Performance evaluation of phase change materials for thermal comfort in a hot climate region

Abstract

A Phase Change Material (PCM) provides heat and cooling by releasing and absorbing energy at the phase transition. They are employed in the construction of building walls in order to optimize thermal-energy-storage and maintain human comfort temperature. However, large numbers of competitive materials available, with each having its own thermophysical properties, the decision for selecting a suitable PCM involves several evaluation criteria. In this paper, a methodology is proposed to allow the decision maker to analyze, evaluate and select the best PCM according to different criteria. Five PCMs are compared in terms of thermal performance by using Analytic Hierarchy Process (AHP) method. After this process, the obtained ranking was verified by using a simulation model and the actual thermophysical properties of the PCMs in the region of Marrakech during summer season. As a result, it turns out that the outputs of AHP are in good agreement with those obtained with the simulation model. Additionally, the BioPCM-Q23 is ranked first in terms of thermal performance. The simulation results indicate that the recommended position for the PCM layer should be at the interior surface, when it is placed after the isolator. Also, the proposed configuration can ensure a comfortable indoor climate with an indoor temperature around 23.5 ℃. Plus, it provides the same energy performance with a decrease in the thickness of the PCM by 1.5 cm, which significantly helps to save energy.