An essential service in all the industries,
The power consumption by the industrial lighting varies between 2 to 10% of the total power depending on the type of industry.
Lightingisanarea,whichprovidesamajorscopetoachieveenergyefficiencyatthedesignstage,by incorporation of modern energy efficient lamps,luminaires and gears,apart from good operational practices.
LIGHTING SYSTEMS AND THEIR
Guided By:- Ar. Mariam Ahmad Mam
M.Arch , Building Services, III-Sem
Faculty of Architecture and Ekistics
Jamia Millia Islamia, New Delhi.
Lighting systems and their design
A n e s s e n t i a l s e r v i c e i n a l l t h e i n d u s t r i e s ,
The power consumption by the industrial lighting varies
between 2 to 10% of the total power depending on the type
Lighting is an area, which provides a major scope to achieve
energy efficiency at the design stage, by incorporation of
modern energy efficient lamps, luminaires and gears, apart
from good operational practices.
The aim of lighting is to create an adequate visual
Thus, there are two components of the visual
1. one is a usually furnished room with
surfaces reflecting light to a greater or
lesser extent , - this is a basically passive
component- and –
2. the other is light, which (as an active
component) makes the room visible.Lighting systems and their design 2
The lighting design should take into consideration the following aspects:
1. ILLUMINATION LEVEL (right quantity of light)
2. PROPER PLACEMENT OF LUMINAIRE ( proper location)
3. WITH EFFICIENT INTEGRATED CONTROLS
Lighting design can be governed on the basis of following criteria’s:
LIGHTING DESIGN / ILLUMINATION PLANNING
Light defines space, enhances color and reveals the intricacies of texture and form.
2. LIGHTING QUALITY AND QUANTITY
A. Illumination levels
B. Adaptation levels
4. SPACE AND WORKPLACE CONSIDERATIONS
B. Appearance of the space and luminaires
C. Color appearance
D. Luminance of room surfaces
E. Flickering of light
F. Direct and reflective glare
1. LIGHT DISTRIBUTION
A. Task and ambient lighting
B. Day lighting integration
C. Light pollution and light trespass
3. LIGHTING ON PEOPLE AND OBJECT
A. Modeling faces and objects
B. Surface characteristics
C. Points of interest
Lighting systems and their design 3
Concept of lighting as a system
Lighting design requires consideration of
• the amount of functional light provided,
• the energy consumed,
• the aesthetic impact
Architectural lighting design focuses on three fundamental aspects of the illumination of
buildings or spaces.
• The first is the aesthetic appeal of a building, an aspect particularly important in the
illumination of retail environments.
• Secondly, the ergonomic aspect: the measure of how much of a function the lighting plays.
• Thirdly is the energy efficiency issue to ensure that light is not wasted by over-illumination,
either by illuminating vacant spaces unnecessarily or by providing more light than needed for
the aesthetics or the task.
Lighting systems and their design 4
Various types of lighting systems used
Generally there are 3types of lighting system
Many call LIGHTING as the 4th element of architecture.
Lighting systems and their design 5
Ambient lighting provides an area with overall illumination.
Also known as general lighting, AMBIENT ILLUMINATION for orientation
and general tasks in the space, like Walking etc.
Ambient lighting is often provided by traditional pendant type
fixtures, down lights, chandeliers, or ceiling mounted fixtures etc.
Ambient lighting :-
Task lights can’t light the balance of the room, and thus
some other type of lighting system is needed to produce
the ambient illumination in the room.
Lighting systems and their design 6
directional lighting .
It can also be used to highlight the texture of a
brick or stone wall, window treatments or
To be effective, accent lighting requires as least
3-times as much light on the focal point as the
general lighting surrounding it.
Accent lighting is usually provided by recessed
and track lighting or wall-mounted picture
ACCENT ILLUMINATION to highlight special
objects of interest or to guide occupants.
Accent lighting is mainly decorative, intended
to highlight pictures, plants, or other elements
of interior design or landscaping.
Lighting systems and their design 7
Task lighting:- Task lighting, or directional lighting, is aimed
at a specific task;
It can be provided by recessed and track
lighting, pendant lighting and undercabinet
lighting, as well as by portable floor and desk
Task lighting should be free of distracting glare
and shadows and should be bright enough to
prevent eye strain.
2) TASK ILLUMINATION for local, more
Task lighting is mainly functional and is
usually the most concentrated, for purposes
such as reading or inspection of materials.
