the ppt is limited to corporate interiors only.

1. • Light is that part of the electromagnetic
spectrum that is perceived by our eyes.
• It is preferable to provide uniform
illumination over the entire workplace by
combining both natural and artificial lighting.
LIGHT
By:
Akshay Bhatia

2. Illumination
Quantity of
illumination
Quality of
illumination
Light sources
Characteristics
of light sources
Incandescent
lamps
Fluorescent
lamps
High-intensity
discharge lamps
Ballasts Luminaries
Efficiency
Directing light
Lighting Fundamentals

3. • Luminous flux (Light Output)
• Illuminance (light level)
• Luminance (brightness)
• Consideration of lamp
Quantity of
illumination

4.  Luminous flux is the quantity of
the energy of the light emitted
per second in all directions.
 The luminous efficiency is the
ratio of the luminous flux to the
electrical power consumed
(lm/W). It is a measure of a light
source's economic efficiency.
 The unit of luminous flux is
lumen (lm)
Luminous flux (light output)

5.  Luminous intensity is the
ability to emit light into a
given direction.
 This is a useful
measurement for directive
lighting elements such as
reflectors. It is represented
by the luminous intensity
distribution curve (LDC).
 The unit of luminous
intensity is candela
Luminous intensity

6.  This definition determines the
amount of light that covers a
surface.
 It decreases by the square of the
distance (inverse square law). Eg.
If distance is 2x, brightness will be
1/4 and if distance is 3x,
brightness will be 1/9.
 B = lumen/4p(d)^2
Illuminance

7.  Luminance L is the luminous
intensity emitted by the surface
area of 1 cm² (or 1 m²) of the light
source.
 It specifies the brightness of a
surface and is essentially
dependent on its
and Colour)
 The human eye does not see
illuminance; it sees luminance.
Luminance

8. Relation between them
Luminous flux Luminous intensity
Luminance Illuminance

9. A range of lighting levels is recommended for each type of
interior/activity. (minimum-medium-maximum)
 General office - 300-500-750 (lux)
 Deep plan office - 500-750-1000 (lux)
 Computer work stations - 300-500-750 (lux)
 Conference room - 300-500-750 (lux)
 Executive office - 300-500-750 (lux)
 Computer and data
preparation room - 300-500-750 (lux)
 Filing rooms - 200-300-500 (lux)
Value of illuminance recommended by NBC-
2005

10. The appropriate type and quantity of lamps and light fixtures may be
selected based on the following:
 Fixture efficiency
 Lamp lumen output
 Reflectance of surrounding surfaces
 Room size and shape
 Availability of natural light
Lamp consideration

11. • Glare
• Uniformity of illuminance
• Colour rendering
Quality of
illumination

12.  Glare is a sensation caused by
luminance in the visual field that are too
bright. Discomfort, annoyance, or
reduced productivity can result.
 A bright object alone does not
necessarily cause glare, but a bright
object in front of a dark background,
however, usually will cause glare.
 Controls
◦ using lighting equipment designed to reduce
glare.
◦ A louver or lens is commonly used to block
direct viewing of a light source.
◦ Indirect lighting
Glare

13. Direct glare
Glare
It is a visual sensation caused by excessive and uncontrolled brightness.
Reflected glare
Cause:
• Luminaires without glare control
• Very bright surfaces
Cure:
• Luminaires with limited luminance levels
Cause:
• Reflective surfaces
• Incorrect luminaire arrangement
• Incorrect workstation position
Cure
• Matching luminaire to workstation (layout)
• Indirect lighting
• Matt surfaces

14.  The uniformity of illuminance is a
quality issue that addresses how
evenly light spreads over a task
 Although a room's average illuminance may be
appropriate, two factors may compromise
uniformity.
◦ improper fixture placement
◦ fixtures that are retrofit with reflectors that
narrow the light distribution.
Uniformity of illuminance

15. Light source

16. • Efficiency
• Colour temperature
• Colour rendering index
CHARACTERSTICS
Light sources

17.  Some lamp types are more
efficient in converting energy
into visible light than others.
 The efficacy of a lamp refers to
the number of lumens leaving
the lamp compared to the
number of watts required by the
lamp
 It is expressed in lumens per
watt.
 Sources with higher efficacy
require less electrical energy
light a space.
Efficiency

