Thermal performance of steel facade profiles: An experimental setup and self-shading assessment

The energy demand for heating and cooling in buildings is impacted by envelope design and construction. This study investigates how the profile shape, direction, orientation, and self-shading potential of common steel sheet profiles affect thermal performance, air flow and heat gain of the envelope. Three steel cladding profiles were tested under solar radiation in Adelaide's Mediterranean climate. Surface, cavity air, and internal space temperatures were recorded at 15-min intervals for different orientations and profile directions, while a fixed weather station monitored air temperature, humidity, wind speed, and solar radiation. The three steel sheet profiles are standing seam, corrugated, and interlocking. The Standing seam profile consistently exhibited the highest cavity temperature, with values exceeding that of the other profiles by up to 20 °C, indicating relatively poorer thermal performance under this setup. The Corrugated profile performed the best, particularly when oriented horizontally, reducing heat gain. The study also showed that airflow through natural convection within the cavity had a significant impact. Under more airtight conditions, the Interlocking profile, which lacked shading provided by the rib protrusion, exhibited higher cavity temperatures, with differences exceeding 14 °C compared to the other two profiles. This research provides valuable insights into the role of steel cladding profiles and self-shading in reducing cooling energy demand. It serves as a foundation for further exploration of steel sheet properties, rib depth, and profile design, supporting the development of energy-efficient building practices.