Energy demand assessment of health care clinics with phase change materials integrated into different facades orientations

This study comprehensively analyzed the energy performance of a health care clinic (HC) building by simulating various phase change material (PCM) integration scenarios under the climatic conditions of Istanbul/Turkiye. PCM with a melting temperature of 25oC was applied to the building envelope in different orientations and combinations, and its effects on heating and cooling energy consumption were assessed. Results showed that PCM's impact on energy performance of the HC building varied based on the number and orientation of facades. During winter, phase change was often limited due to low ambient temperatures, resulting in increased natural gas consumption in scenarios with limited facade coverage. Conversely, in the cooling season, PCMs effectively reduced electricity demand, especially when applied to facades with high solar exposure. When active phase change occurred on both internal and external walls, savings increased to 1100 kWh (24%) in electricity and 71 kWh (1%) in natural gas. External wall-only applications led to a 791 kWh reduction in electricity but a 372 kWh increase in natural gas use. Among single-facade applications, the south facade was most effective in reducing cooling loads. Multi-facade configurations, particularly North+East+West and East+West+South, achieved up to 666 kWh in electricity savings. The results highlighted that optimal PCM integration strategies should consider facade orientation, surface coverage, and seasonal dynamics to enhance energy efficiency in HC buildings.