University of Southern California Dissertations and Theses

Measuring daylight: analysis of daylighting at LACMA's Resnick Pavilion

(USC Thesis Other)

Measuring daylight: analysis of daylighting at LACMA's Resnick Pavilion

PDF

Download a page range

Download transcript

Copy asset link

Request this asset

Transcript (if available)

Content 1 Measuring Daylight: Analysis of Daylighting at LACMA’s Resnick Pavilion by Joyce Hahn Presented to the FACULTY OF THE SCHOOL OF ARCHITECTURE UNIVERSITY OF SOUTHERN CALIFORNIA In partial fulfillment of the Requirements of degree MASTER OF BUILDING SCIENCE AUGUST 2016 2 COMMITTEE Marc Schiler Professor of Architecture USC School of Architecture marcs@usc.edu (213) 740-4591 Karen Kensek Assistant Professor USC School of Architecture kensek@usc.edu (213)740-2081 Kyle Konis Assistant Professor USC School of Architecture kknois@usc.edu 3 ABSTRACT Museums are a ubiquitous building type; they are located in every major city, hold cultural significance, and house public activities. Providing daylighting in museums poses a series of conflicting objectives. While natural lighting conditions are desired for energy efficiency, improving occupant experience, and ideal viewing conditions, the control or omission of sunlight is also desired for the artwork. In addition to the changing seasonal sunlight, many museum galleries house rotating exhibits with a variety of contents and layouts that create the need for adaptable daylighting controls. The Resnick Pavilion at the Los Angeles County Museum of Art (LACMA) was analyzed as a case study for the research of daylighting in this context, which can be applied to future cases. Illuminance data was gathered on-site at the Resnick Pavilion at LACMA. A digital Rhino model of the space was calibrated to the “as-is” site conditions and run through DIVA daylight analysis. The comparative results between the simulations and the site data showed a similarity in daylight performance patterns. A script tool was created through Grasshopper to simulate multiple variables including shading configurations and times of year. The results of these simulations informed a shading controls program for a proof-of-concept case to maximize the use of daylight to meet the exhibit’s illuminance requirements. Additionally, the steps of the research process form the basis of a prototype protocol that can be applied to an existing building to create a solar controls program that adapts to changing daylighting conditions. HYPOTHESIS For the application of daylighting remediation in existing buildings, the results of a digital model calibrated through real site conditions can direct a strategy of daylighting controls responsive to dynamic program needs. 4 TABLE OF CONTENTS Committee 2 Abstract & Hypothesis 3 List of Figures 7 Chapter 1: An Introduction to Daylighting and Museums 10 1.1 Overview 10 1.2 Daylighting Design 10 1.2.1 Benefits of Daylighting 11 1.2.2 Daylighting Design in Architecture 11 1.2.3 Daylighting Design in Museums 12 1.3 Examples of Daylighting in Museums 12 1.4 Concepts and Terms in Daylighting Analysis 16 1.4.1 Units of Light 16 1.4.2 Additional Terms 17 1.4.3 Measuring Illuminance 17 1.4.4 Solar Patterns 17 1.5 Chapter Summary 19 1.6 Structure of Following Chapters 19 Chapter 2: Background and Literature Review 20 2.1 Chapter Introduction 21 2.2 Lighting for Museums 21 2.2.1 Introduction 21 2.2.2 Light and Art Display 21 2.3 Case Studies 23 2.4 Literature Review 28 2.5 Summary 29 Chapter 3: Methodology 30 3.1 Chapter Introduction 30 3.2 Plan, Phases and Modes of Data Collection 30 3.2.1 Important Steps 30 3.2.2 Reasons for Selected Tools 32 3.3 Scope of Work 34 3.3.1 Research Goals 34 3.3.2 Deliverables 34 3.3.3 Hypothesis Statement 34 3.4 Domain of Study 34 3.5 Study Boundaries 35 3.5.1 Domain of Study: Site 35 3.5.2 Description: Site Limitations 35 3.6 Summary 36 Chapter 4: Site Research 37 4.1 Introduction 37 4.1.1 Illuminance level data collection 37 5 4.1.2 Shading Description 38 4.2 August Daylight Data 38 4.3 September Data 38 4.3.1 Conditions 38 4.3.2 Illumination Levels 40 4.4 October Data 41 4.4.1 Conditions 41 4.4.2 Illuminations Levels 43 4.5 November Data 45 4.5.1 Conditions 45 4.5.2 Illumination Levels 46 4.6 December Data 47 4.6.1 Conditions 47 4.6.2 Illumination Levels 48 4.7 Site Data Analysis 49 4.7.1 Data Analysis and Comparisons 49 4.7.2 Site Research Summary 51 4.7.3 Summary 52 Chapter 5: Digital Model Research: Calibration, Simulation, and Protocol Development 53 5.1 Introduction 53 5.2 Calibration 53 5.2.1 Shading Characteristics 53 5.2.2 Calibration Model 55 5.2.3 Digital Simulation and On-Site Illuminance Level Comparison for October 29 55 5.2.4 Digital Simulation and On-Site Illuminance Level Comparison for December 21 57 5.3 Calibration Data Analysis 60 5.3.1 Simulations Results in DIVA/Rhino Format 61 5.4 Simulations 63 5.4.1 Summer Solstice Simulation with Vertical Facades Blacked Out & Skylights Open 64 5.4.3 Fall Equinox Simulation with Vertical Facades Blacked Out & Skylights Open 64 5.4.4 Winter Solstice Simulation with Vertical Facades Blacked Out & Skylights Open 65 5.4.5 Fall Equinox Simulation with Vertical Facades Open & Skylights Blacked Out 66 5.4.6 Winter Solstice Simulation with Vertical Facades Open & Skylights Blacked Out 67 5.4.7 Simulaton Analysis 68 5.5 Shading Controls Script with Grasshopper through DIVA/Rhino 68 5.5.1 Grasshopper Script for the Resnick Pavilion 69 5.5.2 Proof of Concept Example 70 5.5.2.1 Proof of Concept Results 71 5.5.3 Proof of Concept Analysis 76 5.6 Digital Model Research Summary 78 6 Chapter 6: Conclusions 79 6.1 Research Products 79 6.2 Grasshopper Tool 79 6.3 Process Research Conclusions 79 6.4 Future Work 80 6.4.1 Reverse Process 80 6.4.2 Additional Mode of Data Collection: Physical Model 80 6.4.3 Improved Grasshopper Script Tool 81 6.4.4 Further Research Into Protocol Development 81 6.5 Conclusion Summary 81 Bibliography 83 References 86 7 LIST OF FIGURES Figure 1. External light factors for the human circadian process. Accessed November 13, 2015. http://www.avstim.com/Circadian_Rhythms.html. 11 Figure 2. Atrium in the Boston Museum of Fine Arts (Dunwell, 2015) 13 Figure 3. Exterior of the West Wing, Boston Museum of Fine Arts by I.M. Pei (Boston Museum of Fine Arts, 1981). 13 Figure 4. Main atrium with plentiful natural light in the Musée D'Orsay in Paris. Accessed January 10, 2015. http://hotel-paris.es/wp- content/uploads/2012/04/museo_Dorsay1.jpg 14 Figure 5. Interior of Enclosed Gallery in the Musée D'Orsay, Paris. Accessed January 10, 2015. http://www.thearttribune.com/Our-Impressions-of-the-New.html 14 Figure 6. Naturally lit gallery at Kimbell Art Museum. Accessed July 28, 2015. http://www.archpaper.com/news/articles.asp?id=6986# 15 Figure 7. Diffuse lighting conditions of the Walter De Maria gallery in Chichu Art Museum by Tadao Ando (Furuyama, 2006) 15 Figure 8. Direct light and shadows of the Walter De Maria gallery in Chichu Art Museum by Tadao Ando. (Pollock, 2005) 16 Figure 9 Elliptical path in which the earth travels around the sun on a constant tilt. (Mazria, 1979) 18 Figure 10. Seasons created by the earth’s tilt. (Mazria, 1979) 18 Figure 11. IES Table of Art Material by Light Sensitivity Categories. (IES Lighting Handbook, 10th Edition) 21 Figure 12. V&A Light Guideilines for Objects on Display (V&A Conservation Dept, 2010) 22 Figure 13. Portrait de Madame Léon Clapisson by Auguste Renoir, reconstruction of original colors vs. faded original. Accessed October 15, 2015 http://www.telegraph.co.uk/culture/art/10637291/Iconic-paintings-true-colours- revealed.html 22 Figure 14. Naturally lit interior of the Menil Collection addition. (http://www.designboom.com/architecture/renzo-piano-completes-expansion-of- kimbell-art-museum-11-14-2013) 23 Figure 15. Diagram of light directed through ceiling baffles at the Menil Collection in Fort Worth, TX. Accessed November 8, 2015. <http://archpaper.com/news/articles.asp?id=7318#.Vvt72XDsc1Y> 23 Figure 16. Passive daylight strategy in the High Museum of Art. Accessed April 2016 < http://archinect.com/features/article/31565/renzo-piano> 24 Figure 17. Skylights in parametric facade distribute diffuse daylight in open gallery (Damonte, 2015). 25 Figure 18. Open and closed monitors of skylights in the Broad Museum by Diller Schofidio and Renfro. (Cochran, 2015) 25 Figure 19. Sawtooth roof with angled fins at Resnick Pavilion. Accessed July 2015. http://inhabitat.com/los-angeles-boasts-worlds-largest-naturally-lit-museum- space/, http://blog.archpaper.com/2010/06/first-look-inside-lacmas-resnick. 26 Figure 20. Interior of Resnick Pavilion at LACMA, Accessed April 2015. http://inhabitat.com/los-angeles-boasts-worlds-largest-naturally-lit-museum- space/. 26 Figure 21. Sawtooth Strategy for Indirect Ambient Daylighting. (by Ove Arup provided by LACMA in 2015) 27 Figure 22. Materials of Sawtooth Roof System. (by Ove Arup provided by LACMA 8 in 2015) 27 Figure 23. Exterior of Winterthur Mueseum of Art and Interior of Beacon Museum. Rice and Lipka Architects, Accessed August 12 2015. http://ricelipka.com/work_detail.php?id=3. 27 Figure 24. Scope of data collection on exhibition plans throughout thesis duration. 30 Figure 25. Grid of calculation points from overlapping exhibit plans. 31 Figure 26. Light meter at 2.5' height. 31 Figure 27. Methodology 32 Figure 28. Glazing in the Resnick Pavilion. 35 Figure 29 Blackout shades in the Resnick Pavilion. 35 Figure 30 Shades in the Resnick Pavilion. 36 Figure 31. Grid point locations through data collection area, numbered by row and column. 38 Figure 32. Resnick Pavilion skylights. In clockwise order from top left: Exterior of skylights with angled shading panels, Skylight glazing without shading, Skylight with blackout shades, and Skylight with translucent shading. 38 Figure 33. Panoramic View of Gehry Exhibit in North Wing, facing the North Façade. 39 Figure 34. Shading Conditions for September 2015 at the Resnick Pavilion 40 Figure 35. Daylight Illumination Levels on September 24 for 9am, 12pm, and 3pm at Resnick Pavilion’s North Wing. 41 Figure 36. Panoramic view of the South Wing's interior and view of south entrance (looking in the southwest direction). 42 Figure 37. Shading conditions for October 2015 at the Resnick Pavilion 42 Figure 38. Image of South Facade Entrance. The sun filters in through a low angle and creates higher contrast light levels. 43 Figure 39. Daylight illumination levels for October 2015 on 9am, 12pm, and 3pm at the Resnick Pavilion’s North Wing. 44 Figure 40. Daylight illumination levels for October 2015 on 9am, 12pm, and 3pm at the Resnick Pavilion’s South Wing. 45 Figure 41.Daylight Illumination Levels for November 2015 on 9am, 12pm, and 3pm at the Resnick Pavilion’s North Wing. 46 Figure 42 .Daylight Illumination Levels for November 2015 on 9am, 12pm, and 3pm at Resnick Pavilion’s South Wing. 47 Figure 43. Daylight Illumination Levels for December 2015 on 9am, 12pm, and 3pm at the Resnick Pavilion’s North Wing. 48 Figure 44. Daylight Illumination Levels for December 2015 on 9am, 12pm, and 3pm at the Resnick Pavilion’s South Wing 49 Figure 45. Illustration on How to Read Monthly Comparison Charts 50 Figure 46. Monthly Light Level Comparison of Site Data 51 Figure 47. Excerpt from document provided by LACMA with Assumed 3% transmittance for shading materials at the Resnick Pavilion. 53 Figure 48. Manufacturer’s description of interior shading used for skylights in the Resnick Pavilion. 54 Figure 49. Specific model of shading used for Resnick Pavilion's skylights, showing 12% light transmittance. 54 Figure 50. Manufacturer’s description of interior shading used for skylights in the Resnick Pavilion. 54 Figure 51. Specific model of shading used for the Resnick Pavilion's North facade shading, showing 10% natural light transmittance 54 9 Figure 52. Specific model of shading used for the Resnick Pavilion's South facade shading, showing 18% natural light transmittance. 55 Figure 53. Table of Material Characteristics defined in Digital Model simulated through DIVA/Rhino 55 Figure 54. Comparison of Daylight Levels taken at the North Wing from On-Site and from DIVA/Rhino Model, October 2015 at 12pm. 56 Figure 55. Comparison of Daylight Levels taken at the South Wing from On-Site and from DIVA/Rhino Model, October 2015 at 12pm. 57 Figure 56. Comparison of Daylight Levels taken at the North Wing from On-Site and from DIVA/Rhino Model, December 2015 at 12pm. 58 Figure 57. Comparison of Daylight Levels taken at the South Wing from On-Site and from DIVA/Rhino Model, December 2015 at 12pm. 59 Figure 58. Comparison Graph Set: Site Light Levels vs. Digital Model Light Values 60 Figure 59. Screenshot of Rhino Model with DIVA analysis: Nodes with colored grid sections at 2.5' horizontal plane. 62 Figure 60. Calibrated model results through DIVA/Rhino for October 29 at 12pm. 62 Figure 61. Calibrated model results through DIVA/Rhino for December 21 at 12pm. 63 Figure 62. DIVA/Rhino result for June 21, 12pm: only skylights open 64 Figure 63. DIVA/Rhino result for September 21, 12pm: only skylights open 64 Figure 64. DIVA/Rhino result for December 21, 12pm: only skylights open 65 Figure 65. Rhino model of Resnick Pavilion’s overhang on South entrance. 65 Figure 66. DIVA/Rhino result for June 21, 12pm: only vertical facades open. 66 Figure 67. DIVA/Rhino result for September 21, 12pm: only vertical facades open. 66 Figure 68. DIVA/Rhino result for December, 12pm: only vertical facades open. 67 Figure 69. Diagram of input options for simulations through DIVA/Rhino. 68 Figure 70. Grasshopper script with labeled components. 69 Figure 71. Material component portion of Grasshopper script. 70 Figure 72. DIVA daylight component and illuminance output components in grasshopper script. 70 Figure 73. Screenshot illustrating DIVA analysis settings 71 Figure 74. Illumination results for shading configurations A-C, for June 21 at 12pm 73 Figure 75. Illustration: Setting custom shading configurations within Grasshopper script. 74 Figure 76. Illumination results for shading configurations D & E, for June 21 and September 21 at 12pm 75 Figure 77. Illumination results for shading configurations G & A, for December 21 at 12pm 76 Figure 78. Recommended shading program for the Resnick Pavilion 77 Figure 79. Diagram of Protocol 80 Figure 80. Diagram of equipment testing process. 81 10 Chapter 1: An Introduction to Daylighting and Museums Chapter 1 introduces the issue of daylighting within museum applications. It covers the benefits of daylight, the application of daylighting in architecture and museum buildings, and concepts in daylighting design. 1.1 Overview The study of museum spaces is significant because they fulfill important cultural and symbolic roles and are ubiquitous across many cities throughout the world. In applicable spaces, there is potential to meet the challenge of maximizing solar daylighting while providing a high-quality indoor environment for the valuable human activities that take place within. This presents a challenge when considering the lighting requirements of the artwork in conjunction with daylighting for occupant conditions and energy savings. The Los Angeles County Museum of Art (LACMA) was used as a case study to research daylighting in a museum context. Specifically, the Resnick Pavilion by Renzo Piano holds interesting potential for daylighting research because of its large amount of glazing, including vertical glass facades and skylights and its rotating art program. Studies were done in real space and through the software Rhino/DIVA. 1.2 Daylighting Design Daylighting design is implemented in architecture for benefitting health, increasing energy efficiency, and enhancing occupant experience. Because artwork has its specific set of needs, daylighting for museum buildings have conflicting issues with architectural daylighting. 1.2.1 Benefits of Daylight Three benefits of daylight are energy reduction, health benefits, and occupant experience. Energy Reduction: Buildings that utilize natural light decrease their energy consumption by reducing their dependence on electricity for lighting. In 2014, the United States used 412 billion kWh (kilowatt hours) of electricity for lighting (USEIA, 2014). In the commercial building sector, 19% of its yearly electricity consumption was used for lighting (USEIA, 2014). Lowering the use of electric light sources decreases energy consumption and CO 2 emissions, which decreases fossil fuel dependency and ozone layer depletion. Since electric power demand affects the cost of energy and often occurs when sunlight levels are high during the day, economic impacts can be also be reduced by incorporating daylighting strategies that meet this demand. This helps lower the cost of energy rates during peak usage times. Health Benefits: Sunlight plays a crucial and beneficial role in human physiological systems. The human circadian cycle is regulated by light throughout the day. The exposure to high intensities of light is required for the human body to secrete important hormones such as serotonin, which regulates alertness (Boubekri, 2014). When high levels of light pass through the eye, the visual cortex of the brain receives impulses that that regulate importation hormonal functions as well as emotions. With low light levels, the body synthesizes melatonin, which is part of the normal relaxing and sleeping phase in the 24-hour light-to-dark cycle (Boyce, 2003). Circadian rhythms are triggered by light levels to the eye and orchestrate many chemical reactions and processes of the human metabolism (Figure 1) This is responsible for a 11 myriad of physiological processes such as “energy and fluid balance, growth and maturation, circulation and breathing, emotional balance, reproduction, heat regulation, and activity and sleep patterns” (Boubekri, 2014). Figure 1. External light factors for the human circadian process. Accessed November 13, 2015. http://www.avstim.com/Circadian_Rhythms.html. Therefore, when melatonin or serotonin is suppressed due to insufficient light in buildings or overexposure to high-intensity artificial light, it causes disruptions in the circadian cycle and to one’s health. Thus solar health benefits include the body’s natural connection to sunlight, which controls the body’s circadian system, which in turn stabilizes mood and enables crucial chemical reactions (Boubreki, 2008). Occupant Experience: Because humans respond dynamically to their environment, the application of daylighting strategies can enhance the experience of a building. When users have exposure to changing sunlight throughout the day or visit the same place during different times of year, their perception of the space becomes richer through the changing light conditions. With access to sunlight, the building occupants’ connection with the natural environment, sensory awareness, and quality of life increases (Boubekri, 2014). The variation in illumination provides the occupant with an awareness of the outside environment. Through the changing patterns of light within the interior of a building, an occupant can sense “whether it is sunny outdoors or overcast and raining, whether it is windy with a rapidly changing sky or is settled and calm” (Tregenza and Wilson, 2011). This adds to the dynamic experience of a building. 