Experiment and simulation analysis of roofing element integrated with phase change material

Abstract

Conventional reinforced concrete (CRC) roofing systems contribute close to 40% of the heat ingress into the ambient environment. This heat ingress is responsible for increased mechanical ventilation inside the built environment. Phase Change Material (PCM) roofs could be a solution to counteract the heat ingress since it stores heat energy when it changes their phase at a specific temperature. In this paper, CRC roofs were integrated with PCM and analyzed using COMSOL Multiphysics v5.6. The simulation results were validated using an insulated chamber, where concrete specimens were tested for temperature. Simulations and experiments were done to get the ideal thickness, type, and position of PCM integrated with CRC. All PCM roofs performed better in bottom fibre temperature than CRC roofs. PCM29 was the better option since their phase change cycle was completed throughout the year compared to PCM37 roofs, which can be used for arid climates. PCM integrated with CRC roofs of varying thicknesses were analyzed, and results were proportional to increasing thickness. The results also showed a saturation level in all the PCM roofs of a thickness of 2 cm. The position of PCM was experimented from top to bottom inside CRC. PCM integrated at the top and bottom with CRC showed hot and cold bottom fibre temperatures, respectively. The other position in which PCM was sandwiched with CRC worked out well since the bottom temperatures of the roof were comfortable. The practical application of such materials in conventional construction will reduce the cooling load requirement and create a better energy-efficient structure.