(**d**) Final corrected thermal temperature models. In each case, the colour palette has been set, adjusted to the minimum and maximum values. and maximum temperature, thus allowing the differences between apparent and real temperatures to be clearly seen. Note that both the wall areas and the external window-frames undergo the highest correction. ### Total Temperature Variations

Table 3 summarizes the results obtained for the variation in temperature for the aforementioned objects after considering the corrections from Stages I and II. In this table, we consider the variations between original vs. apparent temperatures (1 \(\Delta_{\rm II}\) 1) and apparent vs. real temperatures (1 \(\Delta_{\rm II}\) 1). The third column is the total sum of both corrections (1 \(\Delta_{\rm total}\) 1). The row below each structural element corresponds to the contribution (percentage) of each specific correction. It is clear that the first correction has the greatest impact on the final temperature, achieving a total average impact of 62.1%, whereas the second factor covers 37.9% of the total variation. The quality of the measurements that the infrared camera provides is, therefore, the main issue to be minimized. Overall, the corrections are in the range of 0.07 \({}^{\circ}\)C to 1.11 \({}^{\circ}\)C, which signifies a variation with respect to the original temperature provided by the infrared camera of up to 7.9%. ### Calculation of Transmittances

As an example of the application of our approach, we present the results obtained when estimating the transmittance, which is an indoor surface heat transfer coefficient, on the basis of experiments carried out on two walls of a building. Although the transmittance is usually in the range of 1.5-2.5 W/m\({}^{2}\)K, without insulation, we expected to attain values in the range of 0.1-0.5 W/m2K, as occurs in most of the buildings in Europe. As is already known, U-values are obtained by employing a large variety of empirical methods, but some authors [26; 27] consider that certain energy parameters, such as the surface heat transfer coefficient, cannot yet be estimated at a reasonable level of uncertainty. Estimations are in the range of 60% for instantaneous values, while this decreases to an average of 12-20% for 8-h and always increases for low-temperature gradients. Furthermore, \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & 1 \(\Delta_{\rm II}\) 1 & 1 \(\Delta_{\rm II}\) 1 & 1 \(\Delta_{\rm total}\) 1 & 1 \(\Delta_{\rm II}\) 1 & 1 \(\Delta_{\rm total}\) 1 & 1 \(\Delta_{\rm I}\) 1 & 1 \(\Delta_{\rm II}\) 1 & 1 \(\Delta_{\rm total}\) 1 \\  & **Door** & **Door** & **Door** & **Win** & **Win** & **Win** & **Wall** & **Wall** & **Wall** \\ \hline SE1 & & & & & & & 0.38 & 0.27 & 0.65 \\ \% & & & & & & & 58.5 & 41.5 & \\ SE2 & & & & & & & 0.12 & 0.42 & 0.54 \\ \% & & & & & & & 22.2 & 77.8 & \\ SE3 & & & & & & & 0.53 & 0.18 & 0.71 \\ \% & & & & & & & 74.6 & 25.4 & \\ SE4 & & & & & & & 0.5 & 0.01 & 0.51 \\ \% & & & & & & & 98.0 & 2.0 & \\ SE5 & & & & & & & 0.96 & 0.14 & 1.10 \\ \% & & & & & & & 87.3 & 12.7 & \\ SE6 & & & 1.40 & 0.19 & 1.59 & 0.70 & 0.41 & 1.11 \\ \% & & & 88.0 & 12.0 & & & 63.1 & 36.9 & \\ SE7 & & & & & & & 0.03 & 0.04 & 0.07 \\ \% & & & & & & & 42.9 & 57.1 & \\ SES & & & & & & & 0.26 & 0.28 & 0.54 \\ \% & & & & & & & 48.1 & 51.9 & \\ SE9 & & & & & & & 0.43 & 0.3 & \\ \% & & & & & & & 58.9 & 41.1 & \\ S10 & 0.37 & 0.03 & 0.41 & 0.42 & 0.05 & 0.48 & 0.4 & 0.19 & 0.59 \\ \% & 91.6 & 9.6 & & 88.5 & 11.5 & & 67.8 & 37.2 & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Corrections I and II of temperatures for detected door frames, window frames and wall areas in Zone 1. SE stands for structural element (floor (SE1), ceiling (SE2) and faces (SE3 to SE10)). there is a relevant impact on the overall uncertainty of the U-value with sensor quality. In our case, this refers to the thermal camera used in the experimentation.