1.2.2 Daylighting Design in Architecture Since light is “the medium that reveals space, form, texture, and colour to our eyes” (Baker & Steemers, 2002), architects consider the integration of light a crucial component in building design. It is through light that a sense of depth, texture, and the form of a space are established, and sunlight emphasizes architectural shapes (Lam 1986). Thus daylighting design plays a crucial role in defining the architectural narrative of a building. Exposure to natural light also enhances the experience of an occupant because a bodily sense of time shift and a connection to nature is evoked. The application of daylighting strategies offers energy saving benefits, increasing efficiency by providing visibility for activities and decreasing electricity 12 consumption. Architecturally and from an energy-efficiency point of view, certain daylighting goals are desired: illuminance, coverage, diffuse daylight, and views (Leslie, RP, 2012). While museums overlap in these goals, they have conflicting requirements to control or limit solar exposure as it presents conservation issues for their artwork. 1.2.3 Daylighting Design for Museums Museums represent a complex building type for incorporating daylighting design, due to the conflicting interests between architects who aim to create an impactful and light-filled environment, visitors who prefer high illuminance levels for viewing, and conservationists who desire minimum light exposure for artwork preservation (Fontoynont, 1999). Museum buildings often serve as a cultural symbol for their city, and are commonly designed with the goals of becoming an architectural icon. As such, the desire for expressive architecture is created so that the museum can be represented as the art attraction itself. Sunlight emphasizes architectural forms, and this often takes precedent over optimum display conditions, conservation, or operating costs (Lam, 1986). On the other extreme, the use of natural light in galleries is sometimes completely eliminated as a response to conservation concerns (Lam, 1986). This is important because the situation in which an artwork is viewed largely influences how it is perceived and interpreted. In the cases where daylight is eliminated, the opportunity is missed for visitors to benefit from naturally lit viewing conditions, and a dynamic experience of the artwork and the space. Additionally, viewing conditions in natural light are optimal, providing the best visual conditions including color rendering for artworks (RPI, 2004). Natural light provides illumination across the entire color spectrum. These conflicting interests present contradictions in lighting needs, with interesting possible solutions. Because museums are a ubiquitous building type throughout the world and represent architectural and cultural significance, their use of daylighting and subsequent controls are important to research. When a gallery program is comprised of rotating exhibitions, dynamic sunlight controls are necessary. 1.3 Examples of Daylighting in Museums Daylighting in museums is addressed through different strategies such as separating daylit circulation spaces with artwork-housing gallery spaces or integrating sunlight into gallery architecture. One strategy architects used to incorporate daylighting design into museums was to separate gallery and circulation spaces. Beautiful light-filled atrium spaces served as grand entry foyers or circulation areas that were independent from gallery spaces that housed the majority of the artwork. In the West Wing of the Boston Museum of Fine Arts constructed in 1981, I.M. Pei designed the elegantly barrel-vaulted main atrium with a glass roof that brings a large amount of skylight into the multi-storied main walk-through space (Figure 2) (Huxtable, 1981). The atrium space could not house the artwork because the illumination levels were above the maximum allowed for most artworks. Therefore separate, controlled galleries were designated in the architecture in order to house the majority of the collections on display. This abundantly day-lit portion was stylistically and physically separate from the gallery 13 sections (Figure 3). Figure 2. Atrium in the Boston Museum of Fine Arts (Dunwell, 2015) Figure 3. Exterior of the West Wing, Boston Museum of Fine Arts by I.M. Pei (Boston Museum of Fine Arts, 1981). The Musée D’Orsay by Jean-Michel Wilmotte, a historic Beaux-Arts train station in France renovated as an art museum in 1986, placed its art collection in closed-off boxes within a large atrium. Although its large vaulted glass ceiling brought plenty of natural light to eliminate the need for electricity use for the main promenade (Figure 4), the large surface area of glass did not provide enough protection from incredibly high exposure levels that are detrimental to the majority of the art collection, which included Impressionist paintings. The solution was to create a complex layout of heavy lower galleries. These mostly cut off the visitor from the brightly lit atrium space into a closed off series of darker, light-controlled boxes. A critic described the 14 galleries as bunker-like and difficult to navigate (Goldberger, 1987) (Figure 5). However in their 2011 renovation, transition areas along with sensors and dimmers to control electric lighting were implemented (Lord and Piacente, 2014). Figure 4. Main atrium with plentiful natural light in the Musée D'Orsay in Paris. Accessed January 10, 2015. http://hotel-paris.es/wp-content/uploads/2012/04/museo_Dorsay1.jpg Figure 5. Interior of Enclosed Gallery in the Musée D'Orsay, Paris. Accessed January 10, 2015. http://www.thearttribune.com/Our-Impressions-of-the-New.html In the Kimbell Art Museum in Fort Worth, TX, Louis Kahn implemented a daylighting strategy into the galleries that served as a functional light source and as an element of highlighting architectural form. He designed a reflector system that spread diffuse light throughout its gallery. Daylight was brought into the long, concrete barrel-vaulted gallery through a central ceiling channel slit along the center of the ceiling. The sunlight was bounced up by pierced-aluminum reflectors that reflected the light across the underside of the barrel-vaulted ceiling surface (Figure 6), eliminating direct glare and providing an ambient distribution of natural light (Igor, 2011). Although under most sky conditions, a large portion of the illumination that reached the walled art display zone was provided by tungsten lighting (Weintraub and Anson, 1990), the natural light penetrating into the gallery created a richer relationship between the gallery’s interior and exterior. 15 Figure 6. Naturally lit gallery at Kimbell Art Museum. Accessed July 28, 2015. http://www.archpaper.com/news/articles.asp?id=6986# The Chichu Art Museum that was built in 2004 in Naoshima, Japan, took a similar approach with incorporating daylighting into its gallery spaces. But in one particular gallery, it brought the approach to another level by designing its natural light sources in conjunction with the display contents to create a site-specific expericnce. The architect, Tadao Ando, and the artist, Walter de Maria, collaborated to create a permanent art installation called Time/Timeless/No Time (Pollock, 2005). It comprised of two sets of stairs with walls that showed gilded vertical forms and a central platform that held a large black metal sphere (Furuyama, 2006). A rectangular skylight in the curved ceiling provided direct sunlight while the open edges between the ceiling and the walls provided peripheral illumination that reflected down and off the vertical walls (Figure 7) The combination of these two sources created dynamic patterns of light patches and shadows that changed with the time of day and the weather (Figure 8). The shadow lines, reflections, and light beams could also be seen from different perspectives throughout the rooms, adding to the powerful sense of changing time and themes of universality of the artwork. Figure 7. Diffuse lighting conditions of the Walter De Maria gallery in Chichu Art Museum by Tadao Ando 16 (Furuyama, 2006) Figure 8. Direct light and shadows of the Walter De Maria gallery in Chichu Art Museum by Tadao Ando. (Pollock, 2005) While Louis Kahn’s strategy applied to the gallery space so that different art works could be displayed, Tadao Ando’s design for the Chichu Art Museum was only possible because it was a permanent exhibition that was created to be permanently located at the site. However, both museum spaces created a powerful sense of connection to the natural environment and used daylight as a natural source of lighting. 1.4 Concepts and Terms in Daylighting Analysis This section covers different units in which to measure light, the reasons behind the selection of illuminance, and additional terms used in daylighting analysis including important days affected by the rotation of the earth around the sun. 1.4.1 Units of Light Light, defined by human vision, is the electromagnetic radiation from the sun that is sensed by the eye (Tregenza and Wilson, 2011). Therefore, light is characterized by its own special set of units. Luminous flux refers to the flow of light, and is described as the rate at which luminous energy is flowing out a source, such as a lamp or window. It is the total output of a source, and the unit is defined in lumens (Kittler, 2011). Luminous intensity is measured in candelas, and is described as the quantity of light flowing in a specific direction from a lamp, or from a patch of sky. It is calculated as lumens per steradian, or lm/sr (Kittler, 2011). Luminance is the measurable brightness of a surface or sky and is defined by the unit of candelas, which equals lumens per steradian per square meter, or cd/m², where luminance is the amount of luminous intensity per area, illuminance is the amount of luminous flux per area. In other words, illuminance measures the amount of light arriving on a surface, and luminance measures the amount of light leaving a surface (Tregenza and Wilson, 2011). Illuminance is the unit used to quantify the light on a surface, and takes the amount of light divided by the area it falls upon. Thus, illuminance is the luminous flux (measured in lumens) falling on a surface, and is a way to characterize indoor light (Fontoynont, 1999). It is defined in lux (lm/ m²) in the metric system, and in 17 footcandles (lm/ ft²) in the English system (IES, 2015). Illuminance is used for most museum lighting standards. 1.4.2 Additional Terms A sawtooth roof is a type of roof with repetitive rows of pitched ridges with glazing that face away from the equator in lighting applications to receive indirect natural light (Asdrubali, 2003). Proof of concept is a term that describes a prototype that is used to determine feasibility; its purpose is to demonstrate principles through precise interpretations that have potential real applications (Carsten, 1989). They can be useful to illustrate an example of a theoretical concept in a practical application. Solar Transmittance is the amount of radiation from the sun that passes through a surface. Although there is an ultraviolet form of energy transmittance, the research deals with visible transmittance (Fontoynont, 1999). The shading used in the case study building at LACMA was characterized by various percentages of transmittance. Diffuse lighting describes the light that was reflected off a surface at many angles rather than arriving through just one angle (Tregenza and Wilson, 2011). This type of light creates an effect of indirect, more evenly distributed lighting effect. 1.4.3 Measuring Illuminance Illuminance is one of the “most frequently used units of light to specify lighting requirements” (Tregenza and Wilson, 2011), and is also the unit used by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) and the Illuminating Engineering Society (IES) for setting indoor lighting recommendations in buildings. Illuminance is commonly measured on the work plane, at 2.5 feet height horizontal plane (Gronzik and Kwok, 2011). Although museums employ a variety of surfaces, the standard 2.5’ height was used to be in conjunction with the ASHRAE standard and because it was applicable to the LACMA case study exhibit, which displayed the majority of the artwork on podiums at various horizontal surfaces. An illuminance meter was used for gathering light level data on-site. This instrument measures the light falling onto a surface with a sensor that is comprised of a white plastic domed disc covering a photocell. The white domed diffuser enabled the instrument to “respond correctly to incident light at different angles” to ensure cosine correction (Tregenza and Wilson, 2011). The light levels were measured at a 2.5 feet height plane. Since The Resnick Pavilion is located in the US and the standards for lighting used by the museum and described by IES were defined through footcandles, illuminance was measured in footcandles for this study. 1.4.4 Solar Patterns Daylighting design considers the direction and position of the sun as it changes through the seasons. Solar radiation passes through various lengths of the atmosphere depending on the time of day and the month of year (Mazria, 1979). This is due to the tilt and rotation of the earth. Since the earth travels around the sun at an ellipse, and rotates once a day on the axis, it is responsible for the variation in solar radiation angles and length of exposure (Figure 9). 18 Figure 9 Elliptical path in which the earth travels around the sun on a constant tilt. (Mazria, 1979) An equinox occurs during a day where the length of day and night is approximately equal. These occur twice annually when the sun crosses the equator, once in each direction. The spring equinox occurs around March 21 and the fall equinox occurs around September 21(Haran, 2013). A solstice is either the longest or the shortest day of the year, and they occur on days when the sun is farthest from the equator (relative to its hemisphere). The summer solstice occurs around June 21 and the winter solstice occurs around December 21 for the northern hemisphere, and vice versa for the southern hemisphere (Haran, 2013). Due to their significance as representative days for seasonal sunlight throughout the year (Figure 10), spring and fall Equinox as well as summer and winter solstice are important dates for daylighting research. Summer Solstice occurs on the day of the year that receives the most exposure to the sun at the highest angle in the sky. Winter Solstice occurs on the day where the day is shortest and receives the least amount of daylight at the lowest angle in the sky. Spring and Fall Equinox represent the middle ground between the two. Because Spring and Fall Equinox have equal lengths of the day, they are considered interchangeable in terms of representative days for daylighting research. Fall Equinox was used in the simulation research. Figure 10. Seasons created by the earth’s tilt. (Mazria, 1979) 19 1.5 Chapter Summary Daylighting in architecture provides health benefits, energy use reduction, and increased occupant experience. It also presents an issue for museum contexts because of the conflict between the desire to daylight and the need to control light levels. Architects have addressed this issue by separating daylighting spaces from gallery spaces or by integrating daylighting design into the galleries. For the study of daylighting, the Summer and Winter Solstice and the Spring and Fall Equinox are set as important dates to consider. 1.6 Structure of Following Chapters Chapter 2 summarizes previous research that has been done regarding daylight studies and points out the relevant information. Chapter 3 goes through the methodology of the LACMA daylight study and details each phase and mode of data collection. Chapter 4 describes the site data and analysis, and Chapter 5 describes the digital model data and analysis. The conclusions in Chapter 6 review the products of the research, and Chapter 7 describes future work. 20 Chapter 2: Background and Literature Review Chapter 2 discusses lighting issues for museums and previous examples of museums that incorporate daylighting for a changing exhibit space. The case study building is described, as well as previous research. 2.1 Chapter Introduction The lighting of museums has posed a complex challenge for many museum designers. This chapter details the conditions and requirements for gallery lighting, discusses case studies, and describes examples of past research. 2.2 Lighting for Museums Lighting in museums is characterized by its effect on the artwork. This section describes important issues regarding the nature of light and artwork and explains light level guidelines followed by museums. 2.2.1 Introduction Up until the 1930s, museum gallery design had evolved to take advantage of available daylight and create ideal conditions for viewing (Cannon-Brookes, 2000). The recognition that light exposure results in damage, the increasing demands for exhibition flexibility, and the development of more affordable electric lighting both contributed to the mounting application of electric lighting to illuminate museums. The development of standards for maximum illumination requirements created a different approach for museum lighting, where the main priority became to control the light exposure and use the most minimal amount of lighting possible or appropriate. 