Thermal Analysis of a Building’s Roof With Cone Frustum Holes Containing PCM

The thermal effectiveness of a building’s roof with Phase Change Material (PCM) is presented in this paper. The considered model consists of a concrete slab with vertical cone frustum holes filled with PCM. The objective of incorporating the PCM into the roof structure is to utilize its high latent heat of fusion to reduce the heat gain during the energy demand peak hours by absorbing the through the melting process in the roof before it reaches the indoor space. The problem is numerically solved in a three-dimensional space using the finite element method. The thermal effectiveness of the proposed roof-PCM system is determined by comparing the heat flux at the indoor surface to a roof without the PCM during typical working hours. A parametric study is conducted to assess the effect of the cone frustum geometry, as well as, the PCM’s type. The results indicate that the heat flux at the indoor surface of the roof can be reduced up to 39% when the PCM is incorporated and a conical geometry for the PCM shows the best thermal performance.