Multivariate Analysis of PCM Glazing Effects on Office Building HVAC Energy Performance in Arid Climates

Enhancing building envelopes is crucial for achieving high-performance buildings. However, passive envelope strategies may lose efficacy due to global warming, leading to a significant increase in cooling demands. Double-glazing filled with Phase Change Material (PCM glazing) can enhance office building envelopes by increasing thermal inertia, thereby improving energy performance and occupant comfort. Despite its potential, studies on PCM glazing's impact on building thermal performance are limited due to the lack of suitable simulation tools. Uribe et al. (2024) addressed this gap by developing and validating a dynamic heat transfer model for PCM glazing, which was integrated into EnergyPlus. Nevertheless, there remains a need for studies on the design variables that maximize the benefits of PCM glazing in reducing office buildings' energy consumption. This paper evaluates the impact of PCM glazing on the energy performance of an office building using multivariate analysis for two arid North American locations (El Paso, TX; Albuquerque, NM). The design parameters include Window-to-Wall Ratio (WWR), façade orientation, and PCM type under low and high internal heat gains. The PCM glazing model by Uribe et al. (2024) was utilized for building energy simulations. The study underscores the importance of PCM in both cooling and heating energy use. The multivariate analysis elucidates the impact of design parameters on building energy performance. Key findings highlight PCM's significant role in optimizing cooling and heating energy consumption, with PCM glazing reducing cooling energy consumption by up to 25%. High internal heat gains notably affect energy consumption, significantly increase cooling energy needs, and enhance PCM glazing's effectiveness in stabilizing indoor air temperature. Additionally, PCM with melting temperatures around 25ºC yields the most substantial cooling energy savings, as it undergoes phase change effectively within typical daily temperature cycles, optimizing heat absorption and release.