Task lighting systems independent from the space’s general
lighting systems (serving specific task) are found in building types
for instance, the display lighting in retail stores is a form of task
lighting. Similarly, task lights are used in industrial manufacturing
and assembly, health care, residential lighting, and many other
interior lighting applications.
– indirect luminaires mounted atop cabinetry or workstations
– Suspended luminaires
– Recessed luminaires
Lighting systems and their design 8
Good task light should provide about 50 to
100 foot candles to the workspace
Well distributed over the work area
Adjustability is very important; you should be
able to direct the light where you need it.
The task light should be designed to avoid
It should be energy-efficient.
Most people prefer warm white to
neutral white. Warm white is normally
associated with a correlated color
temperature between 3,000 and
Task Lighting Tips
• Your light should be located to the side of
the task – not in front of it – to avoid glare.
• If you’re right-handed, place your light on
the left side of your work area – and vice-
versa, for lefties. Helps reduce the chance
• The light source should not shine in your (or
anyone’s) eyes; adjust it downward, onto
the task surface and/or the task at hand
(such as a document you are reading).
A recommended ratio between localized task
lighting and ambient lighting is 5:1.
Regarding Task lighting
Lighting systems and their design 9
Informational lighting (Guidance Lighting)
The light in your closet, the light by your
doorbell, and night lights, as well as path
lighting and motion lights, are all good
examples of informational lighting.
It can be beautiful as well as functional, and
can create dramatic statements.
Lights inset on stairs can create pathways that
Light strips, pendants, chandeliers, and
sconces are all examples of light fixtures
that draw attention to themselves and add
character to the place being lighted.
Many are also used for general lighting.
Lighting systems and their design 10
Key Light, Fill Lighting:-
• Multi-directional or diffuse light Reduces shadows
on an object caused by the key light.
Single point source of light Provides highlights and
casts shadows providing contrast and producing
Lighting systems and their design 11
Techniques used in controlling Directionality of light
• Occurs when light strikes a surface
at a sharp angle, nearly parallel
to a rough surface.
• Enhances any variations in surface
depth, revealing texture.
• Will also emphasize flaws and
unevenness in surfaces.
Places a light source below an
Produces shadows that are
reversed from how an object is
shadowed in daylight.
Creates an eerie, unnatural
effect because it replaces the
more familiar overhead
orientation of the light source.
Light source is used not to
illuminate an object itself, but its
Applicable when one aims to
reveal the outline of an object
against a brighter surface and to
create separation between the
object and its background.
• Occurs when light
strikes a surface at a
• Provides even lighting
on a vertical space,
increase luminances of
wall surfaces, and
extend the space.
Lighting systems and their design 12
• Candlepower Distribution Curve: A curve, generally polar,
represents the variation of luminous intensity of a lamp or
luminaire in a plane through the light center.
Visual Edge: The line on an isolux chart that
has a value equal to 10% of the
Light distribution same in all planes. Usually
Circular or ‘Bowl shaped’ luminaire
Luminaire distribution is confined to two vertical planes separately.
Typical distribution for Fluorescent Lamp luminaires and Road Lighting
Asymmetry present in one of the
Planes of measurement.
• Isolux Chart: A series of lines plotted on any appropriate set
of coordinates, each line connecting all the points on a
surface having the same illumination.
Lighting design curves/charts:
Lighting systems and their design 13
The image above is a candle power
distribution curve, which provides
information on how light is emitted
from a lamp or light fixture.
The diagram represents a section
cut through the fixture and shows
the intensity of light emitted in
The portion of the graph above the
horizontal 90°-270° line indicates
light that shines above the fixture
(indirect), while the portion of the
graph below represents light
shining down (direct).
The straight lines radiating from the
center point identify the angle of
the light emitted while the circles
represent the intensity. For
instance, point A above shows that
the intensity of light at 80° is
approximately 110 candlepower.
Point B shows that at 30° you will
get about 225 candlepower.
The image is a candle power distribution curve,
which provides information on how light is emitted
from a lamp or light fixture
Lighting systems and their design 14
Lighting Luminaire components definition
•Baffle: An opaque or translucent element that serves to shield a light source from direct view at certain
angles, or serves to absorb unwanted light.
•Ballast: An auxiliary device consisting of induction wires wound around a metal core and sometimes
includes a capacitor for power correction. It is used with fluorescent and HID lamps to provide the necessary
starting voltage and to limit the current during operation.
•Lamp: An artificial source of light (also a portable luminaire equipped with a cord and plug).