2.2.2 Light and Art Display Museums have a unique set of needs in their objectives for interior lighting; they are assigned with the tricky task of creating a lit atmosphere for viewing while controlling the illumination to protect from damage. Important issues are color rendering, damage caused by radiation, guidelines for light levels, and the relationship the architect and the curator. Color Rendering Accurate color rendering is one benefit of using natural light to display art. For the human eye to correctly register any color, light of that specific wavelength must be present in the light source. For example, a green artifact will appear gray when displayed with red light, just as white light (comprised of all colors) will show the green color because it can reflect the green component of the light. (McGlinchey, 1993). Since a continuous band of radiation through the visible light spectrum is emitted by the sun, that continuous range of wavelengths provides an “unbiased color registration for all colors” (McGlinchey, 1993). The Color Rendering Index (CRI) is a metric to represent how true the colors of an object appeared when illuminated by light or blackbody radiation, on a scale of 0-100, where daylight or an incandescent source at the given color temperature is considered to be a CRI of 100 (Schiler, 1997). Damage However the energy that causes chemical change in the artwork and the UV and visible radiation that comes from natural light raises concerns for conservationists. As radiant energy, light causes materials to deteriorate. Exposure to light causes fading in the form of photochemical damage. The light energy hitting an object is either absorbed or reflected, and the absorbed energy creates chemical changes in the material of the artifact, causing photochemical damage (De Graaf, 2014). For 21 museum lighting, the “safe” standards that an artifact’s material can be exposed to are described in terms of maximum illumination levels in footcandles (lumens/ft 2 ). Light Level Guidelines The current set of recommended light levels from the Illuminating Engineering Society (IES) categorizes art by material sensitivity to light (Figure 11). They are categorized by high light sensitivity, low light sensitivity, and no light sensitivity. Figure 11. IES Table of Art Material by Light Sensitivity Categories. (IES Lighting Handbook, 10th Edition) However, each museum also holds their own guidelines, and LACMA adopted the Victoria and Albert (V&A) Museum’s guidelines which categorized the art by material into light-sensitive, light-durable, and light stable. The light level categories were assigned ranges of illumination levels with light sensitive at 5-10fc, light durable at 5-25 fc, and light stable at >25 fc (V&A Conservation Department, 2010) (Figure 12). These values were used for setting maximum requirements during the simulation portion of the research. 22 Figure 12. V&A Light Guideilines for Objects on Display (V&A Conservation Dept, 2010) Architect vs. Curator Daylight provides variability and depth in the sensory perception of a space, compared with the controlled gallery box that presents a static condition. The variability delivers cues to the eyes of a viewer and enhances the museum experience, including overall intensity, distribution, and color temperature. When these cues are controlled and constant, the visitor overlooks them subconsciously, and perception of a museum and its artwork is altered. Another advantage attributed to natural light deals with the freedom of confinement from a sealed enclosure (Weintraub and Anson, 1990). But because photochemical exposure causes color fading (Figure 13) and damage to the material of the artwork (Weintraub and Anson, 1990), the desire for tightly- controlled spaces by the museum stems from the need to conserve their valuable artwork. Figure 13. Portrait de Madame Léon Clapisson by Auguste Renoir, reconstruction of original colors vs. faded original. Accessed October 15, 2015 http://www.telegraph.co.uk/culture/art/10637291/Iconic-paintings-true- colours-revealed.html Therefore, many museum designs create a brightly lit atrium or open entry space while displaying artwork in light-controlled gallery spaces such as the Musée D’Orsay by Jean-Michel Wilmotte. Three dimensional artwork, such as sculpture, is often durable and is also more clearly understood with some shadowing, often tolerating or benefitting from higher or more direct light levels. With this commonly proposed solution, one important factor to consider is the adaptation of the eye to varying intensities of light. Stepping from bright to dark spaces create a “cave” effect, where the eye goes from abrupt extremes and creates an uncomfortable feeling of enclosure. A successful design would include a transition with gradually decreasing levels of illumination to allow for the eye to fully adapt to the illumination change. (Weintraub and Anson, 1990). These objectives seem contradictory and the challenge of the museum designer is to synthesize of a solution that meets the requirements of good lighting and conservation (Weintraub and Anson, 1990). 23 2.3 Case Studies There are many techniques that museums use to incorporate architectural daylighting. They include toplighting through skylights, translucent surfaces, sawtooth ceilings, and coffers, and sidelighting through clerestories, louvered windows, slot windows, and translucent surfaces (Lam, 1986). Some museums utilize a combination of these techniques, or a façade surface made of components with these techniques. Several contemporary museum projects with Ove Arup collaborations integrated these daylighting strategies, most of which housed rotating exhibits. Menil Collection at the Kimbell Art Museum by Renzo Piano Building Workshop/Ove Arup For the addition of the Menil Collection building at the Kimbell Art Museum, the use of light in the original Louis Kahn gallery was considered. The architecture featured natural lighting filtered from repeated curved baffles and perforated screens in the ceiling(Figure 14). The geometry of the solar controls running along the length of the ceiling followed the original Louis Kahn design. This also created a way to bring in diffuse light and simultaneously control the sunlight coming into the space (Figure 15). These screens could be opened and closed to alter the amount of daylight in the gallery, and could be customized depending on the range of footcandles needed for the material on display. The open floor plan incorporated movable walls, which marked a significant precedent for contemporary art museums to respond to the need for flexible exhibits. (Seward, 2014). Figure 14. Naturally lit interior of the Menil Collection addition. (http://www.designboom.com/architecture/renzo- piano-completes-expansion-of-kimbell-art-museum-11-14-2013) Figure 15. Diagram of light directed through ceiling baffles at the Menil Collection in Fort Worth, TX. Accessed November 8, 2015. <http://archpaper.com/news/articles.asp?id=7318#.Vvt72XDsc1Y> 24 High Museum of Art Addition by Renzo Piano Building Workshop/Ove Arup A passive daylighting system was designed for an addition to the High Museum of Art in Atlanta, Georgia. The gallery used toplighting through a system on the roof of the pavilion. This system consists of three elements: white tubular units that diffuses and directs light into the space from the skylight, round angled skylights point facing north, and white aluminum scoops called velas that work to diffuse the light. The elements of this system repeat themselves throughout the entire roof span. These velas bring in diffused sunlight throughout the interior of the gallery without allowing direct sunlight (Boubreki, 2014). Figure 16. Passive daylight strategy in the High Museum of Art. Accessed April 2016 < http://archinect.com/features/article/31565/renzo-piano> The Broad Museum by Diller Scofidio + Renfro/ Ove Arup The Broad Museum in Los Angeles was built in 2015 to house rotating exhibits of work from the Broad Art Foundation’s collection. The building’s structural envelope was a perforated parametric façade made of glass-fiber reinforced concreted panels that encased a steel web (Amelar, 2015). These perforations that brought in sunlight were sized and angled differently based on the location and the lighting requirements of the interior space. For the upper gallery, daylight came in through the 318 skylight monitors that were tilted towards the north direction, only allowing indirect light (Amelar, 2015). The repetition of skylights created an even distribution of natural light throughout the gallery, providing low-contrast and glare-free viewing conditions for the large-scale art that was displayed (Figure 17). The structural façade freed the museum interior from load bearing walls and columns, which made possible a completely flexible exhibit layout. In addition to the changing times of year, the shifting of walls and the rotation of artwork added to the need of solar controls in the gallery. Because the museum was designed for a changing program of artwork and the art material came with different illumination requirements, the skylights were designed to open and close with shades that could block out the sunlight (Figure 18). 25 Figure 17. Skylights in parametric facade distribute diffuse daylight in open gallery (Damonte, 2015). Figure 18. Open and closed monitors of skylights in the Broad Museum by Diller Schofidio and Renfro. (Cochran, 2015) Resnick Pavilion at LACMA by Renzo Piano Building Workshop/Ove Arup For LACMA’s addition of the Resnick Pavilion onto its campus of gallery buildings, the architect Renzo Piano worked with Ove Arup to create a naturally lit space. The Resnick Pavilion has two sources of natural sunlight: vertical glazing on the south and north entrances, and angled fins on the roof (Figure 19). 26 Figure 19. Sawtooth roof with angled fins at Resnick Pavilion. Accessed July 2015. http://inhabitat.com/los- angeles-boasts-worlds-largest-naturally-lit-museum-space/, http://blog.archpaper.com/2010/06/first-look-inside- lacmas-resnick. Figure 20. Interior of Resnick Pavilion at LACMA, Accessed April 2015. http://inhabitat.com/los-angeles-boasts- worlds-largest-naturally-lit-museum-space/. The Resnick Pavilion was designed to light its interior with diffused natural sunlight (Figure 20). The gallery has an open floor plan, creating flexible spaces for changing exhibitions. The open gallery could house a combination of walls and other display elements such as podiums or casework. Similar to previous museum architecture designed by Renzo Piano Building Workshop/Ove Arup such as the Menil Collection, the building incorporates natural light through vertical glazing at the entrances and filtered through ceiling apertures. In this case, the roof consists of sawtooth skylights facing away from the equator, whose geometry allows light from the north to enter the building while excluding direct sunlight. The sawtooth skylights of this roofing system utilizes passive daylighting techniques and are angled at 45 degrees. This orientation prevents direct sunlight penetration from the south and diffuses sunlight penetration from the north (Figure 21). The sunlight bounces off fin surfaces into the gallery. The rows of fins repeat themselves, allowing an even distribution of light. 27 These fin panels have a matte finish, preventing specular reflections (LACMA, 2008). Motorized shading systems (Figure 22) were installed to control the amount of daylight through shading at various visual transmittance levels. Figure 21. Sawtooth Strategy for Indirect Ambient Daylighting. (by Ove Arup provided by LACMA in 2015) Figure 22. Materials of Sawtooth Roof System. (by Ove Arup provided by LACMA in 2015) Because of its ability to control sunlight for exhibition spaces, daylighting designs using sawtooth toplights are used in other museums as well (Figure 23). Annette Gigon and Robert Irwin utilized this design for the Extension of the Winterthur Museum of Art and the Beacon Museum (Kim, 2011). Figure 23. Exterior of Winterthur Mueseum of Art and Interior of Beacon Museum. Rice and Lipka Architects, Accessed August 12 2015. http://ricelipka.com/work_detail.php?id=3. 28 2.3 Literature Review Daylighting analysis uses multiple methods of data collection, which include on-site data collection, physical model testing, and digital software simulation. Previous projects show that using more than one method supports stronger research. Collecting data on-site is incredibly valuable because of the ability to illustrate the true nature of the building’s daylight performance. Post-occupancy research proves valuable in allowing for on-site measurements. However, site data is limited to time of collection as well as the specific conditions characterizing the site at that time. Daylighting analysis through software is a useful mode of data collection because of its ability to simulate many variables such as times of year and combinations of solar controls. Post-occupancy research of existing buildings are useful for understanding daylighting performance because it offers the ability to study real situations. A post- treatement analysis of glare remediation researched the thermal and visual glare issues caused by the shape and material of the Walt Disney Hall’s building façade (Suk, 2007). This post-occupancy project studied the remediation methods applied to the façade from on-site data such as temperature levels through data loggers and site photography, as well as computer simulations of light and reflected light. The on-site data was then taken through digital analysis software programs and compared against previous data sets. Suk’s methodology of collecting point-in-time data and software data was a helpful reference when creating methodology that involved on-site data and software analysis for the LACMA research. Other projects used two methods of data collection that included a physical model and digital software simulation, illustrated the value of comparisons between data sets to strengthen results (Kim and Chun, 2011). This group used digital models in Radiance to study daylighting effects of natural sunlight from a roof source in a real building, the Seoul Museum of Art. Upon comparison of the physical data and software simulation data, differences were found between scale model measurements and the results from computer simulations. A correction factor and corrected simulations were made to address the differences (Kim and Chun, 2011). This research was an applicable reference to understand variation in data across different modes. Another example of the utilization of physical models and software simulations used Radiance (Freewan, 2009). This study found Radiance software results to be close to physical model data. This study also used one type of sky condition to stay consistent with the actual weather during physical model testing times. Although there are various weather conditions that are possible for testing illuminance conditions in digital modes, for this project clear sky conditions were used (Freewan, 2009).The testing of the effects of variable surface characteristics also shows useful in understanding their affects on solar penetration levels. By delving into testing variables on the resulting internal spatial conditions within the specific glazing category of skylights, the importance of glazing materials including UV resistance, color, and light-to-solar- gain ratio can be further understood (Al-Obaidi, et. al 2014) . These studies show the strength of research that comes from two methods of data collection, the interest in solar remediation techniques of existing buildings, and the capabilities of running multiple options with software simulations in daylight analysis. 29 2.4 Summary This chapter described the issue concerning lighting in museums: although natural provides positive color-rendering conditions, the properties of light cause damage the artwork. There are guidelines that set footcandle level standards for art material categories. For museums with rotating exhibits, the interior light levels of the interior space would fall under many different standards, thus creating a need for dynamic solar controls. Research shows that using more than one mode of data collection for daylight analysis, such as on-site data and software simulation data, can strengthen the understanding of a building’s daylight performance. 30 Chapter 3: Methodology 3.1 Chapter Introduction This chapter describes the methodology of researching daylighting at the Resnick Pavilion at LACMA. It lays out the modes of data collection, an outline of each phase, and a description of the tools being used. 3.2 Plan, Phases and Modes of Data Collection The plan covers three phases. The first involved researching the architectural site and museum daylighting. The second involved the actual data collection on site and simulations of a digital model. The third required analysis and conclusions. Illuminance data was collected and daylighting conditions were analyzed through real space measurements and through digital simulation. 3.2.1 Important Steps Phase 1: • Researched various daylighting simulation software programs and made a selection of the best software and methods to utilize. • Researched lighting requirements for artwork and optimum lighting conditions for visitors. • Worked with BuroHappold and LACMA to develop scope of research and accessibility of the gallery space. Learned the scope of what areas, times, and conditions can be tested (Figure 24). Figure 24. Scope of data collection on exhibition plans throughout thesis duration. Phase 2: A.) Collected data on the LACMA case study building. • Light levels were taken hourly via light meter during walk-through data collection. • Light levels tested at points on a horizontal grid layout (Figure 25) throughout the determined area at 2.5’ height (Figure 26) • Resnick Pavilion housed the Frank Gehry exhibit from 9/13-3/20, creating a consistent environment during that time period for lighting conditions and grid points to test throughout the exhibition. 