LIGHTING
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Light
Reflection & Transmission
Color
Glare
ID 320 – LIGHTING\ACOUSTIC\HVAC
Done by: Amjad AlFawaz
LIGHT
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LIGHT is the portion of the electromagnetic
spectrum to which our eyes are visually sensitive to.
The power with which light is
emitted from a lamp is
measured in Lumens (lm)
Done By: Amjad AlFawaz
LIGHT
Efficacy: The ratio of light output to energy input
Light out = Lumens = EFFICACY
Energy in watts
Candlepower: Describes the intensity of the beam in
any direction.
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Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
LIGHT
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Illuminance: Is equal to the number of lumens
falling on each square foot(meter) of a surface.
The unit of illumination or light : footcandle ( lux)
lux =
Done By: Amjad AlFawaz
lumens
square meter
LIGHT
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Object’s Brightness refers to the perception of a
human observer.
Object’s Luminance refers to the objective
measurement of a light meter.
Done By: Amjad AlFawaz
LIGHT
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Light falling on an object can be:
Transmitted
Reflected
Absorbed
Done By: Amjad AlFawaz
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Reflection of Light:
1-Specular Reflection  smooth, polished
surfaces.
(the angle of reflection is = to the angle of incidence)
2- Semi-specular reflection  irregular surfaces
such as hammered, brushed or sandblasted
materials.
(part of the light spread and the greatest intensity reflected
at an angle equal or near the angle of incidence)
3- Diffuse Reflection  matte, rough surfaces.
Done By: Amjad AlFawaz
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Transmission of light:
1- Clear, transparent material  transmit light.
2- Diffusing translucent material  scatter light.
Done By: Amjad AlFawaz
COLOR
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White light is a mixture of various wavelengths of
visible light.
Color Temperature:
Used to describe the warmness and coolness of a light
source.
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Low CT, warm  yellow,orange,red colors
High CT, cool  green, purple, blue colors
Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
GLARE
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Glare is a visual noise that interferes with visual
performance.
Glare occurs when one part of the visual field is much more
brighter than the average brightness to which the visual system
is adapted.
This causes: discomfort, or loss in visual performance and
visibility.
1- Direct Glare.
2- Indirect\Reflected Glare.
Done By: Amjad AlFawaz
Direct Glare is caused by a light source sufficiently
bright to cause annoyance, discomfort or loss in
visual performance.
-from light fixtures, ceiling and windows.
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Done By: Amjad AlFawaz
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-distance between an offending light source to the center
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of vision.
Can reduce glare using shielding devices
The closer the worse
Done By: Amjad AlFawaz
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Using optical controllers to eliminate or reduce
direct glare.
Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
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window blinds or perforated screens to limit the
amount of direct sunlight coming into the space.
Done By: Amjad AlFawaz
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Upward to the ceiling
Done By: Amjad AlFawaz
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Indirect Glare is caused by the reflection of light
sources on a glossy surface.
Can be avoided by:
-using matte, less glossy materials.
-Relocating the light source.
-rearranging the interiors
Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
Page 367, Activity Needs
Done By: Amjad AlFawaz
Biological needs
1- the need for spatial orientation:
 Define changes of levels
 Direct people
Done By: Amjad AlFawaz
Biological needs
2- the need to understand structural form:
 Direct light gives form to objects while diffuse light
flatten objects (three-dimensional quality)
Done By: Amjad AlFawaz
3- The need to focus on activities:
 Highlighting important areas to create order and
attention
Done By: Amjad AlFawaz
4-the need for cheerful spaces:
 Right amount of light to eliminate any gloomy
feeling
 Combing different lighting types create cheerful
spaces
Done By: Amjad AlFawaz
Done By: Amjad AlFawaz
5-the need for security:
 Darkness is a lack of visual information; cause fear
and expect danger.
 A man needs to be aware of his surroundings and
get information.
Done By: Amjad AlFawaz
6- the need for communication.
Done By: Amjad AlFawaz
Lighting Design
First: Determine tasks and activity in the space.
Second: Illuminate things based on the determined
activity.
Third: create a level of brightness contrast
Done By: Amjad AlFawaz