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Development of circadian-effective toplighting strategies: using multiple daylighting performance goals for dementia care communities

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Development of circadian-effective toplighting strategies: using multiple daylighting performance goals for dementia care communities

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DEVELOPMENT OF CIRCADIAN-EFFECTIVE TOPLIGHTING
STRATEGIES

Using multiple daylighting performance goals for dementia care communities

By

Tannaz Tahmassebi

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 2019

i

ACKNOWLEDGEMENTS

This work is dedicated to my family that helped and supported me along the way. I wouldn’t be able to make it without
your support and patience. I would also like to express my appreciation to my thesis chair, Professor Kyle Konis, and
my committee members, Professor Victor Albert Regnier, and Professor Karen M. Kensek.

I would like to thank the faculty and friends in Master of building Science program, University of Southern California
for your support.

ii

COMMITTEE MEMBERS

CHAIR:

Kyle Konis, Ph.D., AIA
Assistant Professor
USC School of Architecture
kkonis@usc.edu

Second Committee Member

Victor Albert Regnier, FAIA
Professor
USC School of Architecture
regnier@usc.edu

Third Committee Member

Karen M. Kensek, LEED BD+C
Professor of Practice
USC School of Architecture
kensek@usc.edu

iii

ABSTRACT

In recent years, there is a growing awareness of the link between lighting and human health. Light is one of the
drivers for the circadian system, which regulates the biological rhythms that control a number of important human
biological functions. Development of circadian-effective top lighting strategies for dementia care communities to
maximize the circadian stimulus is important. Corridors within dementia care communities are important for patients
as they can spend a considerable amount of their time during the day in such spaces. A proper EML must be
achieved for circadian effect and appropriate illuminance with minimum glare.

The 350 EML (Equivalent Melanopic Lux) threshold specified in the WELL Building Standard is the metric used
for circadian stimulus. The lighting quantity “melanopic illuminance” is a metric for measuring the non-visual effect
of light weighed by the sensitivity of the melanopsin containing light detectors within the human eye (Al Enezi et
al., 2011). Utilization of daylight can be an effective strategy for supporting healthy circadian rhythms, which, in
turn, are associated with better sleep, improved mood, and behavior in patients with dementia and Alzheimer
disease.

ALFA (Adaptive Lighting for Alertness), a circadian lighting design software, was used to analyze and predict
circadian stimulus EML (Equivalent Melanopic Lux) for different skylight designs, sky conditions, and hours
throughout the year in a dementia care facility to satisfy 350 EML defined by WELL building standards. Six
different test cases were created in Rhino and integrated in with ALFA to perform circadian analysis and glare
simulation. Design strategies that performed better were found and scored based on the simulation result.

The results showed that light scoop can be an effective strategy for overcast climate condition. Clerestory has the
best overall performance and can be an effective strategy for a climate, like Los Angeles with year-round mostly
sunny days.

KEY WORDS: Circadian lighting, dementia care facility, WELL building standards, daylighting, EML

HYPOTHESIS

The dosage of light over the course of a day can be controlled by implementing circadian-effective daylighting
strategies in building skylights without the need for supplemental electric lighting.

Research Objectives

• Create a new daylighting guidelines and design workflow for designers that focuses on circadian-effective
strategies.
• Use the new circadian lighting analysis software (ALFA) to run the circadian lighting simulations and
visual comfort for this research.
• Focus on the importance of corridor spaces in dementia care communities, based on the importance of higher
level of circadian stimulus during the early morning hours and declining level of circadian stimulus in the
afternoon.
• Control the dosage of light over the course of a day with implementing circadian-efficient daylighting
strategies in buildings during the day without the need of electric lighting.

iv

TABLE OF CONTENTS

ACKNOWLEDGEMENTS ........................................................................................................................................... i
COMMITTEE MEMBERS ........................................................................................................................................... ii
ABSTRACT .................................................................................................................................................................iii
TABLE OF CONTENTS…………………………………………………………………………………………… ..iv
1. INTRODUCTION ..................................................................................................................................................... 1
1.1 Circadian System ................................................................................................................................................ 1
1.2 Benefits of Daylight ............................................................................................................................................ 2
1.3 WELL Building Standard ................................................................................................................................... 2
1.4 ALFA .................................................................................................................................................................. 2
1.5 24-Hour Lighting……………………………………………………………………………………………… .3
1.6 Causes of Circadian disruption ........................................................................................................................... 3
1.6.1 Jet Lag Disorder……………………………………………………………………………………………4
1.6.2 Shift-work Sleep Disorder ………………………………………………………………………………...4
1.6.3 Aging Adults………………………………………………………………………………………………..4
1.6.4 Office workers in winter…………………………………………………………………………………....4
1.7 Terminology ....................................................................................................................................................... 4
1.7.1 Circadian Stimulus………………………………………………………………………………………. .4
1.7.2 Equivalent Melanopic Lux ……………………………………………………………………………….5
1.8 Summary………………………………………………………………………………………………...………5

2. BACKGROUND AND LITERATURE REVIEW .................................................................................................... 7
2.1 Introduction ........................................................................................................................................................ 7
2.2 Daylighting Design Reviews……………………………………………………………………………………7
2.3 Lighting in Long term care communities ............................................................................................................ 9
2.4 Circadian Lighting ............................................................................................................................................ 10
2.4.1 Ganglion cells……………………………………………………………………………………………..10
2.4.2 24-Hour Lighting Scheme…………………………………………………………………………………11
2.4.3 Circadian Daylight in Practice…………………………………………………………………………….12
2.5 Visual Discomfort……………………………………………………………………………………………..14
2.6 Standard ............................................................................................................................................................ 14
2.6.1 WELL Building Standard………………………………………………………………………………...15
2.6.2 LEED. ....................................................................................................................................................... 16
2.7 Evaluation Tool ................................................................................................................................................. 16
2.7.1 Rhino……………………………………………………………………………………………………..16
2.7.2 ALFA…………………………………………………………………………………………………….17
2.8 Case Study………………………………………………………………………………………………………17
2.9 Summary………………………………………………………………………………………………………..18
3. METHODOLOGY .................................................................................................................................................. 19
3.1 Introduction ...................................................................................................................................................... 19
3.2 Desgin (performance) objectives ...................................................................................................................... 19
3.3 Create 3D Model .............................................................................................................................................. 19
3.3.1 Skylights ................................................................................................................................................... 20
3.4 Analysis Setting ................................................................................................................................................ 21
3.4.1 Set Weather Conditions Parameters .......................................................................................................... 22
3.4.2 Assign Material Parameters ...................................................................................................................... 23
3.5 Simulation Settings ........................................................................................................................................... 23
3.5.1 Configure Analysis Grid…………………………………………………………………………………..23
3.5.2 Set Simulation Quality Settings…………………………………………………………………………...25
3.5.3 Visual Comfort…………………………………………………………………………………………….25
3.6 Data Analysis…………………………………………………………………………………………………..26
3.6.1 Sample Quantitative Data…………………………………………………………………………………26
3.6.2 Visual Data………………………………………………………………………………………………..27
3.7 Performance Evaluation………………………………………………………………………………………..27
v

3.8 Summary………………………………………………………………………………………………………..28
4. RESULTS ................................................................................................................................................................ 30
4.1 Test Cse Scenarios ............................................................................................................................................ 30
4.1.1 Clerestory Tes Case…………………………………………………………………………………..…....31
4.1.2 Light Scoop 45-degree Test Case…………………...……………………………………………...……..33
4.1.3 Light Scoop 60-degree Test Case…………………………………………………………………………35
4.1.4 Sawtooth Skylight Test Case……………………………………………………………...………………37
4.1.5 Clerestory Angled Test Case Test Case……………………………………………………………..……39
4.1.6 North-facing Vertical Light Scoop Test Case…………………..………………………………………...41
4.2 Overall Performance Evaluation........................................................................................................................ 43
4.3 Comparison of circadian lighting evaluation based on different sky condition ................................................ 44
4.4 Comparison of circadian lighting evaluation based on different seasons ......................................................... 44
4.5 Overall Final Score ........................................................................................................................................... 45
4.6 Summary .......................................................................................................................................................... 46
5. DISCUSSION ......................................................................................................................................................... 47
5.1 Evaluation of different test case models ........................................................................................................... 47
5.1.1 Evaluation of Clerestory Test Case Model…………………………………………...………………..….48
5.1.2 Evaluation of Light Scoop 45-degree Test Case Model.…………………………………………...……..48
5.1.3 Evaluation of Light Scoop 60-degree Test Case Model…..………………………………………………35
5.1.4 Evaluation of Sawtooth Skylight Test Case Model…………………..…………………...………………49
5.1.5 Evaluation of Clerestory Angled Test Case Test Case Model…...…………………………………..……50
5.1.6 Evaluation of North-facing Vertical Light Scoop Test Cas Model.………..……………………………...50
5.2 Comparison of overall performance evaluation ................................................................................................ 51
5.3 Comparison of circadian lighting evaluation results based on different sky conditions ................................... 52
5.4 Comparison of circadiana lighting evaluation results based on different seasons…………………………….52
5.5 Overall final score……………………………………………………………………………………………..53
5.6 Summary………………………………………………………………………………………………………53
6. CONCLUSION ....................................................................................................................................................... 55
6.1 Improvements to the current workflow............................................................................................................. 55
6.1.1 More Variables. .......................................................................................................................................... 56
6.1.2 Use of optimization Software…………………………………………………………………………..…56
6.1.3 More Locations……………………………………………………………………………………………56
6.1.4 Simulation for 365 days throughout a year………………………………………………………………..56
6.1.5 Interpreting the best- and worst-case Scenario……………………………………………………………56
6.1.6 Design Objectivee Assumptions…………………………………………………………………………..58
6.1.7 More Lighting Strategies………………………………………………………………………………….58
6.2 Future Work ...................................................................................................................................................... 58
6.2.1 Circadian Lighting ...................................................................................................................................... 58
6.2.2 Better Base case Location .......................................................................................................................... 58
6.2.3 Other Rooms Instrad of Corridors .............................................................................................................. 58
6.2.4 Glare Avoidance and Automated Shading Systems.................................................................................... 58
6.2.5 Electric Lighting and Color tuninig LEDs………………………………………………………………...58
6.2.6 Physical Model and More Real Case Studies……………………………………………………………..59
6.2.7 Solar Heat Gain………………………………………………………………...………………………….59
6.3 Summary……………………………………………………………………………………………………….59
REFERENCES ............................................................................................................................................................ 60

1
1. INTRODUCTION

According to the World Alzheimer’s association annual report, “Every 3.2 seconds, a new case of dementia occurs
somewhere in the world.” At least 46.8 million people are suffering from dementia around the world. Previous
studies have shown the importance of daylight on people with dementia (Konis, 2018b). Lighting is emerging as a
key factor due to the discovery of the intrinsically photosensitive retinal ganglion cells (ipRGCs), which are light
sensitive neurons in the retina of the eye that plays a major role in synchronizing the circadian rhythms (Lucas et al.,
2014) . This growing awareness led to develop new requirements by the international building standards like the
WELL Building Standard. In this sense, circadian design becomes a broader notion among designers and engineers.
These requirements are still being developed for dementia care communities. There is no specific guidance for
indoor lighting other than those requirements by Illuminating Engineering Society (IES). However, it doesn’t have
any specific requirements for circadian lighting.

This chapter introduces circadian system terminology, benefits of daylight, WELL building standard, ALFA, 24-
hour lighting scheme, causes of circadian disruption, and terminology.

1.1 Circadian System Terminology

Circadian rhythm is a 24-hour biological cycle that occurs in human beings, plants, animals, fungi, and cyanobacteria
(Edgar et al., 2012). Circadian is derives from the Latin phrase “Circa diem”, which means “about a day” (M. H.
Vitaterna, Takahashi, & Turek, 2001). This rhythm occurs every 24 hours that indicates the “day and night cycle”
which has a strong relationship between the living being biological clock (figure 1-1).

Figure 1-1: Overview of biological circadian clock in humans (“File:Biological clock human.svg - Wikimedia Commons,” n.d.).
Researchers at Harvard shown that this period is close to but not exactly 24 hours (M. Vitaterna, Takahashi, & Turek,
2001). This 24-hour cycle is linked with the hormone suppression such as melatonin and serotonin, brain activity and
other biological activities which are coordination to keep the 24- hour of living being. Melatonin is a hormone that
can help humans to sleep (figure 1-2). The pineal gland, which is in middle of the brain, is responsible for melatonin
suppression (Figueiro & Rea, 2015). This circadian rhythm can help humans to wake up every day at the same time
and getting to sleep in the same hour as previous days. The circadian rhythm is regulated by some nerve cells called
suprachiasmatic nuclei (SCN) (M. H. Vitaterna et al., 2001). These cells send signals to parts of the brain that can
control body temperature, hormones like melatonin which links to our sleep pattern (M. H. Vitaterna et al., 2001).
Circadian rhythm plays a pivotal role in human beings’ health. People who have the irregular pattern of sleep suffer
from the disruption in the sleep-wake cycle (Edgar et al., 2012) . Circadian rhythm has some main properties which
is common in all organisms (Edgar et al., 2012) . A healthy circadian system can reset itself to follow the pattern every
day, when the organisms will be devoid of external stimuli like exposure to too much light at night.

2

Figure 1-2: Fluctuation in melatonin levels over a 24-hour period (“Melatonin and Sleep - Gateway Psychiatric,” n.d.)

1.2 Benefits of Daylight

Daylight is defined as light that is available during the day from the sun and sky. Since humans spend most of their
times indoor, it is important to design a building in a way that provides enough exposure to daylight. One way that
designers can bring natural daylight to the building is by skylights. Daylight is critical to the health and well-being of
building occupants, and studies have shown the strong relation between exposure to daylight and disruption in mood
and sleep/wake cycle and can help reduce the symptoms of depression in people living in dementia care communities
(Konis, 2018b). Daylight has aesthetic and health benefits over the electrical lighting. Exposure to natural light can
regulate our internal body clock and improve our alertness, mood, and health (Figueiro & Rea, 2015). Buildings that
have efficient daylighting strategies can reduce their energy consumption (Kischkoweit-Lopin, 2002).

The occupant experience in building can be richer during different time of the day and the variance in illumination
from the daylight (Boubekri, Cheung, Reid, Wang, & Zee, 2014). Utilizing natural light is critical to support healthy
circadian entrainment in buildings. Daylight can be delivered into spaces via windows and skylights. Spatial
orientation, view to outdoors, increasing the interest are some of the benefits of using daylighting strategies in
buildings (Design, 2004) .

1.3 WELL Building Standard

Developed by Delos Living LLC and managed by International WELL Building Institute (IWBI), the WELL
Building Standard stepped further for its distinguishing visual lighting and circadian lighting (International WELL
Building Institute, 2018). Under the Light category, in section 54, WELL uses “Melanopic Light Intensity” as an
index for circadian lighting evaluation of mainly four categories which are working areas, living environments,
breakrooms, and learning areas (International WELL Building Institute 2015). Melanopic light intensity is
calculated by a unit of “Equivalent Melanopic Lux,” which will be discussed in section 2.3.3. WELL provides a
relatively easy approach for architects to design based on humans’ circadian rhythm.

1.4 ALFA

ALFA (Adaptive Lighting for Alertness) is a software, developed by Solemma, 2018, is able to predict the non-
visual effects of light that will help architects and lighting designers to design healthier environments for people.
This software allows designers to adjust various weather conditions, materials, and luminaires for different times of
the day. After installation, ALFA runs inside the Rhino user interface and comes with a catalog of many different
materials to ensure more accurate results and it also provides various spectral luminaire and glazing library. This
3

software provides 360-degree renderings for any view position in the model which can calculate the light spectrum
and the equivalent melanopic lux reaching at the back of the eye. ALFA uses Radiance (a lighting engine) to carry
out 81 color channels renderings (figure 1-3) (“Solemma LLC,” n.d.). This allows designers to apply several
strategies in the early design stage of the project and calculate the requirements by international building
certification systems, including the WELL Building Standard.

Figure 1-3: ALFA uses Radiance to carry out 81 color channel (“Solemma LLC,” n.d.)

1.5 24 - hour lighting scheme

Illuminating Engineering Society (IES) has proposed some indoor lighting guidance for the Aging and Partially
Sighted Community, but there isn’t any requirement specifically for circadian lighting. A 24-hour lighting scheme is
a proposal by the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute for older adults that not only
provides good lighting for visual effect of light concerns but also introduce some requirements to promote the
circadian stimulation during the day and night (Figueiro, 2008). This lighting scheme suggests higher circadian
stimulation in the morning for at least 2 hours after waking. Daytime lighting scheme levels can be as high as 1,000
lux in the morning, and it may be reduced to no less than 600 lux. Evening lighting scheme level can be no more
than 60 lux during the evening hour (figure 1-4).

Figure 1-4: 24-hour lighting Scheme concept (Figueiro, Gonzales, & Pedler, 2016)
4

1.6 Causes of circadian disruption

This section introduces Jet Lag Disorder (JLD), shift-work sleep disorder (SWSD), aging adults, and office workers
in winter as the examples of circadian disruption.

1.6.1 Jet Lag Disorder (JLD)

Jet lag disorder is one of the best examples of circadian disruption. When you fly to another time zone during a long-
distance flight, the temperature and light conditions are different from the place of departure and place of destination
(Noell-Waggoner, 2006). The whole circadian rhythm gets disturbed due to such differences (ILP,2015). During the
flight the light conditions in the cabin remains the same, and it is mostly dark. The lack of exposure to the right amount
of light in the right time can cause the circadian disruption.

1.6.2 Shift-work Sleep Disorder (SWSD)
Some people must work during the night. So, the sleep-wake cycle in these people is not aligned with the biological
clock. In other words, these people suffer from the circadian misalignment. These people go to work at night and most
of the time they are under the electric light. They need to stay awake when the biological clock tells them to go to
sleep. Using saturated red light in the increases brain activity and reduces reaction time and sleepiness which does not
suppress melatonin and cause circadian disruption (Figueiro et al., 2016).