31 • Data was collected for the times of 9am, 12pm, and 3pm. • Existing conditions were tested. LACMA’s daylight coverage conditions were not able to be changed during this study, so the site data collected was used to make a calibrated digital model whose behavior matched the real space as closely as possible. Figure 25. Grid of calculation points from overlapping exhibit plans. Figure 26. Light meter at 2.5' height. B.) Create digital model of the space. • A digital model was created through Rhino with the as-is site exhibition layout and shading conditions, to calibrate the model in order to test additional daylighting conditions during summer solstice, winter solstice, and fall equinox. These additional variables consisted of isolating the vertical façade glazing and the skylight glazing to 32 assess their separate contribution to the daylight performance of the building. These simulations were performed with the intention of creating custom shading configurations with Grasshopper software. • To increase the accuracy of results, the characteristics of architectural materials inside the Resnick Pavilion were rendered. Available definitions and descriptions of materials and/or finishes of the interior were researched. • Although scope remained in the central core, the surrounding bays will be constructed and tested through the calibrated model since they were connected to the central core during the on-site data collection, thus affecting the light levels (Figure 25). Phase 3: • Simulations were run on the space using the existing shading control options (Figure 27). • Simulation results were used to create a process that recommended a shading controls program in order to achieve desired light levels by maximizing as much daylight contribution as possible. Figure 27. Methodology 3.2.2 Reasons for Selected Tools On-site Measurement, Calibration, and Digital Model “For any method that is used, doubt will exist concerning the validity of the tool. However for existing buildings, on-site observations and measurements can detect aspects of daylighting that are difficult to pinpoint compared to prediction tools, including the exact performance of systems and the dynamics of daylight in the building” (Fontoynont, 1999). During the process of setting up plans with LACMA, certain limitations were revealed about the daylighting conditions and areas of testing. For example, the placement of HOBO data loggers was restricted on the site. Also, certain areas were closed off during various points of the site research because a separate exhibit was in the setup process. Shading mechanisms that covered the windows were not able to be altered. Therefore, another mode of data collection, simulation of a calibrated digital model, was added to test the desired variables. Because on-site data measurements are limited to time, accessibility, and the chosen daylight control option at the time of measurement, daylighting software was utilized for its added benefit of simulating multiple times of year and shading conditions. Although software results are never completely accurate, they show the effects of certain design decisions that can inform energy efficient daylight remediation tactics. 33 Calibration involves checking and adjusting the digital model results in comparison with the site results. It is an added step to increase the accuracy of the results and add to the significance of the research, with the end goal of influencing solar control decision for maximizing daylighting. The purpose is to match the “as-is” site conditions, from exhibit walls and podium layout to surface material properties, so that the digital model can be used to simulate additional variables such as multiple times of years and multiple combinations of shading controls. Although there are a group of options to choose from when considering the right daylight analysis software to perform simulations, Sebanti Banerjee’s Daylight Prediction: An Evaluation of Daylighting Simulation Software for Four Cases tested multiple aspects of interior lighting results through software programs (AGi32, Ecotect/Radiance, Rhino/Diva, and Rhino/Grasshopper/Honeybee), and compared simulation results with the goal of helping designers assess buildings more accurately. The material described the strengths and weaknesses of the software capabilities, and provided information on choosing Rhino/DIVA as the program for the LACMA case study research since it allows users to perform “optimized and parametric daylighting” as well as “conduct whole building simulations along with daylighting and compliance tests” (Banerjee, 2015). Software Program: DIVA/Rhino Rhino is a 3D computer design software that was chosen for its ability to model complex surfaces with material choices and its ability to work with multiple plug-ins, including DIVA. DIVA, a daylighting plug in, was chosen for its ability to create photorealistic renderings and evaluate daylighting conditions over multiples points in time. It uses Radiance, a lighting simulation program that implements the ray-tracing technique to predict light behavior. This ray tracing methodology “follows light backward from an observer to the light source of the hypothetical scene. Once a path has been found, the luminance associated with each ray is computed from the candle power distribution of the light source and the reflective properties of the intervening surfaces.” (Ander, 2003). This is important because this technique of ray tracing means that it can compute direct lighting more quickly than a path tracing simulation, which will need to calculate eah light bounce (Pelovitz, 2014). It streamlines the process of simulation because when a light ray is applied to a scene, a separate equation sums up the lighting in the scene and applies the pixel value across the scene bounce (Pelovitz, 2014). Grasshopper Grasshopper is a plugin integrated with Rhino that works as a visual algorithm editor comprised of components that are related to objects in the Rhino model (Loomis, 2011). Settings can be placed on these components and run with DIVA daylighting analysis. Through Grasshopper a script tool can be created to enable many variations of a model to be simulated with directed inputs and outputs. This is incredibly useful when the subject building has a dynamic program in which a group of material options and the solar conditions for different times of year need to be studied. Grasshopper can be used to create a script, or algorithm, set to the Rhino model that helps inform shading configurations for custom exhibits and display times. 34 3.3 Scope Of Work 3.3.1 Research Goals One goal of the research was to gain a clear understanding of daylighting levels influenced by vertical facade and horizontal roof apertures in a museum context. Another goal was to use real site data and simulation data to inform a protocol that will help inform design decisions. This included software and data analysis. In addition, a deeper goal was to gain a higher understanding of how to apply this knowledge to contribute to energy efficient practices by maximizing daylight as a light source and minimizing the use of artificial lighting when possible. Specifically, this meant operational guidance into defining year round daylighting control programs through shading settings for LACMA, maximizing daylight as a lighting source use depending on necessity and time of year. In summary, the research purposes were to gather conclusions on the following: • The role of overhead roof apertures with vertical wall facades for daylighting conditions in museums. • Strengths and weaknesses of physical data methods and digital data simulations for methodology. • A deeper understanding of daylighting remediation methods used, and their strengths and weaknesses in terms of daylighting control for a dynamic, year- round program. • Guidelines for energy efficiency of lighting a museum space in the studied context. The results can be applied to develop the process of other daylighting remediation applications, especially in museum buildings that use shading controls for a rotating display of artwork. “Given the difficulties in estimating and measuring dosage, most museums have limited data on their actual lighting performance, and guidance is sparse on how such targets can be met” (Cannon-Brookes, 2000). 3.3.2 Deliverables The first deliverable was illuminance data for the real space analysis periods under as- is shading conditions. Further illuminance data for variable shading conditions and times of year came from digital simulations through daylighting software was provided, along with an analysis of the daylighting conditions from both sources. Finally, the research resulted in the development of a process that informed shading methods that maximized daylight usage for a dynamic building program. 3.3.3 Hypothesis Statement For the application of daylighting remediation in existing buildings, the results of a digital model calibrated through real site conditions can direct a strategy of daylighting controls responsive to dynamic program need. 3.4 Domain of Study Illumination levels in footcandles are used for the study of daylighting in the Resnick Pavilion and its digital model, due to the IES Lighting Handbook standard’s use the unit in footcandles as well as LACMA’s use of illumination as a unit in which to monitor light conditions in their space. Due the case study building’s focus on illumination levels and visual transmission of shading devices for daylighting control, ultraviolet(UV) radiation for artwork is not considered; UV blocking glass is 35 assumed. In this research, illumination levels are calculated and compared for the site data and simulation data. The site access and period restriction shaped the domain of the research, which limited the ability to gather more on-site data but was enough to collect a data set for calibration of a digital model. 3.5 Study Boundaries 3.5.1 Domain of Study: Site Due to access restriction on-site, the domain of the study was restricted to the south and north sections periodically. Because the west and east sides are blocked off at varying times throughout the testing period, the central core is the area of study. Access was given to both sections starting in October, therefore the calibration method incorporated the October data set. 3.5.2. Description: Site Limitations During the time of data collection in the museum, there were three phases of exhibition changes. The ceiling fin coverage conditions are determined by the exhibition contents and placements. These conditions are determined by program and not changeable. There were three measures in which the sawtooth fins were controlled for sunlight during the data collection periods: 1. Glass 2. Blackout Shades (roll-down) 3. Shades (roll-down) Figure 28. Glazing in the Resnick Pavilion. Figure 29 Blackout shades in the Resnick Pavilion. 36 Figure 30 Shades in the Resnick Pavilion. Artwork and exhibition wall placement also affected the light levels. Large sculptures, display walls, and podiums altered the light levels at each point of measurement as well as the ability to measure at consistently symmetric grid points. These limitations were considered with the simulation data calculations. 3.6 Summary The methodology was created to encompass a more accurate way of data collection for existing buildings, but was also altered to coincide with realistic limitations of working with real building situations and the museum organization itself. The modes together can provide a comprehensive knowledge of the daylighting conditions and inform a useful controls protocol for future program use. 37 Ch 4: Site Research Chapter 4 describes the light level data collected on-site at the Resnick Pavilion and analyzes important aspects to be considered for the research done through the digital model. Chapter 5 covers the calibration of a digital Rhino model and its subsequent DIVA simulations and Grasshopper script development. 4.1 Introduction This section covers the data and analysis from the research on-site at the Resnick Pavilion where on-site illumination data was gathered. Each section describes the location, time, and solar control methods of the space during the time of data collection. 4.1.1 Illuminance level data collection The Resnick Pavilion was divided into three longitudinal sections. Because certain portions of the west and east sides were restricted in access during different phases of the research, the scope of study stayed within the central section. The exhibition space at Resnick Pavilion was also divided into two latitudinal sections, referred to as the North Wing and South Wing (Figure 31). Access to both the North and South Wings were available for data collection starting at the October date. The points of measurement were set on a symmetrical grid. Since the exhibit contained walls and display podiums directly in the way, the grid points were then shifted in certain spots to accommodate the exhibit layout. At each point, a light meter was used to measure the illuminance at a height of 2.5’ from the floor level. Because there were electric lights on during the day, the levels that were measured included daylight and electric lights. Therefore, this process was repeated during the night time in order to measure the electric light levels. These electric light values were subtracted from the values taken during the day, in order to isolate the daylight levels. Points were named by the corresponding horizontal rows of the floorplan. In the South Wing, the rows start from the direction facing into the building from the entrance. The three columns of the grid are also named from left to right in the direction facing into the building from entrance. The North Wing follows the same format, with the numbered rows starting at the North entrance (Figure 31). 38 Figure 31. Grid point locations through data collection area, numbered by row and column. 4.1.2 Shading Description The Resnick Pavilion employed shading devices on a mechanized roller system. There was one type of shading for the North façade entrance that covered the entire exterior of the glazing area (Figure 33) and one type of shading for the South façade entrance that covered the exterior top half of the glazing. There were two shading options for the skylights. One was shading that filtered in partial daylight, and the second was blackout shading that completely blocked out exterior daylight (Figure 32). The transmittance values for the shades were further researched after on-site data collection during the calibration phase (see Ch. 5 for more detail). Figure 32. Resnick Pavilion skylights. In clockwise order from top left: Exterior of skylights with angled shading panels, Skylight glazing without shading, Skylight with blackout shades, and Skylight with translucent shading. 39 4.2 August Daylight Data Daylight levels were measured in August at the Resnick Pavilion; however access was restricted to the South Wing. The exhibit on display at that time differed from the exhibit throughout the duration of the study. For these two reasons, this data was not used for calibrating the digital model. 4.3 September Data 4.3.1 Conditions The exhibit that took place in September displayed architectural models and drawings by the architect Frank Gehry. Printed screens were hung from the ceiling and framed drawings were hung from the walls. White walls that reached up to the ceiling were constructed throughout the exhibit, with display stands dispersed across the floor. The architectural models were placed on a horizontal plane on the top surface of these stands at various heights (Figure 33). The placement of these objects affected the illumination levels, especially at the grid points located directly on or next to the stands (Figure 34). Figure 33. Panoramic View of Gehry Exhibit in North Wing, facing the North Façade. The material in the Gehry exhibit comprised of paper, TV monitors, books, and architectural models made of paper, wood, plastic, and other mixed media. In the central core and the western section of the gallery, daylight filtered into the gallery through skylights with shading. In the eastern section of the gallery, there were no shading devices used. The exhibit sections were organized according the daylight level; the west section contained the oldest drawings and models from Frank Gehry that needed the most preserving while the east section showed the newer models that had been created in the last two decades. Figure 33 shows an image of the east section without shading and the central and west section with shading. 40 Figure 34. Shading Conditions for September 2015 at the Resnick Pavilion 4.3.2 Illumination Levels The graph shows illumination levels in footcandles (1fc-10.764 lux) for the central core of the North Wing (Figure 35). Each point of the graph can be referred back to Figure 1 to pinpoint exactly where on the floor plan the light measurement was taken (i.e. North Wing, point 9B). Because the central core of the gallery was exposed on each side to the east and west galleries, this affected the daylight levels in the space. Light levels increased on the side facing east and decreased on the side facing west. The light levels also increase as the points reach closer to the façade, which was shaded with an outdoor mechanized shade but still allowed natural light. Although the placement of the exhibit podiums altered the light levels (Point 5A was placed behind a wall), one can see a general decrease in footcandle levels as the light reaches deeper into the space (Points 12A, 12B, and 12C). 41 Figure 35. Daylight Illumination Levels on September 24 for 9am, 12pm, and 3pm at Resnick Pavilion’s North Wing. 4.4 October Data On October 29, the second portion of the exhibit was opened at the Resnick Pavilion, and light levels were measured through the entire central core including the South and North Wing. Because it was the first date with light levels from both wings, and it was the closest date to the fall equinox, the data from this day was used to calibrate a digital model. 4.4.1 Conditions The exhibit layout and solar shading conditions in October in the North Wing stayed the same as the September conditions. The South Wing contained works of Japanese art from the LACMA collection that inspired Frank Gehry and served as the first transition space before entering into the North Wing to view Gehry’s body of work. The South Wing contained Japanese drawings and paintings from the 15 th to the early 20 th centuries. Given the delicate nature of the material, the daylight levels were September 24, 2015 North Wing Illumination Levels 9am 12pm 3pm 42 minimized by implementing blackout shades for the South Wing (Figure 37). However, the first to rows of skylights used the translucent shading. The south entrance also vertical glazing with the top half covered in an exterior translucent shading. This entrance section with diffused sunlight and the Japanese exhibit section was separated by two perpendicular walls to block off most of the sunlight coming in from the shaded skylights and the shaded south façade entrance. Figure 36. Panoramic view of the South Wing's interior and view of south entrance (looking in the southwest direction). Figure 37. Shading conditions for October 2015 at the Resnick Pavilion 43 4.4.2 Illumination Levels The daylight levels in the North Wing in October were lower than those of September but the spatial patterns remained consistent. The points of extreme high or low levels pertained to the grid point placement directly by a wall or art podium, and the general levels increased as the points reached toward the north façade glazing (Figure 39). This differs from the sharp increase in daylight levels in the South Wing (Figure 40) due the change in skylight shading from blackout shades to translucent shades, as well as the floor-to-ceiling wall. As the levels increase toward the south façade glazing, the 9am and 3pm times show irregular spikes at Point 2B (Figure 40). This occurs as the sun is lower in the sky during those times, and filters in with more contrast as it can be blocked by mullions or people. (Figure 38). In addition, each set of grid points was measured at the approximate times of 9am, 12pm, and 3pm. This means that for the 9am time, points 2A, 2B, or 2C (Figure 40, Figure 42, and Figure 44) could have been measured at 8:58am while another point is measured at 9:03am. The time difference of a couple minutes would alter the placement of mullion shadows as well as the angle of sun, therefore at the South Wing in particular this creates opportunity for large swings in footcandle levels (Figure 38). Figure 38. Image of South Facade Entrance. The sun filters in through a low angle and creates higher contrast light levels. 