Comfort
Air temperature Surrounding surfaces temperature Thermal criteria : Thermal permeability Relative air speed Relative air humidity Air quality : Air purity, odors Noise level, noise pollution Acoustic : Reverberation time (echo duration) Natural and artificial lighting Colors Visual : Interior volumes distribution Level of occupancy Other influences : "ambiance"
Comfort: Sensitivity to factors
0 1 2 3
Température de l'air
mpérature des surfaces
Courants d'air
Rayonnement solaire
Humidité de l'air
Pureté de l'air
Eclairage
Couleur
BruitsNoise
Color
Lighting
Air purity
Air humidity
Solar radiation
Drafts
Surfaces temperature
Air temperature
Visual comfort
Key aspects of daylit environmentVisual performancePhysiological conditionsVisual quality
Visual comfort
Key aspects of daylit environment
ObjectivesHarmonious luminance distribution (no strong contrasts)Good color rendering (continuous spectrum, appropriate color T°) Adequate illuminance levelNo disturbing reflectionsNo direct glare
Visual comfort
Key aspects of daylit environment
Objectives
Recommended illuminances
Illuminance [lux]Type of space and function Min Mid MaxCirculation, corridors, theatres, concert halls 50 100 200Workshops, retail centres 200 300 400Schools, offices, usual tasks, reading, writing, computer work, … 300 400 500
Delicate work, drawing, technical tasks, ... 500 750 1000Precision workshops, clockwork, color control, visual quality control, … 1000 to 5000
Visual comfort
Visual adaptation
1
/m2
1j/m
2
10 100 1000 0.01
Adaption Level cd
0.1
10
100
Glare
Black Shadow Ob
ect L
umin
ance
cd
1000
10000
100000
Useful Range of Discrimination
Figure by MIT OCW.
Visual comfort
Visual adaptation
Visual field
oo
o o
o
o
o o
o
o
o 0o
330210
240Panorama Ergorama
270300
30
6090
120
150
180 70 50 30 10
Figure by MIT OCW.
Visual comfort
Visual adaptation
Visual field
3
1
Panorama Ergorama
Figure by MIT OCW.
Visual comfort
Visual adaptation
Visual field
1
1
Ergorama
10 10
Panorama
Figure by MIT OCW.
Visual comfort
Visual adaptation
Visual field
Visual performanceperson & taskilluminance on work planeluminance contrastvisual fatigue
Visual comfort
Visual adaptation
Visual field
Visual performanceperson & taskilluminance on work planeluminance contrastvisual fatigueexample: work place
Image courtesy of Prof. B. Paule, Estia SA, Lausanne, Switzerland.
Visual comfort
Visual adaptation
Visual field
Visual performance
Glarephysiological (disability)psychological (discomfort)
Visual comfort
Visual adaptation
Visual field
Visual performance
Glarephysiological (disability)psychological (discomfort)sources: glazed openings & sun patches
Visual comfort
Visual adaptation
Visual field
Visual performance
Glarephysiological (disability)psychological (discomfort)sources: glazed openings & sun patches specular reflections
Visual comfort
Visual adaptation
Visual field
Visual performance
Glarephysiological (disability)psychological (discomfort)sources: glazed openings & sun patches specular reflections inappropriate electric lights
Visual comfort
Tractebel, Brussels
8% 4%
Room 1, Third Floor Room 2, Third FloorN
2% 1% 0.5% 0.5% 1% 2% 4% 8%
Figure by MIT OCW.
Visual comfort
Tractebel, Brussels
Stansted airport, London
W. Richartz Museum, Köln
Visual comfort
Users’ preferencesnatural lightingopen viewvisual effectsharmonious colorsspecific conclusions daylight sunlight windows
Visual comfort
Users’ preferences
Daylight & healthintensity
1 2 3 4 5 6 7 8 9
3
a
c d
e f
b
2.9
Hig
hly
Satis
fied
= 1
Hig
hly
Dis
satis
fied
= 5
Satis
fact
ion
Proportion of Staff Sitting Next to a Window
2.95
3.1
3.05
3.15
3.2
3.25
3.3
3.35
R-squared: .974
Figure by MIT OCW.
Visual comfort
Users’ preferences
Daylight & healthintensityexposure to UV