1.6.3 Aging Adults

Visual capabilities in aging people are reduced due to the thickening of the eye lens (Figueiro, n.d.). The amount of
light that they receive at the back of the eye is less than the young people. Various design methods have been
introduced in the circadian lighting just for the older people. Using low light level and warm colour LEDs to avoid
sleep disruption, and it should also trigger their daily circadian system (Figuerio, 2016).

1.6.4 Office Workers in Winter

Morning light or daylight is needed to promote entrainment (Figueiro et al., 2016). Many office workers can arrive
and leave work in the dark and there is less opportunity for them to be exposed to the daylight which is essential for
the alertness. These people suffer from poor sleep, low concentration, mood disorder and lack of performance (ILP,
2015).

1.7 Terminology

This section introduces circadian stimulus and Equivalent Melanopic Lux (EML) to describe the circadian lighting
metrics.

1.7.1 Circadian Stimulus (CS)

Circadian Stimulus (CS) is a metric proposed by the Lighting Research Center at Rensselaer Polytechnic Institute
(LRC) to quantify light effects on the human circadian system (Figueiro et al., 2016). Circadian stimulus is based on
the extent to which a given light source of specific amount of spectrum that suppress melatonin. Although humans
don’t produce melatonin during the day, CS can be used as a surrogate metric for how much a given light affects the
biological clock. It ranges from 0.1 (threshold) to 0.7 (saturation). For example, CS=0.1 is used for high melatonin
levels in dim light, CS=0.7 is the maximum suppression that has been observed (Figueiro et al., 2016). Based on a
research by Lighting Research Center, CS (Circadian Stimulus) can be different based on the building type and the
age of occupants (Figueiro et al., 2016). To calculate the CS, since the human’s eye is vertical, the eye level with a
vertical plane needs to be considered, since the photosensitive cells inside the eye are responsible for the non-visual
effect of light on human-being (Figueiro et al., 2016).

5

1.7.2 Equivalent Melanopic Lux (EML)

EML stands for Equivalent Melanopic Lux. EML is a metric for measuring the biological effects of light on
humans.EML is a proposed alternate metric by Lucas. Photosensitive retinal ganglion cells (ipRGCs) are the non-
image forming photoreceptors in human eyes that can regulate the human circadian system once they are exposed to
light (Lucas et al., 2014). Based on a research by Lucas, the role of these photoreceptors in our eyes is not related to
image production (Lucas et al., 2014). EML as a metric is weighted to the ipRGCs response to light and translates
how much spectrum of a light stimulates ipRGCs and affects the circadian system (Zofchek, 2016) (Hagen &
Richardson, 2016).

The melanopic and photopic sensitivity curves are different. Since the circadian system is more sensitive to blue
light with shorter wavelength, the melanopic relative power reaches its peak in shorter wave length while the
photopic relative power reaches its peak in a longer wavelength (figure 1-5).

Figure 1-3: Melanopic Sensitivity vs Visual Optical Sensitivity Curves (International WELL Building Institute, 2018)

1.8 Summary

The concept of circadian lighting is an emerging topic. Circadian rhythm is a 24-hour cycle that is common in all
human beings, plants, and animal. This 24-hour cycle is linked with the hormone suppression such as melatonin and
serotonin, brain activity and other biological activities which are coordination to keep the 24- hour of living being.
Exposure to natural light can regulate our internal body clock and improve our alertness, mood, and health (Figueiro
& Rea, 2015). The lack of exposure to the right amount of light at the right time over the course of a day can cause
circadian disruption. Utilizing natural light is critical to support healthy circadian entrainment in buildings. Daylight
can be delivered into spaces via windows and skylights. The WELL Building Standard is the first rating system that
uses circadian lighting.

ALFA (Adaptive Lighting for Alertness) is a software, developed by Solemma, 2018, can predict the non-visual
effects of light that will help architects and lighting designers to design healthier environments for people. The 24-
hour lighting scheme proposed by Lighting Research Center (LRC), suggests higher circadian stimulation in the
morning for at least 2 hours after waking. Daytime lighting scheme levels can be as high as 1,000 lux in the
morning, and it may be reduced to no less than 600 lux. Evening lighting scheme level can be no more than 60 lux
during the evening hour.

Jet Lag Disorder (JLD), Shift-work Sleep Disorder (SWSD), aging adults, and office workers in winter, are the best
examples of circadian disruption. These people suffer from poor sleep, low concentration, mood disorder and lack of
performance. Since they are not exposed to daylight at the right time.

6

Circadian Stimulus (CS) is a metric proposed by the Lighting Research Center (LRC) to quantify light effects on the
human circadian system (Figueiro et al., 2016). Circadian stimulus is based on the extent to which a given light
source of specific amount of spectrum that suppress melatonin. To calculate the CS, since the human’s eye is
vertical, the eye level with a vertical plane needs to be considered, since the photosensitive cells inside the eye are
responsible for the non-visual effect of light on human-being (Figueiro et al., 2016).
7

2. BACKGROUND AND LITERATURE REVIEW

This chapter is about daylighting design reviews, lighting in long term care communities, circadian lighting, visual
discomfort, standards, evaluation tool, and a case study.

2.1 Introduction

In the United States, it will be expected to have more people over age 65 than under age 17, by 2030 (Ortman,
Velkoff, & Hogan, 2014). The population of people living with dementia is predicted to increase to 74.7 million by
2030 (Prince et al., 2015). People living with dementia require to stay in long-term care communities, which will
increase the demand for buildings which are designed for this purpose. It’s crucial to enhance the design and quality
of this communities that will serve residents. A pilot study conducted supports the hypothesis that increased access
to daylight indoors has the potential to improve the well-being of people living in dementia care communities
(Konis, Mack, & Schneider, 2018). Daylight has many health impacts on people. The emerging knowledge of non-
visual effects of light which is responsible for regulating the circadian rhythm and physiological functions such as
hormone suppression, body temperature, alertness, and mood. Daylight design focuses on visual lighting quality,
solar heat gain, and solar radiation, but with the discovery of circadian lighting concept designers need to step
further and bring well-being of occupants as a factor in design considerations. The new rating systems such as the
WELL Building standard introduced circadian lighting requirement in the lighting sections with a minimum
threshold of 250 EML in different spaces, but there is no specific requirement targeting the dementia and long-term
care communities. Now, designers are more likely to ignore effective daylighting and trying to meet these
requirements by color-tunable LED lighting.

2.2 Daylighting Design Reviews

Architects know the benefit of daylight over electrical lighting, but the question is what the healthy dosage of light
is, and when human body needs to be exposed to daylight (Konis, 2017). The circadian system is more sensitive to
shorter wavelength of light, that is more similar to the light spectrum of the clear sky. In the early stages of design,
designers can adjust the building form, orientation, ceiling height, and aperture size to maximizing the area with the
highest circadian entrainment (Konis, 2017). Depression symptoms among study participants in the daylight
intervention group were, on average, found to decrease after a 12-week pilot study (Konis et al., 2018). There are
some guidelines focusing on visual effect of light in dementia care communities, but no one started tuning the
specific aperture for circadian lighting. A design guideline can help designers and daylighting expert to make
decisions in the early stages of the design process. Daylighting design objectives, circadian lighting, and lighting in
dementia care buildings are introduced in this chapter.

Based on a field study, distance from windows, view orientation has a strong impact on the predicted circadian
stimulus in a space (Konis, 2018a). For example, spaces 0m to 3m away from windows can be considered as a
circadian effective zone. However, the design guidelines for daylighting describes the range of a daylit zone 1.5 to
2.5 times the window head height (Konis, 2018a). Views looking at windows in the range of 3m to 5m distances
resulted in lower percentage of circadian-effective zone. View orientation is another factor that can affect the
circadian stimulus. Since people activities in a space require different directions, lighting designers should consider
the occupants activities with multiple direction in lighting analysis. However, most of the existing daylighting
metrics such as Spatial Daylight Autonomy (SDA), that is a horizontal-based metric, do not consider orientation as a
factor in daylighting performance. It’s important to map the circadian-effective zone in a building especially those
area that has the high circadian stimulus during the morning periods and this will help designers to achieve their
design goals (Konis, 2018a).

Light Scoops

Developed by the Lighting Research Center (LRC), is a south-facing skylight that uses tilted panels to bring direct
sunlight into the space (figure 2-1) (Radetsky & Brons, n.d.). Light scoops provide less direct sunlight during the
summer while provides more sunlight in winter. Light scoops work better in overcast sky conditions. There are some
advantages associated with light scoops over the conventional skylights. To increase the light scoop efficiency, wall
finishes should be light colored, high visible-transmittance glazing should be used. Adding a well or baffles is
8

recommended to avoid glare. LRC recommends tilting the glazing by 45- and 60-degree angle will provide efficient
solution depending on the latitudes (table 2-1).

Figure 2-1: Light Scoop (Radetsky & Brons, n.d.)

Table 2-1: Different Light Scoop Parameters (Radetsky & Brons, n.d.)

Angle Glazing Area Back Sides Height Glass
specification
White
color
Light
Scoops
45
degree
60
degree
To increase the
illuminance the
amount of
glazing area or
quantity of light
scoops.
Short,
curved,
and long
back.
Splayed
sides to
increase
daylight
penetration.
Light
scoop’s
well height
should be
minimized.
high visible-
transmittance
glazing.
Interior,
roof
membrane,
should be
light
colored.

LRC compared four different types of top lighting strategies, such as roof monitors, horizontal skylight, light scoops
with 2 different angles, with clear glazing and same area in New York. The result showed that light scoops work
more efficiently to bringing daylight in to the space, which can be a strategy to reduce the energy consumption since
it can illuminate the space adequately during day hours (figure 2-2) (Radetsky & Brons, n.d.).
9

Figure 2-2: Comparison of different top lighting strategies (Radetsky & Brons, n.d.)

Based on a comparative study of different windows, clerestories, and skylights by Treado, skylights are the most
efficient daylighting strategies in terms of solar heat gain and lighting (Treado, et al., 1984). Skylights can lower the
electricity usage by 77% in comparison with a base case that has no daylighting strategy. Clerestories are more
efficient in terms of daylighting and energy in comparison with windows of the same size. South-facing clerestories
and windows are more efficient than north-facing ones (Treado et al., 1984)

Skylights with a height/width ratio near 1/1 are more efficient in terms of uniformity of daylight (Acosta et al.,
2015). Skylights that has less spacing in between, provide greater daylight and the more appropriate monitor
skylight has the distance proportional to the height/width ratio (Acosta et al., 2015) . In terms of illuminance
distribution, the distance between skylights should be the same as height of the space. Sawtooth, curved shapes
skylights are more efficient than the rectangular ones, in terms of bringing more daylight into the space (Acosta et
al., 2015). Splaying the ceiling back is one of the strategies to increase the illuminance in the surface (Ladan
Ghobad , Wayne Place, n.d.). Based on a study by Acosta on different monitor skylights, rooms implemented with
monitor skylights with a height to width ratio of 1/1 provides highest daylight factors regardless of the size of the
room (Acosta et al., 2015) . This study focuses on slanted, rectangular, sawtooth, and curved monitor skylights.
While Rectangular monitor skylights provides the lowest daylight factors.

2.3 Lighting in long term care communities

As mentioned in previous chapter, the aging eye is less sensitive to light, because the amount of light that reaches
the retina in the eye is less (Figueiro, n.d.) . The amount of light that reaches the retina in the age of 65 is one third
of the amount of light reaches the eye of a person in their 20s (Noell-Waggoner, 2006) . Based on a survey of 53
nursing homes in united states, 45 percent of hallways, 17 percent of activity rooms and 51 percent of the rooms are
not adequately illuminated (Noell-Waggoner, 2006). Since aging people experience the visual impairment 13 to 15
times more than other people, so it’s crucial to design places with enough daylight. A study showed that the day
light exposure for people age 60-100 years living in long term care communities is only 9 minutes daily (Ancoli et
al., 2002). Another detriment of living in long term care communities that are not illuminated appropriately is lack
of calcium and vitamin D, that interior lighting cannot provide the appropriate light with the specific light spectrum
10

(Noell-Waggoner, 2006) . A study in Japan mentioned that 15 minutes of sunlight exposure during clear weather
every day will reduce the hip fractures by 84 percent (Noell-Waggoner, 2006). There are some lighting guidelines
for older people that focusing on glare, visibility task, and design considerations for corridor spaces (table 2-2).

Table 2-2: summary of lighting guidelines for older people (Torrington, Tregenza, & Noell-Waggoner, 2007)
Minimize direct glare Generally, light sources should be as far as possible above the occupants’ eye level.
It is recommended to not place windows at the end of corridors, otherwise the
brightness should be reduced by blinds or curtains. Using of blinds or other shading
strategies to block the low elevation daylight.
Increase the visibility of
tasks
Increase the illuminance level for different tasks like reading, socializing with other
people, walking. Enhance the contrast within the task area.
Minimize reflected glare Surface materials should be matte and not glossy to avoid the reflected glare.

General lighting without
large brightness
differences
Similar rooms need to be illuminated with different lighting and decoration.
Use of electric lighting during the night to avoid falling at night.

Design considerations
for corridor spaces
The circulation areas such as corridors and hallways should be considered as an
important space. Lighting design should help occupants with wayfinding. These
circulations areas should be an attractive spot through the building.
The interior spaces should be designed in a way that people with dementia can
recognize it since they don’t have memory or recent activities.

2.4 Circadian Lighting

Circadian lighting is an emerging topic. Since the word light is defined as the optical radiation which can produce
visual sensation in humans, the word circadian should be used with the word light to refer to the non-visual effects
of light and human body response. Circadian light is a stimulus to the circadian system in human bodies.
Researchers at lighting research center in New York (LRC) have defined the term “circadian light” based on the
light capability of nocturnal melatonin suppression (Rea, Figueiro, Bierman, & Bullough, 2010).

Designers should know the effect of light into human bodies. This section explains the ganglion cells, the 24-hour
lighting scheme, and circadian daylight in practice.

2.4.1 Ganglion cells

As a stimulus, light is converted into signal by ganglion cells in the brain. Ganglion cells work for the non-visual
part of light (figure 2-3). Rods and cones are the most well-known ganglion cells that work for human beings’
visual function. Another ganglion cell, called intrinsically photoreceptive retinal ganglion cell, outside the retina is
critical to non-visual comfort (Lucas et al., 2014) . The rod is most sensitive photoreceptor to the wavelength at
500nm with photopigment called rod opsin (Lucas et al. 2014). Other photoreceptors, called cones, consist of three
subcomponents, which are short-wavelength cones (most sensitive to 420nm) with photopigment called S-cone
photopsin, medium-wavelength cones (most sensitive to 535nm) with photopigment called M-cone photopsin and
long-wavelength cones (most sensitive to 565nm) with photopigment called L-cone photopsin (Roenneberg and
Merrow 2016). The photoreceptor named ipRGC is most sensitive to wavelength at 480nm with photopigment
called melanopsin (Panda 2005). An ipRGC firing pattern consists of these two components while it is not the only
pattern. Even though ipRGC only takes a small part in ganglion cells according to quantity, it is still critical because
it projected to most non-visual response (Gooley et al. 2001).
11

Figure 2-3: Non-visual light response generation (Lucas et al. 2014).

2.4.2 24-hour lighting scheme

This section is from a 24-hour lighting scheme proposed by Lighting Research Center (LRC) at Rensselaer
Polytechnic Institute for older adults that not only provides good lighting for visual effect of light concerns but also
introduce some requirements to promote the circadian stimulation during the day and night (Figueiro, 2008).

The Illuminating Engineering Society (IES) has proposed some indoor lighting guidance for the Aging and Partially
Sighted Committee but there isn’t any requirement specifically for circadian lighting. 24-hour lighting scheme is a
proposal by the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute for older adults that not only
provides good lighting for visual effect of light concerns but also introduce some requirements to promote the
circadian stimulation during the day and night (Figueiro, 2008). This lighting scheme suggests higher circadian
stimulation in the morning for at least 2 hours after waking. Daytime lighting scheme levels can be as high as 1,000
lux in the morning and it may be reduced to no less than 600 lux. Spectrum or color of the light is important when
one considers the right amount of light for the circadian system. For example, light sources with higher CCTs
provide higher circadian stimulus. Evening lighting scheme level can be no more than 60 lux during the evening
hour. Based on this research, people need to receive at least 0.3> CS (Circadian Stimulus) during the day, especially
during the morning hours, and the dosage of no greater the 0.1< CS (Circadian Stimulus) in the evening hours. The
best way to get the recommended morning CS is to be outdoors after day break (figure 2-4).

It is suggested by LRC to exposed to daylight at least 1 hour in the morning to receive sufficient light at the back of
your eye even in the over cast sky condition. If it is not possible to get benefit from daylight, then electric lighting
can be used to deliver the desired CS. The electric lighting needs to be dimmable and tunable to be able to adjust the
spectrum or color or the level of light. Tunable lighting can be programmed to provide high levels of cool white
light in the morning for high CS to match the spectrum and color of natural light. CS can be gradually reduced after
lunch by providing lower level of neutral white light in the mid afternoon and even lower levels of warm white light
in the early evening. One way to keep the light level low in the evening is by using warm white light, otherwise
using the orange goggles or glasses are recommended to avoid the bright light in the evening. Using electric devices
can be disturbing since it will increase the desired amount of CS during the evening hours but watching television
from the typical distance provide lower amount of CS and it wouldn’t disturb our circadian rhythm.
12

Figure 2-4: the 24-hour lighting profile (Figueiro, 2008)

2.4.3 Circadian daylight in practice

In the early stages of design, lighting designers should consider the circadian lighting concept. The computational
workflows will help designers to adjust their design based on the effect of light on the building occupants (Inanici,
Brennan, & Clark, 2015). Daylight is an important factor in reducing the energy demand in the buildings and it has
benefit for human circadian system over the electrical lighting (Hagen & Richardson, 2018).
Base on the WELL standards, daylighting is considered a healthier choice than the electrical lighting (Hagen &
Richardson, 2018) . Researchers in Atelier Ten, which is a sustainability consultant firm, introduced two simulation
methods for calculating lighting focusing on daylight in office spaces. These methods can be used in the early stages
of design (Hagen & Richardson, 2018). Visual comfort and thermal comfort weren’t in the scope of their research
paper (Hagen & Richardson, 2018).