•Capacitor: An electric energy storage device which when built into or wired to a ballast changes it from
low to high power factor.
Lighting systems and their design 15
•Class “P” Ballast: Contains a thermal protective device that deactivates the ballast when
the case reaches a certain critical temperature. The device resets automatically when the case
temperature drops to a lower temperature
•Cone Reflector: Parabolic reflector that directs light downward thereby eliminating
brightness at high angles.
•Dimming Ballast: Special fluorescent lamp ballast, which when used with a dimmer
control, permits varying light output.
•Lens: Used in luminaries to redirect light into useful zones.
• Louver: A series of baffles used to shield a source from view at certain angles or to absorb
unwanted light. The baffles usually are arranged in a geometric pattern.
•Pattern Control: A blade, in the air passage of an air handling luminaire, which sets the
direction of air flow from the luminaire.
Lighting systems and their design 16
Lighting systems and their design 17
Luminaires designed for general illumination of large areas
constitute the majority of lighting installations and the
majority of the energy consumed for lighting. These lighting
systems consist of a luminaire layout pattern that provides
uniform lighting throughout the space.
Open direct systems do not employ shielding at all. These systems include surface- and pendantmounted
strip fluorescent fixtures and suspended open industrial and commercial luminaires.
Unless equipped with reflectors, these systems radiate light in all directions. Open direct lighting
systems are often very efficient, with high CU values, but they may cause visual discomfort and disability
Shielded Direct Lighting Systems
Shielded systems use some form of lens, louver, or baffle to
prevent direct viewing of the lamps at normal angles of view (see
Figure 2). Surface and suspended luminaire types include
industrial HID downlights, baffled industrial fluorescent luminaires,
fluorescent wrap-around lens luminaires, and commercial
fluorescent lens luminaires.
Recessed systems include HID downlights and a wide range of fluorescent “troffers” using lenses, louvers, or
baffles to control glare.
Lighting systems and their design 18
Parabolic Louvered Recessed Troffers
An increasingly popular commercial general lighting fixture
is the recessed parabolic troffer, which uses specular
parabolic louvers to control the luminaire’s light
distribution, providing sharp cut-off glare control.
Depending on the spacing between the louvers, these
luminaries can be classified as large-cell and small-cell
parabolic luminaires. Large-cell luminaires are generally
more efficient, with relatively high CU values, while smaller
cells can offer better glare control. Many standard sizes are
available, including 2’x 4’, 2’x 2’, 1’x 4’ The extent of glare
control depends on the specific louver design.
Standard Lensed Troffers
Standard lensed troffers typically have higher efficiency and CU values than parabolic louvered
troffers, but provide less precise glare control. Many lens types can be used (i.e., patterned
prismatic, batwing, linear batwing, and polarizing), though final photometric performance also
depends on a number of other factors such as reflector type, number of lamps, lamp type, and
Lighting systems and their design 19
Indirect Lighting Systems
Lighting systems that radiate light up to a reflecting
ceiling are called indirect lighting systems. These
systems generally employ luminaires suspended from
the ceiling, though cove lights and lights mounted to
walls and furniture can also be used. Indirect lighting
systems using well-designed and properly spaced
luminaires can provide excellent illumination,
uniformity, and freedom from glare. Their success
depends on maintaining a high ceiling reflectance in
combination with nearly uniform brightness. In this
way, a maximum amount of light is reflected down to
the work plane, yet light patterns are less likely to
create reflected glare in VDT screens.
Indirect Lighting Luminaire
Cove Lighting System
Recent designs in fluorescent indirect lighting
systems use lenses or imaging reflectors to
achieve high luminaire efficiency, by producing
a broad batwing light distribution while
allowing for close-to-ceiling mounting. These
designs can increase an indirect system’s CU to
nearly that of traditional lensed troffer
Other new designs in indirect lighting
luminaires, especially for cove and
coffer installations, increase the
effectiveness of traditional strip
lights and eliminate socket shadows.
Lighting systems and their design 20
These systems combine the benefits of both
traditional direct lighting and indirect lighting
systems. Combing the high CU of direct
illumination with the uniformity and glare
control of indirect lighting can be an ideal
solution for many spaces. The appropriate
balance of direct and indirect light is
dependent on the nature of individual
Direct/Indirect Lighting Systems
Architectural lighting systems, which are generally used in building spaces such as lobbies and
corridors include recessed downlights, wall washers, track lights, and wall sconces. Since these
luminaires are employed mainly for highlighting high-quality spaces, aesthetics is a principal
consideration in their design and selection. Nevertheless, there are many opportunities to utilize
efficient lighting in these applications.
