Energy, economic and environmental (3E) analysis of residential building walls enhanced with phase change materials

The building sector has recently been responsible for the world's energy consumption growth. Heating and cooling accounts for more than 30 % of building energy consumption. A phase change storage wall heat transfer module considering phase change material hysteresis in TRNSYS was developed in this article. A binary variable is defined to determine the enthalpy curve in heat transfer calculation, which solves the problems of overestimate the latent heat and difficult temperature convergence in the previous hysteresis model for non-complete transformation processes. An extensive study, including energy, economic and environmental analyses, has been proposed to assess the benefits of phase change materials which integrated into building walls in Xi'an. In the study of phase change storage wall building, the energy efficiency, heating and cooling loads of phase change walls with different structures were calculated. It was found that the optimal melting temperature of the phase change layer was close to the summer indoor setting temperature. EPS-Brick-PCM is the optimal phase change insulation composite exterior wall structure. A life cycle economic analysis and carbon emission study were conducted on the phase change wall. It was found that the phase change exterior wall without insulation has better economic efficiency and more carbon emission reduction. The phase change exterior wall with insulation is less economic efficient and has less carbon emission reduction. The thicker the insulation layer of the phase change insulation composite wall, the worse the economic and environmental benefits.