light analyses, orientation of building
amount of light, how to control day light in different direction of sun, by using natural light analaysis dialux and ecotect
7. Day Light Analysis
Section drawing illustrating a deep
wall section providing some self-
shading. This allows easy integration
of a light shelf, creates surfaces that
mitigate glare, and reduces noise
transmission. Sloped surfaces also
help soften glare. A blind or shade
can be added in the clerestory to
manage glare from a low sun angle.
8. Day Light Analysis
•Determining Required Net Glazing Area
• Average Daylight Factor. Use:
1. if low-light spaces are desired.
2. if average spaces are desired.
3. if bright spaces are desired.
Note: The Daylight Factor concept has limitations as a metric for developing and
assessing daylighting solutions, but it also has value, so we use it here and refer to it
elsewhere in this guide.
9. Day Light Analysis
Building type Location Daylight factor %
Dwellings Living rooms 1
Bedrooms 0.5
Kitchens 2
Offices and banks General offices, count- 2
Typing tables, business 4
Drawing offices General 2
Drawing boards 6
• Total Area of Interior Surfaces. Add up total surface area of walls, ceiling, and
floor.
• Area-Weighted Average Reflectance. Ratio between 0 and 1. Add up total
surface area of walls, ceiling, floor, windows, partitions, and furniture, and
calculate the weighted average reflectance (see equation), or use 0.5 as a default
10. Day Light Analysis
Visible Transmittance. Use:
0.70 for small windows.
0.50 for medium windows.
0.30 for large windows.
Vertical Angle of Sky. Estimate the angle, from the center of the window.
Value between 0 and 90. If no obstruction, the vertical angle is 90
11. Day Light Analysis
• Location: Addis Ababa (38.70° N 9.00° E)
• Reference sky type: Clear sky (Direct
sunlight)
• Date and time: 5/4/2022 12:00 PM (E.
Africa Standard Time)
12. Room 1 (store)
•Height of room: 2.800 m, Reflection
factors: Ceiling 70.0%, Walls 50.0%, Floor
20.0%, Light loss factor: 0.80
•Location: Addis Ababa (38.70° N 9.00°
E)
•Reference sky type: Overcast Sky
•Date and time: 5/4/2022 12:00 PM (E.
Africa Standard Time)
•Zenith luminance: 6863 cd/m²
•Ambient condition: Clean
•Pollution category: Medium to heavy
traffic, dust exposure under 600
microgram/cubic metre
13. Day Light Analysis
•SurfaceResult Mean (target) Min Max Min/average Min/max
•1 Workplane 1 Perpendicular illuminance [lx] 344 (500) 33.7 1790 0.10 0.02
•Height of working plane: 0.800 m, Wall zone: 0.000 m
•Lighting power density: 0.00 W/m² = 0.00 W/m²/100 lx (Ground area 4.80
m²) Consumption: 0 kWh/a of maximum 200 kWh/a
14. Room 2 (Maids room)
•Height of room: 3.000 m, Reflection factors:
Ceiling 70.0%, Walls 50.0%, Floor 20.0%,
Light loss factor: 0.80
•Location: Addis Ababa (38.70° N 9.00° E)
•Reference sky type: Clear sky (Direct
sunlight)
•Date and time: 5/4/2022 12:00 PM (E. Africa
Standard Time)
•Zenith luminance: 6863 cd/m²
•Ambient condition: Clean
•Pollution category: Medium to heavy traffic,
dust exposure under 600 microgram/cubic
meter
•Pollution Factor: 0.80
15. Day Light Analysis
Surface Result Mean (target) Min Max Min/average Min/max
1 Workplane 2 Perpendicular illuminance [lx]