Lighting systems and their design 21
Recessed Low-Wattage HID Downlights
New HID downlights, equipped with high-CRI
compact metal halide and white high pressure
sodium lamps, can replace traditional
incandescent downlights in high-quality and/or
low-ceiling spaces, thereby achieving
significant energy savings and extended lamp
Recessed Compact Fluorescent Downlights
The popular compact fluorescent down light is now available in a variety of configurations, and
some units include dimmable lamps designed for use with electronic ballasts. In general,
compact fluorescent lamps replace incandescent down lights on a 1 watt for 3 watts basis. A
relatively recent development, the 1’x 1’ parabolic down light for compact fluorescent lamps is
extremely efficient, allowing replacement of incandescent lamps on a 1 watt for 4 watts basis.
Lighting systems and their design 22
Track-Mounted Lighting Task Lights
Several interesting recent designs in track
luminaires using compact fluorescent and
lowwattage HID lamps offer significant energy
savings over standard incandescent track
luminaires Track lighting systems provide
flexibility in design and make it possible to
accommodate changing displays.
Task lights work in conjunction with general
lighting systems to meet diverse needs of
individual occupants for specific visual tasks.
Compact fluorescent lamp technology has
special relevance for task lighting applications.
In VDT applications where high levels of
ambient light often interfere with visibility, task
lighting may be especially important for non-
VDT tasks, particularly when those visual tasks
are difficult to perform because of low
contrast, high speed, and/or worker age.
Lighting systems and their design 23
A renaissance in decorative lighting fixtures in the form of pendants, wall sconces, chandeliers,
exterior lanterns, and landscaping lights occurred in the 1980s. In most instances, decorative
lighting luminaires are used to provide general or ambient lighting in areas where a more
customized appearance is desired. Although decorative lighting is still most often used in
restaurants and hotels, an increasing number of applications exist in offices, retail stores,
apartment buildings, and other commercial spaces. Many decorative luminaires employ efficient
light sources, increasing opportunities for using less energy.
Many traditional applications for incandescent
wall-mounted sconces and brackets can be
replaced with similar-appearing luminaires
designed specifically for compact fluorescent
or HID lamps. See Figure 10 for an example.
Compact Fluorescent Pendants and Chandeliers
Luminaire designs continue to evolve for compact fluorescent
decorative chandeliers and pendants used in applications once
limited to traditional incandescent fixtures.
Lighting systems and their design 24
Combined diagram for spotlights
Light distribution curve
Color is defined with a variety of metrics but the 2 most common are:
1. Correlated Color Temperature (CCT).
2. Color Rendering Index (CRI).
Correlated Color Temperature (CCT):
• Represents the relative whiteness of a light
source, whether the source appears warm, cool or
• Measured in Kelvin (°K).
• Acceptable range of CCTs for indoor environments
is between 2500°K and 5000°K, with the higher
value representing a cooler source.
Color Rendering Index (CRI)
CRI rating indicates how well an
object’s colors are rendered by a
It is a comparison of 8 specific test
colors under an ideal light source in
When color rendering is important, a
source with a high CRI (e.g. 3500°K
fluorescent with a CRI of 85) should
Correlated color temperature and the ambient temperature
Lighting systems and their design 26
• Light Level or Illuminance, is the total luminous flux incident on a work plane, per unit area.
The work plane is where the most important tasks in the room or space are performed.
• There are recommended minimum illuminance for each place or task that must be followed,
• Direct glare is caused by excessive light entering the eye.
• Direct glare can be minimized with careful equipment selection and placement.
• In interior applications, indirectly light the walls and ceiling A limited amount of direct light
can provide accent and task lighting.
• In exterior applications, use fully shielded luminaires that directs light downwards towards
the ground or a building façade.
Lighting systems and their design 27
how we can select the proper lamp type for a certain application.???
The answer will be as follows:
1. Efficacy, Life, Lumen Depreciation
All of these have an effect on life cycle cost. If a lamp's lumen output declines rapidly during its life, the
prudent designer initially provides more lumens than is required so that as the lamp declines with age, a
sufficient amount of light is still available. In other words, if seven luminaires are required to provide the
right amount of light for a space initially, we might put eight luminaires in our design so that the space is
over lit at first, but the installation will still provide enough light later on as the lamps provide less than their
rated lumen output due to ageing. Comparing the rate of lumen depreciation from one type of lamp to the
next thus becomes an important part of the cost analysis.
