## 3 Results and Discussion  
The ambient air temperature (AAT) was measured throughout the year with a minimum of \(-15.9\)\({}^{\circ}\)C on 28 February 2018 and a maximum of 34.5 \({}^{\circ}\)C on 4 August 2018 (Figure 3). The average temperature during the measuring period accounted for 10.6 \({}^{\circ}\)C (standard deviation (SD) 9.4 \({}^{\circ}\)C). AAT was well correlated with the air temperature in the ventilation layer (VAT) (\(R=0.99\)), the bottom face layer of the wooden shingles (SST) (\(R=1.00\)), and the air temperature in the attic (AtAT) (\(R=0.95\)) (Tables 1 and 2). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Measured Values** & **Mean** & **SD** & **Min** & **Max** \\ \hline temperature ambient air (AAT) & \({}^{\circ}\)C & 10.6 & 9.4 & \(-\)15.9 & 34.5 \\ surface temperature wall (WST) & \({}^{\circ}\)C & 10.2 & 9.3 & \(-\)15.7 & 34.2 \\ air temperature ventilation centre (VATc) & \({}^{\circ}\)C & 11.3 & 10.0 & \(-\)14.7 & 39.5 \\ air temperature attic (AtAT) & \({}^{\circ}\)C & 12.1 & 8.6 & \(-\)7.8 & 30.1 \\ dew-point temperature ventilation (VDT) & \({}^{\circ}\)C & 6.3 & 7.0 & \(-\)17.9 & 21.4 \\ surface temperature shingles bottom (SST) & \({}^{\circ}\)C & 10.6 & 9.7 & \(-\)16.9 & 35.5 \\ SST—VDT & \({}^{\circ}\)C & 2.9 & 3.0 & \(-\)6.3 & 19.0 \\ air speed ventilation centre (VASc) & m/s & 0.19 & 0.14 & 0.00 & 1.03 \\ air speed ventilation border (VASb) & m/s & 0.19 & 0.14 & 0.00 & 1.08 \\ r.h. ambient air (AAM) & \% & 76 & 17 & 22 & 100 \\ r.h. vent. centre (VAM) & \% & 74 & 16 & 22 & 99 \\ r.h. attic (AtAM) & \% & 74 & 13 & 27 & 98 \\ vapour pressure ambient air (AVP) & Pa & 1140 & 603 & 124 & 4117 \\ vapour pressure ventilation (VVP) & Pa & 1156 & 605 & 135 & 3351 \\ vapour pressure attic (AtVP) & Pa & 1208 & 581 & 221 & 2952 \\ global radiation & W/m\({}^{2}\) & 134.0 & 219.5 & 0.0 & 969.4 \\ precipitation & mm/m\({}^{2}\) & 0.1 & 0.6 & 0.0 & 15.0 \\ wind speed & m/s & 1.0 & 1.0 & 0.0 & 8.2 \\ wind direction & degree & 199 & 112 & 0 & 360 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Descriptive statistics of measured values and climate data. Figure 3: Various temperatures over the total measuring time. The relative humidity of the ambient air (AAM) was characterized by a minimum of 22% on 9 April 2018 and a maximum of 100% several times during the winter of 2017/2018. The average relative air moisture content during the measuring time was 76% (SD = 17%). AAM was correlated with that of the ventilation layer (VAMc) (\(R\) = 0.84) and that in the attic (AtAM) (\(R\) = 0.62). Nevertheless, AAM and VAMc were not perfectly correlated as only 71% of the variation in the VAMc could be explained by AAM (shown by the coefficient of variation = \(R^{2}\)). On average, VAMc was 2% lower than AAM (Figure 4). Whilst the SD of AAM was 17%, the SD of AtAM was only 13% and, in this respect, more languid. Focusing on specific time intervals, like that in mid-April 2018 (chosen because of great moisture uptake on the shingles' underside) (Figure 5), the air temperature rose from the morning until the afternoon, which caused the relative humidity to drop and the water vapour pressure to rise (Figure 4). After reaching the top temperature around 4:00 p.m., the relative humidity of the air rose, the vapour pressure dropped, and the shingle lower surface was wetted during the night. This could be observed throughout the year (the dry-out rate was negative 45% of the year). The 24 h balance of Dry-out rate_w_m was predominantly positive (i.e. drying) from the end of November 2017 until mid-April 2018 and varied the rest of the year. Whenever the slope of the cumulated dry-out curve in Figure 6 is low, the shingles' lower surface was partly wetted by the inflowing air. Periods with a low slope of the dry-out timeline indicate a low balance of the dry-out. The vapour pressure (AVP) was positively correlated (\(R\) = 0.91) with the air temperature (AAT). Figure 4: Air moisture content in mid-April 2018.