Height of working plane: 0.800 m, Wall
zone: 0.000 m
270 (500) 24.1 1805 0.09 0.01
Daylight
Daylight factor effective area 2 Daylight
factor [%]/ /
Rotation: X:0.0°, Y:0.0°, Z:0.0°, Height:
0.850 m, Wall zone: 1.000 m
1.761 1.387 2.232
16. Room 3(Living ,dining,&
kitchen
•Height of room: 3.000 m, Reflection factors:
Ceiling 70.0%, Walls 50.0%, Floor 20.0%,
Light loss factor: 0.80
•Location: Addis Ababa (38.70° N 9.00° E)
•Reference sky type: : Clear sky (Direct
sunlight)
•Date and time: 5/4/2022 12:00 PM (E. Africa
Standard Time)
•Zenith luminance: 6863 cd/m²
•Ambient condition: Clean
•Pollution category: Medium to heavy traffic,
dust exposure under 600 microgram/cubic
meter
•Pollution Factor: 0.80
17. Day Light Analysis
Surface Result Mean (target) Min Max Min/average Min/max
1 Workplane 3 Perpendicular illuminance [lx]
Height of working plane: 0.800 m, Wall zone:
0.000 m
Lighting power density: 0.00 W/m² = 0.00
W/m²/100 lx
(Ground area 55.74 m²) Consumption: 0
1976 (500) 59.2 47797 0.03 0.00
Daylight
Daylight factor effective area 3 Daylight factor
[%]
Rotation: X:0.0°, Y:0.0°, Z:0.0°, Height: 0.850
m, Wall zone: 1.000 m
2.317 0.654 6.296
18. Room 4(Master Bed Room)
•Height of room: 3.000 m, Reflection
factors: Ceiling 70.0%, Walls 50.0%, Floor
20.0%, Light loss factor: 0.80
•Location: Addis Ababa (38.70° N 9.00° E)
•Reference sky type: : Clear sky (Direct
sunlight)
•Date and time: 5/4/2022 12:00 PM (E.
Africa Standard Time)
•Zenith luminance: 6863 cd/m²
•Ambient condition: Clean
•Pollution category: Medium to heavy
traffic, dust exposure under 600
microgram/cubic metre
•Pollution Factor: 0.80
19. Day Light Analysis
Surface Result Mean (target) MinMax Min/average Min/max
1
Workplane
4
Perpendicular illuminance [lx]
Height of working plane: 0.800 m, Wall zone: 0.000 m
213 (500) 40.31158 0.19 0.03
Daylight
Daylight factor effective area 4 Daylight factor
[%] /
Rotation: X:0.0°, Y:0.0°, Z:0.0°, Height: 0.850 m, Wall
zone: 1.000 m
1.050 0.301 3.066
20. Room 5 (WC)
•Height of room: 3.000 m, Reflection
factors: Ceiling 70.0%, Walls 50.0%, Floor
20.0%, Light loss factor: 0.80
•Location: Addis Ababa (38.70° N 9.00° E)
•Reference sky type: Overcast Sky
•Date and time: 5/4/2022 12:00 PM (E.
Africa Standard Time)
•Zenith luminance: 6863 cd/m²
•Ambient condition: Clean
•Pollution category: Medium to heavy
traffic, dust exposure under 600
microgram/cubic meter
•Pollution Factor: 0.80
22. Room 6 (BED ROOM)
•Height of room: 3.000 m, Reflection
factors: Ceiling 70.0%, Walls 50.0%, Floor
20.0%, Light loss factor: 0.80
•Location: Addis Ababa (38.70° N 9.00° E)
•Reference sky type: Overcast Sky
•Date and time: 5/4/2022 12:00 PM (E.
Africa Standard Time)
•Zenith luminance: 6863 cd/m²
•Ambient condition: Clean
•Pollution category: Medium to heavy
traffic, dust exposure under 600
microgram/cubic meter
•Pollution Factor: 0.80
23. Day Light Analysis
Surface Result Mean (target) Min Max Min/average Min/max
1 Workplane 6 BED
ROOM
Perpendicular illuminance [lx]
Height of working plane: 0.800 m, Wall zone: 0.000 m
383 (500) 35.82661 0.09 0.01
Daylight
Daylight factor effective area 6 Daylight factor [%]
Rotation: X:0.0°, Y:0.0°, Z:0.0°, Height: 0.850 m,
Wall zone: 1.000 m
2.153 1.089 3.554