2.PATTERN OF DISTRIBUTION
It is sometimes desirable to have diffuse light rather than highly directional light since the latter may cause
harsh shadows. An area source or a linear source (such as a fluorescent lamp) generates more diffuse light
and softer shadows than a point source.
Some lamps are more easily dimmed than others. One must consider if simple on/off control is acceptable, if
inexpensive dimming is desired, or if it is reasonable to incur the larger expenditures to get higher quality
4. Color Rendition
One of the key areas of concern for the architect, interior designer and lighting engineer is the lighted
appearance of the space. Most light sources are available in a variety of spectral power distributions, yielding a
variety of color-rendering indices (CRI) and color temperatures. The lighting designer must be thoroughly familiar
with these concepts in order to properly achieve the desired effect with the chosen lamps.Lighting systems and their design 28
5. Distribution Control
Light distribution from a small lamp can be controlled more easily than light emitted from a large lamp. This
is simply because it is easier to shape a reflector around a small lamp than a large one. Some lamps are as
small as 10 mm in length, and others are as large as 1 m long. The pattern of light from the former can be
controlled very precisely whereas the best we can hope to do with the latter is to throw light in one general
direction or another. We idealize a small light source with the concept of a "point source." The smaller the
light-emitting element of a lamp, the more closely it resembles the ideal of a mathematical point source.
6. Air Conditioning Load
All artificial lighting adds an additional heat load to a building. Lamps with a higher efficacy will put less heat
into a space for a given amount of light output. The most thermally efficient form of lighting is diffuse
daylight, followed by direct sunlight, low-pressure then high-pressure gaseous discharge.
The worst of all is incandescent lamps.
7. Consistency and Reliability of Supply Voltage
High-pressure gaseous discharge lamps are more sensitive to voltage variation than low-pressure lamps. If
the arc is extinguished due to a dip in voltage, the high-pressure lamp may require up to 15 minutes to
return to full light output.
8. Ambient Temperature and Humidity
Some lamps, notably fluorescents, are very sensitive to temperature and humidity. These lamps are difficult
to start when the ambient temperature is low, and once started may not produce full light output.
Some lamps are quite cheap to purchase, initially. However, these tend to have low efficacy and relatively
short lives. One must consider not only the initial cost, but the cost to operate the system over its entire life,
including energy costs and the requirement to pay a worker to change the burned-out lamps frequently.
Fluorescent lights and LEDs are often a cost improvement on incandescents for this reason alone, even
without energy savings.
Lighting systems and their design 29
A 100 watt incandescent bulb produces 100 watts of heat (actually power). From an energy
point of view, it puts out 100 Joules of energy every second.
What temperature rise this causes depends on a lot of factors, room size, air flow, etc.
specific heat capacity of dry air is 1.00 kJ/kgC
Density of air at 30C is 1.2 kg/m³
Take a small closed room, 4 m x 4 m x 3 m or 48 m³ with 1 100w bulb.
48 m³ x 1.2 kg/m³ = 58 kg of air
100J = 1000 J/kgC x ∆T x 58 kg
∆T = 0.0017 deg C, very small change in temp.
but this occurs every second, so in an hour, we would have a 6 degree C rise. or 11 deg F
So in a small enclosed room, one 100w bulb will cause the temp to go up 11 degrees F per
hour. Actually a lot.
Add a few more bulbs and it goes up a lot more. But make the room larger or open a door,
and it goes up a lot less. Lighting systems and their design 30
Free-standing or portable
such as Table lamp fixtures, standard lamp fixtures, and office task light luminaires.
1- Recessed light : the protective housing is concealed behind a ceiling or wall, leaving only the
fixture itself exposed. The ceiling-mounted version is often called a downlight.
Cans, downlighting , uplights placed on the floor, Troffer light (recessed fluorescent lights ), Cove
light ( recessed into the ceiling in a long box against a wall), Torch lamp (floor lamp).
2- Surface-mounted light : the finished housing is exposed, not flush with surface.
3- Pendant light : suspended from the ceiling with a chain or pipe.
4- Sconce : provide up or down lights; can be used to illuminate artwork, architectural details;
commonly used in hallways or as an alternative to overhead lighting.
5- Track lighting fixture: individual fixtures can be positioned anywhere along the track, which
provides electric power.
Lighting systems and their design 31
6- Under-cabinet light : mounted
below kitchen wall cabinets.
