## 3 Results
### Results from the Drying Simulations  
#### 3.5.1 Model Validation  
The model validation was made based on the relative humidity and moisture content in the measurement positions presented in Section 2.2. The validation results are presented in Figure 9. The relative humidity in the baseline wall differentiated, at most, 10% in the drying stage (Figure 9a,b). For wall HI1, the relative humidity differentiated, at most, 20% correspondingly. The differences in RH became small after 17-34 days. However, for the HI1 wall a difference of 8% stayed between simulated  
Figure 8: (**a–d**) Measured moisture content from the wood frame during the leakage test. Measurement locations are described in the subfigure headings.  
and measured RH at the cold side of the frame (Figure 9a). This could be connected to the differences in heat transfer between the simulation and the built-in moisture test. However, the actual simulations were made with similar heat transfer properties, which leads to comparable results between simulation cases. The higher simulated RH, compared to the measured value, results in secure results when evaluating moisture safety of structures. In the drying phase, the simulated moisture content varied according to depth of the wood, after which the moisture content became steady and independent on the wood depth (Figure 9c-f). This shows how the initially unevenly moist wood frame equalizes the MC during the drying period. At the cold side of the frame the simulated MC was higher than the measured MC (Figure 9c,e). At the warm side of the frame simulations were more accurate and the MC was mostly below the measured MC (Figure 9d,f).  
Figure 9: (**a,b**) the relative humidity and (**c–f**) the wood moisture content results from the simulation model of the BL and HII walls, compared to the measurement values. The moisture contents are presented in three different depths in the wood frame, whereas the measurement represents the maximum value in the depths between 10–20 mm. Measurement locations are described in the subfigure headings.  
There are many factors that affect the similarity of simulated and measured RH and wood MC. Relative humidity is closely related to temperature; therefore, the aforementioned differences in heat transfer in simulated and measured structures is one factor. Especially for wood MC, the initial moisture level plays a major role. In the present experimental test, the initial moisture in the frame was strongly uneven. Most of the moisture was in the outer part of the frame. For calculation purposes, this was simulated with a limited amount of wood layers. The second factor affecting the MC results is the wood sorption curve, which can vary a lot, even for samples from same wood species. The wood planks used in the experimental walls had densities between 367-437 kg/m\({}^{3}\) while the average density of the sorption test samples was 514 kg/m\({}^{3}\). Another factor is the moisture measurement principle. The measurement depth can vary at least \(\pm\)1 mm. Also, the measurement indicates the maximum moisture content between the electrodes. Considering all these error sources, the observed deviances were understandable, and the validation results were considered acceptable.