Yi-Szu Liao / Lighting Design Thesis

DAYLIGHT EVALUATION: The Influence of Vertical Luminance on Visual Preference in Daylit Environment

YI-SZU LIAO

DAY LIG HTI N G BENEFITS and CONCERNS Daylighting is considered as an important architectural design approach not only because it enables reduction of energy consumption but also provides high illuminance, good color rendering to interior space, view connection with outdoors, and many other benefits.

However, without careful design, daylight might also cause discomfort glare, veiling effects, and visual fatigue.

H ow to evalua te day light env iro nm ent?

ELECTRIC LIGHTING EVALUATION

IES RECOMMANDATIONS

Targ e t I l l u mi n an ce Leve l

Contra st Ra tio

adequacy of illuminance

illuminance uniformity

HOW ABOUT DAYLIGHTING?

PREMISES

D ayl i g ht d e l i ve rs h i g h e r i l l u mi n an ce l eve l s to a s p ac e , i t i s n ot e qu i val e n t to u s e th e s ame m etric to eval u ate day l i g h t e n vi ron me n t.

Lu m i n an c e i s more re l ate d to h u man vi s u al c o m f o r t th an i l l u mi n an ce from previous studies of: - visual performance studies - visual comfort metrics - daylight glare index - daylight glare probability 76 fc (10am)

7 fc (8pm)

TODAY’S DAYLIGHT STUDY TOOLS

Recent software developments for daylight study have increased access to luminance-based data, but there is still not a method to effectively relate the data to human impression of daylight environment.

DI VA

HDR Photo

Feb. 9th 1:00pm clear sky

Feb. 9th 4:00pm clear sky

Min: 0.447

Min: 0.369

Max: 6870

Max: 901

Mean: 35.4

Mean: 37.6

Unit: cd/m2

Unit: cd/m2

EVALUATING A NEW SUITE OF LUMINANCE-BASED DESIGN METRICS FOR PREDICTING HUMAN VISUAL COMFORT IN OFFICES WITH DAYLIGHT

A previous daylight comfort study conducted an experiment to examine a series of luminance-based visual comfort metrics, trying to evaluate their potential to explain human visual preference in daylit spaces.

The participants ra bar semantic differe 100) to “too dim” ( nor too dim midway

48 participants were included for daylong experiments in a daylit mock private office, spending a full working day assessing 16 daylight conditions under naturally occurring sky condition.

1. When I look up of me seems: (fro 2. When I look to m scene) 3. When I look to (right-scene) 4. I find the ceiling

Two Series of Questions were asked in the experiment: - Perception of visual preference - Perception of brightness

at 14:41 23 October 2015

Fig. 1

(left) scene from a participant’s point of view; (right) light redirecting blind.

T5HO recessed direct electric light fixture was located near the center of the room.

2.2. Questionnaire Items Participants independently created 16 unique lighting con-

2.3. Analysis m

High dynamic rang for 93 participant-d ing in 1488 individ scenes were remove [Van Den Wymelen sequence (100 part ticipants accidentall

EVALUATING A NEW SUITE OF LUMINANCE-BASED DESIGN METRICS FOR PREDICTING HUMAN VISUAL COMFORT IN OFFICES WITH DAYLIGHT

unmasked image

X01_scene

X02_greycard

X03_circletask

X04_wholetask

X05_desktask

X06_monitortask

X07_papertask

X08_wholewindow

X09_upperwindow

X10_lowerwindow

X11_rightwall

X12_frontwall

X13_leftwall

X14_ceiling

X15_light

X16_foveal

X17_binocular

X18_peripheral

X19_human

X20_40band (horizontal 40°band)

X21_0_60 (central 60° fov)

X22_60_120 (fov from 60°-120°)

X23_120_180 (fov from 120°-180°)

O ver 2 0 0 0 un i q u e l u m i n an c e me tri cs : Minimum, maximum, mean (¯x), standard deviation (σ), coefficient of variation (σ/¯x) of mask luminance.

Downloaded by [University of Washington Libraries] at 14:41 23 October 2015

Several luminance percentiles (2nd, 10th, 50th, 75th, 90th, 98th) and ratios of these (e.g. 2nd, 98th percentile).

Percentage of mask pixels above or below certain absolute luminance thresholds (below 5, 10, 40, 50, 100, 250, 500, 1000 cd/m2; above 1500, 2000, 2500, 3000, 4000, 5000 cd/m2) and ratios of these (for example, percentage below 5 cd/m2: percentage above 5000 cd/m2).

2 3 scene ma s k s :

Were examined by using over 2000 luminance metrics. In order to find which metric has the highest squared correlation coefficient for the questionnaire.

Fig. 2

Masks applied to an example scene (X01 is Mask 01).

