Thermal performance of outer and inner multi-layered walls in buildings

Buildings’ outer walls are as a rule multi-layered, i.e. consisting in a sequence of homogeneous layers of different materials, some of which endowed with essentially resistive thermal features (light and insulating layers), some others with essentially capacitive thermal features (heavy layers, provided with mechanical resistance). Under steady state conditions, the thermal behaviour of a multi-layered wall is defined by its thermal transmittance, whose value is independent of the layer sequence order. Under dynamic thermal conditions, the behaviour of an outer multi-layered wall is defined by these two parameters: periodic thermal transmittance and time shift; whose value are strongly dependent on the layer sequence order. This study focus on how far these parameters are dependent on the sequence order of the layers forming the outer walls with the aim to detect the "ideal summer time stratigraphies".