18.  This is a measurement of "warmth" or "coolness" provided by the lamp.
 Color temperature refers to the color of a blackbody radiator at a given
absolute temperature, expressed in Kelvins.
 A blackbody radiator changes color as its temperature increases ( first to
red, then to orange, yellow, and finally bluish white at the highest temperature.
Colour temperature

19.  Color rendering describes how a light source makes the color of an object
appear to human eyes.
 The Color Rendering Index (CRI) is a scale from 0 to 100 percent indicating how
accurate a "given" light source is at rendering color when compared to a
"reference" light source.
 The higher the CRI, the better the color rendering ability.
Color rendering

20. Color rendering index
Colour rendering groups CIE general color
rendering Index(Ra
)
QUALITY
1A Ra > 90 Wherever accurate color
rendering is required
1B 80 < Ra < 90 Wherever good color
rendering is required
2 60 < Ra < 80 Wherever moderate color
rendering is required
3 40 < Ra < 60 Wherever color rendering is of
little significance
4 20 < Ra < 40 Wherever color rendering is of
no importance at all

21. • Standard Incandescent Lamp
• Tungsten-Halogen Lamps
Incandescent
lamps
Light sources

22. Light sources

23.  Incandescent lamps are one of the
oldest electric lighting technologies
available.
 Colour temperature- 2500 k-3000 k
 Efficiency- 6-20 lm/W
 Life- 1000 hrs
 Colour rendering- 1A
 Luminous flux- 200-40,000 lm
Standard Incandescent Lamp

24.  Colour temperature- 2800 k-33 00 k
 Efficiency- 13-22 lm/W
 Life- 2000-3000 hrs
 Colour rendering- 1A
 Luminous flux- 1300-44,000 lm
Tungsten-Halogen Lamps

25. • Full-size fluorescent lamps
• Compact fluorescent lamps(CFL)
Fluorescent
Lamps
Light sources

26. Standard Incandescent Lamp

27.  Full-size fluorescent lamps are
available in several shapes,
including straight, U-shaped, and
circular configurations. Lamp
diameters range from 1" to 2.5".
 Colour temperature- 2900 k-6500 k
 Efficiency- 50-105 lm/W
 Life- 7500-15000 hrs
 Colour rendering- varies
 Luminous flux- 1000-5400 lm
Full-size fluorescent lamps

28.  Reductions of tube diameters have
facilitated the development of
compact fluorescent lamps.
 Colour temperature- 2900 k-6500 k
 Efficiency-
◦ 36-65 lm/W (with ballast)
◦ 50-90 lm/W (without ballast)
 Life- 7500-15000 hrs
 Colour rendering- 1A, 1B
 Luminous flux- 250-2900 lm
Compact fluorescent lamps(CFL)

29. • Mercury Vapor
• METAL HALIDE LAMPS
• HIGH PRESSURE SODIUM LAMPS
High-
intensity
discharge
lamps
Light sources

30.  Clear mercury vapor lamps, which
produce a blue-green light, consist
of a mercury-vapor arc tube with
tungsten electrodes at both ends.
 Colour temperature- 3000 k-4200 k
 Efficiency- 18-28 lm/W
 Life- 7500-15000 hrs
 Colour rendering- 3
 Luminous flux- 3000-14,000 lm
Mercury Vapor

31.  These lamps use metal halide
additives inside the arc tube along
with the mercury and argon. These
additives enable the lamp to produce
more visible light per watt with
improved color rendition.
 Colour temperature- 3000 k-6000 k
 Efficiency- 55-110 lm/W
 Life- 2000-10,000 hrs
 Colour rendering- 1A, 1B OR 2
 Luminous flux- 2400-300,000 lm
METAL HALIDE LAMPS

32.  The high pressure sodium
(HPS) lamp is widely used for outdoor
and industrial applications. Its higher
efficacy makes it a better choice than
metal halide for these applications,
especially when good color rendering
is not a priority
 Colour temperature- 2000 k-2200 k
 Efficiency- 60-150 lm/W
 Life- 10,000-28,000 hrs
 Colour rendering- 3 OR 4
 Luminous flux- 2000-130,000 lm
HIGH PRESSURE SODIUM LAMPS

33. LED (Light Emitting Diodes)
LEDs (Light Emitting Diodes) use a fraction of the electricity of standard incandescent
bulbs and have become the best energy-saving light sources. LED’s are long-lasting,
reliable and produce a comfortable white light, which is essential for secure uniform
lighting
Pros:
 LED lamps last up to 20 years
 LED lamps reach full brightness immediately
 LEDs do not radiate infrared or ultraviolet light or contain mercury
 LED lamps have no start up problems because of cold temperatures
 LED is the most efficient light source available till now.

