Van Den Wymelenberg, Kevin; Inanici, Mehlika; Johnson, Peter. (2010). The Effect of Luminance Distribution Patterns on Occupant Preference in a Daylit Office Environment. Leukos, 7(2), 103 – 122.
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Abstract
New research in daylighting metrics and developments in validated digital High Dynamic Range (HDR) photography techniques suggest that luminance based lighting controls have the potential to provide occupant satisfaction and energy saving improvements over traditional illuminance based lighting controls. This paper studies occupant preference and acceptance of patterns of luminance using HDR imaging and a repeated measures design methodology in a daylit office environment. Three existing luminance threshold analysis methods [method1: predetermined absolute luminance threshold (for example, 2000 cd/m(2)), method2: scene based mean luminance threshold, and method3: task based mean luminance threshold] were studied along with additional candidate metrics for their ability to explain luminance variability of 18 participant assessments of 'preferred' and 'just disturbing' scenes under daylighting conditions. Per-pixel luminance data from each scene were used to calculate Daylighting Glare Probability (DGP), Daylight Glare Index (DGI), and other candidate metrics using these three luminance threshold analysis methods. Of the established methods, the most consistent and effective metrics to explain variability in subjective responses were found to be; mean luminance of the task (using method3; (adj)r(2) = 0.59), mean luminance of the entire scene (using method2; (adj)r(2) = 0.44), and DGP using 2000 cd/m(2) as a glare source identifier (using method1; (adj)r(2) = 0.41). Of the 150 candidate metrics tested, the most effective was the 'mean luminance of the glare sources', where the glare sources were identified as 7* the mean luminance of the task position ((adj)r(2) = 0.64). Furthermore, DGP consistently performed better than DGI, confirming previous findings. 'Preferred' scenes never had more than similar to 10 percent of the field of view (FOV) that exceeded 2000 cd/m(2). Standard deviation of the entire scene luminance also proved to be a good predictor of satisfaction with general visual appearance.
Keywords
Glare; Daylight Metrics; Luminance Based Lighting Controls; Discomfort Glare; Occupant Preference; High Dynamic Range
Inanici, Mehlika; Hashemloo, Alireza. (2017). An Investigation of the Daylighting Simulation Techniques and Sky Modeling Practices for Occupant Centric Evaluations. Building And Environment, 113, 220 – 231.
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Abstract
Occupant centric performance approaches in daylighting studies promote design decisions that support human visual comfort, productivity, and visual preferences, along with more conventional energy efficiency criteria. Simulating per-pixel luminance values and luminance distribution patterns for the entire scene allows us to analyze the occupant centric metrics and performance criteria. However, there are a number of different sky models, complex fenestration models, and simulation techniques that produce either conventional point in time images or annual luminance maps. This paper discusses the similarities and differences between different techniques; and a comparison analyses provides insight about their impact on occupant centric lighting measures. The comparisons for sky modeling include the conventional CIE skies (Clear, Intermediate, and Overcast), measurement based CIE models, Perez all-weather skies, and high dynamic range image based skies. The comparison of simulation techniques include point in time simulations, image based lighting simulations, and annual luminance simulations (threephase and five-phase methods). Results demonstrate that measurement based sky models match real world conditions with reasonable proximity, and generic CIE skies consistently underestimate the indoor lighting conditions. Annual simulation methods provide a large database of temporal luminance variations, where individual instances are comparable to point in time simulations. Long term luminance simulations provide opportunities to evaluate the percentage of the year that a given luminance based criteria is met or violated. (C)2016 Elsevier Ltd. All rights reserved.
Keywords
Complex Fenestration Systems; Scattering Distribution-functions; Discomfort Glare; Visual Comfort; Daylit Spaces; Validation; Radiance; Performance; Offices; Design; Sky Models; Daylight Simulations; Point In Time Simulations; Image Based Lighting; Annual Lighting Simulations; Annual Luminance Maps
Huang, M.; Simonen, K. (2020). Comparative Environmental Analysis of Seismic Damage in Buildings. Journal Of Structural Engineering, 146(2).
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Abstract
In studying the environmental impacts of buildings, earthquake hazards are rarely considered, but their environmental impacts can be significant. This case study paper demonstrates how the US Federal Emergency Management Agency's Performance Assessment Calculation Tool (PACT) can be used to analyze the environmental impacts of buildings using probabilistic seismic hazard assessment. PACT was used to evaluate 10 case study buildings that varied by five types of lateral systems and two risk categories. For each building, PACT generated 1,000 realizations at five earthquake intensities. The resulting environmental impacts were analyzed according to their distribution, median, and average values, and the differences among building component types, risk categories, and lateral force-resisting systems were explored. In this study, building components that were categorized under Exterior Enclosures, Interior Finishes, and Heating, Ventilation, and Air-Conditioning (HVAC) produced notably higher environmental impacts in response to seismic damage, and their vulnerability to displacement- or acceleration-induced damage could be attributed to the characteristics of the lateral systems. Although these observations are notable, they should not be taken as universally applicable to all buildings. Instead, these findings exemplify how the environmental impact results from PACT can be analyzed and interpreted to address both the seismic and environmental aspects of building design. (C) 2019 American Society of Civil Engineers.
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Impact
The Aga Khan Award for Architecture (AKAA) recently announced 20 shortlisted projects for the 2022 Award cycle. The projects will compete for a share of the US$ 1 million prize, one of the largest in architecture. The 20 shortlisted projects were selected by an independent Master Jury from a pool of 463 projects nominated for the 15th Award Cycle (2020-2022). The Aga Khan Award for Architecture was established by His Highness the Aga Khan in 1977 to identify and encourage…
Launching the Inspire Fund: An early step for CBE’s Office of Research “For a small college, CBE has a broad range of research paradigms, from history and arts, to social science and engineering.” — Carrie Sturts Dossick, Associate Dean of Research Upon taking on the role of Associate Dean of Research, Carrie Sturts Dossick, professor in the Department of Construction Management, undertook listening sessions to learn about the research needs of faculty, staff and students across the College of Built…
The EarthLab Innovations Grant Program was launched in 2019 to fund actionable environmental research. The 2022-23 EarthLab Innovation Grants program received 33 high-quality proposals for research at the intersection of climate change and social justice. One awarded project titled, “Centering Place and Community to Address Climate Change and Social Justice” was led by P.I. Daniel Abramson, Associate Professor of Urban Design & Planning and Adjunct Associate Professor of Architecture & Landscape Architecture, and Community Lead, Jamie Judkins, of the Shoalwater…
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In 2021 the College of Built Environments launched the CBE Inspire Fund, designed to support CBE research activities for which a relatively small amount of support can be transformative. The second year of awards have just been announced, supporting five projects across 4 departments within the college as they address topics such as food sovereignty, anti-displacement, affordable housing, and health & wellbeing. This year’s awardees include: Defining the New Diaspora: Where Seattle’s Black Church Congregants Are Moving and Why Rachel…
Ken Tadashi Oshima is Professor in the Department of Architecture at the University of Washington, Seattle, where he teaches trans-national architectural history, theory and design. He has also been a visiting professor at the Harvard Graduate School of Design and UCLA, and has taught at Columbia University and the University of British Columbia. He earned an AB degree, magna cum laude, in East Asian studies and visual and environmental studies from Harvard College, an MArch degree from University of California,…