Coupled Numerical Model for the Transient Thermal Simulation of Rooms with Building Envelopes Composed of Phase-Change Materials

Abstract

This work presents a coupled numerical model for simulating the transient thermal response of rooms with building envelopes composed of phase-change materials (PCM) that exhibit enthalpy hysteresis. The numerical scheme simultaneously solves for the indoor air temperature and the thermal distribution in the walls, roof, and floor. Heat transfer in the building envelope is modeled using the finite element method (FEM) under an enthalpy–temperature mixed formulation, while the room temperature is obtained from an integral energy balance. The external boundary conditions are defined based on hourly meteorological data from standard climate files and include shortwave solar radiation, longwave radiation, and external convection.