4000, 5000 cd/m2 ) and ratios of these (for example, per-

• Daylight Glare Probability (DGP), Daylight Gla

X01_scene

X02_greycard

X03_circletask

Downloaded by [University of Washi

unmasked image

X12_frontwall

X13_leftwall

X14_ceiling

X15_light

EVALUATING A NEW SUITE OF LUMINANCE-BASED DESIGN METRICS FOR PREDICTING HUMAN VISUAL COMFORT IN OFFICES WITH DAYLIGHT X04_wholetask

X05_desktask

X06_monitortask

X07_papertask

X16_foveal

X17_binocular

Stan d ard Devi ati on of T h e Lu mi n an ce of the E n ti re Wi n dow

X08_wholewindow

X09_upperwindow

X10_lowerwindow

X14_ceiling

2 ) and ratios of these (for example, per4000, 5000 cd/m 7 centage below 5 cd/m2 : percentage above 5000 cd/m2 ).

glare metrics were calculated for the entire 5 scene only (Mask 01):

2 2 2

4 3 2

X17_binocular 2000 2000 2000

4000 4000 4000

X18_peripheral 6000 6000 6000

8000 8000 8000

Standard Standard Deviation Deviation of of the the Luminance Luminance (cd/m (cd/m^^22)) of of the the Entire Entire Window Window (Mask (Mask 08) 08) Standard Deviation of the Luminance (cd/m^2) of the Entire Window (Mask 08)

10000 10000 10000

Right_Scene Right_Scene vs. vs. Standard Standard Deviation Deviation of of the the Luminance the (Mask 08) Composite Data vs. Standard the Luminance of of Right_Scene the Entire Entire Window Window (Mask Deviation 08) Using Using of Composite Data Set Set Luminance of the Entire Window (Mask 08) Using Composite Data Set

X20_40band (horizontal 40°band)

X21_0_60 (central 60° fov)

0

250

500

750

1000

1250

1500

1750

Mean Luminance (cd/m^2) of the Horizontal 40° Band (Mask 20) Right_Scene vs. Mean Luminance of the Horizontal 40° Band (Mask 20) Using Composite Data Set

(b)

1st.deg_adj.r^2 1st.deg_adj.r^2 = = 0.383 0.383 X22_60_120 1st.deg_adj.r^2 = 0.383

(fov from 60°-120°)

1

X19_human

oo Bright)

X16_foveal 00 0

90 90

1st.deg_adj.r^2 = 0.223 • Daylight Glare Probability (DGP), D (DGI), Visual Comfort Probabilit Glare Rating (UGR), CIE Glare I age luminance of the glare sourc the entire scene, calculated using Ev

Luminance-Based Design Metrics

3 3 3

100 100 100

X23_120_180 (fov from 120°-180

QU1 vs. Mean Luminance of the Horizontal 40° Band (Mask 20) Using Composite Data Set

X15_light The following

4 4 4

1 1 1

oo Bright) o Bright) Bright)

X13_leftwall

X22_60_120 (fov from 60°-120°)

Fig. 2 Masks applied to an example scene (X01 is Mask 01).

(a)

QU1 Likert Response

X12_frontwall

5 5 5

(b) (b) (b)

X21_0_60 (central 60° fov)

6

14:41 23 October 2015

QU1 QU1 QU1 Liker Liker Liker t Response t tResponse Response

6 6 6

X20_40band (horizontal 40°band)

X11_rightwall

1st.deg_adj.r^2 1st.deg_adj.r^2 = = 0.267 0.267 1st.deg_adj.r^2 = 0.267

7 7 7

X19_human

Mea n Lum ina nce of the Horizo ntal 4 0 0 Band

QU1 QU1 vs. vs. Standard Standard Deviation Deviation of of The The Luminance of the Entire Window (Mask 08) Using Composite QU1 vs.

Standard Deviation of The Luminance of the Entire Window (Mask 08) Using Composite Data Data Set Set Luminance of the Entire Window (Mask 08) Using Composite Data Set

(a) (a) (a)

X18_peripheral

X23_120_180 (fov from 120°-180°)

100 90

1st.deg_adj.r^2 = 0.307

unmasked image X01_scene

Downloaded by [University of Washington Libraries] at 14:41 23 October 2015 Downloaded by [University of Wash

unmasked image

X01_scene X02_greycard

X12_frontwall X04_wholetask X02_greycard X03_circletask

X13_leftwall X14_ceiling X05_desktask X03_circletask X06_monitortask

X07_

VERTICAL ROOM SURFACES

d by [University of Washington Libraries] at 14:41 23 October 2015

The metrics that have a higher correlation coefficient to human visual comfort response are not based on the entire field of view. Most of them X16_foveal X17_binocular X18_peripheral X04_wholetask mask. X06_monitortask X05_desktask X08_wholewindow X06_monitortaskX09_upperwindow X07_papertask X10_lowerwindow X04_wholetask X05_desktask X07_papertask are based on the vertical-surface-related

X08_wholewindow

X08_wholewindow X09_upperwindow

X20_40band X21_0_60 X09_upperwindow X12_frontwall X10_lowerwindow X13_leftwall X11_rightwall X10_lowerwindow X11_rightwall (horizontal 40°band) (central 60° fov)

X22_60_120 X14_ceiling (fov from 60°-120°)

X11_X

X X1 (fov f

Fig. 2 Masks applied to an example scene (X01 is Mask 01).

