Visual Comfort Assessment of Different Shading Strategies in a Commercial Office Building in the Southeastern US

Abstract

It is challenging to design buildings that simultaneously consider both the dynamic nature of daylight and specific occupant preferences. The authors have investigated this problem by studying the performance of four specific shading strategies using quantitative measurements of occupants visual comfort: discomfort glare and daylight availability. This paper specifically evaluates the performance of four shading strategies, two types of electrochromic (EC) glass, an automated fabric roller shade, and a venetian blind in a building located in the Southeastern United States. This paper examines how these technologies impact occupant visual comfort and it also examines how the buildings perform relative to the two metrics outlined in IES LM-83-12. Horizontal illuminance and high dynamic range images were recorded to assess the existing luminous environment in order to better understand the potential of various shading strategies. Calibrated daylighting models were also constructed in DIVA. Our results suggest that perimeter-zone occupants benefits from EC glass as it can reduce more than 40% of glare annually in this zone. Findings from the interior zones are shown that all four shading strategies perform quite similarly in regards to reducing the glare. This study suggest that by providing a designer at early-design-stage with direct information related to the level of daylight availability and glare condition within a space will lead to improve occupant's visual comfort.

An Architectural Solution to a Biological Problem: A Systematic Review of Lighting Designs in Healthcare Environments

“…Among the wide range of lighting strategies and designs, circadian lighting is designed to positively affect human circadian system by sending appropriately timed signals to the central clock in the brain [27][28][29]. In healthcare settings, the design of circadian lighting aims to synchronize the lighting environment with the natural circadian rhythm.…”

Simulations of non-image-forming effects of light in building design: A literature review

“…Spectral information was also included by performing simulations of photometric quantities and post-processing the results based on the spectral power distribution (SPD) of the light source. 35,36,38,44,47,66,[68][69][70]73,75,[80][81][82][83]85 This method disregards that the SPD that reaches the eye is modified by the spectral properties of materials, which might be a reasonable assumption in neutrally coloured spaces. For non-neutrally coloured spaces, a simplified approach was to multiply the SPD of the light sources with the spectral reflectance of the materials and use this to post-process photometric results.…”

Validation of spectral simulation tools for the prediction of indoor daylight exposure

“…This last characteristic calls for spectrally resolved simulation workflows, or simply "spectral simulations" i.e., simulations in which light transport computations, material and light parameters span the entire visible spectrum and are defined based on N channels with N being more than three . According to this definition, most light simulation platforms (Ayoub, 2020;Ochoa et al, 2012) -including the ubiquitous Radiance rendering engine (Ward, 1987), are not proper spectral simulation tools, since they are usually based on a three-dimensional (e.g., RGB) color space, though they have already been used to discuss nonvisual responses to light (Acosta et al, 2017;Amirazar et al, 2018;Amundadottir et al, 2017;Amundadottir et al, 2013;Andersen et al, 2011;Borisuit et al, 2016;Konis, 2016;Pechacek et al, 2008). A framework based on aopic spectral sensitivity functions (Lucas et al, 2014) has since been adopted by the International Commission on Illumination (CIE) to describe the ability of optical radiation to trigger non-visual effects of light in humans (CIE, 2018).…”