44 Figure 39. Daylight illumination levels for October 2015 on 9am, 12pm, and 3pm at the Resnick Pavilion’s North Wing. October 29, 2015 North Wing Illumination Levels 9am 12pm 3pm 45 Figure 40. Daylight illumination levels for October 2015 on 9am, 12pm, and 3pm at the Resnick Pavilion’s South Wing. 4.5 November Data 4.5.1 Conditions The shading conditions during the November data collection date remained constant with the October shading conditions. The light level patterns remained constant on a larger scale but also echoed the slight irregularity of the peaks (Figure 42) for the section of the South Wing closest to the façade glazing (Point 2C, 9am and 3pm). This follows the same reasoning as with the October data, with the low angle of the October 29, 2015 South Wing Illumination Levels 9am 12pm 3pm 46 sun causing shadows and higher contrast across the horizontal plane of measurement. The overall levels in the North Wing show a slight decrease, since in November there is a decrease in diffuse sunlight coming in through the vertical façade glazing on the north side (Figure 41). 4.5.2 Illumination Levels Figure 41.Daylight Illumination Levels for November 2015 on 9am, 12pm, and 3pm at the Resnick Pavilion’s North Wing. November 24, 2015 North Wing Illumination Levels 9am 12pm 3pm 47 Figure 42 .Daylight Illumination Levels for November 2015 on 9am, 12pm, and 3pm at Resnick Pavilion’s South Wing. 4.6 December Data 4.6.1 December Conditions In December the shading conditions also stayed constant through both the North and South Wings. Therefore the overall shape of the graphs is similar; however there is a jump in light levels in the North Wing that is lower than the previous months due to the decreased amount of light contribution from the un-shaded east section as well as the north façade glazing (Figure 43). The North Wing daylight levels in the researched central section stays at its most consistent in December. In contrast, the South Wing still follows the previous months’ large spike in levels towards the south façade entrance, since the sun coming from a lower winter angle in the southern November 24, 2015 South Wing Illumination Levels 9am 12pm 3pm 48 direction provides ample direct lighting that is only filtered throught the translucent shades (Figure 44). 4.6.2 Illumination Levels Figure 43. Daylight Illumination Levels for December 2015 on 9am, 12pm, and 3pm at the Resnick Pavilion’s North Wing. December 23, 2015 North Wing Illumination Levels 9am 12pm 3pm 49 Figure 44. Daylight Illumination Levels for December 2015 on 9am, 12pm, and 3pm at the Resnick Pavilion’s South Wing 4.7 Site Data Analysis 4.7.1 Data Analysis and Comparisons The light levels in the North Wing vary depending on the grid point location due to the sensors’ proximity to an exhibit stand or artwork. Each point of the graph can be referred back to pinpoint exactly where on the floorplan the light measurement was taken (i.e. North Wing, point 9B in Figure 43 refers to point 9B in Figure 31). This is an important observation to consider when comparing levels to a digital model. December 23, 2015 South Wing Illumination Levels 9am 12pm 3pm 50 Because the central core of the gallery was exposed on each side to the east and west galleries, this affected the daylight levels in the space. Light levels increased on the side facing east and decreased on the side facing west. The light levels also increase as the points reach closer to the façade, which was shaded with an outdoor mechanized shade but still allowed natural light. Although the placement of the exhibit podiums altered the light levels (Point 5A was placed behind a wall), one can see a general decrease in footcandle levels as the light reaches deeper into the space (Points 12A, 12B, and 12C in Figure 44). Note that line for October does not contain South Wing values because the data collection during that time was limited to the North Wing. Figure 45. Illustration on How to Read Monthly Comparison Charts 51 Figure 46. Monthly Light Level Comparison of Site Data 4.7.2 Site Research Summary The advantage of collecting data from the actual site is its accuracy. The data gathered are true to the specific conditions pertaining to the time of measurement. The location, sun angles, materials, and all other characteristics are from the real environment, and therefore the light levels reflect the actual performance of the building. However since the research measures the light levels at the specific time, there are factors in the real space that are uncontrollable. For example a cloud could be passing during a minute of measurement during which certain grid point values are affected, while the rest of the values reflect the typical sunny day. Site visits were also made during gallery open hours, and placement of people could not be controlled. A group of museum visitors standing nearby a highly reflective surface would block that contribution to the light measurement. While these occurrences were avoided as much as possible by being observant during the site research process, it is worth noting as part of the process of on-site data collection. The site data was invaluable because it recorded the true light values in the building, using it as the sole source of information limits a complete understanding of the building’s daylighting performance. With the site research, one could not see the effects that a group of different shading settings had on the space. The results from site research were restricted to “as-is” conditions. They are also limited to the time that data collection is performed, when ideally the daylight levels for many times of 52 year are desired. A digital model provides the opportunity to explore simulated results for many different shading settings and times of year. It was important to procure the site data so that the calibrated model could have a true set to be compared against. The patterns in the site data were studied and served as a reference for validating a calibrated model. 4.7.3 Summary Although the information from the architecture department at LACMA stated that the translucent shading for the Resnick Pavilion glazing blocked out all but 3% of the incoming sunlight, the light levels in the space did not seem to reflect that transmittance level, especially considering the high illuminance values at the entrance of the South Wing. From the on-site data, the digital model was calibrated with October and December data. October at 12pm (when the sun is highest in the sky) was chosen because it was the closest month to fall equinox that had access to north and south wings. The December (winter solstice) date’s data set was also chosen to be compared against because the building has the least amount of sunlight access from the lowest angle during the winter solstice date. 53 Ch 5: Digital Model Research: Calibration, Simulation, and Protocol Development Chapter 5 covers the research done with a digital Rhino model of Resnick Pavilion. The digital model went through a calibration process, a DIVA daylight analysis process, and the creation of a Grasshopper script using DIVA and proof-of concept process. 5.1 Introduction This chapter goes through three parts of the research. The first section describes the calibration process of the model created in Rhino and run through DIVA daylight analysis. The second portion presents simulations done with the calibrated model with shading (sun control) and time variables through DIVA/Rhino. Finally, the development and proof-of-concept examples of a protocol is covered. Calibration data was formatted in the same way as the on-site model, through lists and graphs based on the light level at the specific grid point, so that results can be compared in the same manner. For the simulations and algorithm portions, the data is no longer limited to limited grid points. Therefore, data is presented in the form of a colored grid. 5.2 Calibration A 3D model created in Rhino software was divided into layers by material and run through a DIVA daylight analysis plugin. “As-is” site conditions were modeled as closely as possible to the actual geometry and placement of the podiums, exhibit walls, and screens in the real space. One of the most significant factors was the visual transmittance levels attributed to the shading materials in the space. The shading played an important role in defining the lighting conditions in the digital space. 5.2.1 Shading Characteristics Based on information from the architecture department at LACMA, the Visual Transmittance level for the shading used in the Resnick Pavilion was at 3% (Figure 47). The lighting levels derived from simulations with this material characteristic showed higher than expected values in the DIVA/Rhino software. Figure 47. Excerpt from document provided by LACMA with Assumed 3% transmittance for shading materials at the Resnick Pavilion. Upon further research with the manufacturing company, the level of incoming natural light varied dependent on the color of the shading screen. The value was depicted as a sun logo (Figure 48), whose value for the color 0701, Pearl Grey, used in the skylights in the Resnick Pavilion was 12. So specifically for the product used, a 12% transmittance level was assigned. 54 Figure 48. Manufacturer’s description of interior shading used for skylights in the Resnick Pavilion. Figure 49. Specific model of shading used for Resnick Pavilion's skylights, showing 12% light transmittance. Two different colors were used for the exterior shading product, 0101 Grey on the north façade glazing and 0207 Pearl on the south façade glazing. The manufacturer’s description for this exterior shading lines showed a logo “NL” which stood for the natural light level allowed through the shading screens. These values were confirmed by the manufacturer and taken to define light transmittance for the north façade shading material in the digital model. Figure 50. Manufacturer’s description of interior shading used for skylights in the Resnick Pavilion. Figure 51. Specific model of shading used for the Resnick Pavilion's North facade shading, showing 10% natural light transmittance 55 Figure 52. Specific model of shading used for the Resnick Pavilion's South facade shading, showing 18% natural light transmittance. The transmittance values for each shading material were applied during the model calibration process (Figure 53), which helped increase the similarity between the real site data set and the calibrated model set (Figure 54 to Figure 57). 5.2.2 Calibration Model The final calibrated digital model used material properties that were consistent with measured and manufacturer based data (Figure 52). While some typical values were used such as 20% reflectance of floors and 80% reflectance values of ceilings, one aspect to note was that an 80% reflectance value was also assigned to the temporary exhibit walls and white-painted podiums. This was attributed to the display surfaces after finding the standard 50% furniture reflectance to be insufficient. However, because these exhibit surfaces were completely new and painted with a bright white paint, it was not unusual to find that their reflectance was at 80% (similar to a white ceiling). With final material values assigned to the building and exhibit surfaces, the simulated results through DIVA/Rhino did not meet the exact values of the on-site model but did follow the same patterns of the real data set (Figure 54). Figure 53. Table of Material Characteristics defined in Digital Model simulated through DIVA/Rhino 5.2.3 Digital Simulation and On-Site Illuminance Level Comparison for October 29 The graph shows a comparison between the daylighting results of the calibrated digital model through DIVA/Rhino at the same grid points where the light was measured on-site for the date of October 29 at 12pm. The calibrated model does not show as high of a peak in light contribution for the non-shaded eastern section, however the general levels follow the same patterns (Figure 54). The more extreme peaks and lows in the on-site data shows that the simulation software does not respond as dramatically to the placement of objects in the space, however the reaction is shown particularly in Point 5A (Figure 54) that was located directly behind an exhibit wall. 56 Figure 54. Comparison of Daylight Levels taken at the North Wing from On-Site and from DIVA/Rhino Model, October 2015 at 12pm. The results for the digital model follow similar the similar sharp incline in light levels in reaction to the light coming in from the south façade entrance. While the values in the entrance section are close, the light levels in the simulations dip more drastically into lower values compared to the daylight contribution measured on the actual site (Points 5A-5C, Figure 55). October 29, 2015 North Wing Illumination Levels 12pm On-Site Data Calibrated Model Data 12pm 57 Figure 55. Comparison of Daylight Levels taken at the South Wing from On-Site and from DIVA/Rhino Model, October 2015 at 12pm. 5.2.4 Digital Simulation and On-Site Illuminance Level Comparison for December While the ranges in the calibrated model fell close to the light ranges in the on-site data set for December 23 at 12pm, there were a few slight differences. Once again the general values for the North Wing of the calibrated model results showed a more even spread compared to the higher (Point 5C, Figure 56) light areas in the on-site data set that came from the proximity to the un-shaded eastern section of the Resnick Pavilion. When comparing the actual South Wing light levels with the calibrated model results, DIVA/Rhino attributed higher levels of daylight contribution coming in from the south façade at 12pm on December 23. Despite the higher reflectance value assigned to the interior exhibit walls, the simulated results also show a deeper drop- off in daylight levels as the graph reaches further in the space (Point 5A-5C, Figure 57). The on-site data also shows more extreme values on Row 2 of the South Wing 12pm October 29, 2015 South Wing Illumination Levels On-Site Data Calibrated Model Data 12pm 58 (Point 2C, Figure 57), which is attributed to the lower sun angles filtering at a low angle, causing high contrast with the shadows of the trees, mullions, and/or people that are present during inconsistencies of the measurements on the real site (Figure 38). While the calibrated model results reveal a smoother transition, the larger patterns remain similar between the on-site data and the calibration data. Figure 56. Comparison of Daylight Levels taken at the North Wing from On-Site and from DIVA/Rhino Model, December 2015 at 12pm. 12pm December 23, 2015 North Wing Illumination Levels On-Site Data Calibrated Model Data 12pm 59 Figure 57. Comparison of Daylight Levels taken at the South Wing from On-Site and from DIVA/Rhino Model, December 2015 at 12pm. 12pm December 23, 2015 South Wing Illumination Levels On-Site Data Calibrated Model Data 12pm 60 5.3 Calibration Data Analysis The values for the calibrated model showed lower levels of daylight contribution as it reached deeper into the core of the building most notably on the South Wing. It also simulated smoother results compared to the variations in high and low peaks affected by the placement of exhibit display objects, most notably in the actual site data from the North Wing. The results for the same model were more accurate in the December 23 simulation than the October 29 simulation. Figure 58. Comparison Graph Set: Site Light Levels vs. Digital Model Light Values Reasons for value differences between the calibrated model and the site data could be attributed to the following: 61 • The site data was measured during “as-is” conditions, including the presence of museum visitors. For example, a group of visitors standing a few feet away from a grid point but next to one or more a reflective surface could have blocked the potential contribution to the total light level at the time of testing. • The calibrated model was run for CIE clear sky conditions. The sky conditions during the dates of site data collection were closest to CIE clear sky conditions, but real weather conditions do not mimic a “perfect” clear sky. Slight cloud coverage varied throughout the day and could have affected higher peaks and lower drops than would be consistent with a perfect clear sky. • The site data was collected at representative 9am, 12pm, and 3pm times. The amount of grid points made it impossible for every point to have been measured precisely at, for example, 3pm. Some point locations were measured at 2:50pm, others at 3:05pm. A difference of a few minutes affects the placement of mullion shadows at the south entrance (Figure 38) over a grid point, which accounts for the more extreme highs and lows at the south entrance in the site data compared to the even levels along the same area in the calibrated model (December 23 Column A and B in Figure 58). • The calibrated model could not completely mimic the characteristics of every possible surface of the real space. Therefore the simulated light results could not represent the real illuminance levels with complete accuracy. But while the values of the calibrated results did not match the exact values of the site results (Figure 58), the overall patterns of the graphs (Figure 54, Figure 55, Figure 56, and Figure 57) were found to be similar to the site data when considering the effects of solar contribution to the interior of Resnick Pavilion. For example at for the values on Column B on December 12, points S8B-N1B (Figure 58), have a difference range of less than 10%. While the specific values at each node of the simulated results could not be absolutely accurate, the comparative results show that the calibrated model is capable of yielding similar daylight contribution patterns that reflect the effects of the shading control variables. Therefore, this calibrated version was used to run further simulations that isolated the daylight contribution from the two sources: North and South glass facades, and the skylights from the sawtooth ceiling. 