Since most contemporary tasks have shifted from physical paper-based horizontal tasks to monitor-based vertical tasks, human visual preference might be mainly affected by the luminance of vertical surfaces in2a space.

X12_frontwall

X16_foveal

X12_frontwall X13_leftwall

X16_foveal X17_binocular

4000, 5000 cd/m ) and ratios of these (for example, percentage below 5 cd/m2 : percentage above 5000 cd/m2 ).

X17_binocular X13_leftwall X14_ceiling X14_ceiling X15_light The following glare X16_foveal metrics were calculated for theX15_light entire scene only (Mask 01):

• Daylight Glare Probabil (DGI), Visual Comfor Glare Rating (UGR), C X18_peripheral X19 age luminance of the the entire scene, calcula

Luminance-Based Design Metrics

X17_binocular X18_peripheral

X18_peripheral X20_40band X19_human

X19_human X21_0_60

X22_60_120

X23_

T he p re fe rre d day l i g h t e n vi ron me n t i s l i kely to b e influenced b y sp a ce configura tion. Instea d of looking at s p e ci fi c s u r face s , i t i s more re as on ab le to eva lua te d a ylight with regions in the field of v iew.

T he s tu dy on l y addre s s ed th e me tri cs tha t a re m ore corresp ond to the sub jects’ resp onses b ut d id not s tu d y w h at affe cts s u bje cts ’ re s pon s e s .

T he s tu dy w as don e i n a s mal l pri vate of fice. Stud y with la rger sha red sp a ce, such a s a school stud y room i s e x pe cte d s i n ce i t can be appl i e d to other sim ila r sp a ce typ es.

l ook i n g at s p e ci fi c s u r face s

m etric

resp onses

sm a ll p riva te office only for one p erson

l ook i n g at re g i on s i n t h e F OV

m etric

resp onses

la rger sha red sp a ce a p p lied to m ore typ es

How does daylight distribution affect visual preference?

What is the main factor that determines visual preference in daylit environments?

METHODOLOGY

RESEARCH SETTINGS Room E 3 0 1 i n 2 5 E 1 3 th St Pa rs on s Sch ool of De s i g n , Ne w York, NY (41° N a nd 74° W )

Right/Inside Wall

Left/Window Wall

Front/Adjacent Wall

view

EXPERIMENTS

PHYSI CAL SPACE (I N- PER SON)

VIRTUAL SPACE ( VISUAL IZ ATION)

- physical experience - real materials - limited weather and lighting conditions

- broader lighting conditions - material modifications - perceived inaccuracy

IN-PERSON EXPERIMENT - Procedure

sub jects a ssessing d a ylight env ironm ent ev ery 15m in 3 s e s s i on s ( 4 s u b j e c t p e r s e s s i on )

exp erimenter collecting d ata

s u bje cts doi ng ta sk on compu te r mon i tor for 30m in exp erim enter ta king p hotos a t the sa m e tim e

Session 1 (03/30/2019)

Session 2 (04/06/2019)

Session 3 (04/06/2019)

0 min

15 min

30 min

0 min

15 min

30 min

0 min

15 min

30 min

1:00 pm

1:25 pm

1:43 pm

2:34 pm

2:51 pm

3:07 pm

4:07 pm

4:23 pm

4:40 pm

Partly Cloudy

Partly Cloudy

Partly Cloudy

Clear Sky

Clear Sky

Clear Sky

Clear Sky

Partly Cloudy

Overcast

IN-PERSON EXPERIMENT - Scenes 0 mi n

15 m in

30 m in

SCE N E P 1

SCE N E P 2

SCE N E P 3

SCE N E P 4

SCE N E P 5

SCE N E P 6

SCE N E P 7

SCE N E P 8

SCE N E P 9

se s s i o n 1 0 3 .30 . 2 0 1 9

se s s i o n 2 0 4 .06 . 2 0 1 9

se s s i o n 3 0 4 .06 . 2 0 1 9

IN-PERSON EXPERIMENT - Questionnaire

X strongly disagree:___1___:___2___:___3___:___4___:___5___: strongly agree

X too dim: ___1___:___2___:___3___:___4___:___5___: too bright

1. This is a visually comfortable environment for a classroom. (QU1) 2. I am pleased with the visual appearance of the room. (QU2) 3. I like the vertical surface brightness. (QU3) 4. I am satisfied with the amount of light for computer work. (QU4) 5. I am satisfied with the amount of light for paper-based reading work. (QU5) 6. The computer screen is legible and does not have reflections. (QU6) 7. The lighting is distributed well. (QU7)

8. I find the wall in front of me to be: (QU8) 9. I find the left wall to be: (QU9) 10. I find the right wall to be: (QU10)

V i su a l P r e f er en ce

11. I find the ceiling to be: (QU11)

Per cei ved B r i gh tn ess

ANALYSIS METHODS - High Dynamic Range Photography (HDR)