34. Ballasts

35.  All discharge lamps (fluorescent and HID) require an auxiliary piece of
equipment called a ballast.
 Ballasts have three main functions:
◦ provide correct starting voltage, because lamps require a higher voltage to start than to
operate
◦ limit the lamp current to prevent immediate destruction,
Ballast

36.  There are three main types of fluorescent
circuits:
◦ rapid start: Users notice a very short delay after
"flipping the switch," before the lamp is started.
◦ instant start: The instant start system ignites the
arc within the lamp instantly.
◦ Preheat: The filament needs some time to reach
proper temperature, so the lamp does not strike
for a few seconds.
Types of Fluorescent Circuits

37. The main function of the luminaire is to direct light using reflective and shielding
materials.
There are several different types of luminaires. The following is a listing of some of the
common luminaire types:
 general illumination fixtures such as 2x4, 2x2, & 1x4 fluorescent troffers
 downlights
 indirect lighting (light reflected off the ceiling/walls)
 spot or accent lighting
 task lighting
 outdoor area and flood lighting
Luminaries

38. A luminaire, or light fixture, is a unit consisting of the following components:
 lamps
 lamp sockets
 ballasts
 reflective material
 lenses, refractors, or louvers
Luminaries

39.  Each of the above luminaire types
consist of a number of components
that are designed to work together to
produce and direct light. The
components used to direct the light
produced by the lamps.
 Reflectors:
 Lenses
 Louvers
Directing light

40.  Reflectors are designed to redirect the
light emitted from a lamp in order to
achieve a desired distribution of light
intensity outside of the luminaire.
 In most incandescent spot and flood
lights, highly specular (mirror-like)
reflectors are usually built into the
lamps.
Reflectors

41.  Lenses made from clear ultraviolet-
stabilized acrylic plastic deliver the
most light output and uniformity of
shielding media.
 they provide less glare control than
louvered fixtures.
 Lenses are usually much less expensive
than louvers.
Lances

42.  Louvers provide superior glare control
and high visual comfort compared
with lens-diffuser systems.
 The most common application of
louvers is to eliminate the fixture glare
reflected on computer screens.
 Deep-cell parabolic louvers provide a
good balance between visual
and luminaire efficiency.
 Small-cell parabolic louvers provide
the highest level of visual comfort,
they reduce luminaire efficiency to
about 35-45 percent.
Louvers

43.  General
Different light provisions
 Localised  Private

44. Light has a triple effect:
1. Light for visual functions: glare-free
and convenient.
2. Light creating biological effects:
Stimulating or relaxing
3. Light for emotional perception:
Creating scenes and effects

45. Different type of light fixtures:

46. Direct
Distribution of lighting
One of the primary functions of a luminaire is to direct the light to where it is needed.
Indirect Direct-Indirect Diffused
90 to 100 percent
of the light is
directed downward
for maximum use.
90 to 100 percent
of the light is
directed to the
ceilings and is
reflected to all parts
of a room.
Portions of the light
are directed
upward and
downward.
Light is projected in
all directions.

47.  Highly directional
 Dark ceiling
 Limited flexibility of work-
station layout
 Energy efficiency on the task
level
Direct lighting

48.  Diffuse lighting conditions
 Room gains in height
 Glare-free
 Workstations can be positioned
anywhere
 Low energy efficiency
Indirect lighting

49.  Pleasant room impression
 High user acceptance
 Good contrast ratios
 Flexible workstation layout
(indirect component > 60 %)
Direct-Indirect lighting

50.  direct/indirect solution
 Workstations can be
positioned anywhere
 Glare-free
 Gives impression of daylight in
room
Diffused lighting

51. Natural light

52.  Light tubes or light pipes are
physical structures used for
transporting or distributing
natural or artificial light for the
purpose of illumination.
 they are also often
called tubular daylighting
devices, sun pipes, sun scopes,
or daylight pipes.
Light pipe

53. Collector
 The Sky Vault Collector capture
daylight without heating the
building interior.

54. Diffuser
 Sky Vault Series Diffuser Assemblies provide precise control over
daylight collected by our optical domes and Spectra light Infinity
Tubing. Each is factory-assembled to make field installation quick and
easy.

55. Extension Tubes
 Extension tube or
pipe for transport of
light to another
location, minimizing
the loss of light.

56. Dimmer

57. Thank you