Method 1- Transformed horizontal illuminance

The horizontal illuminance level should be double of that of the vertical illuminance level (Leslie, Radetsky, &
Smith, 2012). Based on the WELL building standard, the circadian lighting level should be as high as 250 EML or
higher, between 9 am to 1 pm for every day during the year (International WELL Building Institute, 2018).
Appendix table 1 in the WELL standard considered the 227-lux level for daylight. Hence, the horizontal illuminance
level should be as high as 466 lux. The simplified office model was generated in DIVA for Rhino for daylight
analysis (Hagen & Richardson, 2018). They created a Python script to specify the grid points that will meet the
requirements of the circadian daylight threshold. The 4-hour time span in the morning was considered as the
minimum hours for the calculation process, based on the WELL building requirements, but the calculation was for
every hour of the year (Hagen & Richardson, 2018). To specify different circadian daylight level in the space, they
used different colors. The areas in red are projected to meet the threshold of at least 4 hours per day every day of the
year (figure 2-6).

Method 2- Multi directional vertical illuminance

In this method invented by researchers in Atelier Ten, horizontal values weren’t considered for the estimation of the
vertical illuminance. Different orientation and location of eight different view directions placing on the floorplate
were used to find the EML values for every hour of the year using Radiance program for detailed daylight
13

simulations (figure 2-5). A point with a view facing any of the yellow orientations in a given location meets the
WELL circadian threshold (figure 2-6).

Figure 2-5: Grasshopper customized script for calculating the vertical illuminance for multiple points (Hagen & Richardson,
2018)

Figure 2-6: Left figure- Method 1 circadian daylight analysis. Right figure- Method 2 circadian daylight result (Hagen &
Richardson, 2018)

The transformed horizontal illuminance method, and the multi directional vertical illuminance method can be used
depending on the different stages in design (Table 2-3).
14

Table 2-3: Comparison of the two different methods (Hagen & Richardson, 2018)
Method 1 Method 2
• Useful for quick circadian analysis.

• Method 2 is eight times more accurate than
method 1.
• Appropriate for early stages of design. • It’s more appropriate for detailed decision
making.

• Less accurate than method 2.

• It’s good for finalizing floor plan.

2.5 Visual Discomfort

Glare is defined as “the sensation produced by luminances within the visual field that are sufficiently greater than
the luminance to which the eyes are adapted, which causes annoyance, discomfort or loss in visual performance and
visibility (IESNA,1993)”. High illuminance intensity of lighting source, adaption ability of human beings, size of
lighting source, and perspective positions are the factors that cause glare issue (Pierson, Wienold, & Bodart, 2017).
Glare occurs when too much light is available, and the range of luminance is too large. There are some parameters
that is introduced by different researchers, that can affect visual performance. Illuminance at the eye (Lehnert,2011),
duration of exposure (Irikura,1999), glare dose (Chen, 2004). Glare is categorized in two different class: disability
glare when the too much light is available and the occupant is not able to see; and discomfort glare when the range
of luminance in occupants’ view field is too large that causes discomfort in the eyes (Carlucci, Causone, De Rosa, &
Pagliano, 2015). Some of the glare indexes and metric are described below:

Daylight Glare Probability (DGP) is a metric presents strong correlations with glare perception occupant
surveys. The DGP formulation uses vertical eye illuminance (Ev), luminance of the light source (Ls), and the solid
angle of the source seen by an observer (Wienold & Christoffersen, 2006).

The recommended threshold by Wienold is (Wienold & Christoffersen, 2006):

Imperceptible glare DGP ≤0.35
Perceptible glare 0.35 > DGP ≤ 0.40
Disturbing glare 0.40 > DGP ≤ 0.45
Intolerable glare DGP > 0.45

It is valuable to introduce multiple metrics and indexes, which is recommended to analyze a more accurate result
(Tables 2-4 & 2-5).

Table 2-4: Overview of point-in-time metrics

Point-in-time Metrics
Illuminance (Ep) Amount and distribution of light
Daylight Factor (DF) Amount and distribution of light
Luminance (L) Surface brightness
CIE Glare Index (CGI) Glare

15

Table 2-5: Overview of annual-based metrics
Annual-based Metrics (A)
Daylight Autonomy Amount and distribution of light
Discomfort Glare probability (DGP) Glare
Continuous daylight autonomy (DAcon) Amount and distribution of light
Useful daylight illuminance (UDI) Amount and distribution of light
Spatial Daylight Autonomy (SDA) Amount and distribution of light
Annual Sunlight Exposure (ASE) Glare Proxy: direct sun in space

• Daylight illuminances less than 100 lx are considered insufficient (Nabil & Mardaljevic, 2006a).
• Daylight illuminances in the range of 100-500 lx are considered effective (Nabil & Mardaljevic, 2006a).
• Daylight illuminances in the range of 500-2000 lx are considered either desirable or at least tolerable (Nabil
& Mardaljevic, 2006a)
• Daylight illuminances higher than 2000 lx are produce visual and thermal discomfort (Nabil &
Mardaljevic, 2006b)

2.6 Standards

Various standards are available in the field of lighting and in healthcare (circadian system). This section describes
the WELL Building Standards, and the LEED ranking system developed by the U.S. Green Building Council. The
WELL Building Standard is the recent guiding standard which have the concept of circadian lighting as one of its
agenda.

2.6.1 WELL-Building Standards

The WELL Building Standard is the first rating system that focuses on health and well-being of the building
occupant (International WELL Building Institute, 2018). The IWBI (2018) declared that the WELL Building
Standard is “the premier standard for buildings, interior spaces and communities seeking to implement, validate and
measure features that support and advance human health and wellness (International WELL Building Institute,
2018).” This rating system is developed by Delos Living LLC focusing on comfort level of building occupants and
trying to improve the design strategies that will affect the well-being of the occupants (International WELL Building
Institute, 2018) . The WELL building standards is the first rating system that introduced the circadian lighting topic
and more stringent requirements for visual lighting. Onsite assessment and performance testing process are required
to achieve the requirements (WELL, 2018). Based on the WELL standards circadian version 1 lighting
preconditions for commercial and office spaces, 75% of the work spaces should achieve at least 250 Equivalent
Melanopic Lux on the vertical plane 1.2 meter above the floor for at least 4 hours per day for every day of the year.
The are some differences between WELL Building Standard version 1 and 2 circadian lighting preconditions. The
newer version is required the lower level of EML values, which can be achieved with either electrical light or
daylight or both (table 2-6).

The WELL Building Standard doesn’t speak about different space types such as residential, school, long term
communities except the general requirement mostly for office and commercial spaces. For example, for spaces like
an office with workstations the light levels might be calculated at 45 cm above the work plane, for other spaces
without workstations, light levels might be calculated at a height of 140 cm (WELL, 2018) (table 2-6).

Table 2-6 : WELL v2 Circadian Lighting requirements (International WELL Building Institute, 2018)
Electric Light Only Electric light and daylight Points
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At least 150 EML OR The project achieves at least 120 EML with
electric light and at least 2 points in Feature L05:
Enhanced Daylight Access
1
At least 240 EML OR The project achieves at least 180 EML with
electric light and at least 2 points in feature L05:
Enhanced Daylight Access
3

Based on a talk with Jon Sargent, one of the developers of the ALFA software:

“Dr. Steven Lockley would hesitate to give a full-throated endorsement of any absolute threshold,
because in reality parameters like duration and history of exposure also matter. More EML is
more alerting, but with quickly diminishing returns (you can assume full saturation occurs after a
few hundred lux). Dr. Lockley also likes to point to the M/P ratio, because it says something about
the efficiency with which an EML dose is achieved. You can always increase EML simply by
increasing installed lighting power density, but for blue-depleted light sources, this may needlessly
increase visual brightness and energy use. You can think of M/P values above 0.9 as being similar
to natural daylight, and those below 0.35 being like a calming campfire. But ultimately, it's the
absolute quantity (EML) that dictates the biological response. As an aside, if you are interested in
achieving an EML target throughout the year using daylight (as in WELL's option 1a), a simple
trick is to test the worst-case scenario: i.e., a heavy rain cloud @ 9am on Dec 21. If you meet the
requirement then, you meet it at all other times as well. (Jon Sargent, e-mail message to author,
February 6th, 2019).”

2.6.2 LEED

LEED ranking system, developed by U.S. Green Building Council, mentions circadian lighting in its Environment
Quality (EQ) credit, the Daylight section (USGBC 2016). LEED requirements in this section focus on saving energy
by presenting more daylighting strategies as an alternative to artificial lighting and support circadian system. LEED
provides three methods listed below for achieving required points (USGBC 2016):
• Spatial Daylight Autonomy and Annual Sunlight Exposure (simulation)
• Illuminance Calculation (simulation)
• Measurement

2.7 Evaluation Tool

3D modeling software and lighting simulations software can used for the daylighting analysis. ALFA (Solemma,
2018), a software to predict non-visual effects of light. Rhino is a 3D modeling software.

2.7.1 Rhino

Rhino is a commercial 3D computer graphics and computer aided design (CAD) application software developed by
Robert McNeel & Associates (Rhinoceros Resources, n.d.). Rhino is used in many applications like 3D modeling,
CAD, and architectural design. Grasshopper is a visual scripting language was developed by Rhino, which is used as
a plugin (Tedeschi Arturo, 2011). It is a plugin for visual programming language developed by David Rutten at
Robert McNeel and associates (Tedeschi Arturo, 2011). Grasshopper plugin was released in September 2007 for the
first time (Rutten David, 2013). One of the applications of Rhino is to create 3d modeling. It also can be used for
generating parametric modeling for structures, architecture, energy analysis and daylighting analysis (Echarri,V.,
2016).
17

Figure 2-7: An example of a 3D model in Rhino

2.7.2 ALFA

ALFA (Adaptive Lighting for Alertness) is a software developed by Solemma, 2018, is able to predict the non-
visual effects of light, which lets architects and engineers design healthier environments for people. This software
allows designers to adjust various weather conditions, materials, and luminaires for different time of the day. This
allows designers to apply several strategies in the early design stage of the project and calculate the requirements by
international building certification systems, including the WELL Building Standard.

ALFA is able to carry out high spectral resolution and accurate simulations. Since the of non-visual system is
sensitive to specific wavelength of blue light, ALFA uses higher resolution lighting engine,81-color spectra, rather
than Red/Green/Blue color channels (Solemma, 2018).

Figure 2-8: An example of the ALFA result

2.8 Case Study

The Lantern of Chagrin Valley assisted living and memory care community in Ohio was selected for the case study.
This building has 20 memory care units and 46 assisted living units. One of the great features of this building is the
fiberoptic ceiling that changes in the morning and at night to simulate the real sky to reset residents’ biological
clock. The corridor space in this building designed in a way that remind the residents the 1930s and 1940s and is
covered with grass-colored carpet, fountains, and furniture that provide a more pleasant space for residents and acts
18

as an indoor courtyard. The apartment units are located along the corridor space with a small front porch (figure 2-
9).

2.8 Summary

The population of people living with dementia is predicted to increase (Prince et al., 2015). People living with
dementia require to stay in long-term care communities, which will increase the demand for buildings which are
designed for this purpose. It is important to know, what the healthy dosage of light is, and when human body needs
to be exposed to daylight (Konis, 2017). The circulation areas such as corridors and hallways should be considered
as important spaces not only for lighting design, but also as a space that potential is used a lot by inhabitants. View
orientation is another factor that can affect the circadian stimulus. Since people activities in a space require different
directions, lighting designers should consider the occupants activities with multiple direction in lighting analysis.

The WELL Building rating system focusing on comfort level of building occupants and trying to improve the design
strategies that will affect the well-being of the occupants. The 24-hour lighting scheme introduced by Lighting
Research Center suggests higher circadian stimulation in the morning for at least 2 hours after waking. Daytime
lighting scheme levels can be as high as 1,000 lux in the morning and it may be reduced to no less than 600 lux.

Based on a comparative study of different windows, clerestories, and skylights by Treado, skylights are the most
efficient daylighting strategies in terms of solar heat gain and lighting. Light scoops are daylighting strategies,
developed by the Lighting Research Center (LRC), which is a south-facing skylight that uses tilted panels to bring
direct sunlight into the space. Light scoop works better in overcast conditions. Rectangular monitor skylights
provide the lowest daylight factors.

Transformed horizontal illuminance and multi directional vertical illuminance are two simulation methods
introduced by researchers in Atelier Ten, for calculating lighting focusing on daylight in office spaces. The
transformed horizontal illuminance method is Appropriate for early stages of design. The multi directional vertical
illuminance method is eight times more accurate than other method, and it is more appropriate for finalizing floor
plans and detailed decision making.

Figure 2-9: The Lantern of Chagrin Valley, Ohio (“Lantern: Dementia Care & Assisted Living Chagrin Falls,
South Russell, OhioLantern,” n.d.)
19

3. METHODOLOGY

3.1 Introduction

This chapter explains the methodology that was used to test the hypothesis, which is to control the dosage of light
over the course of a day with implementing circadian-effective daylighting strategies in buildings during the day
without the need for supplemental electric lighting. EML values for circadian lighting analysis, and visual comfort
values for glare analysis for 3 different test case models were evaluated. The methodology outline makes the
research clear, as it defines the workflow and next steps of the research (figure 3-1).

First a test model was generated in the software program Rhino to run lighting simulations using ALFA. Building
orientation, ceiling height, glazing materials, surface materials, length and width of the model are fixed in this
workflow. Sky conditions, time, and skylight configurations are the features that are parametric. ALFA (Adaptive
Lighting for Alertness) was used to predict EML (Equivalent Melanopic Lux) values. ALFA runs inside the Rhino
with the enhanced user interface. Two different sky conditions including a clear sky and overcast sky were used for
the simulations, for three different days during the year. To support the 24-hour lighting scheme, simulations were
carried out from early in the morning till evening.

This chapter explains the design objectives, create 3D model, analysis setting, simulation setting, and the data
analysis.

Figure 3-1: Methodology diagram

3.2 Design Objectives

WELL Building Standards is the organization that provides certification for buildings to deliver health and wellness
benefits to all people within them. Based on the WELL Building Standard Circadian Lighting design feature, 250
EML (Equivalent Melanopic Lux) is introduced as the threshold for the office spaces, but since the aging eye is less
sensitive to light, 350 EML is the proposed threshold. Visual comfort is another objective with the 1000 lux as the
threshold. The simulation period starts from 7:00 am to 6:00 pm to support the importance of higher light stimulus
during morning hours and declining level of light in the afternoon. The EML values during the morning period need
to be high and the visual comfort value needs to be low to be marked as a positive value.

3.3 Create 3D Model

A corridor space area in a single-story long-term care facility building is used as the case study. A simplified
building geometry, with 5m by 16m layout were used as a base model. Higher ceiling height 4 m is used in the
20

model geometry for more penetration of light and diffused light. The Lantern long term care facility in Ohio was
selected as a prototype (Figure 3-2). It was designed to encourage the use of the corridor.

Figure 3-2: Lantern Care Facility, Ohio (“Unique Assisted Living Facility Uses Nostalgia to Make Alzheimer’s Patients Feel at
Home,” n.d.)

3.3.1 Skylights

Three different daylighting strategies were considered in this workflow: sawtooth skylight, light scoops, and
clerestories, as the top lighting strategies because of their prevalent use in buildings (figure 3-3, 3-4, 3-5). These
strategies offer advantages over conventional horizontal skylights since it gives the higher amount of light with a
larger depth of penetration for daylight with a minimum amount of direct sunlight. The north-south orientation is
chosen control daylight and to prevent excessive solar heat gain and glare. North facing sawtooth skylight was
chosen since north light has some advantages for uniform and soft daylighting. In the 3D model, all the surfaces
such as wall, windows, ceiling, and floors are drawn as a single surface. All the surfaces vectors need to be pointing
out to the correct direction. For example, glass pointing out to outside, walls pointing out inside, floor pointing up,
ceiling pointing down.

Figure 3-3: left figure- Test model with clerestories. Right figure- test model with angled clerestories.

21

Figure 3-4: left figure- test model with light scoop 45 degree. Right figure- test model with light scoop 60 degree.

Figure 3-5: Left figure- test model with north facing light scoop. Right figure-test model with sawtooth skylight.

3.4 Analysis Setting

ALFA can predict EML (Equivalent Melanopic Lux) and is able to carry out high spectral resolution and accurate
simulations. Since the of non-visual system is sensitive to specific wavelength of blue light, ALFA uses higher
resolution lighting engine,81-color spectra, rather than red/green/blue color channels (Solemma, 2018). Weather
conditions, such location, sky conditions, date, and time can be adjusted based. Material selections are through the
ALFA material library and can be assigned easily (figure 3-6).

22

Figure 3-6: Screenshot of ALFA Material Library

3.4.1 Set Weather Conditions Parameters

Daytime sky is an important driver of human circadian rhythm and sun is the only source of light during daytime.
ALFA deploys spectral calculations using best-in-class radiative transfer library, libRadtran. This gives the ALFA
users to choose the clear, hazy, or overcast skies for any location on earth. The case study uses Los Angeles as the
location for the simulations with 34.05 Latitude (N), -118.24 Longitude (E), and 96 m elevation (figure 3-7). Clear
and over cast sky has chosen with the uniform ground spectrum and 0.15 albedo. March 21
st
, June 21
st
, and Dec 21
st

were chosen as three different season condition for the simulation during the year. Since ALFA can only calculate
point-in- time simulations, 7 different sets of hours were chosen for the simulation period starting from 7 am to 6 pm
for every hour.

Figure 3-7: Screenshot of ALFA Location Settings

23

3.4.2 Assign Materials Parameters

The materials have to be selected for the interior. The light spectra changes between emission from a surface and
arrival at the human eye by transmission and reflection off material surfaces. The color of the material is an
important feature for circadian lighting effect. The colors which are tested here are yellow walls, white ceiling, and
dark grey floor. The ceiling material was white painted room ceiling with 82.2% reflectance. The wall material was
yellow painted wall with 52% reflectance, and dark grey floor tiles with 20% reflectance (table 3-1).