5.3.1 Simulation Results in DIVA/Rhino Format Previous graphs for simulation results were presented in the same format as the on- site data in order to make comparisons. These were point-by-point analysis of light levels at a specific grid point. However the light level data shown through DIVA/Rhino were simulated in a colored mesh throughout the entire testing (Figure 59). A grid of nodes on the horizontal plane at 2.5’ height from the floor were created and at each grid square a color represented the illumination value on an assigned minimum/maximum scale (Figure 60). The graphics of the DIVA/Rhino simulations show a larger-scale idea of illumination levels over a complete test area rather than values at a few points. This format allows for a more comprehensive understanding of the space that can be read in one image. The remainder of the research was conducted through the visual format of DIVA/Rhino results. 62 Figure 59. Screenshot of Rhino Model with DIVA analysis: Nodes with colored grid sections at 2.5' horizontal plane. A maximum illumination value for the colored scale was set to 200fc (2135 lux) to stay consistent with the comparison graphs in Figure 54 through Figure 58. These were set based on the range of actual maximum values in the South Wing. Therefore, the highest areas depicted in red for the DIVA/Rhino graphics were not intended to be interpreted as “too bright” but merely as the highest set of illuminances in the space. For reference, the illumination level at the same 2.5’ height from the ground on October 29 under a clear sky at 12pm was 6,520fc (70180.7) and 634fc (6824 lux) in the shade. The illumination levels at the same locations on December 23 under a clear sky at 12pm was 5,655fc (60870 lux) and 558fc (6006.26 lux) in the shade. Although DIVA/Rhino results are in a different visual format than the site data results, the graphs reflect the same analysis: one can read that the light levels increase dramatically toward the South façade as the representative colors turn red in Figure 60 and Figure 61, which shows in the higher values of the previous grid point graphs in Figure 57. Figure 60. Calibrated model results through DIVA/Rhino for October 29 at 12pm. 63 Figure 61. Calibrated model results through DIVA/Rhino for December 21 at 12pm. 5.4 Simulations The simulation research covers results run for an “empty building”, or “base case”, DIVA/Rhino with the calibrated model. This means that the Gehry exhibit that was modeled in Rhino in order to calibrate with the as-is site conditions was removed. The “empty building” digital model of the Resnick Pavilion was tested on dates of the summer solstice, fall equinox, and winter dolstice (June 21, September 21, and December 21, respectively). The fall equinox run will represent for the spring equinox as well since the sun should be at the same angle in the sky (Figure 3 of Ch. 1) and yield similar results. The time of day at 12pm was chosen because the sun is at the highest point at noon, so the simulation would represent the peak potential solar contributions for that day. In order to gain a deeper understanding of the solar performance of the glazing in the skylights and the glazing of the vertical facades in the North and South Entrances, the two groups were isolated for each simulation: • Facades blacked out and skylights open. • Skylights open and Facades blacked out. The simulations were run for a CIE clear sky in order to use the worst case scenario where the maximum amount of sunlight would need to be controlled. This also stayed consistent with the sky conditions of the testing dates on-site. 5.4.1 Summer Solstice Simulation with Vertical Facades Blacked Out & Skylights Open Illuminance levels were simulated for the Resnick Pavilion on June 21 at 12pm (Figure 62). The summer solstice is the day of year that receives the longest exposure to sunlight and has the highest angle of the sun. The vertical glazing is completely blocked and the diagram shows an even distribution of daylight throughout the central area of the gallery coming in from the skylight glazings in the sawtooth roof, with a the light reaching 300fc max towards the center and slight decrease towards the south side and a sharper decrease towards the minimum 50fc towards the north side. 64 Figure 62. DIVA/Rhino result for June 21, 12pm: only skylights open 5.4.2 Fall Equinox Simulation with Vertical Facades Blacked Out & Skylights Open The same shading variables run for September 23 at 12pm (Figure 63). The central area shows a distribution of levels from 100fc-200fc, with a drop in levels along the periphery. Illuminance levels stay about 100fc lower than the highest values shown during the Summer Solstice date. Figure 63. DIVA/Rhino result for September 21, 12pm: only skylights open 5.4.3 Winter Solstice Simulation with Vertical Facades Blacked Out & Skylights Open The same conditions were simulated for December 21 at 12pm. The winter solstice date receives the smallest amount of exposure to the sun as well from the lowest angle in the sky (Figure 64) The central area shows that light levels peak towards the core of the South Wing at 175fc. There is a less even distribution of the light in the gallery floor compared to the previous dates. Although the vertical glazing access is blacked 65 out in this simulation, the affect of the lower angle of the sun directed from the south into the skylights still contributes to higher amounts of light contribution on the south side of the gallery (Figure 64). The area closest to the north facade is dark compared to the rest of the space because the sun rays coming from the south aiming north at a low angle bounces off the reflectors and is redirected to aim south. Figure 64. DIVA/Rhino result for December 21, 12pm: only skylights open 5.4.4 Summer Solstice Simulation with Vertical Facades Open & Skylights Blacked Out Illuminance levels were simulated for the Resnick pavilion on June 21 at 12pm (Figure 66). The skylight glazing is completely blacked out, which is an actual shading option available in the building. The diagram shows larger daylight contribution levels on the north façade than the south. One main reason is that the north side is comprised of glazing that reaches along the entire façade, where the south side has one third the glazing amount. Another reason is that the angle of the sun during the Summer Solstice at 12pm is at the highest possible position of the year, so the sun rays hit the overhang (Figure 65) causing the solar radiation into the south entrance to come from indirect reflected sources. The maximum daylight levels close to the North façade reach 150fc and penetrate further into the space than at the South façade where it reaches about 85 fc at the most. Figure 65. Rhino model of Resnick Pavilion’s overhang on South entrance. 66 Figure 66. DIVA/Rhino result for June 21, 12pm: only vertical facades open. 5.4.5 Fall Equinox Simulation with Vertical Facades Open & Skylights Blacked Out Illuminance levels were simulated for the Resnick pavilion on June 21 at 12pm (Figure 66). The skylight glazing is completely blacked out, which is an actual shading option available in the building. The diagram shows larger daylight contribution levels on the north façade than the south. One main reason is that the north side is comprised of glazing that reaches along the entire façade, where the south side has one third the glazing amount. Another reason is that the angle of the sun during the summer solstice at 12pm is at the highest possible position of the year, so the sun rays hit the overhang causing the solar radiation into the south entrance to come from indirect reflected sources (Figure 65). Figure 67. DIVA/Rhino result for September 21, 12pm: only vertical facades open. 5.4.6 Winter Solstice Simulation with Vertical Facades Open & Skylights Blacked Out The simulation run for the same conditions but for 12pm on December 21 shows the reverse in terms of sunlight contribution from the vertical facades (Figure 68). 67 Because the sun is coming in at a much lower angle during the winter solstice and at the most straight forward angle at 12pm, the light levels that show through the south glazing are much stronger than through the north entrance. There is a more diffuse effect of daylight with a more gradual decline coming from the north glazing. The south entrance shows more extreme levels of daylight contribution with a sharper drop-off into the surrounding area. Figure 68. DIVA/Rhino result for December, 12pm: only vertical facades open. 5.4.6 Simulation Analysis Based on the results from the simulation analysis, changing the access of sunlight through the glazing surfaces of the Resnick Pavilion can drastically alter the light levels and distribution throughout the gallery interior. The strongest amount of daylight from the southern vertical façade came through the winter and decreased as it reached summer due to the horizontal overhangs. The highest levels of illuminance into the northern façade occurred during the summer solstice simulation when the sun was at its highest angle in the sky. The simulations for natural light contribution through the skylights created a much more even distribution across a much greater area of the gallery, with larger decreases towards the north side compared to the southern side. When determining skylight vs. façade shading options for an specific exhibit in future, the more consistent values across a broader area of space for skylight contribution show that a higher amount of potential of shading control variations. Isolating each type of glazing allowed for a deeper understanding of the role it played in bringing daylight into the gallery. This information was used to determine components that created an algorithm to address shading control options for different times of year under dynamic program conditions. This tool was created using Grasshopper. 68 5.5 Shading Controls Script with Grasshopper through DIVA/Rhino The simulation analysis for the “base case” calibrated model were useful in testing separate glazing variables and comprehending their role in daylight access to the gallery interior. However, a myriad of options can be run with the time of year, sky conditions, and glazing options alone. In addition, the program of the gallery hosts new exhibit layouts after each display period. This presents an infinite amount of conditions that can be simulated (Figure 69). Figure 69. Diagram of input options for simulations through DIVA/Rhino. Grasshopper enables the user to create an algorithm made of components connected to each other through input and output nodes. These components can be assigned different values and settings. They can also be connected to each other so that various settings can affect outcomes in many possible ways. The combination of components in Grasshopper creates an algorithm, or script, that allows for a large variety of input combinations to be controlled. This script was made to enable the simulation of multiple shading control configurations for the Resnick Pavilion with the goal of informing a dynamic shading control program for changing exhibits. For the duration of the Gehry Exhibit at the Resnick Pavilion, the shading configuration stayed constant. Light levels were measured on-site and a shading setting was determined based on the lighting needs of the exhibit during the opening dates in October. The daylight levels change throughout the months (Figure 46) based on the changing sun angles, but the shading configuration did not change to accommodate the shifts in natural daylight patterns. One goal set for the Grasshopper tool was to simulate shading configuration possibilities that maximize daylight to fulfill the illuminance levels in the space as much as possible. A larger objective was for the tool to be applied to other buildings with changing types of exhibits with the potential to maximize daylight use via solar remediation techniques. 69 5.5.1 Grasshopper script for the Resnick Pavilion An algorithm was created in Grasshopper that ran all the assigned surfaces in the calibrated base-case Rhino model through DIVA daylight analysis components(Figure 70). This enabled the user to create a custom exhibit layout, to assign custom or standard materials to grouped surfaces, and to run it through a combination of inputs (Figure 69). Through this protocol it was made possible to make small material or geometric changes to surfaces or layouts and see DIVA daylight results for the desired combination of conditions. Figure 70. Grasshopper script with labeled components. Objects in the Rhino model belonging to to a material category and could be selected and assigned to its own component (Figure 71). These objects could be re-grouped as the building layout changes. Those components were connected to materials components through which the user could assign materials. This allowed for a great deal of flexibility when setting up many different options of either the layout design or the shading controls. These materials component were then connected to the geometry input in the DIVA daylight analysis component (Figure 71). Through the DIVA daylight analysis component in Grasshopper, the additional inputs were assigned through settings. These inputs included the time of year and time of day, the data type, and sky conditions. Through the illuminance output node, a gradient component was created in order to visualize the illuminance results (Figure 72). 70 Figure 71. Material component portion of Grasshopper script. Figure 72. DIVA daylight component and illuminance output components in grasshopper script. 5.5.2 Proof of Concept Example In order to test the research objective to inform a dynamic shading program that changes with the seasons, the tool was run through a proof-of-concept case. This set 71 standards for an example scenario with a specific set of exhibit needs throughout a months-long display schedule. For the proof-of-concept, the lighting requirement for the gallery interior was set at a maximum allowable illuminance of 25 fc and a minimum level of 5fc. This was taken from the guideline that LACMA had for the art material category of “Light Durable Material” which includes engravings, pencil and charcoal drawings, painted furniture, painted sculpture, and plastics. In the DIVA daylight analysis settings, this was represented visually by setting 5fc as the minimum illuminance and 25fc as the maximum illuminance value. Figure 73. Screenshot illustrating DIVA analysis settings The duration of the exhibit was set from June to December. The Grasshopper tool through DIVA/Rhino was used to run different shading configurations to meet the lighting requirements for the exhibit with as much daylight as possible. June 21 was chosen as a testing date and time because the summer solstice date represents the date in the calendar year with the most amount of sunlight in the day, at the highest angle in the sky. December 21 was chosen because the winter solstice represents the date with the least amount of sunlight at the lowest angle in the sky. Simulations were also run for September 21 because the fall equinox represents a median case of sunlight exposure and sky position. These simulations were run for a CIE clear sky because this gives a worst-case scenario for these shading configurations. It is easier to meet the illuminance requirements and not exceed the maximum allowable level when the sky is cloudy. 12pm noon was chosen for the testing times for these dates because noon represents the point at which the sun is highest in the sky. 5.5.2.1 Proof of Concept Results From what was learned in previous simulations and site data results, the south façade throughout each time of year lets in the most amount of daylight compared to the other glazing sources in the Resnick Pavilion. From this information, the shading was implemented for all tested configurations. The only option for the Resnick Pavilion shading program was to have the 10% shading pulled halfway down. In addition, the first two central rows of skylights had their blackout shades applied throughout all tested configurations. In the following results, the areas of the gallery that fall out of the minimum range are black, and the areas above the maximum range are bright magenta. In all the simulated results, (Figure 74, Figure 76, Figure 77, and Figure 78) the area closest to the south entrance was above the allowable 25fc for the exhibit artwork even with these shading controls applied. However, since the area can be considered a transition space, artwork did not need to be placed right at the entrance. 