded at 1.1 m. Moreover, T\({}_{\rm a,c}\)-T\({}_{\rm a,31}\) could reach \(-\)5.6 \({}^{\circ}\)C around 15:00 on 21 January or \(-\)5.0 \({}^{\circ}\)C at 6:30 on 1 February. This means that non-uniformity was due both to external conditions (e.g., effect of solar radiation) and position or operating mode of the fan coil units.