Table 3-1: Material Parameters using in this workflow
Parameter Material Reflectance
Wall Yellow painted wall 52%
Floor Dark grey floor tiles 20%
Ceiling White painted room ceiling 82.2%
Glazing Double IGU Clear Tvis Tvis 45%

The glazing system is an important factor for providing daylight access inside a building. The software is compatible
with the international Glazing Database and with over 500 spectral materials. Double IGU Clear Tvis (Visible
Transmittance) 45% was used for the glazing material (figure 3-8). Visible transmittance is the amount of light in
the visible spectrum that can passes through a glazing unit. A higher VT means the amount of light that can passes
through a glazing unit is higher.
.

Figure 3-8: Screenshot of ALFA Glazing Material
3.5 Simulation Settings

After location, sky condition, date, and time are set for the simulation, grid settings and simulation quality setting
needs to be adjusted. This is where all the grid spacing, view directions of each grid points, view plane and work
plane offset from floor can be adjusted. Radiance engine is stochastic, so the results will not be the same pass to pass
or run to run. by increasing the number of passes, which means more and more sample rays accumulate, the results
will converge.

3.5.1 Configure Analysis Grid

The light entering the eye of the occupant is a feature that we need to consider for analysis grid configuration, as the
ipRGCs are in the retina of the eye. The vertical plane at human eye level is used for the simulations. ALFA has the
specific setting for work plane and view plane offset. View planes are vertical sensors that are approximating the
24

view of occupant within the space which is 1.2 meters by default. Work planes are horizontal sensors at the table
height which is 0.76 meters by default. The 1.2 meters offset above the finish floor which is equal to the eye height
of a seated person, was used for the simulation’s settings in ALFA. The grid layout needs to be drawn in Rhino
model. From the top view the analysis grid is a 14 m by 4 m rectangle with 0.5 m offset from the walls. Offsetting
the analysis grid is important for the more accurate analysis. Evaluation points with 4 different view directions are
set at the analysis grid plane with 0.25 m in radius; these values were recommended by the ALFA developers (figure
3-9) (figure 3-10).

Figure 3-9: Screenshot of ALFA Grids Setting

Figure 3-10: Screenshot of a Rhin 3D model with analysis plane

25

3.5.2 Set Simulation Quality Settings

Ambient bounces (ab) is an important factor for the quality of the simulations. The number of ambient bounces is
the maximum number of diffuse inter-reflections before a ray path is discarded. “ When the number of ambient
bounces is set to 0 the ambient lighting calculations are switched off, so only direct sun/sky light patches are
considered (“Daylighting Calculation Options,” n.d.) “. For a simple building without any complicated façade
elements, the value of 5 (ab) is recommended. Radiance is stochastic, so the results will not be the same pass to pass
or run to run. By increasing the number of passes, which means more and more sample rays accumulate. The
number of passes that used for the analysis is 20 which is the default of the software. Ambient bounces (6) was
chosen to guide ALFA how to carry out the simulation (figure 3-11).

Figure 3-11: Screen Shot of ALFA simulation quality settings

3.5.3 Visual Discomfort

Visual discomfort is also important to consider Since the result of excessive light in a space is glare and visual
discomfort. It is important to take into consideration the potential of visual discomfort and glare. The visual
discomfort illuminance calculation was done inside the ALFA. Daylight illuminances higher than 2000 lux produce
visual and thermal discomfort (Nabil & Mardaljevic, 2006b). Since the aging eye is more sensitive to the glare and
visual discomfort and sometimes it might cause some difficulties in walking and their balance, the 1000 lux was
used for maximum threshold. Those cases that has the higher percentage of viewpoints above the 350 EML values
and lower percentage of viewpoints below the 1000 lux visual discomfort values were scored as circadian-effective
cases (figure 3-11).

26

Figure 3-12: Screen shot of Defined EML and Lux threshold in ALFA Settings

3.6 Data Analysis

The results section includes the numerical and graphical data for 6 different case models. To support the 24-hour
lighting profile, the simulations carried out for 12 hours from 7am to 6 pm and for each hour to calculate the EML
values and Lux values. The percentage of all the grid points that are above the 350 EML threshold, and below the
1000 lux for every hour is collected in the excel sheet in form of tables and graphs.

3.6.1 Sample Quantitative Data

The sky condition, type of daylighting strategy, date, hour, percentage of view points above the 350 EML values,
and percentage of viewpoints above the 1000 Lux values are collected in form of tables (figure 3-12). Higher values
in the EML% section and lower values in the visual discomfort section ranges from 0 to 100 are desired. The
average of all the hourly percentage of viewpoints above the 350 EML and the average of all the hourly percentage
of viewpoints above the 1000 lux threshold Lux is calculated to analyze the overall performance of each case test
model.

SKY
CONDITION SKYLIGHT DATE HOUR %viewpoints>350 EML %VIEWPOINTS>1000Lux
Clear Light scoop 45
March
21st 7:00 AM 9.9 0
Clear Light scoop 45
March
21st 8:00 AM 68.2 24.5
Clear Light scoop 45
March
21st 9:00 AM 75.5 52.1
Clear Light scoop 45
March
21st 10:00 AM 80.2 67.2
27

Clear Light scoop 45
March
21st 11:00 AM 80.7 67.2
Clear Light scoop 45
March
21st 12:00 PM 80.2 60.9
Clear Light scoop 45
March
21st 1:00 PM 81.8 66.1
Clear Light scoop 45
March
21st 2:00 PM 80.7 65.1
Clear Light scoop 45
March
21st 3:00 PM 76 52.1
Clear Light scoop 45
March
21st 4:00 PM 67.2 22.4
Clear Light scoop 45
March
21st 5:00 PM 18.2 0
Clear Light scoop 45
March
21st 6:00 PM 0 0

Figure 3-13: % viewpoints above the EML threshold and % viewpoints above the lux threshold for different parameters

3.6.2 Visual Data

The graphical data based on the tables that discussed above is another form of data visualization. The graphical data
will be scored higher if the blue line in the graph reaches higher percentages and the orange line reaches lower
percentages (figure 3-14).

`
Figure 3-14: the example of a graphical data that will be analyzed based on the EML%, LUX%.

3.7 Performance Evaluation

The different scenarios are examined for different parameters like average EML values, average visual discomfort
lux values. Los Angeles location was used for the simulation results at March 21
st
, June 21
st
, and December 21
st
,
during 7 am to 6 pm. To examine the best, moderate, and worst-case scenarios. As discussed in the previous section,
the average EML% values and the average Lux % values for every hour is calculated and evaluated in the form of a
0
20
40
60
80
100
Percentage
Hour
EML% Lux %
0
20
40
60
80
100
Percentage
Hour
EML% Lux %
28

chart (figure 3-14). Performance evaluation is based on the average hourly data conservations. The case scenarios
fall within the top-left section were scored as the best performance, the case scenarios fall within right-below section
were scored as the poor performance, and the case scenarios in top-right and left-below sections were scored as the
moderate performance (figure 3-15).

Figure 3-15: Performance Evaluation of different case scenarios

3.8 Summary

The methodology diagram explains the design objectives, create 3D model, analysis setting, simulation setting, and
the data analysis (figure 3-16). The scope of the thesis focuses on a corridor space in a single floor dementia
community building. Six different tests case scenarios were created in Rhino to be evaluated based on the design
objectives. The analysis setting in ALFA were adjusted for the lighting simulations. Clear and over cast sky has
chosen with the uniform ground spectrum. Since the aging eye is more sensitive to the glare and visual discomfort
and sometimes it might cause some difficulties in walking and their balance, the 1000 lux was used for maximum
threshold, and the 350 EML was used for the maximum circadian lighting threshold. The color of the material is an
important feature for circadian lighting effect. The colors which are tested here are yellow walls, white ceiling, and
dark grey floor. The simulations carried out for 12 hours from 7am to 6 pm and for each hour to calculate the EML
values and Lux values. The percentage of all the grid points that are above the 350 EML threshold, and below the
1000 lux for every hour is collected in the excel sheet in form of tables and graphs.

The hourly average of EML percentages of all the grid points higher than 350 EML and the hourly average of lux
percentages of all the grid point higher than 1000 lux were arranged in the graphical form for the analysis. Finally,
all the case scenarios were evaluated in a form of chart.

Performance evaluation is based on the average hourly data conservations. The case scenarios fall within higher
EML values and lower Lux values sections in a graph were scored as the best performance, the case scenarios fall
within the higher lux values and lower EML values sections in the graph were scored as the poor performance, and
the case scenarios in other part of the sections were scored as the moderate performance (figure 3-16).
7 4
11 5
2
1
3 8
9
6
10
0
10
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50 60 70 80 90 100
Average percentage of viewpoints above the EML
threshold
Average percentage of viewpoints above the Visual disomfort threshold
Performance Evaluation of different test case scenarios
Best performance
Poor performance
Moderate performance
Moderate performance
29

Figure 3-16: Methodology Diagram

The following chapter explains the comparison of the six different test models, judging different parameters and the
capabilities in accordance with the human circadian system and people living in dementia care communities. This
will help designers to use the framework during their design process.

30

4. RESULTS

A design decision support framework was proposed that can be applied in the early stages of design to aid in
supporting decision-making related to goals of circadian effective light stimulus in dementia care communities. This
chapter reports the data based on different design top lighting strategies. This first section shows the result from
ALFA. More than 20 solutions were simulated and analyzed with their performance indicators. Six case study
solutions were picked to analyze their performance in detail.

Four objectives for this chapter are listed below:

1. To differentiate performance of various design options.
2. To evaluate the top lighting strategies based on their outcome and to find which strategy works best.
3. To understand if different sky condition has on impact on circadian lighting effects.
4. To evaluate changes based on different season.

The EML and visual discomfort values contain 12 time-spots per day (7am~6pm), three days during the year (March
21
st
, June 21
st
, and Dec 21
st
) and two different sky conditions (clear and over cast). For each time-spot, there are
percentage of viewpoints above the EML threshold and the percentage of viewpoints above the visual discomfort
threshold values.

The second section illustrates daily average of hourly conservations. The percentage of views above the 350 EML
threshold for the Y axis, and the hourly average percentage of views above the 1000 lux visual discomfort threshold
for the X axis per case in order to be scored for the best, moderate, and poor performance strategies. The
performance evaluation graph helped in finding the more efficient design strategies among different design
strategies in respect to circadian lighting and visual discomfort. To better display the data and illustrate, the selected
data information was converted into the graphical form.

This chapter explains the results from different test case scenarios, overall performance evaluation, comparison of
circadian evaluation result based on different sky condition, comparison of circadian lighting evaluation results
based on different seasons, and the overall final score.

4.1 Test case scenarios

For all test scenarios, he first column (in Figure 4-1) describes the different sky conditions that was used for the
simulations. The second column is the type of daylighting strategy that was used that was used. The third column
describes the date. March 21
st
, June 21
st
, and December 21
st
were used for the simulations. The fourth column
describes the time spots per day that started from 7 am to 6 pm. The “EML Values” was the percentage of all the
viewpoints in the grid setting higher than 350 EML which is the threshold that mentioned in previous chapter that
was the vertical illuminance collected at the eye point (1.2 meter above the floor surface). EML is defined by the
amount of light reaching the circadian system through eye (WELL, 2014). The “Visual Discomfort” was the
percentage of all the viewpoints in the grid setting higher than 1000 lux, which was the threshold introduced in
previous chapter. The visual discomfort values are measured in lux. In order to achieve a higher score, we need to
maximize the EML values while minimizing the visual discomfort values. A higher value of EML indicates that this
strategy is more circadian-effective.

31

Figure 4-1: layout of Excel file for results

The EML and Visual Discomfort values mentioned are the main axis of the performance evaluation graph. The
average EML values of all hours was used for the Y axis and the average Visual comfort values of all hours was
used for the X axis of the graph. This graph shows the best, moderate, and poor performance of different strategies
(figure 4-2). This graph helps designers and architects to choose better design strategies for their project.

Figure 4-2: Sample performance evaluation graph

Six different case studies were simulated. They were clerestory, light scoop 45-degree, light scoop 60-degree,
sawtooth skylight, clerestory angled, and north-facing vertical light scoop.

4.1.1 Clerestory test case

The first design was the corridor space with clerestories strategy (figure 4-3). The data collected for this model is
illustrated in the form of tables (figure 4-4, 4-5, 4-6). In charts like Figure 4-7, the point plotted is the average of all
observations in column EML%, and the average of all observations from column Lux% in the corresponding table
(e.g. figure 4-4).

.

SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear Clerestories March 21st 7:00 AM 0 0
Clear Clerestories March 21st 8:00 AM 13.5 0
Clear Clerestories March 21st 9:00 AM 33.9 0.5
Clear Clerestories March 21st10:00 AM 47.4 1
Clear Clerestories March 21st11:00 AM 54.2 0.5
Clear Clerestories March 21st 12:00 PM 56.8 2.6
Clear Clerestories March 21st 1:00 PM 54.2 0.5
Clear Clerestories March 21st 2:00 PM 52.1 0
Clear Clerestories March 21st 3:00 PM 32.8 0
Clear Clerestories March 21st 4:00 PM 9.4 0
Clear Clerestories March 21st 5:00 PM 0.5 0
Clear Clerestories March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear Clerestories Jun 21st 7:00 AM 13.5 0
Clear Clerestories Jun 21st 8:00 AM 15.1 0
Clear Clerestories Jun 21st 9:00 AM 32.3 0
Clear Clerestories Jun 21st 10:00 AM 22.4 0
Clear Clerestories Jun 21st 11:00 AM 30.7 0
Clear Clerestories Jun 21st 12:00 PM 31.8 0
Clear Clerestories Jun 21st 1:00 PM 24.5 0
Clear Clerestories Jun 21st 2:00 PM 30.7 0
Clear Clerestories Jun 21st 3:00 PM 20.8 0
Clear Clerestories Jun 21st 4:00 PM 17.7 0
Clear Clerestories Jun 21st 5:00 PM 6.3 0
Clear Clerestories Jun 21st 6:00 PM 2.6 2.1
32

Figure 4-3: The clerestory test case model

Figure 4-4: left figure- Daily percentage of hourly conservation for clerestories under clear sky condition, March 21st. Right
figure- Daily percentage of hourly conservations for clerestories under clear sky conditions, June 21st.

Figure 4-5: Left figure- Daily percentage of hourly conservation for clerestories under clear sky condition, December 21st. Right
figure- Daily percentage of hourly conservations for clerestories under overcast sky condition, March 21
st
.

Figure 4-6: Left figure- Daily percentage of hourly conservation for clerestories under overcast sky condition, June 21st. Right
figure- Daily percentage of hourly conservations for clerestories under overcast sky conditions, December 21st.

SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear Clerestories March 21st 7:00 AM 0 0
Clear Clerestories March 21st 8:00 AM 13.5 0
Clear Clerestories March 21st 9:00 AM 33.9 0.5
Clear Clerestories March 21st10:00 AM 47.4 1
Clear Clerestories March 21st11:00 AM 54.2 0.5
Clear Clerestories March 21st 12:00 PM 56.8 2.6
Clear Clerestories March 21st 1:00 PM 54.2 0.5
Clear Clerestories March 21st 2:00 PM 52.1 0
Clear Clerestories March 21st 3:00 PM 32.8 0
Clear Clerestories March 21st 4:00 PM 9.4 0
Clear Clerestories March 21st 5:00 PM 0.5 0
Clear Clerestories March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear Clerestories Jun 21st 7:00 AM 13.5 0
Clear Clerestories Jun 21st 8:00 AM 15.1 0
Clear Clerestories Jun 21st 9:00 AM 32.3 0
Clear Clerestories Jun 21st 10:00 AM 22.4 0
Clear Clerestories Jun 21st 11:00 AM 30.7 0
Clear Clerestories Jun 21st 12:00 PM 31.8 0
Clear Clerestories Jun 21st 1:00 PM 24.5 0
Clear Clerestories Jun 21st 2:00 PM 30.7 0
Clear Clerestories Jun 21st 3:00 PM 20.8 0
Clear Clerestories Jun 21st 4:00 PM 17.7 0
Clear Clerestories Jun 21st 5:00 PM 6.3 0
Clear Clerestories Jun 21st 6:00 PM 2.6 2.1
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear clerestories Dec 21st 7:00 AM 0 0
Clear clerestories Dec 21st 8:00 AM 3.1 0
Clear clerestories Dec 21st 9:00 AM 55.7 22.9
Clear clerestories Dec 21st 10:00 AM 64.6 23.4
Clear clerestories Dec 21st 11:00 AM 65.1 17.2
Clear clerestories Dec 21st 12:00 PM 70.3 15.1
Clear clerestories Dec 21st 1:00 PM 70.3 21.9
Clear clerestories Dec 21st 2:00 PM 63.5 25.5
Clear clerestories Dec 21st 3:00 PM 41.1 20.3
Clear clerestories Dec 21st 4:00 PM 0 0
Clear clerestories Dec 21st 5:00 PM 0 0
Clear clerestories Dec 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast clerestories March 21st 7:00 AM 0 0
over cast clerestories March 21st 8:00 AM 1 0
over cast clerestories March 21st 9:00 AM 29.7 0
over cast clerestories March 21st10:00 AM 41.1 0
over cast clerestories March 21st11:00 AM 63 4.2
over cast clerestories March 21st 12:00 PM 63 4.7
over cast clerestories March 21st 1:00 PM 53.6 0.5
over cast clerestories March 21st 2:00 PM 49 0.5
over cast clerestories March 21st 3:00 PM 28.1 0
over cast clerestories March 21st 4:00 PM 1 0
over cast clerestories March 21st 5:00 PM 0 0
over cast clerestories March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast Clerestories Jun 21st 7:00 AM 2.1 0
over cast Clerestories Jun 21st 8:00 AM 42.2 0
over cast Clerestories Jun 21st 9:00 AM 45.8 0
over cast Clerestories Jun 21st 10:00 AM 62.5 8.9
over cast Clerestories Jun 21st 11:00 AM 68.8 19.8
over cast Clerestories Jun 21st 12:00 PM 72.4 16.7
over cast Clerestories Jun 21st 1:00 PM 66.7 11.5
over cast Clerestories Jun 21st 2:00 PM 59.9 6.3
over cast Clerestories Jun 21st 3:00 PM 51 0.5
over cast Clerestories Jun 21st 4:00 PM 32.3 0
over cast Clerestories Jun 21st 5:00 PM 2.1 0
over cast Clerestories Jun 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast Clerestories Dec 21st 7:00 AM 0 0
over cast Clerestories Dec 21st 8:00 AM 0 0
over cast Clerestories Dec 21st 9:00 AM 0 0
over cast Clerestories Dec 21st 10:00 AM 3.1 0
over cast Clerestories Dec 21st 11:00 AM 10.4 0
over cast Clerestories Dec 21st 12:00 PM 16.7 0
over cast Clerestories Dec 21st 1:00 PM 10.9 0
over cast Clerestories Dec 21st 2:00 PM 2.6 0
over cast Clerestories Dec 21st 3:00 PM 0 0
over cast Clerestories Dec 21st 4:00 PM 0 0
over cast Clerestories Dec 21st 5:00 PM 0 0
over cast Clerestories Dec 21st 6:00 PM 0 0
33

Figure 4-7: Performance evaluation of clerestories test case model
4.1.2 Light scoop 45-degree test case

The second design was the light scoop 45-degree test case scenarios (figure 4-8). The data was collected for the
Light scoop with 45-degree angle, was represented in the figure 4-9. The data was collected in the same manner as
that for the first design with the same table format. The data collected for this model is illustrated in the form of
tables (figure 4-9, 4-10, 4-11). In charts like Figure 4-12, the point plotted is the average of all observations in
column EML%, and the average of all observations from column Lux% in the corresponding table (e.g. figure 4-9).

