Thermal performance analysis of novel foam concrete composites with PCM for energy storage and environmental benefits in buildings

The management and disposal of water treatment sludge (WTS) released in water treatment plants is an important problem awaiting solution. To address this, WTS can be used efficiently in thermal energy storage applications with phase change materials (PCMs). Energy demand from building heating and cooling loads also can be decreased with the help of this innovative solution. Another issue is that during integration into the building, PCMs are compatible with other building elements and no-leakage and high absorption capacity of support material. This study looked at the ability of WTS, which was employed as support substance in synthesis of shape-stable methyl palmitate (MP) composites, to control indoor temperature when incorporated in foam concrete. Shape-stable WTS/MP composites were prepared by vacuum impregnation and no leakage occurred at 35% (by weight) MP content. Melting temperature and latent heat values for this composite and prepared foam concrete (WTS/MP100) were measured as 26.71˚C, 24.44˚C and 85.92 J/g, 24.23 J/g, respectively. Depending on WTS content, flow diameter and dry unit weight of foam concrete composites decreased, while water absorption and porosity increased. Compressive strength at 28th days dropped to 6.97 MPa, and both flexural and compressive strengths also showed a downward trend. Proposed concrete (WTS/MP) can keep indoor ambient cooler for about 8 hours 40 min with a maximum difference of 2.97 ℃ compared to reference case at high solar intensity and ambient temperature hours. Moreover, it can provide a warmer indoor temperature (ΔTmax of 0.57 ℃) during night hours and when the ambient gets cold. Results indicate that utilization of WTS/MP foam concrete composite in buildings allows energy savings and low carbon emissions by reducing heating/cooling loads.