Van Den Wymelenberg, Kevin; Inanici, Mehlika. (2016). Evaluating a New Suite of Luminance-Based Design Metrics for Predicting Human Visual Comfort in Offices with Daylight. Leukos, 12(3), 113 – 138.
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Abstract
A new suite of visual comfort metrics is proposed and evaluated for their ability to explain the variability in subjective human responses in a mock private office environment with daylight. Participants (n = 48) rated visual comfort and preference factors, including 1488 discreet appraisals, and these subjective results were correlated against more than 2000 unique luminance-based metrics that were captured using high dynamic range photography techniques. Importantly, luminance-based metrics were more capable than illuminance-based metrics for fitting the range of human subjective responses to data from visual preference questionnaire items. No metrics based upon the entire scene ranked in the top 20 squared correlation coefficients, nor did any based upon illuminance or irradiance data, nor did any of the studied glare indices, luminance ratios, or contrast ratios. The standard deviation of window luminance was the metric that best fit human subjective responses to visual preference on seven of 12 questionnaire items (with r(2) = 0.43). Luminance metrics calculated using the horizontal 40. band (a scene-independent mask) and the window area (a scene-dependent mask) represented the majority of the top 20 squared correlation coefficients for almost all subjective visual preference questionnaire items. The strongest multiple regression model was for the semantic differential rating (too dim-too bright) of the window wall (R-adj(2) = 0.49) and was built upon three variables; standard deviation of window luminance, the 50th percentile luminance value from the lower view window, and mean luminance of the 40. horizontal band.
Keywords
Discomfort Glare; Controls; Daylighting; Visual Perception
Cheng, Renée. (2020). Opinion: Change Agency, Value Change. Architect, 109(9), 20 – 20.
Keywords
Attitude Change (psychology); Air Flow; Hand Washing
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.
Keywords
Impact
Ilyas, Salman; Emery, Ashley; Heerwagen, Judith; Heerwagen, Dean. (2012). Occupant Perceptions of an Indoor Thermal Environment in a Naturally Ventilated Building. Ashrae Transactions, 118(2), 114 – 121.
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Abstract
A strong emphasis is currently being placed on the use of natural ventilation as a means for providing a safe and healthful indoor environment as part of green building programs. There has been an increasing interest in developing natural ventilation design strategies that can furnish adequate fresh air to the building interior and simultaneously control the indoor air quality effectively, while providing significant energy savings. In naturally ventilated spaces, furnishing a suitable air exchange rate between the building exterior and interior can create a thermally comfortable and healthy indoor environment. However, the air exchange must occur such that the indoor air quality of the building is not compromised and thermally comfortable conditions for the occupants can be maintained. Architecture Hall is a recently renovated, naturally ventilated building located on the University of Washington campus in Seattle. The natural ventilation in this building was evaluated using a variety of experimental techniques, which included measurement of carbon dioxide (CO2) levels, air exchange rates and air velocities. High CO2 concentrations are a good indicator of inadequate ventilation rates and poor air movement in a space. Hence, a number of standards and certification programs specify the use of outdoor air monitoring based on CO2 concentrations in an occupied space. Occupant surveys, based on a U.S. EPA study, were also administered to understand and analyse occupant perceptions about the indoor thermal environment and to identify the prevalence of any building related illness symptoms. The discussion in this paper will focus on the findings of the occupant surveys and how they relate to the measured CO2 levels, air exchange rates and air velocities in the naturally ventilated spaces. The natural ventilation function in Architecture Hall is largely climate driven. For the period of November through March particularly, outside temperatures are quite low and windows are seldom opened by the occupants, in spite of a large number of occupants being dissatisfied with the indoor environmental quality. Consequently, CO2 concentrations consistently exceed acceptable levels and very little air movement is recorded. [ABSTRACT FROM AUTHOR]; Copyright of ASHRAE Transactions is the property of ASHRAE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Keywords
Thermal Comfort; Natural Ventilation; Energy Consumption Of Buildings; Indoor Air Quality; Heat Exchangers; Carbon Dioxide
Ochsner, Jeffrey Karl. (2017). The Past and Future of Pioneer Square Historic Character and Infill Construction in Seattle’s First Historic District. Change Over Time-an International Journal Of Conservation And The Built Environment, 7(2), 320 – 343.
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Abstract
Seattle designated the Pioneer Square Preservation District, the city's first historic district, nearly fifty years ago. Over the past half century, the district has seen significant infrastructure improvements, a changing resident population, and an evolving mix of businesses. Although many buildings underwent interior alteration, the visible external character of the historic fabric has remained largely intact. The district's Preservation Board reviews a constant stream of small exterior restoration and rehabilitation projects, but it is the relatively few examples of new infill construction that have presented the most challenging questions as the board has had to balance the desire for new development and the activity it brings with the wish to protect historic character. Although the Pioneer Square District ordinance, the Secretary of Interior's Standards, and rules developed by the board all offer guidance, every new design presents questions about the exact meaning of terms like compatible and differentiated. Today, with Seattle's booming economy and growing population, more new projects of a larger scale are being proposed. As a result, the Pioneer Square Preservation District presents a singular case study demonstrating continuing efforts to protect the historic built environment while still allowing appropriate growth.