Figure 4-8: The light scoop 45-degree test case model

34

Figure 4-9: left figure- Daily percentage of hourly conservation for light scoop 45 degree under clear sky condition, March 21st.
Right figure- Daily percentage of hourly conservations for light scoop 45 degree under clear sky conditions, June 21st.

Figure 4-10: Left figure- Daily percentage of hourly conservation for light scoop 45 degree under clear sky condition, December
21st. Right figure- Daily percentage of hourly conservations for light scoop 45 degree under Overcast sky condition, March 21
st
.

Figure 4-11: Left figure- Daily percentage of hourly conservation for light scoop 45 degree under overcast sky condition, June
21st. Right figure- Daily percentage of hourly conservations for light scoop 45 degree under overcast sky conditions, December
21
st
.

SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear Light scoop 45 March 21st 7:00 AM 9.9 0
Clear Light scoop 45 March 21st 8:00 AM 68.2 24.5
Clear Light scoop 45 March 21st 9:00 AM 75.5 52.1
Clear Light scoop 45 March 21st10:00 AM 80.2 67.2
Clear Light scoop 45 March 21st11:00 AM 80.7 67.2
Clear Light scoop 45 March 21st 12:00 PM 80.2 60.9
Clear Light scoop 45 March 21st 1:00 PM 81.8 66.1
Clear Light scoop 45 March 21st 2:00 PM 80.7 65.1
Clear Light scoop 45 March 21st 3:00 PM 76 52.1
Clear Light scoop 45 March 21st 4:00 PM 67.2 22.4
Clear Light scoop 45 March 21st 5:00 PM 18.2 0
Clear Light scoop 45 March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear Light scoop 45 Jun 21st 7:00 AM 28.6 4.2
Clear Light scoop 45 Jun 21st 8:00 AM 65.6 16.1
Clear Light scoop 45 Jun 21st 9:00 AM 74 50.5
Clear Light scoop 45 Jun 21st 10:00 AM 76.6 53.1
Clear Light scoop 45 Jun 21st 11:00 AM 79.7 552
Clear Light scoop 45 Jun 21st 12:00 PM 78.6 53.1
Clear Light scoop 45 Jun 21st 1:00 PM 78.6 54.2
Clear Light scoop 45 Jun 21st 2:00 PM 72.9 53.6
Clear Light scoop 45 Jun 21st 3:00 PM 71.4 45.8
Clear Light scoop 45 Jun 21st 4:00 PM 63.5 7.3
Clear Light scoop 45 Jun 21st 5:00 PM 25 0
Clear Light scoop 45 Jun 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear Light scoop 45 Dec 21st 7:00 AM 0 0
Clear Light scoop 45 Dec 21st 8:00 AM 46.4 1
Clear Light scoop 45 Dec 21st 9:00 AM 74.5 48.4
Clear Light scoop 45 Dec 21st 10:00 AM 90.1 79.7
Clear Light scoop 45 Dec 21st 11:00 AM 94.3 89.6
Clear Light scoop 45 Dec 21st 12:00 PM 94.3 88
Clear Light scoop 45 Dec 21st 1:00 PM 91.7 84.4
Clear Light scoop 45 Dec 21st 2:00 PM 84.4 75.5
Clear Light scoop 45 Dec 21st 3:00 PM 70.3 29.7
Clear Light scoop 45 Dec 21st 4:00 PM 6.3 0
Clear Light scoop 45 Dec 21st 5:00 PM 0 0
Clear Light scoop 45 Dec 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast Light scoop 45 March 21st 7:00 AM 0 0
over cast Light scoop 45 March 21st 8:00 AM 27.1 0
over cast Light scoop 45 March 21st 9:00 AM 51.6 6.3
over cast Light scoop 45 March 21st10:00 AM 64.1 18.8
over cast Light scoop 45 March 21st11:00 AM 76.6 41.7
over cast Light scoop 45 March 21st 12:00 PM 77.1 51.6
over cast Light scoop 45 March 21st 1:00 PM 77.6 43.2
over cast Light scoop 45 March 21st 2:00 PM 65.1 19.3
over cast Light scoop 45 March 21st 3:00 PM 56.8 5.7
over cast Light scoop 45 March 21st 4:00 PM 36.5 0
over cast Light scoop 45 March 21st 5:00 PM 0.5 0
over cast Light scoop 45 March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast Light scoop 45 Jun 21st 7:00 AM 29.7 0
over cast Light scoop 45 Jun 21st 8:00 AM 55.7 8.3
over cast Light scoop 45 Jun 21st 9:00 AM 71.4 33.3
over cast Light scoop 45 Jun 21st 10:00 AM 80.2 47.9
over cast Light scoop 45 Jun 21st 11:00 AM 83.3 57.3
over cast Light scoop 45 Jun 21st 12:00 PM 84.4 60.9
over cast Light scoop 45 Jun 21st 1:00 PM 80.8 49.5
over cast Light scoop 45 Jun 21st 2:00 PM 77.6 46.4
over cast Light scoop 45 Jun 21st 3:00 PM 68.8 26.6
over cast Light scoop 45 Jun 21st 4:00 PM 53.1 1
over cast Light scoop 45 Jun 21st 5:00 PM 22.4 0
over cast Light scoop 45 Jun 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast Light scoop 45 Dec 21st 7:00 AM 0 0
over cast Light scoop 45 Dec 21st 8:00 AM 0 0
over cast Light scoop 45 Dec 21st 9:00 AM 7.8 0
over cast Light scoop 45 Dec 21st 10:00 AM 40.6 0.5
over cast Light scoop 45 Dec 21st 11:00 AM 46.4 3.1
over cast Light scoop 45 Dec 21st 12:00 PM 48.4 1.6
over cast Light scoop 45 Dec 21st 1:00 PM 45.3 0
over cast Light scoop 45 Dec 21st 2:00 PM 29.2 0
over cast Light scoop 45 Dec 21st 3:00 PM 5.2 0
over cast Light scoop 45 Dec 21st 4:00 PM 0 0
over cast Light scoop 45 Dec 21st 5:00 PM 0 0
over cast Light scoop 45 Dec 21st 6:00 PM 0 0
35

Figure 4-12: Performance evaluation of Light scoop 45 degree

4.1.3 Light scoop 60-degree test case

The third design was the light scoop 60-degree test case scenarios (figure 4-13). The data was collected for the light
scoop with 60-degree angle, was represented in the figure 4-14. The data was collected in the same manner as that
for the first design with the same table format. The data collected for this model is illustrated in the form of tables
(figure 4-14, 4-15, 4-16). In charts like Figure 4-17, the point plotted is the average of all observations in column
EML%, and the average of all observations from column Lux% in the corresponding table (e.g. figure 4-14).

Figure 4-13: The light scoop 60-degree test case model

36

Figure 4-14: left figure- Daily percentage of hourly conservation for light scoop 60 degree under clear sky condition, March
21st. Right figure- Daily percentage of hourly conservations for light scoop 60 under clear sky conditions, June 21st

Figure 4-15: Left figure- Daily percentage of hourly conservation for light scoop 60 under clear sky condition, December 21st.
Right figure- Daily percentage of hourly conservation for light scoop 60 under overcast sky condition, March 21st.

Figure 4-16: Left figure- Daily percentage of hourly conservation for light scoop 60 under overcast sky condition, June 21st.
Right figure- Daily percentage of hourly conservations for light scoop 60 under overcast sky conditions, December 21st.

SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear Light scoop 60 March 21st 7:00 AM 5.2 0
Clear Light scoop 60 March 21st 8:00 AM 62.5 12
Clear Light scoop 60 March 21st 9:00 AM 75.5 49.5
Clear Light scoop 60 March 21st10:00 AM 81.8 64.1
Clear Light scoop 60 March 21st11:00 AM 82.3 64.6
Clear Light scoop 60 March 21st 12:00 PM 80.2 60.9
Clear Light scoop 60 March 21st 1:00 PM 80.2 62.5
Clear Light scoop 60 March 21st 2:00 PM 80.2 59.9
Clear Light scoop 60 March 21st 3:00 PM 75 45.3
Clear Light scoop 60 March 21st 4:00 PM 63.5 7.8
Clear Light scoop 60 March 21st 5:00 PM 11.5 0
Clear Light scoop 60 March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear Light scoop 60 Jun 21st 7:00 AM 9.9 0
Clear Light scoop 60 Jun 21st 8:00 AM 49.5 0.5
Clear Light scoop 60 Jun 21st 9:00 AM 70.8 37
Clear Light scoop 60 Jun 21st 10:00 AM 70.3 45.8
Clear Light scoop 60 Jun 21st 11:00 AM 73.4 45.3
Clear Light scoop 60 Jun 21st 12:00 PM 71.4 44.8
Clear Light scoop 60 Jun 21st 1:00 PM 71.4 44.8
Clear Light scoop 60 Jun 21st 2:00 PM 69.3 42.2
Clear Light scoop 60 Jun 21st 3:00 PM 69.3 19.3
Clear Light scoop 60 Jun 21st 4:00 PM 47.9 0
Clear Light scoop 60 Jun 21st 5:00 PM 9.9 0
Clear Light scoop 60 Jun 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear Light scoop 60 Dec 21st 7:00 AM 0 0
Clear Light scoop 60 Dec 21st 8:00 AM 38 0.5
Clear Light scoop 60 Dec 21st 9:00 AM 77.1 47.9
Clear Light scoop 60 Dec 21st 10:00 AM 88 79.7
Clear Light scoop 60 Dec 21st 11:00 AM 93.8 88
Clear Light scoop 60 Dec 21st 12:00 PM 94.8 91.1
Clear Light scoop 60 Dec 21st 1:00 PM 94.8 87.5
Clear Light scoop 60 Dec 21st 2:00 PM 86.5 74.5
Clear Light scoop 60 Dec 21st 3:00 PM 69.8 38
Clear Light scoop 60 Dec 21st 4:00 PM 8.9 0
Clear Light scoop 60 Dec 21st 5:00 PM 0 0
Clear Light scoop 60 Dec 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast Light scoop 60 March 21st 7:00 AM 0 0
over cast Light scoop 60 March 21st 8:00 AM 13 0
over cast Light scoop 60 March 21st 9:00 AM 41.1 3.1
over cast Light scoop 60 March 21st10:00 AM 55.7 14.1
over cast Light scoop 60 March 21st11:00 AM 69.3 24.5
over cast Light scoop 60 March 21st 12:00 PM 71.9 27.6
over cast Light scoop 60 March 21st 1:00 PM 67.2 26
over cast Light scoop 60 March 21st 2:00 PM 59.4 6.3
over cast Light scoop 60 March 21st 3:00 PM 44.3 4.2
over cast Light scoop 60 March 21st 4:00 PM 19.8 0
over cast Light scoop 60 March 21st 5:00 PM 0 0
over cast Light scoop 60 March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast Light scoop 60 Jun 21st 7:00 AM 14.6 0
over cast Light scoop 60 Jun 21st 8:00 AM 44.3 3.1
over cast Light scoop 60 Jun 21st 9:00 AM 58.3 18.8
over cast Light scoop 60 Jun 21st 10:00 AM 70.3 37
over cast Light scoop 60 Jun 21st 11:00 AM 77.6 43.8
over cast Light scoop 60 Jun 21st 12:00 PM 77.1 47.4
over cast Light scoop 60 Jun 21st 1:00 PM 72.9 43.8
over cast Light scoop 60 Jun 21st 2:00 PM 70.3 35.4
over cast Light scoop 60 Jun 21st 3:00 PM 55.7 10.4
over cast Light scoop 60 Jun 21st 4:00 PM 38.5 0
over cast Light scoop 60 Jun 21st 5:00 PM 16.1 0
over cast Light scoop 60 Jun 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast Light scoop 60 Dec 21st 7:00 AM 0 0
over cast Light scoop 60 Dec 21st 8:00 AM 0 0
over cast Light scoop 60 Dec 21st 9:00 AM 8.9 0
over cast Light scoop 60 Dec 21st 10:00 AM 25 0
over cast Light scoop 60 Dec 21st 11:00 AM 40.1 0
over cast Light scoop 60 Dec 21st 12:00 PM 35.9 0.5
over cast Light scoop 60 Dec 21st 1:00 PM 33.3 1
over cast Light scoop 60 Dec 21st 2:00 PM 24 0
over cast Light scoop 60 Dec 21st 3:00 PM 0.5 0
over cast Light scoop 60 Dec 21st 4:00 PM 0 0
over cast Light scoop 60 Dec 21st 5:00 PM 0 0
over cast Light scoop 60 Dec 21st 6:00 PM 0 0
37

Figure 4-17: Performance evaluation of light scoop 60 degree

4.1.4 Sawtooth skylight test case

The fourth design was the north facing sawtooth skylight test case scenarios (figure 4-18). The north facing skylight
was selected for the simulations. Since north light provides a more diffused light during the day. The data was
collected in the same manner as that for the first design with the same table format. The data collected for this model
is illustrated in the form of tables (figure 4-19, 4-20, 4-21). In charts like Figure 4-22, the point plotted is the average
of all observations in column EML%, and the average of all observations from column Lux% in the corresponding
table (e.g. figure 4-19).

Figure 4-18: The sawtooth skylight test case model

38

Figure 4-19: left figure- Daily percentage of hourly conservation for north facing sawtooth skylight under clear sky condition,
March 21st. Right figure- Daily percentage of hourly conservations for north facing sawtooth skylight under clear sky conditions,
June 21
st
.

Figure 4-20: Left figure- Daily percentage of hourly conservation for north facing sawtooth skylight under clear sky condition,
December 21st. Right figure- Daily percentage of hourly conservation for north facing sawtooth skylight under overcast sky
condition, March 21st.

Figure 4-21: Left figure- Daily percentage of hourly conservation for north facing sawtooth skylight under overcast sky
condition, June 21st. Right figure- Daily percentage of hourly conservations for north facing sawtooth skylight under overcast
sky conditions, December 21st.

SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear North facing Sawtooth March 21st 7:00 AM 0 0
Clear North facing Sawtooth March 21st 8:00 AM 2.6 0
Clear North facing Sawtooth March 21st 9:00 AM 5.2 0
Clear North facing Sawtooth March 21st10:00 AM 8.3 0
Clear North facing Sawtooth March 21st11:00 AM 10.9 0
Clear North facing Sawtooth March 21st 12:00 PM 9.4 0
Clear North facing Sawtooth March 21st 1:00 PM 13 0
Clear North facing Sawtooth March 21st 2:00 PM 6.8 0
Clear North facing Sawtooth March 21st 3:00 PM 4.7 0
Clear North facing Sawtooth March 21st 4:00 PM 0.5 0
Clear North facing Sawtooth March 21st 5:00 PM 0 0
Clear North facing Sawtooth March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear North facing Sawtooth Jun 21st 7:00 AM 37 0
Clear North facing Sawtooth Jun 21st 8:00 AM 38.5 2.6
Clear North facing Sawtooth Jun 21st 9:00 AM 42.2 0
Clear North facing Sawtooth Jun 21st 10:00 AM 40.1 0
Clear North facing Sawtooth Jun 21st 11:00 AM 41.7 0
Clear North facing Sawtooth Jun 21st 12:00 PM 42.2 0
Clear North facing Sawtooth Jun 21st 1:00 PM 45.3 1
Clear North facing Sawtooth Jun 21st 2:00 PM 41.7 0.5
Clear North facing Sawtooth Jun 21st 3:00 PM 31.8 0
Clear North facing Sawtooth Jun 21st 4:00 PM 36.5 0
Clear North facing Sawtooth Jun 21st 5:00 PM 31.8 3.1
Clear North facing Sawtooth Jun 21st 6:00 PM 15.1 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear North facing Sawtooth Dec 21st 7:00 AM 0 0
Clear North facing Sawtooth Dec 21st 8:00 AM 0 0
Clear North facing Sawtooth Dec 21st 9:00 AM 0 0
Clear North facing Sawtooth Dec 21st 10:00 AM 0 0
Clear North facing Sawtooth Dec 21st 11:00 AM 0 0
Clear North facing Sawtooth Dec 21st 12:00 PM 0 0
Clear North facing Sawtooth Dec 21st 1:00 PM 0 0
Clear North facing Sawtooth Dec 21st 2:00 PM 0 0
Clear North facing Sawtooth Dec 21st 3:00 PM 0 0
Clear North facing Sawtooth Dec 21st 4:00 PM 0 0
Clear North facing Sawtooth Dec 21st 5:00 PM 0 0
Clear North facing Sawtooth Dec 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast North facing Sawtooth March 21st 7:00 AM 0 0
over cast North facing Sawtooth March 21st 8:00 AM 5.2 0
over cast North facing Sawtooth March 21st 9:00 AM 26.6 0.5
over cast North facing Sawtooth March 21st10:00 AM 32.8 0
over cast North facing Sawtooth March 21st11:00 AM 42.2 1.6
over cast North facing Sawtooth March 21st 12:00 PM 50 8.9
over cast North facing Sawtooth March 21st 1:00 PM 46.9 5.2
over cast North facing Sawtooth March 21st 2:00 PM 32.8 1.6
over cast North facing Sawtooth March 21st 3:00 PM 22.4 0.5
over cast North facing Sawtooth March 21st 4:00 PM 5.2 0
over cast North facing Sawtooth March 21st 5:00 PM 0 0
over cast North facing Sawtooth March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast North facing Sawtooth Jun 21st 7:00 AM 7.8 0
over cast North facing Sawtooth Jun 21st 8:00 AM 26.6 0
over cast North facing Sawtooth Jun 21st 9:00 AM 40.1 4.2
over cast North facing Sawtooth Jun 21st 10:00 AM 52.6 15.1
over cast North facing Sawtooth Jun 21st 11:00 AM 58.9 21.4
over cast North facing Sawtooth Jun 21st 12:00 PM 62 20.3
over cast North facing Sawtooth Jun 21st 1:00 PM 57.8 17.2
over cast North facing Sawtooth Jun 21st 2:00 PM 49.5 7.8
over cast North facing Sawtooth Jun 21st 3:00 PM 35.9 3.6
over cast North facing Sawtooth Jun 21st 4:00 PM 20.8 0
over cast North facing Sawtooth Jun 21st 5:00 PM 5.2 0
over cast North facing Sawtooth Jun 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast North facing Sawtooth Dec 21st 7:00 AM 0 0
over cast North facing Sawtooth Dec 21st 8:00 AM 0 0
over cast North facing Sawtooth Dec 21st 9:00 AM 0 0
over cast North facing Sawtooth Dec 21st 10:00 AM 5.2 0
over cast North facing Sawtooth Dec 21st 11:00 AM 11.5 0
over cast North facing Sawtooth Dec 21st 12:00 PM 9.4 0
over cast North facing Sawtooth Dec 21st 1:00 PM 13 0
over cast North facing Sawtooth Dec 21st 2:00 PM 4.2 0
over cast North facing Sawtooth Dec 21st 3:00 PM 5.7 0
over cast North facing Sawtooth Dec 21st 4:00 PM 0 0
over cast North facing Sawtooth Dec 21st 5:00 PM 0 0
over cast North facing Sawtooth Dec 21st 6:00 PM 0 0
39

Figure 4-22: Performance evaluation of north facing sawtooth skylight

4.1.5 Clerestory angled test case

The fifth design was the angled clerestories test case scenarios (figure 4-23). The data was collected for the sawtooth
skylight was represented in the table 4-5. The data was collected in the same manner as that for the first design with
the same table format. The data collected for this model is illustrated in the form of tables (figure 4-24, 4-25, 4-26).
In charts like Figure 4-27, the point plotted is the average of all observations in column EML%, and the average of
all observations from column Lux% in the corresponding table (e.g. figure 4-24).

Figure 4-23: The Clerestory angled test case model

40

Figure 4-24: left figure- Daily percentage of hourly conservation for angled clerestory under clear sky condition, March 21st.
Right figure- Daily percentage of hourly conservations for angled clerestory under clear sky conditions, June 21
st
.

Figure 4-25: Left figure- Daily percentage of hourly conservation for angled clerestory under clear sky condition, December
21st. Right figure- Daily percentage of hourly conservation for angled clerestory under overcast sky condition, March 21st.

Figure 4-26: Left figure- Daily percentage of hourly conservation for angled clerestory under overcast sky condition, June 21st.
Right figure- Daily percentage of hourly conservations for angled clerestory under overcast sky conditions, December 21st.

SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear clerestories angled March 21st 7:00 AM 10.4 0
Clear clerestories angled March 21st 8:00 AM 48.4 2.6
Clear clerestories angled March 21st 9:00 AM 65.6 6.8
Clear clerestories angled March 21st10:00 AM 66.7 10.4
Clear clerestories angled March 21st11:00 AM 55.2 2.1
Clear clerestories angled March 21st 12:00 PM 34.9 0
Clear clerestories angled March 21st 1:00 PM 25.5 0
Clear clerestories angled March 21st 2:00 PM 18.2 0
Clear clerestories angled March 21st 3:00 PM 1.6 0
Clear clerestories angled March 21st 4:00 PM 0 0
Clear clerestories angled March 21st 5:00 PM 0 0
Clear clerestories angled March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear clerestories angled Jun 21st 7:00 AM 56.8 3.6
Clear clerestories angled Jun 21st 8:00 AM 63.5 2.1
Clear clerestories angled Jun 21st 9:00 AM 66.1 2.1
Clear clerestories angled Jun 21st 10:00 AM 52.1 1.6
Clear clerestories angled Jun 21st 11:00 AM 37 0
Clear clerestories angled Jun 21st 12:00 PM 21.4 0
Clear clerestories angled Jun 21st 1:00 PM 16.1 0
Clear clerestories angled Jun 21st 2:00 PM 6.8 0
Clear clerestories angled Jun 21st 3:00 PM 4.2 0
Clear clerestories angled Jun 21st 4:00 PM 0 0
Clear clerestories angled Jun 21st 5:00 PM 0 0
Clear clerestories angled Jun 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear clerestories angled Dec 21st 7:00 AM 0 0
Clear clerestories angled Dec 21st 8:00 AM 27.6 5.2
Clear clerestories angled Dec 21st 9:00 AM 63 31.8
Clear clerestories angled Dec 21st 10:00 AM 64.6 19.3
Clear clerestories angled Dec 21st 11:00 AM 50.5 8.3
Clear clerestories angled Dec 21st 12:00 PM 30.2 0
Clear clerestories angled Dec 21st 1:00 PM 18.2 0
Clear clerestories angled Dec 21st 2:00 PM 8.9 0
Clear clerestories angled Dec 21st 3:00 PM 0.5 0
Clear clerestories angled Dec 21st 4:00 PM 0 0
Clear clerestories angled Dec 21st 5:00 PM 0 0
Clear clerestories angled Dec 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast clerestories angled March 21st 7:00 AM 0 0
over cast clerestories angled March 21st 8:00 AM 0 0
over cast clerestories angled March 21st 9:00 AM 9.4 0
over cast clerestories angled March 21st10:00 AM 20.3 0
over cast clerestories angled March 21st11:00 AM 40.1 0
over cast clerestories angled March 21st 12:00 PM 43.2 0.5
over cast clerestories angled March 21st 1:00 PM 33.9 0
over cast clerestories angled March 21st 2:00 PM 29.7 0
over cast clerestories angled March 21st 3:00 PM 8.9 0
over cast clerestories angled March 21st 4:00 PM 0 0
over cast clerestories angled March 21st 5:00 PM 0 0
over cast clerestories angled March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast clerestories angled Jun 21st 7:00 AM 0.5 0
over cast clerestories angled Jun 21st 8:00 AM 9.9 0
over cast clerestories angled Jun 21st 9:00 AM 30.2 0
over cast clerestories angled Jun 21st 10:00 AM 45.8 2.1
over cast clerestories angled Jun 21st 11:00 AM 51 0
over cast clerestories angled Jun 21st 12:00 PM 56.3 5.7
over cast clerestories angled Jun 21st 1:00 PM 49.5 3.6
over cast clerestories angled Jun 21st 2:00 PM 44.8 1
over cast clerestories angled Jun 21st 3:00 PM 28.1 0
over cast clerestories angled Jun 21st 4:00 PM 2.1 0
over cast clerestories angled Jun 21st 5:00 PM 0 0
over cast clerestories angled Jun 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast clerestories angled Dec 21st 7:00 AM 0 0
over cast clerestories angled Dec 21st 8:00 AM 0 0
over cast clerestories angled Dec 21st 9:00 AM 0 0
over cast clerestories angled Dec 21st 10:00 AM 0 0
over cast clerestories angled Dec 21st 11:00 AM 5.2 0
over cast clerestories angled Dec 21st 12:00 PM 1.6 0
over cast clerestories angled Dec 21st 1:00 PM 2.6 0
over cast clerestories angled Dec 21st 2:00 PM 0 0
over cast clerestories angled Dec 21st 3:00 PM 0 0
over cast clerestories angled Dec 21st 4:00 PM 0 0
over cast clerestories angled Dec 21st 5:00 PM 0 0
over cast clerestories angled Dec 21st 6:00 PM 0 0
41

Figure 4-27: Performance evaluation of angled clerestory

4.1.6 North-facing vertical light scoop

The sixth design was the angled clerestories test case scenarios (figure 4-28). The data was collected for the
sawtooth skylight was represented in the table 4-5. The data was collected in the same manner as that for the first
design with the same table format. The data collected for this model is illustrated in the form of tables (figure 4-29,
4-30, 4-31). In charts like Figure 4-32, the point plotted is the average of all observations in column EML%, and the
average of all observations from column Lux% in the corresponding table (e.g. figure 4-29).

Figure 4-28: The North-facing vertical light scoop test case model

42

Figure 4-29: left figure- Daily percentage of hourly conservation for north-facing vertical light scoop under clear sky condition,
March 21st. Right figure- Daily percentage of hourly conservations for north-facing vertical light scoop under clear sky
conditions, June 21
st
.

Figure 4-30: Left figure- Daily percentage of hourly conservation for north-facing vertical light scoop under clear sky condition,
December 21st. Right figure- Daily percentage of hourly conservation for north-facing vertical light scoop under overcast sky
condition, March 21st.

Figure 4-31: Left figure- Daily percentage of hourly conservation for north-facing vertical light scoop under overcast sky
condition, June 21st. Right figure- Daily percentage of hourly conservations for north-facing vertical light scoop under overcast
sky conditions, December 21st.

SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear lightscoop broad March 21st 7:00 AM 0 0
Clear lightscoop broad March 21st 8:00 AM 0 0
Clear lightscoop broad March 21st 9:00 AM 0.5 0
Clear lightscoop broad March 21st10:00 AM 6.8 0
Clear lightscoop broad March 21st11:00 AM 14.1 0
Clear lightscoop broad March 21st 12:00 PM 9.4 0
Clear lightscoop broad March 21st 1:00 PM 6.3 0
Clear lightscoop broad March 21st 2:00 PM 3.1 0
Clear lightscoop broad March 21st 3:00 PM 0.5 0
Clear lightscoop broad March 21st 4:00 PM 0 0
Clear lightscoop broad March 21st 5:00 PM 0 0
Clear lightscoop broad March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear lightscoop broad Jun 21st 7:00 AM 3.1 0
Clear lightscoop broad Jun 21st 8:00 AM 3.1 0
Clear lightscoop broad Jun 21st 9:00 AM 3.6 0
Clear lightscoop broad Jun 21st 10:00 AM 11.5 0
Clear lightscoop broad Jun 21st 11:00 AM 13 0
Clear lightscoop broad Jun 21st 12:00 PM 16.1 0
Clear lightscoop broad Jun 21st 1:00 PM 13.5 0
Clear lightscoop broad Jun 21st 2:00 PM 6.3 0
Clear lightscoop broad Jun 21st 3:00 PM 0.5 0
Clear lightscoop broad Jun 21st 4:00 PM 3.6 0
Clear lightscoop broad Jun 21st 5:00 PM 0.5 0
Clear lightscoop broad Jun 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
Clear lightscoop broad Dec 21st 7:00 AM 0 0
Clear lightscoop broad Dec 21st 8:00 AM 0 0
Clear lightscoop broad Dec 21st 9:00 AM 0 0
Clear lightscoop broad Dec 21st 10:00 AM 0 0
Clear lightscoop broad Dec 21st 11:00 AM 0 0
Clear lightscoop broad Dec 21st 12:00 PM 0 0
Clear lightscoop broad Dec 21st 1:00 PM 0.5 0
Clear lightscoop broad Dec 21st 2:00 PM 0 0
Clear lightscoop broad Dec 21st 3:00 PM 0 0
Clear lightscoop broad Dec 21st 4:00 PM 0 0
Clear lightscoop broad Dec 21st 5:00 PM 0 0
Clear lightscoop broad Dec 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast lightscoop broad March 21st 7:00 AM 0 0
over cast lightscoop broad March 21st 8:00 AM 0 0
over cast lightscoop broad March 21st 9:00 AM 0 0
over cast lightscoop broad March 21st10:00 AM 8.9 0
over cast lightscoop broad March 21st11:00 AM 10.4 0
over cast lightscoop broad March 21st 12:00 PM 15.1 0
over cast lightscoop broad March 21st 1:00 PM 16.7 0
over cast lightscoop broad March 21st 2:00 PM 3.7 0
over cast lightscoop broad March 21st 3:00 PM 3.1 0
over cast lightscoop broad March 21st 4:00 PM 0 0
over cast lightscoop broad March 21st 5:00 PM 0 0
over cast lightscoop broad March 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast lightscoop broad Jun 21st 7:00 AM 0 0
over cast lightscoop broad Jun 21st 8:00 AM 3.6 0
over cast lightscoop broad Jun 21st 9:00 AM 5.2 0
over cast lightscoop broad Jun 21st 10:00 AM 25 0
over cast lightscoop broad Jun 21st 11:00 AM 28.1 0
over cast lightscoop broad Jun 21st 12:00 PM 34.4 0
over cast lightscoop broad Jun 21st 1:00 PM 29.2 0
over cast lightscoop broad Jun 21st 2:00 PM 18.2 0
over cast lightscoop broad Jun 21st 3:00 PM 10.9 0
over cast lightscoop broad Jun 21st 4:00 PM 1 0
over cast lightscoop broad Jun 21st 5:00 PM 0 0
over cast lightscoop broad Jun 21st 6:00 PM 0 0
SKY CONDITIONSKYLIGHT DATE HOUR EML % LUX%
over cast lightscoop broad Dec 21st 7:00 AM 0 0
over cast lightscoop broad Dec 21st 8:00 AM 0 0
over cast lightscoop broad Dec 21st 9:00 AM 0 0
over cast lightscoop broad Dec 21st 10:00 AM 0 0
over cast lightscoop broad Dec 21st 11:00 AM 0 0
over cast lightscoop broad Dec 21st 12:00 PM 0 0
over cast lightscoop broad Dec 21st 1:00 PM 0 0
over cast lightscoop broad Dec 21st 2:00 PM 0 0
over cast lightscoop broad Dec 21st 3:00 PM 0 0
over cast lightscoop broad Dec 21st 4:00 PM 0 0
over cast lightscoop broad Dec 21st 5:00 PM 0 0
over cast lightscoop broad Dec 21st 6:00 PM 0 0
43

Figure 4-32: Performance evaluation of the north-facing vertical light scoop

4.2 Overall performance evaluation

The EML and Visual Discomfort mentioned below were the main axis of the graph (figure 4-33). The average EML
values of all hours in 3 different days was used for the Y axis and the average Visual discomfort values of all hours
in 3 different days was used for the X axis of the graph. This graph shows the best, moderate, and poor performance
of different strategies. This graph helps designers and architects to choose better design strategies for their project.
In charts like Figure 4-33, the point plotted is the average of all observations in column EML%, and the average of
all observations from column Lux% in the corresponding table (e.g. figure 4-31).

Figure 4-33: Overall performance evaluation of all test case model
Best performance
Poor performance
Moderate performance
Moderate performance
Theoretical best
performance
Theoretical worst
performance
44

4.3 Comparison of circadian lighting evaluation results based on different sky condition

- Clear Sky Condition
The overall score is the subtraction of the visual discomfort values from the circadian stimulus values. Lower visual
discomfort values show better performance. The higher overall score indicates the better performance. The
performance of the test case model with clerestory strategy, under clear sky condition with the overall score of 25 is
the best strategy among the six different test case models. Angled clerestory with the overall score of 23 and light
scoop with 60-degree angle with the overall score of 20 has the better overall score. North-facing vertical light scoop
with the overall score of 6 has the poorest performance evaluation (figure 4-34).

- Overcast Sky Condition
The overall score data under the overcast condition was collected in the same manner as that for the clear sky
condition. The performance of the test case model with 45-degree angle light scoop strategy, under overcast sky
condition with the overall score of 26 is the best strategy among other test case models. Light scoops provide less
direct sunlight during the summer while provides more sunlight in winter. Light scoops work better in overcast sky
conditions (Radetsky & Brons, n.d.). 60-degree angle light scoop with the overall score of 24 and clerestory with the
overall score of 22 has the better overall score. Like the clear sky condition, north-facing vertical light scoop with
the overall score of 4 hast the poorest performance evaluation (figure 4-34).

Figure 4-34: Comparison of different test case models under clear & overcast sky condition

4.4 Comparison of circadian lighting evaluation results based on different seasons

The final score is the sum of the overall percentages of circadian stimulus and visual discomfort values under
overcast and clear sky condition for March 21
st
, June 21
st
, and December 21
st
. The final score is the sum of all
observations in column overcast total and all observations from column clear total in the corresponding table (figure
4-35). For example, clear total column is the subtraction of CS observations under clear sky condition and the glare
observations under clear sky condition (figure 4-35).
0
10
20
30
40
50
60
70
80
90
100
Lightscoop 45 Lightscoop 60 Clerestory Angled clerestory Sawtooth skylight North Light scoop
Overall Score
Six different test case model
Comparison of different test case models under clear & overcast
sky condition
Clear Sky Condition Overcast Sky Condition
45

The higher percentage of final score indicates the better overall performances of different case test scenarios. All of
the test case models have a higher score in June 21
st
, except the test case model with 45-degreee angle light scoop.
45-degre light scoop is more efficient in March 21
st
and December 21
st
. The test case model with clerestory and 60-
degree angle light scoop have a similar score in June 21
st
and March 21
st
(figure 4-36).

In charts like Figure 4-35, the column plotted is the final score of all observations in column final score in the
corresponding table (figure 4-35).