7- Emergency lighting or exit light :
connected to a battery backup or to
an electric circuit that has emergency
power if the mains power fails.
8- High- and low-bay lighting
: typically used for general lighting for
industrial buildings and often big-box
9- Strip lights or industrial lighting :
often long lines of fluorescent lamps
used in a warehouse or factory.
10- Soffit : can be general or a
decorative wall-wash, sometimes used
to bring out texture on a wall, though
this may also show its defects as well.
The effect depends heavily on the
exact type of lighting source used. Lighting systems and their design 32
• When luminaires direct 90 to 100% of their output
• The distribution may vary from widespread to
highly concentrated, depending on the reflector
material, finish and contour, and on the shielding or
control media employed.
• Troffers and downlights are two forms of direct
• Can have the highest utilization of all types, but this
utilization may be reduced in varying degrees by
brightness-control media required to minimize
• Reflected glare and shadows may be a problem
with direct lighting unless close spacings are
Lighting systems and their design
glass or grey spun
• The distribution is predominantly downward (60 to 90%) but with a small
upward component to illuminate the ceiling and upper walls.
• The same as for direct lighting except that the upward component will tend
to soften shadows and improve room brightness relationships.
• Care should be exercised with close-to-ceiling mounting of some types to
prevent overly bright ceilings directly above the luminaire.
Semi- Indirect Lighting
• Lighting systems that emit 60 to 90% of their output
• The characteristics are similar to those of indirect
systems except that the downward component
usually produces a luminaire luminance that closely
matches that of the ceiling.
• However, if the downward component becomes too
great and is not properly controlled, direct or
reflected glare may result. Lighting systems and their design 34
Lighting systems and their design
Lighting systems and their design 36
Soffit lighting is used to
direct more light to wall
surfaces and to horizontal
surfaces, such as kitchen and
bath countertops, wall desks,
music centers, and computer
Cove lighting directs light
(usually fluorescent) onto
ceiling surfaces and indirectly
reflects light into the center
of a room. The soffit should
hide the fixture from view
from any position in the room.
Valance lighting directs light upward to
the ceiling and down over the wall or
window treatment. Valance faceboards
can be flat, scalloped, notched,
perforated, papered, upholstered,
painted, or trimmed with molding.
Cornice lighting directs all light
downward. It is similar to soffit lighting.
except cornice lights are totally exposed
at the bottom.
General Diffuse Lighting
• When downward and upward components of light from luminaires are about equal (each 40
to 60% of total luminaire output).
• Direct-indirect is a special category within this classification for luminaires that emit very
little light at angles near the horizontal. Since this characteristic result in lower luminances in
the directglaze zone, direct-indirect luminaires are usually more suitable than general-
diffuse luminaires that distribute the light about equally in all directions.
• General-diffuse units combine the characteristics of direct lighting and those of indirect
• Brightness relationships throughout the room are generally good and the upward light
reflected from the ceiling softens shadows from the direct component.
• Pendant-mounted luminaires designed to provide a general-diffuse or direct-indirect
distribution are frequently installed on or very close to the ceiling.
• Such mountings change the distribution to direct or semidirect since the ceiling acts as a top
reflector redirecting the upward light back through the luminaire.
Lighting systems and their design 37
• Lighting systems which direct 90 to 100% of the light upward to the ceiling and upper
• In a well-designed installation, the entire ceiling becomes the primary source of illumination,
and shadows will be virtually eliminated.
• Also, since the luminaires direct very little light downward, both direct and reflected glare
will be minimized if the installation is well planned.
• It is also important to suspend the luminaires a sufficient distance below the ceiling to obtain
reasonable uniformity of ceiling luminance
• Since the indirect lighting the ceiling and upper walls must reflect light to the work plane, it is
essential that these surfaces have high reflectances. Care is needed to prevent overall ceiling
luminance from becoming too high and thus glaring.
Lighting systems and their design 38
Downlights,aimed (recessed or surface mounted)
• Downlights have a rotationally symmetric beam that is downwards.
• They are offered with narrow-beam symmetric light distribution.
• The cut-off angle of narrow-beam downlights means they are largely free of glare.
• This gives a luminaire with the widest beam possible while simultaneously having an
optimised light output ratio.
• The use of a diffuser reduces the luminance in the luminaire and thereby improves the visual
comfort and the evenness.
