PCM enhanced concrete panels allow to reduce overheating in lightweight buildings

The article presents the results of research on the thermal and mechanical properties of concrete slabs with pumice aggregate soaked with dodecanol (duodecyl alcohol), i.e. an organic material that changes its phase at a temperature +24oC. It is possible to implement this type of integration of phase-change material with a typical building material in any precast concrete plant without additional expenditure on equipment and without technically difficult vacuum impregnation. The use of concrete panels with a 4% mass content of PCM as the internal cladding of building components allows for a significant change in the internal heat capacity of the building and, consequently, a change in the thermal properties of the buildings. In a very simple modeled object with a light wooden structure, intensively cooled during the night, the influence of the type of internal cladding on the internal thermal comfort in the summer was analyzed. It has been shown that the cladding in the form of a concrete PCM panels with a thickness of 3.5 cm, compared to a standard gypsum board, effectively limits the temperature increase and significantly shortens the duration of discomfort conditions. The maximum daily fluctuation of operative temperature during summer, which was approximately 15 K in a lightweight building, has been limited to approximately 8 K thanks to PCM concrete panels. The difference in the average values for the entire simulation period, equal to 1.76 K, does not fully illustrate the improvement of thermal conditions during periods of high heat load. Reduction of the plate thickness to 2 cm only slightly worsened the conditions in the analyzed facility and can be treated as a reasonable compromise solution for lightweight construction technologies. In the case of an unreasonably large window area, regardless of the actual space thermal capacity, it is not possible to obtain the acceptable conditions inside only by means of the passive methods.