Figure 4-35: The final score of different test case models in March 21st

Figure 4-36: Performance evaluation of test case models based on different season

4.5 Overall final score

The design decision support framework can be applied in the early stages of daylight design for circadian
effective solutions in dementia care communities. It’s important to combine the overall performance score under
clear and over cast sky conditions for a better decision making. The average of hourly percentages of viewpoints
above the Circadian Stimulus threshold starting from 7am to 6 pm for three different days throughout the year under
clear and overcast sky condition, were collected in the form of a table (Table 4-1,4-2). Since the lower visual
discomfort values indicates a better performance, the overall score for each sky condition is the subtraction of the
visual discomfort values from circadian stimulus values. The final score is the sum of the overall percentages of
circadian stimulus and visual discomfort values under overcast and clear sky condition (Table 4-3). The higher
percentage of final score indicates the better overall performances of different case test scenarios. The clerestories
test case scenario has the highest final score, it means it has the best overall performance evaluation.
clear cs overcast cs clear glare overcast glare clear total overcast total final score
Test model Mar. 21st Mar. 21st Mar. 21st Mar. 21st Mar. 21st Mar. 21st Mar. 21st
Lightscoop 45 60 44 40 16 20 28 48
Lightscoop 60 58 37 36 9 22 28 50
Clerestory 30 28 0.5 1 29.5 27 56.5
Angled clerestory 28 16 2 1 26 15 41
Sawtooth skylight 6 22 0 2 6 20 26
N-facing light scoop 4 5 0 0 4 5 9
46

Table 4-1: Left table- the percentages of views above the threshold for CS for 6 different test case models under clear sky. Right
table- the percentages of views above the threshold for CS for 6 different test case models under overcast sky.

Table 4-2: Left table- the percentages of views above the threshold for glare for 6 different test case models under clear sky.
Right table- the percentages of views above the threshold for glare for 6 different test case models under overcast sky.

Table 4-3: the final score of 6 different test case models, based on the overall score under clear and overcast sky condition.

4.6 Summary

If designers want to consider circadian lighting, then they must use software that supports giving them that
information, for example making decisions related to goals of circadian effective light stimulus in dementia care
communities. This chapter reported the data based on different design top lighting strategies. The performance
evaluation based on different season, different sky conditions, and the overall best-case scenarios, and the overall
worst-case scenarios.

Based on research objectives for this chapter, the data were collected in the form of tables and graphs to differentiate
performance of various design options. The overall performance evaluation graphs help designers to choose
different top lighting strategy in the early stages of design to aid in supporting decision-making to goals of circadian
effectiveness. Since the sky condition has an impact on the amount of light entering the space, understanding the
impact of different sky conditions on circadian lighting effects was studied; results will be discussed in chapter 5.

The average of hourly percentages of viewpoints above the Circadian Stimulus threshold starting from 7am to 6 pm
for three different days throughout the year under clear and overcast sky condition, were collected in the form of a
table. Since the lower visual discomfort values indicates a better performance, the overall score for each sky
condition is the subtraction of the visual discomfort values from circadian stimulus values. The final score is the sum
of the overall percentages of circadian stimulus and visual discomfort values under overcast and clear sky condition
(Table 4-3). The higher percentage of final score indicates the better overall performances of different case test
scenarios. The clerestories test case scenario has the highest final score; it means it has the best overall performance
evaluation.
Test model March 21st June 21st December 21st Average of 3 days/clear sky
Lightscoop 45 60 60 55 59
Lightscoop 60 58 51 54 55
Clerestory 30 21 37 30
Angled clerestory 28 27 22 26
Sawtooth skylight 6 37 0.1 15
N-facing light scoop 4 7 1 4
Clear sky condition
% of views above thresh CS
Test model Mar 21st Jun 21st De 21st Average of 3 days/Overcast sky
Lightscoop 45 44 59 19 41
Lightscoop 60 37 50 14 34
Clerestory 28 43 4 25
Angled clerestory 16 27 1 15
Sawtooth skylight 22 35 5 21
N-facing light scoop 5 13 0 6
% of views above thresh CS
Overcast sky condition
Test model Mar 21st Jun 21st De 21st Average of 3 days/clear sky
Lightscoop 45 40 74 41 52
Lightscoop 60 36 23 42 34
Clerestory 0.5 0.2 12 5
Angled clerestory 2 1 6 3
Sawtooth skylight 0 1 1 1
N-facing light scoop 0 0 0 0
% of views above thresh for glare
Clear sky condition
Test model Mar 21st Jun 21st De 21st Average of 3 days/Clear sky
Lightscoop 45 16 28 0.5 15
Lightscoop 60 9 20 0.1 10
Clerestory 1 6 0 3
Angled clerestory 1 1 0 1
Sawtooth skylight 2 8 0 4
N-facing light scoop 0 0 0 0
Overcast sky condition
% of views above thresh for glare
Test model Total % CS Total % glare Over all Total % CS Total % glare Over all Final Score
Lightscoop 45 59 52 7 41 15 26 33
Lightscoop 60 55 34 21 34 10 24 45
Clerestory 30 5 25 25 3 22 47
Angled clerestory 26 3 23 15 1 14 37
Sawtooth skylight 15 1 14 21 4 17 31
North Light scoop 4 0 4 6 0 6 10
Over cast sky condition Clear sky condition
47

5. DISCUSSION

This chapter explains the evaluation of different test case models, comparison of overall performance evaluation,
comparison of circadian lighting evaluation based on different sky condition, comparison of circadian lighting
evaluation based on different seasons, and overall final score.

The results were presented in the previous chapter. This chapter discusses the results of the analysis of the six test case
models. The overall best-test case model and worst test case model are compared to show a guide to daylighting
designers in the early stages of design. It is important to know how much different strategies can impact the circadian
lighting effects. The hourly average percentage of viewpoints above the defined threshold for circadian stimulus and
the hourly average percentage of viewpoints above the defined threshold for visual discomfort results are discussed.
Different sky conditions have an impact on the circadian lighting and glare effects. It is critical to understand if there
are some changes based on different season and to differentiate performance of various design options; this would
depend upon the specific design.

5.1 Evaluation of different test case models

This section discusses the evaluation of clerestory, light scoop 45-degree, light scoop 60-degree, sawtooth skylight,
clerestory angles, and north facing vertical light scoop test case models in details.

Figure 5-1: left figure- Test model with clerestories. Right figure- Test model with light scoop 45-degree.

Figure 5-2: left figure- Test model with light scoop 60-degree. Right figure- Test model with sawtooth skylight.

48

Figure 5-3: Left figure- Test model with angled clerestory. Right figure- Test model with north-facing light scoop.

5.1.1 Evaluation of clerestory test case model

The test case model with clerestory has a higher number in the circadian stimulus section; this can be evaluated as a
positive indicator for the analysis. Based on the performance evaluation chart most of the average hourly observations
fall within the moderate performance section (figure 5-4). The data for June 21
st
under overcast sky condition has the
highest performance score. The visual discomfort values are very low near zero in most of the average hourly
observations, that indicates the better performance in terms of glare issues. The percentage values for circadian
stimulus sections during the period starting from 9 am to 3 pm are above the 50%. It means that almost half of
viewpoints in the grid analysis has the circadian stimulus values higher than 350 EML, that can be evaluated as a
circadian-effective solution.

Figure 5-4: Performance evaluation of clerestory test case model.

5.1.2 Evaluation of light scoop 45-degree test case model

The test case model with light scoop 45-degree has higher number in the visual discomfort section. Light scoop 45-
degree performance under overcast sky condition observations falls within the best performance section in the
corresponding chart (figure 5-5). The data for June 21
st
under overcast sky condition has the highest circadian stimulus
and the lowest visual discomfort values. Figure 5-5 shows that light scoop 45 degree can be a good strategy for over
cast conditions as well.

49

Figure 5-5: Performance evaluation of light scoop 45-degree test case model.

5.1.3 Evaluation of light scoop 60-degree test case model

The test case model with light scoop 60-degree has higher number in the visual discomfort section. Light scoop 45-
degree performance under overcast sky condition observations falls within the best performance section in the
corresponding chart (figure 5-6). The data for June 21
st
under overcast sky condition has the highest circadian stimulus
and the lowest visual discomfort values. Figure 5-6 shows that light scoop 45 degree can be a good strategy for over
cast conditions as well.

Figure 5-6: Performance evaluation of light scoop 60-degree test case model.

5.1.4 Evaluation of sawtooth skylight test case model

The test case model with sawtooth skylight has a relatively low percentage in both circadian stimulus and glare section.
The data from figure 5-7 shows that the circadian stimulus and glare values are almost zero for all the hourly
observations. It means this strategy doesn’t perform well during the winter season. figure 5-7 shows that all of the
50

point plotted in the chart falls within the “moderate performance” section. The data in June 21
st
for both overcast and
clear sky conditions have higher circadian stimulus values.

Figure 5-7: Performance evaluation of sawtooth skylight test case model.

5.1.5 Evaluation of clerestory angled test case model

The test case model with clerestory angled has a relatively high circadian stimulus especially during 9am to 11 am.
This strategy can be applied to areas that needs higher amount of EML during the morning hours. This strategy
performs well early in the morning, but since the EML values decreases after the morning hours, the average of hourly
observations is relatively low. Glare is not a big issue in this test case model (figure 5-8).

Figure 5-8: Performance evaluation of clerestory angled test case model.

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5.1.6 Evaluation of north-facing vertical light scoop test case model

The average hourly observation for the test case model with north-facing vertical light scoop indicates that both the
circadian stimulus values and visual discomfort values are very low in terms of percentages. Figure 5-9 shows that the
almost all the hourly observations’ values are near zero especially during the winter season. Most of the average hourly
observations under both sky conditions fall within the data for June 21
st
under overcast sky condition has the highest
circadian stimulus and the lowest visual discomfort values.

Figure 5-9: Performance evaluation of north-facing vertical light scoop test case model.

5.2 Comparison of overall performance evaluation

In charts like Figure 5-10, the point plotted is the average of all observations in column EML%, and the average of
all observations from column Lux% in the corresponding table (e.g. figure 4-29). This graph helps designers and
architects to choose better design strategies for their project. The light scoop 60-degree test case model is the only
test case that falls within the “Best performance” section in figure 5-10.

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Figure 5-10: Comparison of overall performance evaluation of different test case models.

5.3 Comparison of circadian lighting evaluation results based on different sky conditions

The performance of the test case model with clerestory strategy, under clear sky condition with the overall score of
25 is the best strategy among the six different test case models. Angled clerestory with the overall score of 23 and
light scoop with 60-degree angle with the overall score of 20 has the better overall score. North-facing vertical light
scoop with the overall score of 6 has the poorest performance evaluation (Figure 5-11). The performance of the test
case model with 45-degree angle light scoop strategy, under overcast sky condition with the overall score of 26 is the
best strategy among other test case models. Light scoops provide less direct sunlight during the summer while
providing more sunlight in winter. Light scoops work better in overcast sky conditions (Radetsky & Brons, n.d.). 60-
degree angle light scoop with the overall score of 24 and clerestory with the overall score of 22 has the better overall
score. Like the clear sky condition, north-facing vertical light scoop with the overall score of 4 has the poorest
performance evaluation.

Moderate performance
Moderate performance
Poor performance
Best performance
Theoretical best
performance
Theoretical worst
performance
53

Figure 5-11: Comparison of different test case models under clear & overcast sky condition

5.4 Comparison of circadian lighting evaluation results based on different seasons

It is critical to understand if there are some changes based on different season. Figure 5-12 shows that sawtooth sky
light can be a circadian-effective solution in summer season. Clerestory and light scoop 60-degree test case model
performance score are almost the same in June March 21
st
, June 21
st
, and December 21
st
. Sawtooth skylight and
north-facing light scoop’s performance final score is very low in Dec 21
st
. Light scoop 45 degree is the only test case
model that in March 21
st
performs better than in June 21
st
. clerestory overall score is very similar in June 21
st
and
March 21
st
.

0
10
20
30
40
50
60
70
80
90
100
Lightscoop 45 Lightscoop 60 Clerestory Angled clerestory Sawtooth skylight North Light scoop
Overall Score
Six different test case model
Comparison of different test case models under clear & overcast
sky condition
Clear Sky Condition Overcast Sky Condition
54

Figure 5-12: Performance evaluation of test case models based on different season

5.5 Overall final score

The higher percentage of final score indicates the better overall performances of different case test scenarios. The
clerestories test case scenario has the higher final score, it means it has the best overall performance evaluation.
The clerestory test case model with the final score of 47, has the highest score among six different test case models.
The test case model with light scoop 60-degree angle with the final score of 45, has the second highest score among
other test case scenarios. the test case model with north-facing vertical light scoop has the poorest performance with
the final score of 10 (Table 5-1).

Table 5-1: the final score of 6 different test case models, based on the overall score under clear and overcast sky condition.

5.6 Summary

The new design decision support framework was proposed that can be applied in the early stages of design to aid in
supporting decision-making related to goals of circadian effective light stimulus in dementia care communities. The
hourly average percentage of viewpoints above the defined threshold for circadian stimulus and the hourly average
percentage of viewpoints above the defined threshold for visual discomfort was compared for the different case
studies.

Test model Total % CS Total % glare Over all Total % CS Total % glare Over all Final Score
Lightscoop 45 59 52 7 41 15 26 33
Lightscoop 60 55 34 21 34 10 24 45
Clerestory 30 5 25 25 3 22 47
Angled clerestory 26 3 23 15 1 14 37
Sawtooth skylight 15 1 14 21 4 17 31
North Light scoop 4 0 4 6 0 6 10
Over cast sky condition Clear sky condition
55

It is critical to understand is there are some changes based on different seasons and to differentiate performance of
various design options. The clerestories test case scenario has the higher final score, it means it has the best overall
performance evaluation. The clerestory test case model with the final score of 47, has the highest score among six
different test case models. Light scoop 60-degree angle with the final score of 45, has the second highest score among
other test case scenarios. The test case model with north-facing vertical light scoop has the poorest performance with
the final score of 10.

A sawtooth sky light can be a circadian-effective solution in summer season. Clerestory and light scoop 60-degree
test case model performance score are almost the same in June March 21
st
, June 21
st
, and December 21
st
. Sawtooth
skylight and north-facing light scoop’s performance final score is very low in Dec 21
st
. Light scoop 45 degree is the
only test case model that in March 21
st
performs better than in June 21
st
. Clerestory overall score is very similar in
June 21
st
and March 21
st
. The angled clerestory has a relatively high circadian stimulus especially during 9am to 11
am. This strategy can be applied to areas that needs higher amount of EML during the morning hours.

The point plotted is the average of all observations in column EML%, and the average of all observations from
column Lux% in the corresponding table (e.g. figure 4-27). The light scoop 60-degree test case model is the only
test case that falls within the “Best performance” section in the figure 5-10.

It is important to understand if different sky condition has an impact on the circadian lighting and glare effects.
The light scoop 45-degree and 60-degree perform better in the overcast sky condition compare to clear sky condition.
It indicates that this strategy can be applied to locations like Seattle that is mostly cloudy, to bring more daylight into
the space.

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6. CONCLUSION

In this chapter, the conclusions drawn from the simulation-based study are covered. A workflow for designers was
proposed focusing on circadian-effective strategies which will help designers in decision making in the early stages
of design (figure 6-1).

Figure 6-1: Methodology diagram

The four main objectives of this research were:

1. Create a design decision support framework and design workflow for designers that focuses on circadian-
effective strategies. This was not accomplished. Instead it is recommended that designers use lighting
software that shows circadian lighting levels for better overall performance

2. Use the new circadian lighting analysis software (ALFA) to run the circadian lighting simulations and
visual comfort for investigating top daylighting schemes.

3. To develop circadian-effective top lighting strategies in order to improve the circadian stimulus and minimize
the potential glare for corridor spaces in dementia care communities. These strategies can be implemented to
benefit from daylight and regulate the circadian cycle of the occupants.

4. To evaluate six different test cases with three different top lighting strategies, focusing on the importance of
corridor spaces in dementia care communities based on the importance of higher level of circadian stimulus
throughout the day and lower level of visual discomfort.

6.1 Improvements to the current workflow

The current workflow is focused on implementing three different top lighting strategies in the corridor space in the
dementia care communities. To achieve higher percentages of circadian stimulus and lower percentages in visual
discomfort were two main design objectives for this workflow. The simulations were carried out for Los Angeles
climate weather conditions for three different days throughout the year. The simulation quality setting is based on
ALFA default which is to guide ALFA how to carry out the simulation. The hourly data observations are collected
in the form of tables and graphs in order to be evaluated based on the design objectives. One of the limitations of
this workflow is that, ALFA can only work with Rhino. It needs to be developed to let users to run the simulations
through different 3D modeling soft wares, such as Revit and Sketch up.

57

This section explains the improvement to the current workflow, focusing on analysis with more variables, use of
optimization software, more locations, simulation for 365 days throughout the year, interpreting the best- and worst-
case scenarios, and different materials.

6.1.1 More variables

More variables could be studied. For example, one of the variables can be the height of the model as the height
plays a major role in the distribution of light through the building. Window to wall ratio and the ratio between
skylight glazing and floor area can be other variables.

6.1.2 Use of optimization software

Each case scenarios could be optimized. For example, a case test model with clerestories can be optimized with
some optimization tool named “Octopus.” This tool has a genetic algorithm, that can run the iterative analysis and
output a great range of answers. Parametric design parameters, including window wall ratio, ceiling height, different
glazing materials and the orientation of the building can be the input for the optimization study.

In the optimization process, it’s important to combine different research objectives to finalize the optional choices
with a balance of different objectives. For example, in the optimization tool named “Octopus”, building orientation,
window wall ratio, ceiling height and the design objectives like circadian stimulus and visual discomfort can be the
input of this optimization workflow.

6.1.3 More locations

Los Angeles was selected for the location in this study, other locations such as Miami, Seattle can be included in the
future work to get the more comprehensive evaluations of different latitude effects. This decision support frame
work can be done focusing on different climates. Los Angeles was the only climate that was chosen under clear and
over cast sky conditions. Seattle, Phoenix, or other cities with more extreme climate conditions and different sky
conditions could demonstrate more clearly how location makes a difference. In addition to clear and cloudy sky
conditions, it would also be useful to use local weather files’ data to get a real mix of clear and cloudy conditions.