Criteria for Downlights:
Choice of lamp determines light colour, functional life, efficiency, light intensity,
•Emission angle determines the beam of light and is defined by the reflector and the lamp,
•Cut-off angle limits glare and increases visual comfort,
•Light output ratio is increased by optimised reflector technology.
Lighting systems and their design 39
Applications of General
lighting- direct, aimed:
Wall-mounted down lights, with their diffuse beam in the room, provide good visual comfort.
They can also be mounted on the ceiling.
Shielded Wall-mounted down lights with half-shielded face offer good visual comfort and illuminate the
floor area in particular.
Criteria for wall mounted down lights:
•Choice of lamp determines light color, functional life, efficiency, light intensity,
•Uniformity: optimized reflector for even illumination of areas,
•Cut-off angle increases visual comfort and limits glare and light pollution.
Recessed floor luminaires with diffuse light intensity distribution are used for marking paths or
emphasizing architectural lines.
Applications of General lighting - direct, diffuse
Overhanging or cantilevered roofs,
Floor lighting on access driveways, paths and public squares.
Lighting systems and their design 40
Lighting systems and their design 41
Advances in materials science have resulted in several key new materials capable of precisely and efficiently redirecting
incident light rays.
While these types of reflector materials are advantageous for some luminaire designs, in other cases, optical performance
requirements dictate the use of standard painted reflectors that produce diffuse, scattered, or wide-spread distribution of
the incident light.
Appropriate use of reflector materials (specular or diffuse) will maximize luminaire efficiency while maintaining the desired
Reflector finishes can be chosen to coordinate with interior design elements, enhance the
tones of the lamp source as well as impact performance and ceiling brightness.
Provides a clear image and a high
level of beam control.
Allows light to be reflected evenly in
all directions, creating uniform
Provides a highly reflective finish that
is durable and easy to clean.
Produces the highest performance of
controlled reflected light.
Provides warm tones, ideal for incandescent
and H.I.D. sources.
Provides warm appearance, ideal for
compact fluorescent sources.
Absorbs light and minimizes glare.
Creates a smooth appearance and even
Provides a warm, soft, uniform illumination.
Most economical choice and blends into
Ideal for reducing glare at the ceiling line.
Blends into white ceilings, helps minimize
Lighting systems and their design 42
Lighting systems and their design 44
.Caused by a view of the light source, often with high contrast to the surroundings.
• Glare is associated not just with lamps, but also with daylight, especially when one is
exposed to low angle, direct sunlight.
– more about the glare caused by lamps, lenses and other overly birght sources of manmade
– less about glare of sunlight and small point sources
– most concerned about sources of glares in relation to the stationary tasks when building
occupants cannot easily relocate themselves or their tasks
Lighting systems and their design 45
• In exterior applications, use fully shielded luminaires that
directs light downwards towards the ground or a building
• Have long been associated with gloss-coated paper, pencil paperwork and computer CRT
(cathode ray tube) screen.
• Indirect lighting, by creating a diffuse and uniform illumination has been advocated as
• Can create specular reflections that can cause glare reducing comfort or disabling the
worker’s vision in particular areas.
• Reflective glare - when system has been optimized to reduce glare – then consider:
• modifying the task to eliminate remaining glare problem such
• as use of flat screen CRT or active matrix.
• Use of ink rather than pencil
• Use of matte-coated or uncoated paper rather than gloss coating paper.
• Changing finishes of polished floors or shiny conference room tables.
Lighting systems and their design 46
Where to place the lighting ?
It can, in the case of lighting close to the wall
(“grazing” rather than “washing”—see
diagram) reveal defects in the workmanship.
Lighting systems and their design 47
ACCENT TASK LIGHTING Lighting systems and their design 48
Working area kitchen
Lighting systems and their design 50
Given the wide choice of different lamps and
luminaires available, there is an almost infinite set of
different arrangements of electric lights within a room
that will provide a certain illumination level.
The primary concern in lighting layout is to avoid glare
on activity surfaces.
