This paper describes a study on 2D and 3D thermal simulation approaches for simulating the thermal performance of various spandrel assemblies and configurations. The results show the simulated thermal performance can vary between 5% and 40% depending on size and adjacent glazing assemblies. Simulated surface temperatures at various spandrel locations can vary by 2% to over 30% between 2D and 3D thermal simulations. Comparisons of simulated and measured laboratory surface temperatures are also made as part of a larger study on spandrel thermal performance to validate 2D and 3D thermal simulation procedures. Findings from this study provide insight into the accuracy of current thermal simulation techniques and question the appropriateness of standard modeling assumptions, including the heat transfer coefficients for exterior and interior air films.
This paper was presented at the ASHRAE 2025 Buildings XVI Conference.