HDR photo

photoshere

2000 850 360 150 65 28 12 0 cd/m2

mutiple exposure photos

false color

ANALYSIS METHODS - Luminance Mapping

s e s s i on 1

session 2

session 3

SC E NE P 1

SCE N E P 2

SCE N E P3

SC E NE P 4

SCE N E P 5

SCE N E P6

SC E NE P 7

SCE N E P 8

SCE N E P9

0 cd/m2 12

28

65

150

360

850

2000

ANALYSIS METHODS - Masks

Mask_1 All Vertical Area

Mask_2 Front Wall

Mask_3 Left Wall

Mask_4 Right Wall

SCENES AND LUMINANCE DATA

SCE N E P 1

Me an L (cd/m 2 )

SCENE P2

Mea n L ( cd /m 2 )

SCENE P3

Mea n L ( c d /m 2 )

A l l ver t i ca l : 102

All v e r tical: 182

All v er t ic a l: 246

Front wa l l : 100

Fron t wall: 170

Fron t w a ll: 231

L eft wa l l : 260

Le f t wall: 415

Le f t w a ll: 574

Ri g ht wa l l : 46

Right wall: 82

Right w a ll: 115

SCE N E P 4

SCENE P5

SCENE P6

A l l ver t i ca l : 176

All v e r tical: 202

All v er t ic a l: 211

Front wa l l : 169

Fron t wall: 201

Fron t w a ll: 210

L eft wa l l : 350

Le f t wall: 414

Le f t w a ll: 440

Ri g ht wa l l : 88

Right wall: 94

Right w a ll: 99

SCE N E P 7

SCENE P8

SCENE P9

A l l ver t i ca l : 93

All v e r tical: 23

All v er t ic a l: 20

Front wa l l : 95

Fron t wall: 22

Fron t w a ll: 18

L eft wa l l : 142

Le f t wall: 54

Le f t w a ll: 46

Ri g ht wa l l : 59

Right wall: 12

Right w a ll: 10

RESULTS

Prefer

5

V ISUAL PREFERENCE V S V ERTICAL B RIGHTNESS 4

All Ver�cal Surfaces

Visual Preference

QU1 - This is a visually comfortable environment for a classroom.

QU3 - I like the vertical surface brightness.

not Prefer

Prefer

3

2

1

20

23

102

Visual Preference

182

5

All Ver�cal Surfaces

3

2

1

202

Mean Luminance of All Ver�cal Surface (cd/m2)

4

not Prefer

176

20

23

102

176

182

202

Mean Luminance of All Ver�cal Surface (cd/m2)

211

246

211

246

RESULTS

5

Too Brigh Window Wall

V ISUAL PREFERENCE V S PERCEIV ED B RIGHTNESS OF 4 FRONT/W INDOW/RIGHT WALL Visual Preference

Front Wall

QU1 - This is a visually comfortable environment for a classroom.

3 QU8 - I find the wall in front of me to be: QU9 - I find the left wall to be: 2 to be: QU10 - I find the left wall

not Prefer

Prefer

1

20

23

102

176

Right Wall

182

202

211

246

Perceived Brightness

Prefer

Too Dim

Mean Luminance of All Ver�cal Surface (cd/m2)

5

Too Bright

Window Wall

5

Right Wall

4

2

1

20

23

102

176

Too Brigh Front Wall

3

2

182

202

211

Too Dim

246

Mean Luminance of All Ver�cal Surface (cd/m2) not Prefer

1

18

22

100

169

170

Mean Luminance of Front Wall (cd/m2)

201

210

231

Perceived Brightness

3

Visual Preference

Visual Preference not Prefer

Prefer

Perceived Brightness

Front Wall

4

Too Dim

RESULTS

Prefer

Too Brigh

5 Window Wall

Perceived Brightness

Visual Preference

V ISUAL PREFERENCE V S PERCEIV ED B RIGHTNESS OF 4 W INDOW W ALL QU1 - This is a visually comfortable environment for a classroom.

QU9 - I find the left wall3 to be:

not Prefer

Prefer

2

1

46

54

260

350

415

417

440

574

Too Dim

Mean Luminance of Le�/Window Wall (cd/m2)

Too Bright

5

Window Wall

Perceived Brightness

3

5

4

2

1

46

54

260

350

Too Brigh

3 Right Wall

2

415

417

440

574

Too Dim

Mean Luminance of Le�/Window Wall (cd/m2) not Prefer

1

10

12

46 82 88 94 2 Mean Luminance of Right Wall (cd/m )

99

115

Perceived Brightness

not Prefer

Prefer

Visual Preference

Visual Preference

4

Too Dim

20

23

102

Front Wall 176

182

202

211

246

3 Right Wall

2

20

23

Too Brigh

V ISUAL PREFERENCE V S PERCEIV ED B RIGHTNESS OF Too Dim 4182 102 176 202 211 246 FRONT WALL

Front Wall

QU8 - I find the wall in 3front of me to be:

not Prefer

2

1

18

22

100

170

5

Front Wall

2

18

22

100

169

170

Mean Luminance of Front Wall (cd/m2)