Good and bad lighting locations, causing or avoiding
Lighting systems and their design 51
Uniform VS Task lighting
Lighting systems and their design 52
Lighting systems and their design 54
Step 1 – the analysis of quality and quantity of light
Step 2 – Consider colour appearance
55Lighting systems and their design
Decide the colour of ‗white light‘
that best suits the application. This
is referred to as colour appearance
and can be different for each type
of lamp or can vary among models
of the same lamp type. Choosing
the most appropriate colour
‗white‘ can enhance the objects
being lit or the ambience of the
Choose the most efficient light source that can
deliver the desired lighting characteristics
required for the application. While the
efficiency of the light source is a key component
of an energy effective lighting solution, it is only
one of a number of selection criteria. Take a low
pressure sodium lamp as an example; it is a very
efficient light source but its poor colour
rendering characteristics make it unsuitable for
Lighting systems and their design 56
Step 3 – Consider colour rendering
Lighting systems and their design 57
Step 6 – CONSIDER luminaire position and maintenance
Ensure that the luminaires are
mounted to provide effective
illumination and are in accessible
locations without the necessity of
hiring or buying special equipment to
maintain them. The luminaires should
be easy to clean and lamps should be
easily accessible for replacement.
Choose a wide or narrow light distribution
pattern depending on the application. An
office normally requires wide and even
light distribution with good uniformity,
whereas a narrow distribution suits
Lighting systems and their design 58
Step 7 – Consider controls and use of daylight
Lighting controls should provide the
right quantity of light as and when
required. Lighting can be controlled
by time, occupancy and daylight
availability. There are a number of
ways to add controls to existing
lighting installations and
opportunities to maximize the use of
daylight in buildings.
The Layered Approach to Lighting Design
Lighting systems and their design 59
Layer #1 -The Ambient or General Lighting Layer
1. Generally the relatively uniform lighting of the space.
2. Includes uniform down lighting, indirect lighting (up lighting and wall washing), and some
special techniques, but can also be the decorative lighting
3. Called “ambient lighting "if lower than task levels
Lighting systems and their design 60
Layer #2 -The Task Layer
•Generally limited to “task lighting "of the HORIZONTAL WORK SURFACE at work locations.
•Tends to help create drama.
•Usually produces 50 fc or more within a small area.
Lighting systems and their design 61
Layer #3 -The Display or Focal Layer
•Generally limited to accent lighting and similar effects, primarily through VERTICAL AND
OTHER NON-HORIZONTAL SURFACE ILLUMINATION.
•Tends to create drama, with greater drama the result of greater contrast between the
brightness created by Focal Lighting and Ambient Lighting.
•Usually involves key displays at 100 fc or more.
Lighting systems and their design 62
Principles of Wall washing
Fixtures at least 24”out from wall and about 1/4 wall height out from wall
Fixtures apart 1 to 1.5 times the distance from the wall
If you don’t need at least three -you shouldn’t be wall washing
The higher the wall the further out to locate
Lighting systems and their design 63
Accent Lighting Technique
Should be located at about 30 degrees off
vertical relative to focal point
Do not get too close to wall -normally
Use 30-60-90 triangle to determine optimum
Only use lighting systems capable of hitting
above 40 degrees (off vertical) in special
PAR36For high ceilings use a low
voltage 6”recessed luminaire and a 50
watt PAR36 low voltage lamp
Lighting systems and their design 64
Layer #4 -the Decorative or Traditional Layer
•In general, adds the decorative luminaires called for by the architecture/interior design style,
•Is usually expected to contribute to the ambient illumination. In many designs, the
decorative lighting will BE the ambient lighting.
•Usually reduces contrast (drama).
Lighting systems and their design 65
• Lighting Design Basics, May 26-27, 2008 By-James R Benya, PE, FIES, FIALD, LC,BENYA LIGHTING DESIGN
• Lighting technologies
• EFFICIENT LIGHTINGSTRATEGIES
• Home Office
• BUILDING TECHNOLOGIES PROGRAM OFFICE OF ENERGY EFFICIENCY AND RENEWABLE ENERGY • U.S. DEPARTMENT OF ENERGY
• ARTIFICIAL LIGHTING, lecture notes, Dr. Habil. András Majoros
• Natural Lighting Systems-Based on Dielectric Prismatic Film, By Daniel
• Ambient bright light in dementia: Effects on behaviour and circadian rhythmicity J. van Hoofa,, M.P.J. Aartsb, C.G. Rensec, A.M.C.
• Net Zero Energy Buildings
• California Energy Commission’s Public Interest Energy Research Program
• Lighting Design Basics With a Green Touch-James
• IEEE Guide for Direct Lightning Stroke Shielding of Substations
• Benya Lighting Design
• Elements of lighting Design
• US department of energy
• Lighting System Considerations and Design Options for Application
• Advance lighting Guidelines
• NPC Experiences
• Clear advantage lighting
• NYC design + construction
• Lighting System Design – Design Methods Dr. Sam C M Hui
• PG&E's energy efficiency programs and other services
Lighting systems and their design 67