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.