Phase Change Materials (PCMs) and Their Optimum Position in Building Walls

Zeyad Amin Al-Absi,Mohd Hafizal Mohd Isa,Mazran Ismail

doi:10.3390/su12041294

Abstract

More than half of the energy consumption in buildings is utilized for the heating and/or cooling of the indoor environment. The building envelope plays a key role in controlling the effects of external weather and, therefore, is linked with many passive design strategies. Thermal energy storage (TES) and phase change materials (PCMs) are efficient techniques, which can store a high density of thermal energy. The PCMs attract many researchers to implement them in the components of buildings for thermal management. In building walls, they were implemented in different positions and have achieved different results. This paper aims to review the related literature that examines PCMs’ application in different positions within the building walls to locate their optimum position and the influential parameters. It was found that the optimum positions of PCMs are highly dependent on performing a daily complete melting/freezing cycle to be ready for the following day. Many parameters can influence this, including climate and weather conditions and the application target, PCMs’ melting temperature and heat of fusion, PCMs’ amount, the thermal properties of the wall’s materials, a mechanical heating/cooling or free-running indoor environment, and wall orientation. An optimization process using the simulation tools is suggested so that the optimum position of the PCMs can be located.

Highlights

Buildings were commonly constructed using local materials
The results showed that the phase change materials (PCMs) layer in the south wall melted only partially in Positions 1 and 2, while the full melting process occurred in Positions 3, 4 and 5
The results demonstrated that the maximum temperature reduction achieved during the summer was with the PCM-sheet in the third position, while it was in the fourth position during winter

Summary

Introduction

Buildings were commonly constructed using local materials. This helped to protect them from local climate conditions and respond to the ambient environment [1]. Traditional buildings were more climate-responsible as they were built to ensure the best control and utilization of climate factors for the inhabitants’ comfort based on the available materials and technologies. They showed a better indoor environment and less energy consumption [2,3]. With people migrating to urban areas, which caused overcrowding, the focus of the building construction sector changed from climatic requirements to economical consideration. This resulted in a high dependency on mechanical systems to achieve thermal comfort. Buildings provide a great opportunity through their envelope to minimize this high energy consumption by introducing more promising solutions, like passive design strategies

Objectives

Findings

Discussion

Conclusion