Ranking PCMs for building façade applications using multi-criteria decision-making tools combined with energy simulations

The use of phase change materials (PCMs) in building envelopes has a potential to improve the energy performance of buildings. Even though Multi-Criteria Decision-Making (MCDM) tools have been widely applied to rank PCMs for various applications, the following issues still need more elaboration: a) How to account for the climate-related factors in the ranking of PCMs? b) How can the environmental footprint and chemical properties of various PCMs be considered in the ranking of PCMs? Therefore, this study presents a methodology for ranking phase change materials based on the AHP–TOPSIS and Fuzzy AHP–Modified Fuzzy TOPSIS methods combined with building energy simulations. Thermophysical (thermal conductivity, latent heat of fusion, phase change temperature, specific heat, density, cycling stability, supercooling), economic (initial cost), chemical (toxicity, flammability, corrosiveness), and environmental (recyclability, embodied energy) criteria were considered. The application of the methodology was demonstrated for eight cities of the tropical savanna climate zone. A comparative analysis was conducted, and the rankings obtained utilizing AHP–TOPSIS and Fuzzy AHP–Modified Fuzzy TOPSIS methods were found to be concordant. A sensitivity analysis indicated that the ranking developed by the proposed methodology has considerable robustness to alteration of weightings of criteria.