201

210

231

Perceived Brightness

Too Bright

3

1

201

Mean Luminance of Front Wall (cd/m2)

4

not Prefer

169

Too Dim

210

231

Perceived Brightness

1

5

2 Mean Luminance of is Alla Ver�cal Surface (cd/m ) QU1 - This visually comfortable environment for a classroom.

Prefer

Too Dim

Mean Luminance of All Ver�cal Surface (cd/m2)

Visual Preference

not Prefer

1

Perceived Brightness

Visual Preference

not Prefer

Prefer

Visual Preference

RESULTS

4

Too Dim

46

54

260

350

415

417

440

574

3

2

46

54

Too Brigh

V ISUAL PREFERENCE V S PERCEIV ED B RIGHTNESS OF Too Dim 4 260 350 415 417 440 574 RIGHT WALL 3 QU10 - I find the right wall to be:

not Prefer

Right Wall

2

1

10

12

5

46 82 88 94 2 Mean Luminance of Right Wall (cd/m )

4

not Prefer

3 Right Wall

2

1

10

12

46 82 88 94 Mean Luminance of Right Wall (cd/m2)

99

115

Perceived Brightness

Too Bright

Too Dim

99

115

Perceived Brightness

1

5

2 ) Mean Luminance ofisLe�/Window Wall (cd/m QU1 - This a visually comfortable environment for a classroom.

Prefer

Too Dim

Mean Luminance of Le�/Window Wall (cd/m2)

Visual Preference

not Prefer

1

Perceived Brightness

Visual Preference

not Prefer

Prefer

Visual Preference

RESULTS

4

Too Dim

RESULTS

600

Window Wall 574

350 QU1 - This is a visually comfortable environment for a classroom.

300

169

100

1:2.1

200

169

210

170

231

Front Wall

2

54 22

1:2.4

1:2.6

1:2.1

1:2.4

1:2.1

1:2.1

P3 NE SC E

P6 NE SC E

P5 NE SC E

P2 NE SC E

P4 NE SC E

NE

P1

1:2.5

1:2.1

P3 NE SC E

P6 NE

1 not Prefer

SC E

P8 NE

P9 NE SC E 1:2.5

1:2.1

4

100

46 18

P5

1:2.4

3 201

1 not Prefe

NE

NE

SC E

574

440

417

5 Prefer SC E

P2

P4 SC E

NE

P1

1:2.6

Window Wall

260

100

2

Visual Preference

300

NE

NE SC E

1:2.4

SC E

P8

P9

1:2.5

350

0

Luminance Ra�o

SC E

NE

400

170

231

Front Wall

54 22

46 18

415

SC E

Ver�cal Mean Luminance (cd/m2)

Luminance Ra�o

210

201

100

0

500

3

260

200

600

4

440

417

Visual Preference

415

SC E

Ver�cal Mean Luminance (cd/m2)

500 V ISUAL PREFERENCE V S LUM INANCE RATIO ( fr on t: Left) 400

5 Prefer

1:2.5

VISUALIZATION EXPERIMENT - Procedure

exp er i mente r g e n e rati n g v i sua l i za ti o n i m ag e s

s u bje cts doi n g on l i n e s u r ve y

sur v ey showing one scene a t a tim e

sub jects a ssessing d a ylight env ironm ent for ea ch scene

ex peri menter c o l l ec ti ng d ata

INTERIOR FINISH REFLECTANCE VALUES

WALL: 0.75

FROSTED GLASS: 0.24 DOOR FRAME: 0.6

PIN-UP WALL: 0.25 COLUMN: 0.64

WINDOW FRAME: 0.8 PIPE: 0.95 SIDE TABLE: 0.16

FLOOR: 0.26

CABINET: 0.56 WOODEN DESK: 0.3

CHAIR: 0.1

DESK: 0.63

SCENE SELECTION

M A RC H 2 1th

JUNE 21th

D EC E M BER 21th

10am clear sky

11am clear sky

12pm clear sky

1pm clear sky

2pm clear sky

3pm clear sky

4pm clear sky

5pm clear sky

10am clear sky

11am clear sky

12pm clear sky

1pm clear sky

2pm clear sky

3pm clear sky

4pm clear sky

5pm clear sky

10am clear sky

11am clear sky

12pm clear sky

1pm clear sky

2pm clear sky

3pm clear sky

4pm clear sky

5pm clear sky

SCENE SELECTION

M A RC H 2 1th

JUNE 21th

D EC E M BER 21th

10am clear sky

11am clear sky

12pm clear sky

1pm clear sky

2pm clear sky

3pm clear sky

4pm clear sky

5pm clear sky

10am clear sky

11am clear sky

12pm clear sky

1pm clear sky

2pm clear sky

3pm clear sky

4pm clear sky

5pm clear sky

10am clear sky

11am clear sky

12pm clear sky

1pm clear sky

2pm clear sky

3pm clear sky

4pm clear sky

5pm clear sky

SELECTED SCENES

Original Scenes

March 21th 12:00pm

March 21th 2:00pm

March 21th 4:00pm

June 21th 2:00pm

December 21th 12:00pm

December 21th 2:00pm

Pin-up Wall Reflectance Modification (from 0.25 to 0.5)