72 The first date to be tested was June 21 with a custom shading configuration (Setting A, Figure 74). This meant that with the exception of the first two central skylight rows, the material applied in the skylight glazing component of the Grasshopper script was the 12% transmittance shading throughout the entire space. The results for Setting A (Figure 74) illustrated an even distribution of light with a high percentage (87.9%) of usable space that fell within the light standards. But there were too many spots (represented in bright magenta) throughout the entire gallery space that reached above the maximum allowance. This indicated that the artwork could be at risk of damage from high levels of light. Because the high spots were spread over the whole area, certain parts of the space could not be put aside as artwork placement sections either. In response, Setting B split up the skylight glazing into northwest, northeast, southwest, and southeast categories. The central core of skylights stayed at a 12% shading setting as well as the center row of skylights running along the entire south to west sides (Setting B, Figure 74). The goal was to bring in diffuse daylight along the central axis of the gallery in the hopes that it would spread through to the outer sections. However, the simulations show a small amount of spread with mostly clear sections of space that did not meet the light requirements with daylight. If different artwork sections were to be assigned under this shading configuration, a clear section at the central core of the North Wing would serve as a usable area for art display. The central core of the South Wing would not be able to house artwork because of the spots it reached above the maximum allowable level. However, using only this small section for artwork was not an efficient use of the gallery space. Setting C (Figure 74) reversed the shading, assigning blackout shading material to the skylights in the central core of the Resnick Pavilion and assigning 12% shading to the northwest, northeast, southwest, and southeast sections. While this simulation showed more light spread into the blacked-out central core due to the reflectance off the wall surfaces and the fact that they surrounded the core on both sides, there were still areas where the daylight was not utilized to meet the requirements. Setting C’s 87.4% of usable space compared to Setting B’s 57.8% was an improvement, however there were also patches of space present that reached beyond the allowable 25 fc level. Therefore, an even more customizable shading configuration was made. 73 Figure 74. Illumination results for shading configurations A-C, for June 21 at 12pm -PPYQMREXMSR6IWYPXWJ SV7LEHMRK'SR½KYVEXMSRW Intent: 5fc - 25 fc allowance Shading Conditions Setting A Setting A 87.9% of area between 5-25fc 57.8% of area between 5-25fc 87.4% of area between 5-25fc Setting B Setting B Setting C Setting C Illumination Results *scale applies to all June 21, 12pm 74 Figure 75. Illustration: Setting custom shading configurations within Grasshopper script. After observing the simulation results for Settings A-C (Figure 74), it was clear that a more complex shading configuration had to be created. Because Setting A showed a desirable distribution of light but resulted in unacceptably high illuminance levels, a configuration was designed to have every other skylight switch off between blackout shading and 12% transmittance shading. With the exception of the first couple rows of central skylights being blacked out as was consistent throughout all the settings, the “every other” shading condition in Setting D was staggered between the east section, central section, and west section (Figure 75) to create more light spread distribution. In Grasshopper, each shading surface was selected and the assigned to a separate materials component (Figure 75). This simulation resulted in a 98.3% of gallery area falling within the required illuminance levels for art display (Setting D, Figure 76). In order to see how the same setting would perform for a different time during the exhibit duration, Setting D was run for September 21 as well. Because the sun came from a lower point in the sky than on June 21, the overall light levels were lower throughout the gallery for the September 21 simulation (Setting D, Figure 76). Some spots showed as falling under the 5fc limit. Since falling under the minimum light level does not damage the art and can be supplemented by electric light, this result is more ideal than exceeding the maximum light limit. However, there was potential during a fall equinox date to take more advantage of the available daylight. For Setting E, the skylights in the east and west sections were all set with 12% shading, and the central core section decreased its “every other” blackout shading arrangement (Setting E, Figure 76). This shading configuration brought in more daylight and raised the overall light levels while remaining within the required 5-25fc category. With Setting E’s DIVA simulation, 98.3% of the interior of Resnick Pavilion was assessed as usable space for displaying artwork. 75 Figure 76. Illumination results for shading configurations D & E, for June 21 and September 21 at 12pm Shading Conditions Setting D Setting D Illumination Results -PPYQMREXMSR6IWYPXWJ SV7LEHMRK'SR½KYVEXMSRW Intent: 5fc - 25 fc allowance June 21, 12pm September 21, 12pm *scale applies to all 98.3% of area between 5-25fc 92.4% of area between 5-25fc 98.3% of area between 5-25fc Setting D Setting D Setting E Setting E *scale applies to all 76 Figure 77. Illumination results for shading configurations G & A, for December 21 at 12pm When setting December 21 shading configurations, the fact that the sun came from the lowest angle compared to the rest of the year was considered. Because a previous simulation (Figure 64) showed that the contribution from unshaded skylights resulted in levels that reached 175 fc (1883.68 lux) in the center of the gallery, 12% shading for the skylights were an assumed necessity even for Winter Solstice. Setting G (Figure 77) shows this configuration, but with the North facade glazing left unshaded in the hope of bringing in additional diffuse daylight. However, the lack of shading allowed too much daylight to penetrate into the space, creating higher levels than allotted for the art content for the proof-of-concept scenario. Setting A was simulated for December 21, and the results showed that 92.4% of the space met the light guidelines (Figure 77). 5.5.3 Proof of Concept Analysis Shading configurations set in Grasshopper and run for daylight analysis in DIVA/Rhino showed a large range of results in illuminance levels and distribution. While there were many possible shading configurations that could be tested, three settings were determined as applicable for a dynamic shading program for the proof- Shading Conditions Illumination Results -PPYQMREXMSR6IWYPXWJ SV7LEHMRK'SR½KYVEXMSRW Intent: 5fc - 25 fc allowance December 21, 12pm *scale applies to all 92.4% of area between 5-25fc 82.3% of area between 5-25fc Setting A Setting A Setting G Setting G *scale applies to all 77 of-concept setting (Figure 78). Figure 78. Recommended shading program for the Resnick Pavilion Setting D was designed to be the shading configuration for the start of the exhibition run in June. Setting E could be applied to maximize the daylighting potential by September 21. By December 21 when the sunlight contribution lowers, Setting A would admit more daylight at that time of year than the previous settings assigned for June and September. In this manner, the Grasshopper script could be used as a tool to help the shading program adapt to changing daylight levels throughout the year. In Recommended Shading Program Intent: 5fc - 25 fc allowance Shading Conditions Illumination Results *scale applies to all 92.4% of area between 5-25fc Setting A Setting A December 21, 12pm 98.3% of area between 5-25fc Setting E Setting E September 21, 12pm Setting D Setting D June 21, 12pm 98.3% of area between 5-25fc 78 other possible uses, specific exhibit layouts can be modeled. The placement of a wall drastically alters the light conditions around it, therefore being able to view simulated results of a plethora of layout options offers a significant advantage for daylight remediation planning. The Grasshopper script allows for an infinite number of variations to be simulated. The variations can be decided based on the footcandle requirements for the artwork, the exhibit display times throughout the calendar year as well as the desired layouts and materials of the exhibit design. 5.6 Digital Model Research Summary Using the data measured on-site at the Resnick Pavilion, a digital model in Rhino software was calibrated to simulate illuminance results as closely as possible. The material characteristics, especially the shading transmittance values, were the most influential factor in mimicking actual daylight conditions. While the calibrated model did not match the exact values of the site data, the patterns of illuminance levels in the gallery space followed the movements of those on the actual. Anomalies were explained and the digital model was determined to be useful in predicting daylight performance for conditions not testable through site research, such as additional shading configurations and times of year. The calibrated Rhino model was run through DIVA daylighting analysis for 12pm times on the summer solstice, fall equinox, and winter solstice. The vertical facade glazing and the horizontal skylight glazing were alternately isolated for the simulations. While running these simulations were not completely necessary before the creation of a Grasshopper tool, understanding the contribution of the separate glazing sources was helpful when making decisions for different shading settings through the Grasshopper script. An algorithm of components in the Grasshopper program was made in order to facilitate many combinations of inputs that were possible for simulated illuminance outputs. Inputs included material surface properties, shading options, content layout, time of day, day of year, and sky conditions. Objects within the Rhino model could be assigned to specific material components within the Grasshopper script and be simulated under multiple times of year and with various shading configurations. Because the Resnick Pavilion houses a rotating cast of exhibits with changing light requirements through different times of year, having an adaptive shading control program maximizes the potential for daylight to meet the illuminance requirements in the space. The tool created through Grasshopper and analyzed through DIVA/Rhino enabled more flexibility in simulating a large number of variables. The proof of concept showed that the tool could be used to run simulations on many shading configurations and determine a specialized shading control program for a specific exhibition need. These results show the possibilities of shading control combinations for different times of year that can meet changing amounts of the light level requirements purely from daylight contribution alone. Through entire process of gathering site data, calibrating a Rhino model to match the data, and utilizing a Rhino script tool to simulate many variables through DIVA daylight analysis, a protocol for creating a shading control program for an existing building was created. This protocol could be applied to other existing sites in order to inform solar remediation options that are adaptable to dynamic conditions. 79 Ch 6: Conclusions Chapter 6 covers the conclusions drawn from the site research and digital software research. It also describes possibilities of future work. 6.1 Research Products The main objective for the research projects was to create a tool to inform a shading program for LACMA’s changing exhibit schedule. This product was created through analysis of site data, calibration of a digital model, and software simulations through a script tool that was customizable for dynamic conditions. The steps followed during the methodology showed potential to become a process that could form protocol that could build a daylight analysis tool based on data collected from site research and software research. 6.2 Grasshopper Tool The tool created through Grasshopper and analyzed via DIVA/Rhino can be used to inform a shading controls program for future exhibits at the Resnick Pavilion. The tool is comprised of a script of components where the user can input material selections and simulation times. It allows the user to test a larger range of combinations through the DIVA analysis settings. The proof-of-concept showed an example of how the algorithm’s components can be altered to reflect a customized shading configuration that changes throughout the course of an exhibit schedule. The exhibit contained artwork which required a 5-25 footcandle range of illumination. A variety of shading configurations were simulated for the duration of the exhibit (June to December), and a shading controls program was designed from the results. Because the daylight conditions shift throughout the calendar year, this tool is used to inform the combination of shading controls that respond to those shifts. Future exhibit layouts can be modeled and assigned to Grasshopper script component geometry. Daylight simulations can be run for the times in which the exhibit will be on display, and the user can determine which combination of shading controls best adapts to the sunlight conditions during the exhibit times. 6.3 Process Research Conclusion In the process of analyzing daylight in a building, site research was crucial. The data gathered from the actual building was invaluable to the accuracy of the research and in providing an understanding of the daylighting performance of the building. On-site research was limited to the access, the conditions of the site, and the time of data collection. Because the layout of the exhibit during the time of data collection had a significant effect on determining the light levels, the values from the site research cannot be considered as a “blank space” result. Therefore, a digital model was implemented to simulate daylight results under multiple shading conditions and times of year. A digital model calibrated to the actual site data offers a more accurate portrayal of the lighting conditions of a building and offers another level of validation for the data it produces. The process of calibrating a model also imparted an understanding of the effect that material settings such as reflectance and transmittance have on the lighting conditions of the space. The use of a DIVA/Rhino software program offered a more controlled state of testing. Although a digital model did not produce 100% accurate results compared to real-site data, the simulated results followed similar patterns to the site data so that one could understand the possible daylighting performance under additional simulated scenarios. 80 If the ideal mode of daylighting research for illumination consists of accuracy as well as results under variable conditions and times of year, neither the site research nor the digital model research fulfills those requirements. But the developed protocol offers a method of taking advantage of both modes of data collection while offering the benefits of both types of research. While these modes of data analysis do not independently offer perfect results, through this protocol they together provide more accurate data then if they were run independently. The protocol used for this site research showed that seasonal variations make a difference in the light levels of the space. Rather than keeping a static setting on shading controls, customizing the shading program according to the time of year can increase the use of daylighting throughout the exhibition time. To set a program of dynamic shading increased the potential to use more daylight to meet illuminance levels in the space, which decreased the use of electricity. Figure 79. Diagram of Protocol 6.4 Future Work 6.4.1 Reverse Process The protocol involved gathering site data, simulating results in a software program, and creating a tool to direct a solar remediation program. A future possibility to further validate the protocol is to predict daylighting performance of the LACMA space with a program under future conditions that will be taking place on-site. Then during the duration of that LACMA exhibition, light levels can be measured to validate the software simulated predictions. 6.4.2 Additional Mode of Data Collection: Physical Model A physical model built to match the material properties of the exhibit during the time of site data collection could be then tested as an empty building with the desired shading variables. Some research has been conducted on this method of daylight prediction. A solar heliodon could be used to tilt the model for the desired times of year. Photometric sensors would be placed on the model where the grid points in the real space were located. In order to convert the data from the sensors into an illuminance value, the equipment would need to go through multiple steps (Figure 80). The photometric sensors go through a voltage converter, which are then ran through a HOBO that processes the information, which is uploaded to a computer via HOBO software, then converted into an illuminance level value through the equation 81 shown in Figure 80. Figure 80. Diagram of equipment testing process. 6.4.3 Improved Grasshopper Script Tool The script tool created in grasshopper can be developed further to better the user interface and increase its customizable capabilities. Further testing can be performed in grouping component categories together in order to simplify the interface and ease the simulation process, incorporating additional parameters, and maximizing the ease of use. Additional parameters such as various glazing types can be created, as well as changing geometry forms of the facade. 6.4.4 Further Research into Protocol Development The steps followed in the LACMA research formed a process that could be applied to other existing buildings with a dynamic program and changing solar needs. The process could be applied to additional museums with other glazing characteristics and programmatic elements. These processes can be compiled and refined to start the foundation of a standard protocol that can inform solar control techniques for operators of existing museum buildings. 6.5 Conclusion Summary Museums are special buildings which have complex issues with the use of natural light. They face opposing constraints of sufficient light for enjoying the artwork and too much light for preserving it. For the application of daylighting remediation in existing buildings, the results of a digital model calibrated through real site conditions can direct a strategy of daylighting controls responsive to dynamic program needs. The project went through a process which involved gathering site data, simulating results in a software program, and creating a tool to direct a solar remediation program. Illuminations levels were collected on-site during as-is gallery conditions throughout multiple times of year, and a digital model was calibrated in comparison with the on-site data. Using site data provided accuracy and real building performance information, while using data from digital simulations via DIVA/Rhino allowed for testing of multiple variables including changing shading configurations and times of year. These steps culminated in a script tool created through Grasshopper that enabled the simulation of many parameters for a customized gallery conditions. This tool could inform a shading controls program for the changing seasons during future exhibit displays. This case study showed that the tool could be applied to other cases. With new gallery exhibit designs and rotating artwork, the lighting level requirements change. Shading 82 configurations can be set to accommodate the necessary illumination levels, however the solar conditions change with the weather conditions and times of day and year. Therefore, the case study illustrated that the tool is useful in guiding a dynamic system that could be applied to many changing and future cases. The variations in solar controls can be decided based on the footcandle requirements for the artwork, the exhibit display times throughout the calendar year as well as the desired layouts and materials of the exhibit design. The process was applied to the Resnick Pavilion at the Los Angeles County Museum of Art and demonstrated the ability to track behavior and evaluate solutions to different dates, types of displays and artwork, including settings for employing lighting controls. This could prove valuable for formation of a protocol that informs the design and management of solar controls in other museum buildings.

