## 3 Results and Discussion
### Panel U-Value Calculation from Unsteady-State Conditions  
The unsteady-state test was performed by changing the air temperature \(T_{ae}\) (\({}^{\circ}\)C) in the cold chamber after a certain amount of time, shown in Table 3. The air temperature was controlled by an electronic controller with a preset temperature program. The temperature in the hot chamber \(T_{ai}\) (\({}^{\circ}\)C) was continuously set at 24 \({}^{\circ}\)C and the temperature in the cold chamber \(T_{ae}\) (\({}^{\circ}\)C) was periodically changed between -13 \({}^{\circ}\)C and +6 \({}^{\circ}\)C for seven days. The preset temperature program was based on average real climate conditions recorded at the local meteorological station, Prague-Suchdol, Czech Republic, in winter 2017. The test panel was always conditioned for 24 h under the pre-set conditions with the air temperature in the hot chamber of 24 \({}^{\circ}\)C and air temperature in the cold chamber of 6 \({}^{\circ}\)C.  
The following data were collected during the experimental tests: the air temperatures \(T_{ae}\) (\({}^{\circ}\)C) and \(T_{ai}\) (\({}^{\circ}\)C), the surface temperatures \(T_{se}\) (\({}^{\circ}\)C) and \(T_{si}\) (\({}^{\circ}\)C), and total energy transmitted through the panel (known as an \(E_{experimental}\) (Wh)) in Figure 7 at time interval of 1 min. The air temperature in the hot chamber \(T_{ai}\) (\({}^{\circ}\)C) was continuously recorded every 1 min as an indication of the test panel to thermal impulse. Figure 7 shows the automatic defrosting cycle of the cooling system after approximately 12 h. Total energy (W) transmitted through the test panel was recorded experimentally as a function of time. Furthermore, it was also calculated from Equation (5) and is shown as an \(E_{sarched}\) in Figure 7. Figure 7 shows results from two independent measurements, comparing the short-cut rapeseed, the short-cut woodclips and the mineral-wood panel reaction to dynamic thermal conditions as described in the previous paragraph. U\({}_{\text{searched}}\) was found after the experimental measurement using a solver function in MS Excel (version 2016, Microsoft, Redmond, WA, USA). The steady-state measurements gave more optimistic thermal properties for the panel filled with mineral wool. The total thermal transmittance of the entire sandwich panel filled with short-cut rapeseed insulation was 0.271 W m\({}^{-2}\) K\({}^{-1}\) and the total thermal resistance value was 3.690 m\({}^{2}\) K W\({}^{-1}\). The thermal conductivity of the short-cut rapeseed itself was 0.042 W m\({}^{-1}\) K\({}^{-1}\). The total thermal transmittance of  
Figure 7: Total energy transmitted through the sample using searched U-value under unsteady-state conditions; (**A**) short-cut rapeseed; (**B**) short-cut woodclips; (**C**) mineral wool; \(T_{ae}\) = air temperature in the cold chamber, \(T_{ai}\) = air temperature in the hot chamber, \(T_{se}\) = surface temperature of the sample in the cold chamber, \(T_{si}\) = surface temperature of the sample in the hot chamber, Experimental = total energy transmitted through the sample (Wh), and Esearched = calculated total energy consumption using U-value given by Solver (Wh). short-cut woodchips insulation panel was 0.404 W m\({}^{-2}\) K\({}^{-1}\) and the total thermal resistance value was 2.475 m\({}^{2}\) K W\({}^{-1}\). The thermal conductivity of the short-cut woodchips was 0.065 W m\({}^{-1}\) K\({}^{-1}\). To compare the results of the bio-waste insulation panels, a sandwich panel with mineral wool was measured. The total thermal transmittance of the entire sandwich panel filled with mineral wool insulation was 0.267 W m\({}^{-2}\) K\({}^{-1}\) and the total thermal resistance value was 3.745 m\({}^{2}\) K \(W^{-1}\). The thermal conductivity of the mineral wool was 0.042 W m\({}^{-1}\) K\({}^{-1}\). Linear thermal transmittance \(\psi\) across the reinforcing stud (wood/HDF) was included in the resulting values of the thermal transmittance, thermal resistance, and thermal conductivity.