## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Room**} & \multirow{2}{*}{**Orientation**} & \multicolumn{2}{c}{**Number of**} & \multicolumn{2}{c}{**Number of**} & \multicolumn{2}{c}{**Number of**} & \multicolumn{2}{c}{**Highest**} \\  & & & **Hours Above** & **Hours Above** & **Hours Above** & **Temperature** & **Temperature** \\  & & & **the Level I** & **the Level II** & **the Level III** & **[\({}^{\circ}\)C]** & **Occurrence** \\ \hline \multirow{2}{*}{A1} & Room & NNE & 132 & 23 & 0 & 29.8 & 17.08, 5 p.m. \\ \cline{2-7}  & Bedroom & SSW & 163 & 42 & 0 & 30.1 & 20.08, 3 p.m. \\ \hline \multirow{2}{*}{A2} & Bedroom & SSW & 0 & 0 & 0 & 26.4 & 20.08, 3 p.m. \\ \cline{2-7}  & Living room & SSW & 5 & 0 & 0 & 28.9 & 20.08, 4 p.m. \\ \cline{2-7}  & Kitchen & NNE & 0 & 0 & 0 & 28.7 & 22.08, 2 p.m. \\ \hline \multirow{2}{*}{A4} & Bedroom & N & 26 & 0 & 0 & 29.0 & 20.08, 4 p.m. \\ \cline{2-7}  & Living room & S & 62 & 3 & 0 & 30.0 & 19.08, 5 p.m. \\ \hline \multirow{2}{*}{A5} & Living + Bedroom + Kitchen & N & 163 & 34 & 0 & 30.3 & 20.08, 4 p.m. \\ \cline{2-7}  & Room & N & 0 & 0 & 0 & 27.4 & 20.08, 4 p.m. \\ \hline \multirow{2}{*}{A6} & Room & S & 0 & 0 & 0 & 28.5 & 20.08, 3 p.m. \\ \cline{2-7}  & Living + Bedroom + Kitchen & S & 92 & 15 & 0 & 30.1 & 19.08, 4 p.m. \\ \hline \multirow{2}{*}{A7} & Living + Bedroom & SSE & 9 & 0 & 0 & 28.9 & 19.08, 4 p.m. \\ \cline{2-7}  & Room & NNW & 0 & 0 & 0 & 27.3 & 20.08, 4 p.m. \\ \hline \multirow{2}{*}{A9} & Living + Bedroom & SSW & 3 & 2 & 1 & 28.0 & 19.08, 4 p.m. \\ \cline{2-7}  & Room & NNE & 2 & 1 & 0 & 28.0 & 21.08, 5 p.m. \\ \hline \multirow{2}{*}{A10} & Living room & SSW & 5 & 0 & 0 & 29.7 & 19.08, 5 p.m. \\ \cline{2-7}  & Bedroom & NNE & 52 & 0 & 0 & 29.0 & 21.08, 5 p.m. \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Number of overheating hours and the maximum internal temperature. Figure 8: Internal vs. running mean temperature. The comfort temperature \(\theta_{c}\) is presumed as:  
\[\theta_{c}=0.33\cdot\theta_{rm}+18.8 \tag{2}\]  
The upper limits of the thresholds for categories I, II, and III were increased by 2, 3, and 4 \({}^{\circ}\)C respectively. The graphs below show the share of hours exceeding the boundary levels of the three categories of the indoor environment (Figure 8). Analyses were presented for the period from 10 July to 12 September, when the data loggers were installed in most of the apartments. Green marks were used for the rooms of northern or near northern orientation, and orange marks were used for the rooms of southern or near southern orientation. In two of the apartments, A2 and A6, there was no overheating registered during monitoring, and the internal temperature was well below the limits for the first level of the internal environment. In the A2 dwelling, the owner was often away during monitoring (almost 51% of the reported period and 64% during July and August). During the absence, curtains were drawn in the bedroom, and the remaining rooms and the windows were closed. When the owner was present, she opened the balcony doors and uncovered its curtains. Cross ventilation was difficult in the apartment because only one external facade was directed to SSW (27\({}^{\circ}\) S of W), but this drawback was somehow balanced by trees shading the outer windows. Apart A6 was oriented almost strictly towards the north and south, which was beneficial from the point of view of summer overheating [58]. The dwelling had average internal gains, and the opposite facades enabled cross-ventilation. The owners did not have a habit of drawing the curtains, even though the monitored rooms were equipped with them. According to the interview, the main strategy adopted to lower the internal temperature was opening and cracking open the windows together with trickle ventilation. Both apartments were situated in the lower part of the buildings, namely the second and third storeys, and had one of the largest glazing-to-floor ratios (22.67% and 20.88%).