Ianchenko, Alex; Simonen, Kathrina; Barnes, Clayton. (2020). Residential Building Lifespan and Community Turnover. Journal Of Architectural Engineering, 26(3).
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Abstract
Environmental impact studies within the built environment rely on predicting building lifespan to describe the period of occupation and operation. Most life cycle assessments (LCAs) are based on arbitrary lifespan values, omitting the uncertainties of assessing service life. This research models the lifespan of American residential housing stock as a probabilistic survival distribution based on available data from the American Housing Survey (AHS). The log-normal, gamma, and Weibull distributions were fit to demolition data from 1985 to 2009 and these three models were compared with one another using the Bayesian information criterion. Analysis revealed that the estimated average housing lifespan in the United States is 130 years given model assumptions, although a probabilistic approach to lifespan can yield higher accuracy on a case-by-case basis. Parameters for modeling housing lifespan as log-normal, gamma, and Weibull survival functions are published with the intent of further application in LCA. The application of probabilistic housing lifespan models to community-wide turnover and integration with existing simulations of natural disaster are proposed as potential ways to achieve community sustainability and resilience goals. (c) 2020 American Society of Civil Engineers.
Keywords
Energy-consumption; Service Life; Cycle; Demolition; Emissions; Design; Impact; Model; Housing Stock Lifetime; Residential Buildings; Housing Turnover; Life Cycle Assessment; Service Life Prediction
Ochsner, Jeffrey Karl; Rash, David A. (2012). The Emergence of Naramore, Bain, Brady & Johanson and the Search for Modern Architecture in Seattle, 1945-1950. Pacific Northwest Quarterly, 103(3), 123 – 141.
Zhu, Panyu; Gilbride, Michael; Yan, Da; Sun, Hongshan; Meek, Christopher. (2017). Lighting Energy Consumption in Ultra-Low Energy Buildings: Using a Simulation and Measurement Methodology to Model Occupant Behavior and Lighting Controls. Building Simulation, 10(6), 799 – 810.
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Abstract
As building owners, designers, and operators aim to achieve significant reductions in overall energy consumption, understanding and evaluating the probable impacts of occupant behavior becomes a critical component of a holistic energy conservation strategy. This becomes significantly more pronounced in ultra-efficient buildings, where system loads such as heating, cooling, lighting, and ventilation are reduced or eliminated through high-performance building design and where occupant behavior-driven impacts reflect a large portion of end-use energy. Further, variation in behavior patterns can substantially impact the persistence of any performance gains. This paper describes a methodology of building occupant behavior modeling using simulation methods developed by the Building Energy Research Center (BERC) at Tsinghua University using measured energy consumption data collected by the University of Washington Integrated Design Lab (UW IDL). The Bullitt Center, a six-story 4831 m(2) (52,000 ft(2)) net-positive-energy urban office building in Seattle, WA, USA, is one of the most energy-efficient buildings in the world (2013 WAN Sustainable Building of the Year Winner). Its measured energy consumption in 2015 was approximately 34.8 kWh/(m(2)a (TM) yr) (11 kBtu/(ft(2)a (TM) yr)). Occupant behavior exerts an out-sized influence on the energy performance of the building. Nearly 33% of the end-use energy consumption at the Bullitt Center consists of unregulated miscellaneous electrical loads (plug-loads), which are directly attributable to occupant behavior and equipment procurement choices. Approximately 16% of end-use energy is attributable to electric lighting which is also largely determined by occupant behavior. Key to the building's energy efficiency is employment of lighting controls and daylighting strategies to minimize the lighting load. This paper uses measured energy use in a 330 m(2) (3550 ft(2)) open office space in this building to inform occupant profiles that are then modified to create four scenarios to model the impact of behavior on lighting use. By using measured energy consumption and an energy model to simulate the energy performance of this space, this paper evaluates the potential energy savings based on different occupant behavior. This paper describes occupant behavior simulation methods and evaluates them using a robust dataset of 15 minute interval sub-metered energy consumption data. Lighting control strategies are compared via simulation results, in order to achieve the best match between occupant schedules, controls, and energy savings. Using these findings, we propose a simulation methodology that incorporates measured energy use data to generate occupant schedules and control schemes with the ultimate aim of using simulation results to evaluate energy saving measures that target occupant behavior.
Keywords
Control-systems; Patterns; Offices; Lighting Control; Ultra-low Energy Building; Occupant Behavior; Building Simulation; Energy Consumption