VISUALIZATION EXPERIMENT - Questionnaire

X strongly disagree:___1___:___2___:___3___:___4___:___5___: strongly agree

X too dim: ___1___:___2___:___3___:___4___:___5___: too bright

1. This is a visually comfortable environment for a classroom. (QU1) 2. I am pleased with the visual appearance of the room. (QU2) 3. I like the vertical surface brightness. (QU3) 4. I am satisfied with the amount of light for computer work. (QU4) 5. I am satisfied with the amount of light for paper-based reading work. (QU5) 6. The computer screen is legible and does not have reflections. (QU6) 7. The lighting is distributed well. (QU7)

8. I find the wall in front of me to be: (QU8) 9. I find the left wall to be: (QU9) 10. I find the right wall to be: (QU10)

V i su a l P r e f er en ce

11. I find the ceiling to be: (QU11)

Per cei ved B r i gh tn ess

ANALYSIS METHODS - Grouped Diffuse Luminance Calculation Points

Le�/Window Wall

Front/Adjacent Wall

Right/Inside Wall

SCENES AND LUMINANCE DATA

Original Scenes

March 21th 12:00pm

March 21th 2:00pm

March 21th 4:00pm

June 21th 2:00pm

December 21th 12:00pm

December 21th 2:00pm

Mean L (cd/m2)

Pin-up Wall Reflectance Modification (from 0.25 to 0.5)

Mean L (cd/m2)

All ver tical: 955

All ver tical: 994

Front wall: 585

Front wall: 610

Left wall: 2493

Left wall: 2505

Right wall: 195

Right wall: 284

All ver tical: 1049

All ver tical: 1104

Front wall: 343

Front wall: 380

Left wall: 3269

Left wall: 3290

Right wall: 242

Right wall: 358

All ver tical: 895

All ver tical: 943

Front wall: 324

Front wall: 353

Left wall: 2709

Left wall: 2726

Right wall: 225

Right wall: 334

All ver tical: 497

All ver tical: 533

Front wall: 249

Front wall: 271

Left wall: 1304

Left wall: 1316

Right wall: 190

Right wall: 270

All ver tical: 218

All ver tical: 260

Front wall: 189

Front wall: 213

Left wall: 334

Left wall: 348

Right wall: 162

Right wall: 263

All ver tical: 167

All ver tical: 208

Front wall: 134

Front wall: 155

Left wall: 250

Left wall: 264

Right wall: 149

Right wall: 249

RESULTS

Prefer 5

Too Brigh

V ISUAL PREFERENCE V S PERCEIV ED B RIGHTNESS OF FRONT/W INDOW/RIGHT WALL 4 QU1 - This is a visually comfortable environment for a classroom.

3 QU8 - I find the wall in front of me to be: QU9 - I find the left wall to be: 2 to be: QU10 - I find the left wall not Prefer 1

167

208

218

261

497

533

Front Wall Right Wall

895

943

955

994

1049

1104

Perceived Brightness

Visual Preference

Window Wall

Too Dim

Mean Luminance of All Ver�cal Surface (cd/m2)

Too Bright

Front Wall

Prefer 5

3 2

not Prefer 1

167

208

218

261

497

533

Right Wall

4 3 2

895

943

955

not Prefer 1 2 Mean Luminance of All Ver�cal Surface (cd/m ) 189 134 155

994 213

1049 249

271

1104 324

Too Bright

Front Wall

Too Dim 343

Mean Luminance of Front Wall (cd/m2)

353

380

585

610

Perceived Brightness

4

Perceived Brightness

Window Wall

Visual Preference

Visual Preference

Prefer 5

Too Dim

RESULTS

Too Brigh

Prefer 5

Window Wall

Perceived Brightness

Visual Preference

V ISUAL PREFERENCE V S PERCEIV ED B RIGHTNESS OF W INDOW W ALL 4 QU1 - This is a visually comfortable environment for a classroom.

