A Novel Process for Selecting a PCM for a Building Energy Retrofit

Retrofitting existing buildings shows promise for reducing energy consumption and greenhouse gas emissions. However, selecting the appropriate energy retrofit strategy (or strategies) requires careful planning, detailed information about a building’s current condition and historical energy consumption patterns, and evaluation of multiple retrofit options. One retrofit strategy, using phase-change materials (PCMs) as a relatively straightforward means of increasing the thermal mass ofan existing building, continues to be ofinterest to building owners, operators, and utilities alike. Despite the seeming ease of installation (e.g., PCMs can be layered on top of existing acousticalceiling tiles rather than removing drywallto add insulation to exterior walls), a few primary factors need to be considered before applying PCMs in existing buildings. This paper presents a novel process for selecting PCMs for building energy retrofits, comprising an evaluation of both the candidate building as well as the PCM. This process includes goal setting for the energy retrofit as well as the PCM installation, evaluation of an existing building to ensure that it is a good candidate for PCM integration, and, finally, analyzing the energy-savings potential of PCM integration as a retrofit strategy. This process was developed based on the results of five case studies conducted by the authors, including three experimental commercial building PCM installations as well as simulation results from two residential buildings. The authors present how the application of this process would have changed the choices made by stakeholders involved in the cases studied, thereby avoiding some of the less desirable results of those projects.