A library of frits for daylight and visual comfort simulation: recommendations and testing in Canadian climates

A library of frit material definitions is curated in the Radiance material format for annual climate-based daylight simulations and rendered visual comfort calculations. Radiance ‘cal’ and ‘rad’ material files for various common patterns, coverage ratios, and irregular gradients are developed and shared via an open source library. Photometric properties for typical architectural frits are created based on measured data, and scattering effects are evaluated using a combination of low-resolution angular transmission measurements and high dynamic range (HDR) luminance photography.

Best-practice methods are discussed for the application of frits in lighting simulation relative to typical direct sun daylight metrics such as annual sunlight exposure (ASE) and lighting sufficiency metrics. Finally, the impact of frits on glare and daylight metrics are benchmarked compared to other alternatives such as reducing the relative size of glazing in a variety of Canadian climates.