## 4 Conclusions  
It is well known that the application of thermal insulation to reduce energy consumption is vital. Laboratory tests of insulation materials are very important for the better characterization and development of new materials. The declared values by the manufacturers are often not complete, which why more and more investigations should be conducted to verify performance. Measurements of the thermal and hygric properties are extremely important to find suitable insulation for any cases. This paper focused on the results of complex laboratory investigations for better understanding of the thermal hygric and morphological properties and behavior of four different micro-fiber glass wool insulation materials under different environmental circumstances. From the measurements, our conclusions are as follows:  
* After examining the samples with scanning electron microscopy, it was revealed that the bases of the materials were mainly silicon, calcium, magnesium, sodium, alumina, and carbon, and possibly their oxides. Moreover, some also contained traces of sulfur. The results showed that the mean pore diameter of the cylindrical fibers varied between 0.5 and 7 \(\upmu\)m at random locations. The presence of colorized binders was also depicted. The increase in the fiber diameter increased the density and resulted in a better thermal insulation capability;
* Through thermal conductivity measurements, it was revealed that thermal conductivity decreased with increasing density independently from the mean temperature of the samples, but due to their loose-filled structure, unfortunately, they cannot be used in situations where they would be exposed to significant mechanical effects. By only applying a 2 kPa load on the sample, their material thickness decreased. This assay determined the applicability limit of the samples;
* From the specific heat capacity measurements, it was shown that C\({}_{\text{p}}\) values of the samples fitted in the normal range of insulation materials (\(\sim\)1000 J/kgK); \begin{table}
\begin{tabular}{c c c} \hline
**Peak Position, [cm\({}^{-1}\)]** & **Vibration Mode** & **Comparison** \\ \hline
100, 110 & Boson peak and glass network [45] & Appeared in both samples, larger intensity for the orange sample \\
480 & Mg–O, Ca–O, and Si–O [45; 46] & Appeared in both samples, larger intensity for the orange sample \\
1378 & Basic bonds of the glassy network [45] & Appeared in both samples, larger intensity for the orange sample \\
1637 & Bonds of acrylic acid [47; 48] & Appeared only for the orange sample \\
1894 & Metal complex bond [49] & Appeared in both samples, larger intensity for the orange sample \\
2892 and 3045 & Symmetric and anti-symmetric stretching vibrations of CH, CH\({}_{2}\) or CH\({}_{3}\) groups [50] & Appeared in both samples, larger intensity for the orange sample \\
3230 & Stretching modes of OH [50] & Appeared in both samples, with the same intensity \\ \hline \end{tabular}
\end{table} 
Table 6: Identification of the signs in Raman spectra. From microscopic tests, we found all the samples to be hydrophobic;
* We have characterized sorption isotherm profiles as showing type III isotherms from the BET theory, which defines weak adsorption under low-relative humidity. It must be mentioned that the materials could be used in cases where the relative humidity of the environment is under 70%. It is also notable that the orange sample had the highest amount of adsorbed water, caused mainly by its declared acrylic content;
* From bomb calorimetry measurements, it was clearly shown that the materials were fire retardant and the heat released during combustion was low (2-4 MJ/kg), except for the orange material with about GHC = 5.5 MJ/kg--possibly due to its slightly different components. All the samples took on a spherical shape after their combustion;
* Differential scanning calorimetry measurements were performed on the samples between 30 and 350 C in order to determine their thermal stability.