Energy Audit in Building A Regional Training Workshop 1 - 5 June, 2010

1. Energy audit
of
lighting systems
RCREEE Energy Audit in Building
Tunis, 1st – 5th June 2010
1
Muhieddin Tawalbeh - National Energy Research Center

2. Overview
1. Introduction
2. Types of Lamps and Applications
3. Street Lighting
4. Energy Conservation Measures
5. Assessment of Lighting Systems
6. Case Studies
2

3. 1. Introduction
Lighting uses more energy in a
typical commercial office building
than any other single...
This segment is growing due
to plug load, mostly
computers
All Others
Heating
Cooling Lighting
It can vary from 25-50% for office buildings.
It will be less for manufacturing, and more for
warehouses or retail
3

4. Break-up of your lighting cost
over 15 years:
Maintenance
Energy Lamps
15 years
Fixtures and
Installation
Energy is by far the largest cost in
owning and operating a typical
lighting system 4

5. All Other Lighting
Heating
Cooling
Cooling Savings Lighting
Savings
lighting energy savings of 30% to 50% are
common,
and additional cooling savings are also often
realized 5

6. • A rule of thumb is 10-15% reduction in
HVAC use with more efficient lighting
systems*
• For new construction applications, you
may also have significantly smaller
HVAC tonnage, reducing construction
costs by tens of thousands of dollars
• *actual HVAC energy savings are, of course, highly
dependent upon the local climate and the design and
operation of the given building
6

7. Basic Theory
• Light: electromagnetic
waves in space
• Light is emitted through:
a) Incandescence
b) Electric discharge
c) Electro luminescence
d) Photoluminescence 7

8. There are two basic kinds of
light:
Light that comes to our eyes directly from
a light source (illuminance)
(
such as fire, the sun, or a light bulb
Light that is reflected off of something
else before it reaches our eyes
(luminance)
• such as the walls of a room, the surfaces of
grass and trees, or the earth’s atmosphere
8

9. To measure quantity of
light from a source
The total light output of a source is measured
in lumens.
• Historically, a lumen was the amount of light from
one candle which fell on one square foot of area,
one foot away from the candle.
Our historic “standard” candle produces 12.57 lumens
A four foot fluorescent lamp produces about 3000 lumens
Your standard 60 Watt light bulb (incandescent)
produces about 900 lumens
One foot One lumen of light falls on a surface one foot
square, which is held one foot away from the
candle.
9

10. To measure the quantity of
light striking a surface
We speak in terms of illuminance,
measured in
• Lumens per square foot,
other wise known as footcandles (fc)
• or, Lumens per square meter
otherwise known as Lux (lx)
These are the common measurements
made by a light meter
One foot-candle = 10.76 lux
10

11. Efficiency Terminology
Efficiency is a ratio of similar inputs to
outputs
• Luminaire efficiency measures the ratio of
the total lumens which exit from the
luminaire to the total lumens emitted by
the lamps within a luminaire
• It is expressed as a percentage
Efficacy is a ratio of input energy to
output results
• Like miles per gallon
• We measure lamp efficacy in lumens per
watt 11

12. Remember, Every Lighting
Application has 3 Elements:
The Source is all the hardware
• This is what most people think of The
as the lighting system, Surface
• but just as important are…
The Surface The
• which is the room environment Sourc
e
and The Purpose
(to read this)
whatever you are looking at
The Purpose
• The reason you need the light.
• The activities or tasks that people
are doing that require certain 12
visual conditions

13. The Color Rendering Index (CRI)
CRI gages the relative ability of lamps to
render a full range of subtle colors
100 = “perfect”
Incandescent lamps are used as the 90-99 = superlative
reference standard for very “warm” 80-89 = very good
sources, and daylight for cooler sources. 70-79 = good
• They are assigned an index of 100 (the 60-69 = fair
highest) 50-59 = marginal
Even though they don’t have “perfect” color <50 = poor
rendering abilities themselves
For example, incandescents are very poor at
rendering blues
• Other light sources are judged
in comparison
CRI has many limitations
but, it’s the most useful, and widely used, color
indication system we have 13

14. Color Temperature
Some light sources seem “warm”. They
are very rich in red light.
However, they mimic the light created by a low temperature
flame, like a candle.
Hence, “warm” lights are called low color temperature
sources.
Some light sources seem “cool” or “cold”.
They are very rich in blue light.
However, they mimic the light created by an intensely hot,
blue flame.
Hence, “cool” lights are called high color temperature
sources.
14