QU9 - I find the left wall3 to be: 2

not Prefer 1

250

264

334

348

1304

1315

2493

2505

2709

2726

3269

3290

Too Dim

Mean Luminance of Le�/Window Wall (cd/m2)

Too Bright

Prefer 5

Perceived Brightness

Prefer 5

3 2

not Prefer 1

250

264

334

348

1304

1315

4 3 2

2493

not Prefer 1

2505

2709

Mean Luminance of Le�/Window Wall 162 (cd/m2190 ) 149

2726 195

3269 225

242

3290 249

Too Bright Window Wall

Right Wall

Too Dim 284

Mean Luminance of Right Wall (cd/m2)

270

284

334

358

Perceived Brightness

4

Visual Preference

Visual Preference

Window Wall

Too Dim

not Prefer 1

167

208

218

261

497

533

895

Too Bright 943

955

994

1049

1104

3

Right Wall

2

208

218

261

V ISUAL PREFERENCE V S PERCEIV ED B RIGHTNESS OF Too Dim 497 533 8954 943 955 994 1049 1104 FRONT WALL Visual Preference

167

Too Bright

2 Mean Luminance ofisAlla Ver�cal Surface (cd/m ) QU1 - This visually comfortable environment for a classroom.

Front Wall

3 QU8 - I find the wall in front of me to be: 2

not Prefer 1

134

155

189

213

249

271

324

343

353

Mean Luminance of Front Wall (cd/m2)

Prefer 5 4 Front Wall

3 2

not Prefer 1

134

155

189

213

249

271

324

343

Mean Luminance of Front Wall (cd/m2)

353

380

585

610

Perceived Brightness

Too Bright

Too Dim

380

585

610

Perceived Brightness

Front Wall

Perceived Brightness

4

not Prefer 1

Too Dim

Window Mean Luminance of AllWall Ver�cal Surface (cd/m2)

Prefer 5

Visual Preference

RESULTS

Visual Preference

Prefer 5

Too Dim

not Prefer 1

Too Bright 250

264

334

1304

1315

2493

2505

2709

Window Mean Luminance of Wall Le�/Window Wall (cd/m2)

2726

3269

3290

2

264

334

348

V ISUAL PREFERENCE V S PERCEIV ED B RIGHTNESS OF Too Dim INDOW AND3269 RIGHT3290 WALL 4 1304 1315 2493 2505 W 2709 2726 Visual Preference

250

Too Bright Window Wall

2 QU1 - This of is aLe�/Window visually comfortable environment for a classroom.

Mean Luminance Wall (cd/m )

Right Wall

3 to be: QU10 - I find the right wall QU9 - I find the left wall to be: 2

not Prefer 1

149

162

190

195

225

242

249

284

270

Mean Luminance of Right Wall (cd/m2)

Prefer 5

Too Bright

4 Right Wall

3 2

not Prefer 1

149

162

190

195

225

242

249

284

Mean Luminance of Right Wall (cd/m2)

270

284

334

358

Perceived Brightness

Window Wall

Too Dim

284

334

358

Perceived Brightness

3

not Prefer 1

Too Dim

Perceived Brightness

4

348

Prefer 5

Visual Preference

RESULTS

Visual Preference

Prefer 5

Too Dim

RESULTS

Dec. 21th 14:00pm

Dec. 21th 12:00pm

Jun. 21th 14:00pm

Mar. 21th 12:00pm

Visual Preference

1

Prefer

2.8 2.3

2.4

3.7

3.5

3.7

3.8

3.9

3.9 3.7 3.2

5

4

3

2

Mar. 21th

Original 12:00pm ModiďŹ ed

Visual Preference

3.2

3.5

3.7

Jun. 21th 14:00pm

2.3

2.4

2

Dec. 21th 12:00pm

2.8

Dec. 21th 12:00pm 3.7

Dec. 21th 14:00pm 3.8

3.9

Prefer

2.8

3

Dec. 21th 14:00pm

2

3.7

3.9

4

2.4

2.4

Visual Preference

3

1

2.4

Visual Preference

5

2 1

0.5

4

3

2.3

0.25

5

4

2.4

Visual Preference

5

not Prefer

Mar. 21th 16:00pm

Mar. 21th 14:00pm

5 Mar. 21th 16:00pm 4

Mar. 21th 14:00pm

3

2 1 1:1.3

1:1.5

Jun. 21th 14:00pm 3.7

3.7

Dec. 21th 12:00pm

Mar. 21th Mar. 21th Modified 16:00pm 12:00pm

Mar. 21th 14:00pm

3.2

3.5

Dec. 21th 14:00pm

3.8

3.9

3.9 3.7

Original

2.8 2.3

2.4

2.4

Visual Preference

3 2

Prefer

Dec. 21th 14:00pm

Dec. 21th 12:00pm

5

Jun. 21th Mar. 21th Mar. Mar. 21th V ISUAL PREFERENCE V S 21th LUM INANCE RATIO 14:00pm 12:00pm4 16:00pm 14:00pm Visual Preference

1

QU1 - This is a visually comfortable environment for a classroom.

not Prefer

Prefer

3

2 1 1:1.3

1:1.5

1:2.5

1:2.6

Luminance Ra�o (all:le�)

5

4 Visual Preference

RESULTS

4

1

not Prefer

3

2 1 1:1.3

1:1.5

1:2.5

1:2.6

Luminance Ra�o (all:le�)

1:2.9

1:3

1:3.1

1:2.9

1:3

1:3.1

DISCUSSION

- H u man vi s ua l p reference i n a da yl i t s p a ce i s pre d omin an tly in f lue n ce d by the pe rce iv e d brightn e ss of the win d ow w a ll i n t h at s pa c e.