6.1.4 Simulation for 365 days throughout a year

One of the major problems is to consider the percentages of all the viewpoints on the grid analysis plane that are
above the defined threshold. The more accurate analysis can be done based on each viewpoints data and the
direction of each viewpoints in the grid analysis can be another factor for consideration. Since ALFA can only do
point-in-time simulations, the simulations should be run for every hour, although the light exposure duration is
critical in circadian system. This workflow takes three different days during the year for the simulation analysis. In
order to get the more comprehensive result, the simulation should run for every day throughout the year instead of
only three days. One of the limitations of the ALFA software is that simulations cannot be run automatically for
multiple date and hours.

6.1.5 Interpreting the best- and worst-case scenario

The current workflow calculated the overall score for each sky condition by subtracting the visual discomfort values
from circadian stimulus values, and the final score is the sum of the overall percentages of circadian stimulus and
visual discomfort values under overcast and clear sky condition. This is one method based on the two variables
having equal weight. However, one could also choose a different balance between them, for example visual comfort
might be worth four times that of circadian stimulus. A sensitivity analysis could be run on different weighting
scenarios.

One of the most challenging aspect of this workflow was to choose the best, moderate, and poor performances.
The current methodology for interpreting the overall performance evaluation is based on the plotted point graph that
categorize the graph into four different section (figure 6-1). Another way to interpret the data can be to measure the
distance between the theoretical best point in the graph and the theoretical worst point in the performance evaluation
58

graph (figure 6-2). The shortest distance between the plotted point and the theoretical best point indicates the better
performance. Other criteria might also be used.

Figure 6-1: The current method of evaluation the overall performance

Figure 6-2: Another method of evaluation the overall performance for future work

Theoretical best
performance
Theoretical worst
performance
59

6.1.6 Design objective assumptions

This workflow uses the 350 EML as the defined threshold for the circadian lighting analysis. Since circadian
lighting is a new topic, research needs to be done to see if this number is appropriate. As this is a relatively new
topic, further research will give better assumptions including the benefits of specific time of day thresholds.

6.1.7 More lighting strategies

In future lighting strategies needs to be studied, such as roof monitors, skylights, and other non-roof options like
windows could be studied.

6.2 Future work

This section explains future work that builds on this research that includes circadian lighting, better case base location,
other rooms instead of corridors, glare avoidance and automated shading system, electric lighting, color tuning LEDs,
physical model, more real case studies, and solar heat gain.

6.2.1 Circadian lighting

A circadian-effective daylighting decision support framework was brought to the existing daylighting design
workflow for the daylighting designers and architects, based on the critical reading of how important corridor spaces
are for people living in senior housing and dementia care communities. An emphasis on circadian rhythm that have
importance placed on morning light levels with declining levels in the afternoon. to support the 24-hour lighting
scheme the electric lighting design, like doing the circadian study during the evening hours can be the topic for other
parties.

6.2.2 Better case base location

This prototype is based on the case study of the Lantern long term care communities in Ohio and the model is 4
meter high. A real project would be more complicated in terms of geometry, model, materials, and furniture layout.
Interior design can be one of the complicated sections for this study. Materials with different percentage of
reflectance, different type of glazing, more realistic furniture, more detailed model can be studied for the future
work. For example, the grid points can be more specific based on the more realistic furniture layout like the analysis
of office spaces that would consider the workstations and monitors layout since nowadays people spend most of
their working hours in front of monitors and digital devices. This parameter should be considered for a more
accurate circadian lighting analysis.

6.2.3 Other rooms instead of corridors

There are often some other spaces like greenhouse enclosures, winter gardens, and atriums that could be studied for
access to daylight for circadian lighting. In addition, if the focus is on senior care facilities, further research could be
done on other rooms that the occupants spend their time in.

6.2.4 Glare avoidance and automated shading systems

Since older people with yellowing lenses are more susceptible to glare that might be a good topic to drill down with
an aging related focus. The average EML and visual comfort values of all the viewpoints were taken for the
simulations. For more accurate result, the analysis can be carried out hourly to cover the glare issue more precisely.

Daylight condition varies over the daily and seasonal periods. Fixed shading system such as louvers and fins cannot
tune the desirable amount of daylight. A dynamic shading system can minimize the solar heat gain and potential
glare from sun and can be tuned based on different hours, days, and season.

60

6.2.5 Electric lighting and color tuning LEDs

Including electric lighting would support the 24-hour lighting profile as it can be done over the 24 hours, like in the
evening when electric lighting can provide the recommended circadian stimulus by the Lighting Research Center.
The recommended Circadian Stimulus values and the IES recommended illuminance values are different for
different building types. For example, there is not any standard like the one recommended by IES for EML values
for dementia care and long-term care communities.

Color temperature can be considered in the future work. CCT (correlated color temperature) is a rating factor for the
warmth and coolness of the lamp. Based on the 24-hour lighting scheme, it’s recommended that Alzheimer’s disease
patients should be exposed to blue light early in the morning and a high CCT light source during daytime (Figueiro,
n.d.). Appropriate electrical lighting system can supply the recommended circadian stimulus dosage over daily
periods (Konis, 2017).

6.2.6 Physical model and more real case studies

The data collection was based on the simulations in the software programs like ALFA and Rhino. Physical model
could also be used, and one could visit and with sensors gather much more data from existing buildings.

6.2.7 Solar Heat Gain

Solar heat gain is another factor that can be considered as it is an issue whenever daylighting is used. Since
orientation, model parameters, glazing types and material selection can affect the solar heat gain in a building. For
example, for engineers the energy performance has more importance, than circadian and visual comfort, while
architects and daylighting designers might consider view and glare more than solar heat gain. Solar heat gain can be
introduced as another performance goal for the proposed workflow.

6.3 Summary

The workflow could help designers delivers projects that can support the circadian system of building occupants.
This workflow was related to goals of circadian effective light stimulus in dementia care communities. It is
important to know how much different strategies can impact the circadian lighting effects. The hourly average
percentage of viewpoints above the defined threshold for circadian stimulus and the hourly average percentage of
viewpoints above the defined threshold for visual discomfort results are discussed. Different sky conditions have an
impact on the circadian lighting and glare effects. The result indicated that light scoop can be an effective strategy
for overcast climate condition. Clerestory has the best overall performance and can be an effective strategy for a
climate, like Los Angeles with year-round mostly sunny days.

Circadian lighting is an emerging and huge topic. There are many aspects for the future work and research in the
circadian lighting field that can be covered, including electric lighting to support the 24-hour lighting profile as it
can be done over the 24 hours, more real case studies, color tuning LEDs, and better base case location.

As the health and well-being of occupants is getting more attention and circadian lighting is an important factor that
can affect occupants, researchers, lighting designers, and architects need to address the importance of this matter and
try to apply the circadian-effective strategies to their design process even in the early stages of design.

61

References:

Acosta, I., Navarro, J., & Sendra, J. J. (2015). Towards an analysis of the performance of monitor skylights under
overcast sky conditions. Energy and Buildings, 88(December), 248–261.
https://doi.org/10.1016/j.enbuild.2014.12.011
Boubekri, M., Cheung, I. N., Reid, K. J., Wang, C.-H., & Zee, P. C. (2014). Impact of Windows and Daylight
Exposure on Overall Health and Sleep Quality of Office Workers: A Case-Control Pilot Study. Journal of
Clinical Sleep Medicine, 10(6), 603–611. https://doi.org/10.5664/jcsm.3780
Carlucci, S., Causone, F., De Rosa, F., & Pagliano, L. (2015). A review of indices for assessing visual comfort with
a view to their use in optimization processes to support building integrated design. Renewable and Sustainable
Energy Reviews, 47, 1016–1033. https://doi.org/10.1016/J.RSER.2015.03.062
Daylighting Calculation Options. (n.d.). Retrieved April 8, 2019, from
https://designbuilder.co.uk/helpv3.0/Content/Daylighting Calculation Options.htm
Design, I. (2004). Guide for Daylighting.
Edgar, R., Green, E., Zhao, Y., van Ooijen, G., Olmedo, M., Qin, X., … Reddy, A. (2012). Peroxiredoxins are
conserved markers of circadian rhythms. Nature, 485(7399), 459–464. https://doi.org/10.1038/nature11088
Figueiro, M. G. (n.d.). 24-hr Lighting Scheme for Older Adults Mariana G . Figueiro , PhD.
Figueiro, M. G. (2008). A proposed 24 h lighting scheme for older adults. Lighting Research and Technology, 40(2),
153–160. https://doi.org/10.1177/1477153507087299
Figueiro, M. G., Gonzales, K., & Pedler, D. (2016). Designing with Circadian Stimulus. Ld+a, (October), 31–33.
https://doi.org/10.7763/IJET.2017.V9.970
Figueiro, M. G., & Rea, M. S. (2015). Measuring Circadian Light : Impact on Health and Well-being, (April).
File:Biological clock human.svg - Wikimedia Commons. (n.d.). Retrieved March 3, 2019, from
https://commons.wikimedia.org/wiki/File:Biological_clock_human.svg
Hagen, E., & Richardson. (2018). Circadian Daylight in Practice Determining a simulation method for the design
process, 1–17.
Inanici, M., Brennan, M., & Clark, E. (2015). Spectral Daylighting Simulations: Computing Circadian Light.
International Building Performance Simulation Association 2015 Conference, (December 2015), 9. Retrieved
from
https://www.researchgate.net/publication/293487289_SPECTRAL_DAYLIGHTING_SIMULATIONS_COM
PUTING_CIRCADIAN_LIGHT
International WELL Building Institute. (2018). The WELL Building Standard V2.0. Retrieved from
https://v2.wellcertified.com/
Kischkoweit-Lopin, M. (2002). An overview of daylighting systems. Solar Energy, 73(2), 77–82.
https://doi.org/10.1016/S0038-092X(02)00036-1
Klauber, M. R., Jones, D. W., Kripke, F., Mason, W., Pat-horenczyk, R., & Fell, R. (2017). Variations in Circadian
Rhythms of Activity, Sleep, and Light Exposure Related to Dementia in Nursing-Home Patients. Sleep, 20(1),
18–23. https://doi.org/10.1093/sleep/20.1.18
Konis, K. (2017). When it comes to design, what is a healthy dose of daylight? - AIA. Retrieved February 15, 2019,
from https://www.aia.org/articles/138651-when-it-comes-to-design-what-is-a-healthy-d:31
Konis, K. (2018a). Field evaluation of the circadian stimulus potential of daylit and non-daylit spaces in dementia
care facilities. Building and Environment, 135(March), 112–123.
https://doi.org/10.1016/j.buildenv.2018.03.007
Konis, K. (2018b). The Importance of Daylight in Dementia Care Communities : A Call to Action, (January).
https://doi.org/10.13140/RG.2.2.32369.53609
Konis, K., Mack, W. J., & Schneider, E. L. (2018). Pilot study to examine the effects of indoor daylight exposure on
depression and other neuropsychiatric symptoms in people living with dementia in long-term care
communities. Clinical Interventions in Aging, 13(May), 1071–1077. https://doi.org/10.2147/CIA.S165224
Ladan Ghobad , Wayne Place, and S. C. (n.d.). DESIGN OPTIMIZATION OF SQUARE SKYLIGHTS IN
OFFICE BUILDINGS Ladan Ghobad , Wayne Place , and Soolyeon Cho, 1, 3653–3660.
Lantern: Dementia Care & Assisted Living Chagrin Falls, South Russell, OhioLantern. (n.d.). Retrieved April
7, 2019, from https://lanternlifestyle.com/chagrinvalley/
Leslie, R. P., Radetsky, L. C., & Smith, A. M. (2012). Conceptual design metrics for daylighting. Lighting Research
and Technology, 44(3), 277–290. https://doi.org/10.1177/1477153511423076
Lucas, R. J., Peirson, S. N., Berson, D. M., Brown, T. M., Cooper, H. M., Czeisler, C. A., … Brainard, G. C. (2014).
Measuring and using light in the melanopsin age. Trends in Neurosciences, 37(1), 1–9.
62

https://doi.org/10.1016/J.TINS.2013.10.004
Melatonin and Sleep - Gateway Psychiatric. (n.d.). Retrieved February 21, 2019, from
https://www.gatewaypsychiatric.com/melatonin-and-sleep/
Nabil, A., & Mardaljevic, J. (2006a). Useful daylight illuminances: A replacement for daylight factors. Energy and
Buildings, 38(7), 905–913. https://doi.org/10.1016/J.ENBUILD.2006.03.013
Nabil, A., & Mardaljevic, J. (2006b). Useful daylight illuminances: A replacement for daylight factors. Energy and
Buildings, 38(7), 905–913. https://doi.org/10.1016/j.enbuild.2006.03.013
Noell-Waggoner. (2006). Lighting in nursing homes - the unmet need, 1–6. Retrieved from
http://www.centerofdesign.org/pdf/LightingNursingHomeUnmetNeed.pdf
Ortman, J. M., Velkoff, V. a., & Hogan, H. (2014). An aging nation: The older population in the United States.
Population Estimates and Projections, 1964, 1–28. https://doi.org/10.1590/S1519-69842001000300008
Pierson, C., Wienold, J., & Bodart, M. (2017). Discomfort glare perception in daylighting: Influencing factors.
Energy Procedia, 122, 331–336. https://doi.org/10.1016/j.egypro.2017.07.332
Prince, M., Wimo, A., Gherchet, M., Ali, G. ., Wu, Y. ., & Prina, M. (2015). World Alzheimer Report 2015: The
Global Impact of Dementia | Alzheimer’s Disease International, 10–35. Retrieved from
https://www.alz.co.uk/research/world-report-2015
Radetsky, L., & Brons, J. (n.d.). Light Scoops.
Rea, M. S., Figueiro, M. G., Bierman, A., & Bullough, J. D. (2010). Circadian light, 1–10.
Rhinoceros Resources. (n.d.). Rhino3d.com. Retrieved from http://www.rhino3d.com/resources/
Solemma LLC. (n.d.). Retrieved February 19, 2019, from https://www.solemma.com/Alfa-Simulations.html
Torrington, J. M., Tregenza, P. R., & Noell-Waggoner, L. C. (2007). Lighting for people with dementia. Lighting
Research and Technology, 39(1), 81–97. https://doi.org/10.1177/1365782806074484
Treado, S., Gillette, G., & Kusuda, T. (1984). Daylighting with windows, skylights, and clerestories. Energy and
Buildings, 6(4), 319–330. https://doi.org/10.1016/0378-7788(84)90015-X
Unique Assisted Living Facility Uses Nostalgia to Make Alzheimer’s Patients Feel at Home. (n.d.). Retrieved March
3, 2019, from http://sixtyandme.com/unique-assisted-living-facility-uses-nostalgia-to-make-alzheimers-
patients-feel-at-home/
Vitaterna, M. H., Takahashi, J. S., & Turek, F. W. (2001). Overview of Circadian Rhythms. Alcohol Research &
Health, 25(2), 85–93.
Vitaterna, M., Takahashi, J., & Turek, F. (2001). Overview of circadian rhythms. Alcohol Research & Health, 25(2),
85–93. Retrieved from http://pubs.niaaa.nih.gov/publications/arh25-2/85-93.htm
Wienold, J., & Christoffersen, J. (2006). Evaluation methods and development of a new glare prediction model for
daylight environments with the use of CCD cameras. Energy and Buildings, 38(7), 743–757.
https://doi.org/10.1016/j.enbuild.2006.03.017

Abstract (if available)

Abstract In recent years, there is a growing awareness of the link between lighting and human health. Light is one of the drivers for the circadian system, which regulates the biological rhythms that control a number of important human biological functions. Development of circadian-effective top lighting strategies for dementia care communities to maximize the circadian stimulus is important. Corridors within dementia care communities are important for patients as they can spend a considerable amount of their time during the day in such spaces. A proper EML must be achieved for circadian effect and appropriate illuminance with minimum glare. ❧ The 350 EML (Equivalent Melanopic Lux) threshold specified in the WELL Building Standard is the metric used for circadian stimulus. The lighting quantity “melanopic illuminance” is a metric for measuring the non-visual effect of light weighed by the sensitivity of the melanopsin containing light detectors within the human eye (Al Enezi et al., 2011). Utilization of daylight can be an effective strategy for supporting healthy circadian rhythms, which, in turn, are associated with better sleep, improved mood, and behavior in patients with dementia and Alzheimer disease. ❧ ALFA (Adaptive Lighting for Alertness), a circadian lighting design software, was used to analyze and predict circadian stimulus EML (Equivalent Melanopic Lux) for different skylight designs, sky conditions, and hours throughout the year in a dementia care facility to satisfy 350 EML defined by WELL building standards. Six different test cases were created in Rhino and integrated in with ALFA to perform circadian analysis and glare simulation. Design strategies that performed better were found and scored based on the simulation result. ❧ The results showed that light scoop can be an effective strategy for overcast climate condition. Clerestory has the best overall performance and can be an effective strategy for a climate, like Los Angeles with year-round mostly sunny days.

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Asset Metadata

Creator Karim Tahmassebi, Tannaz (author)

Core Title Development of circadian-effective toplighting strategies: using multiple daylighting performance goals for dementia care communities

School School of Architecture

Degree Master of Building Science

Degree Program Building Science

Publication Date 08/07/2019

Defense Date 08/06/2019

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

Tag circadian lighting,daylighting,dementia care facility,EML,OAI-PMH Harvest,WELL building standards

Format application/pdf (imt)

Language English

Contributor Electronically uploaded by the author (provenance)

Advisor Konis, Kyle (committee chair), Kensek, Karen M. (committee member), Regnier, Victor Albert (committee member)

Creator Email karimtah@usc.edu,tannaz.kt87@gmail.com

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c89-209130

Unique identifier UC11662807

Identifier etd-KarimTahma-7757.pdf (filename),usctheses-c89-209130 (legacy record id)

Legacy Identifier etd-KarimTahma-7757.pdf

Dmrecord 209130

Document Type Thesis

Format application/pdf (imt)

Rights Karim Tahmassebi, Tannaz

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