Evaluating the potential of optimized PCM-wallboards for reducing energy consumption and CO 2 emission in buildings

Phase Change Materials (PCMs) in building envelopes have the potential to reduce building energy consumption. The effectiveness of PCMs is influenced by their thermophysical properties, such as melting temperature and transition range, which affect their year-round utilization and overall energy impact. It is therefore important to identify PCM properties that are suitable for each climate. This study aims to identify the optimal melting temperature and transition range that minimize energy consumption across 16 U.S. cities using DOE reference buildings. In addition, to assess the realistic CO 2 reduction potential of optimal PCMs, we utilize dynamic CO 2 emission factors for electricity generation. The results highlight that improperly selected PCM can lead to increased energy consumption or CO 2 emissions. It was also found that the optimal PCM transition range varies with outdoor temperature fluctuations. Optimal PCMs can lead to substantial energy savings - up to 18.7%, and significant CO 2 reductions - up to 15% for electricity and 38% for natural gas. The results and findings support the deployment of PCM-wallboards with the optimal PCM properties tailored to the target location and climate, which enhance energy performance and contribute to buildings sustainability.