Abstract (if available)

Abstract Museums are a ubiquitous building type

Linked assets

University of Southern California Dissertations and Theses

Conceptually similar

PDF

Daylighting study of a LEED platinum laboratory building: a post-occupancy evaluation comparing performance in use to design intent

PDF

Environmentally responsive buildings: multi-objective optimization workflow for daylight and thermal quality

PDF

Evaluation of daylighting circadian effects: Integrating non-visual effects of lighting in the evaluation of daylighting designs

PDF

Façade retrofit case study: the Edith Green-Wendell Wyatt Federal Building

PDF

Daylight and health: exploring the relationship between established daylighting metrics for green building compliance and new metrics for human health

PDF

Studies in preliminary design of fenestration: balancing daylight harvesting and energy consumption

PDF

The intelligent control strategy of kinetic façades for daylight and energy performance: evaluating the daylight effect of adaptive systems based on parametric workflow

PDF

Integrating non-visual effects of lighting in the evaluation of electrical lighting designs for commercial offices

PDF

District energy systems: Studying building types at an urban scale to understand building energy consumption and waste energy generation

PDF

Double skin façades performance: effects on daylight and visual comfort in office spaces

PDF

Simulation-based electric lighting control algorithm: integrating daylight simulation with daylight-linked lighting control

PDF

Daylight prediction: an evaluation of daylighting simulation software for four cases

PDF

Enhanced post occupancy evaluation (POE) for office building: improvement of current methodology to identify impact of ambient environment

PDF

Environmental adaptive design: building performance analysis considering change

PDF

Visualizing thermal data in a building information model

PDF

Daylighting in Riyadh and Los Angeles: comparison of cultural factors in potential market penetration

PDF

Comparing visual comfort metrics for fourteen spaces using simulation-based luminance mapping

PDF

Automating fire code compliance using BIM and Revit plug-ins

PDF

Exterior glare simulation: understanding solar convergence from concave facades using heat maps

PDF

Effective light shelf and form finding: development of a light shelf design assistant tool using parametric methods

Asset Metadata

Creator Hahn, Joyce (author)

Core Title Measuring daylight: analysis of daylighting at LACMA's Resnick Pavilion

School School of Architecture

Degree Master of Building Science

Degree Program Building Science

Publication Date 02/08/2018

Defense Date 04/29/2016

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag Building Science,daylight,daylighting,museum,OAI-PMH Harvest

Format application/pdf (imt)

Language English

Contributor Electronically uploaded by the author (provenance)

Advisor Schiler, Marc (committee chair), Kensek, Karen (committee member), Konis, Kyle (committee member)

Creator Email hahnjoyc@usc.edu,joycebhahn@gmail.com

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c40-300782

Unique identifier UC11279577

Identifier etd-HahnJoyce-4762.pdf (filename),usctheses-c40-300782 (legacy record id)

Legacy Identifier etd-HahnJoyce-4762.pdf

Dmrecord 300782

Document Type Thesis

Format application/pdf (imt)

Rights Hahn, Joyce

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the a...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus MC 2810, 3434 South Grand Avenue, 2nd Floor, Los Angeles, California 90089-2810, USA