Simulation of PCM- Integrated Wall Designs for Residential Buildings in Sacramento

Phase Change Materials (PCMs) have the potential to reduce cooling and heating energy consumption of buildings as well as displace the peak loads. The climatic conditions of the building and the thermophysical properties of the PCMs play a crucial role in determining how effective a PCM solution will be and hence, the energy impact of using a particular PCM product in a particular climatic condition needs to be understood thoroughly (Lee et al. 2015). In this research, the performance and heat transfer characteristics of two PCMs integrated into a typical residential wall in California are characterized using simulations. PCM1 is a spackle-type product and consists of 53% PCM. PCM2 is a salt-based PCM and is encapsulated inside plastic panels. The typical residential wall without PCM was used as a baseline and a total of 4 PCM-integrated wall designs were studied. Their impact on changing the cumulative heat flows throughout the 24-hour cycle are analyzed relative to the baseline case. The Sacramento weather is used in these studies and representative days of winter and summer were simulated. The integration of PCM1 to the inner wall surface slightly increases cumulative heat flowing from inside the building to the outside for the winter day and slightly increases cumulative heat flowing from outside to inside the building for the summer day. The integration of PCM2 to the inner wall surface for the winter day slightly increases cumulative heat flowing from inside the building to the outside and slightly reduces the cumulative heat flowing from outside to inside the building for the summer day. In a different wall design, PCM is integrated into selective areas next to the studs. For the PCM located next to studs, the behaviors of PCM1 and PCM2 are significantly different. The cumulative heat flowing from inside the building to the outside for the winter day increases in PCM1 and PCM2 cases but a higher increase is seen in the case of PCM2. For all the different wall designs tested in the Sacramento weather, no significant changes in the cumulative heat flows from an energy savings standpoint are generated using the two specific PCMs characterized in this simulation study.