- T h e r e s u l t s up p or t s Va n Den Wymel enb erg a n d In an ici’s stud y - T h e s c e ne - i ndep endent s t udy ca n b e a p p l i ed to more similar space ty pe s

1 2 3 i mpa c t

p rev ious stud y - sce n e -d e pe n d e n t

sce n e -in d e pe n d e n t

DISCUSSION

I t i s no t i d ent i fi ed t ha t vi s ua l p reference a s un comf or table whe n the me an lumin an ce of the win d ow wall is rate d a s “di m” (b el ow a p p rox. 260cd/ m2). I t i s reason able be cause the stud y is base d on that ev e ry sce n e me e ts the bas i c t a s k i l l umi na nce l evel s .

Prefer

5

Too Bright

meet basic illuminance

Window Wall

levels on t ask plane

not Prefer

Perceived Brightness

Visual Preference

4

3

2

1

46

54

260

350

415

417

Mean Luminance of Le�/Window Wall (cd/m2)

440

574

Too Dim

DISCUSSION

T h e vi s u al i za t i on i s not ca p a b l e of crea t i ng v isual d iscomf or t situation sin ce it can n ot re pre se n t the high l u mi n a n c e wel l enoug h to ca us e t he s ens a t i on of v isual d iscomf or t.

AGi Calculation: 2500 cd/m2 Perceived Luminance: 112 cd/m2

Too Bright

Prefer 5 4

Perceived Brightness

Visual Preference

Window Wall

3 2

not Prefer 1

250

264

334

348

1304

1315

2493

2505

2709

Mean Luminance of Leďż˝/Window Wall (cd/m2)

2726

3269

3290

Too Dim

DISCUSSION

T h e di f f e r e nces i n a b s ol ut e l umi na nce va l ue s an d lumin an ce ratios be twe e n the re al space an d the v isualiz ation s a r e du e to di fferent mea s ure met hods . The l umin an ce n umbe r of win d ow wall of v isualiz ation is n ot what human a c t u al l y pe rcei ve i n t he rea l s p a ce.

Real Space

Luminance Measurement view point

Perception

Visualization

PHYSI CAL SPACE (I N- PER SON)

VIRTUAL SPACE ( VISUAL IZ ATION)

Mor e s tudies ar e ne ede d in or der to find a cle ar er r elations hip betwee n abs olute luminance leve ls and vis u a l pr efer e nce , which may provide us e ful infor mation for futur e architects and lighting de s igne r s when cons ide r i n g daylighting des ign.

- Make in-s cale phys ical mockups - Include lar ge r s ample s ize and braoder lighting condit i o n s - Study differ e nt s pace type s

B i b l i o g rap hy: I n a n i ci M . 2005. P e r -p i x e l Li g h t i n g Da t a A n a l y si s. < ht t ps : //e s c ho lars hip. o rg/uc /it e m/688137z g#main> Ac c e s s e s 2019 14 F e bua ry.

I n a n i ci M . 2006. Eva l u a t i on of H i g h Dy n a m i c R a n g e P ho to graphy as a Luminanc e Dat a Ac quis it io n S ys t e m. Light ing Re s e arc h a n d T e chn o l o gy . 38(2) : 123-134.

L e e E, C l e ar R, Wa r d G , Fe r n a n d e s L. 2 007. Com m i ss io ning and ve rif ic at io n pro c e dure s f o r t he auto mat e d ro lle r s hade s ys t e m a t the Ne w Yo rk T i me s h e a d q u a r t e r s, N e w Yor k , N e w Yor k . <ht t p: //e t a- public at io ns . lbl. gov/s it e s /de f ault /f ile s /nyt - s hade - c x - pro c e du res. pd f > A cce s s e s 20 19 1 2 Fe b r u a r y .

L o e L , M an s f i e l d K P, R ow l a n d s E . 1994. A p p e a ra n c e o f lit e nviro nme nt and it s re levanc e in light ing de s ign: e x pe rime nt al s t udy.

L i ghti n g Re s T e c h n ol . 26: 119-33.

Sto kke rman s M, Vog e l s I , De Kor t Y, H e y n d e r i c k x I . 2018. A C o mparis o n o f Me t ho do lo gie s to I nve s t igat e t he I nf lue nc e o f Ligh t on the Atmo s phe re of a S p a c e . LE U KOS . 14(3) : 16 7-191.

Va n D e n Wy me le n b e r g K G , I n a n i c i M . 20 10. Th e Effec t o f Luminanc e Dis t ribut io n Pat t e rns o n Oc c upant P re f e re nc e in a Daylit Office En v i ro n me n t. L E U KOS . 7 (2 ) : 103-122 .

Va n D e n Wy me le n b e r g K G , I n a n i c i M . 20 16. Eva l u a t i n g a Ne w S uit e o f Luminanc e - Bas e d De s ign Me t ric s f o r P re dic t ing Human Visua l C o mf o r t i n Of f i c e s w i t h Da y l i g h t . LE U KOS . 12(3) : 1 13- 138.