A Numerical Investigation of a Novel Composite Clay Block With Integrated NEPCM for Enhanced Building Thermal Performance

Enhancing the thermal performance of building envelopes is critical for reducing global energy consumption and improving occupant comfort. While conventional insulation provides static resistance, dynamic thermal management using phase change materials (PCMs) offers a more advanced solution. This study numerically investigates a novel composite clay block featuring a solid clay fill for high thermal mass and a matrix infused with nano‐encapsulated PCM (NEPCM) for latent heat storage. By employing a PDE‐based model under realistic, time‐varying conditions, the analysis isolates the intrinsic thermal benefits of this synergistic design, focusing on the impacts of NEPCM volume fraction ( φ ) and outdoor temperature amplitude (Δ T s ). Findings reveal that the incorporation of NEPCM significantly dampens thermal fluctuations. At an outdoor temperature amplitude of Δ T s = 15°C, a 10% NEPCM volume fraction reduces the peak indoor heat flux by a substantial 35% while also inducing a beneficial time lag. Furthermore, this enhancement translates to a more stable indoor environment; under high thermal stress (Δ T s = 30°C), the daily indoor surface temperature swing was suppressed by 24%, from 1.25 to 0.95°C. These results highlight the effectiveness of combining sensible and latent heat storage, providing a strong quantitative basis for developing advanced, thermally responsive building materials.