Climate-Responsive Thermal Management with Reconfigurable PCM-Based Building Envelopes

Abstract

The building sector accounts for nearly 40% of global energy-related CO₂ emissions, with heating and cooling demands representing a major share. Phase Change Materials (PCMs) integrated into building envelopes offer high latent heat storage density, but conventional static implementations lose effectiveness under real climate variability, leading to incomplete cycling and eventual saturation over multi-day events. This thesis addresses this limitation through a reconfigurable cylindrical PCM system in which foam insulation, PCM, and an aluminum conductive shell are integrated into a rotating module embedded in the wall. Rotation reorders the sequence of materials along the dominant heat flux direction, enabling switching between three heat flux topology states: Block, Buffer, and Transmit, without any change in materials or hardware. Different climates demand different topology sequences, and identifying and implementing the appropriate sequence becomes the primary design decision.

The system is designed through parametric simulation in COMSOL Multiphysics, from which seven design rules governing geometry, material selection, and rotation strategy are derived. A laboratory prototype demonstrates sustained thermal cycling with 71% attenuation of the exterior temperature swing, while an equivalent static configuration progressively saturates over extended operation under identical conditions. Evaluation across five representative climate profiles establishes three distinct topology regimes: alternating Block-Transmit configurations under strong summer gradients, inverted Transmit-Block assignment under transitional winter conditions, and permanent Block topology under persistent cold, where active switching is counterproductive. A reduced-order RC model enables trajectory simulation approximately three orders of magnitude faster than COMSOL, and an LSTM surrogate achieves accurate long-horizon prediction through a temperature-increment formulation. Together, these models form a digital twin for real-time evaluation of rotation schedules.

These contributions establish a framework for transforming PCM systems from passive thermal storage elements into actively controlled, climate-adaptive building envelopes.