Comparative Thermal Evaluation of Two Systems of Wall Panels Exposed to Hot and Arid Arabian Environmental Weather Conditions

Thermal evaluation of twin wall panel systems was assessed under vibrant hot and arid conditions of weather in the Arabian Peninsula. Two systems of wall panels (0.6 m × 0.6 m) were prepared. The first system was prepared with a 5.0 cm thick extruded polystyrene (XPS) board. While the second system was prepared with 5.0 cm thick layer of foam-mortar encompassing expanded polystyrene (EPS) beads. Both the thermal insulative layers were sandwiched between two 7.5 cm thick concrete layers. The two wall panel systems were thermally evaluated at the same time in a carefully designed test room. Comparison was accomplished between the two wall systems by measuring the U-value (thermal transmittance) and R-value (resistance). The U-value (air to air) for sandwiched XPS concrete wall system was 0.837 W/m² K while it was 2.527 W/m² K for sandwiched EPS beads foam-mortar concrete wall system. The mean U-values (surface to surface) of the sandwiched XPS concrete wall system was 1.143 m² K/W and 0.293 m² K/W for sandwiched EPS beads foam-mortar concrete wall system. The sandwiched XPS concrete wall system was more efficient than the sandwiched EPS beads foam-mortar concrete wall system in terms of thermal performance. About 4.5 h of time lag was observed for both the wall panel systems between the external surface temperature and the heat transmission in the internal surface. The output of the FEM simulation by ABAQUS is compared with the measured data for Set-1 (period 16-Aug-2022 to 26-Aug-2022). The hourly temperature change on the outer and inner surfaces has good agreement for both sandwiched XPS concrete wall system and sandwiched EPS beads foam-mortar concrete wall system. The simulation can also predict the heat flux through the two wall systems investigated.