15. Common Color Temperatures
CCT CRI
Candle light 1800K 100 CRI
Daylight (Note that the color temperature of daylight changes
throughout the day)
• Sunrise, Sunset 3000K 100 CRI
• Noon sun and sky 5500K
100 CRI
• Cloudy day 7500K 100 CRI
• North sky only (no sun) 10,000K
100 CRI
Incandescent lamps
• Edison era carbon filament 2400K
100 CRI
• Modern tungsten filament 2800K
100 CRI
• Tungsten halogen lamp 3100K 100 CRI
• Theatrical halogen lamp 3200K 100 CRI
• Photoflood lamp 3400K 100 CRI
15

16. Incandescent lamps give off light at In this slide, fluorescent light sources
2700 Kelvin, which is very warm. at 4100 Kelvin (4100K) create a
crisp, cool appearing space.
Photo courtesy: IES
16

17. 2. Types of Lamps
17

18. Basic families of common
commercial lamp types
1.) Incandescent
2.) Fluorescent
3.) High Intensity Discharge
4.) LED
18

19. The Incandescent Lamp
Electricity flows through a coiled wire,
called a filament. As it does, it heats the
filament , causing it to emit white light.
The lamp is filled with an inert gas, usually
argon, to prevent oxidation of the filament.
The base can be one of many different
types and sizes. The most common is the
medium base, also called the Edison base.
19

20. Incandescent Lamp Shapes
There are many incandescent lamp Note the most
familiar “A” lamp
shapes, each serving a specific
purpose.
The bulbs are typically made of an
ordinary hard glass which can
break. Some lamps, like the PAR
lamp, are resistant to breaking as
well as to water and temperature.
Special lamps, like rough service
lamps, are beefed up to survive in a
hostile environment. Teflon coated
lamps will break but stay together
20
like a soft boiled egg.

21. Color Characteristics
& Efficacy
Standard incandescent lighting is familiar to us all as
the typical residential “light bulb”
• It has a “warm” orange glow
Because it puts out most of its light in the orange and red parts of
the spectrum
It is very deficient in the blue and purple wavelengths
• It is used as the reference standard (CRI=100) for other
light sources at similar color temperatures (2500-3000K)
• Incandescent Efficacy 10-20 lm/W
•
21

22. A more efficient incandescent
lamp
Halogen technology allows the filament
to run at a higher temperature than
regular incandescent lamps
• This produces a “whiter” light
• This is also more efficient, producing more
visible light and less heat per watt of input
22

23. Fluorescent Lamps
23

24. What is a Fluorescent
Lamp?
Arc
In a fluorescent lamp, an electric current
passes in an arc, like lightning, through an
inert gas (argon or krypton).
The arc emits radiation in the visible and UV
ultraviolet bands.
The inside of the lamp’s glass tube is Visible
Lamp
coated with phosphorescent minerals wall
which fluoresce (emit visible light) when
struck by the UV light.
The combination of minerals, or phosphors,
determines the lamp’s color temperature Visible
and CRI.
24

25. Tube Size Matters
T-12 = 1 1/2 inch diameter Because fluorescent
lamps are virtually always
tubes of some shape, the
bulb style is called “T”
T-10 = 1 1/4 inch diameter (like tubular, man!)
followed by the lamp
diameter in 1/8’s of an
T-8 = 1 inch diameter inch.
The diameter of the tube
effects cost of production
T-5 = 5/8 inch diameter (less material = less cost
to manufacture and ship)
The smaller diameter tubes also tend to have higher light output
per unit of surface area . Whereas the eye can look comfortably
at a bare T12 bulb, the light from a T5 can be more intense and 25
glaring.

26. Main Shapes of
Fluorescent Lamps
The ends of standard T-8
Full size lamps lamps: The black ended
Linear with bases on each lamp with 1 pin is the
F96T8 59-watt instant start
end lamp; the others are
2 feet to 8 feet long standard rapid start T-8
lamps with medium bi-pin
4 to 215 watts bases.
U-bent lamps
Straight lamps bent Various T-8 U-bent lamps:
into a “U” The industry standard, 6”
leg spacing lamp is made
Just a few types by all manufacturers - only
Compact Fluorescent one company (Osram
Sylvania) currently makes
Lamps (CFL) the narrow legged U-
4 to 32 watts lamps shown with it.
Lots of shapes
26

27. Lamp Nomenclature 48”
Here is General Electric’s product number for a standard, 32 watt,
T-8 lamp with high CRI and 3500K color temperature:
F for
F32T8/SP35 Lamp color:
SP means
fluorescent special for a
high CRI (70+)
35 refers to
Either 3500K
Watts or
nominal T for tubular
length in
inches
The equivalent Philips product is F32T8/TL735
Lamp
diameter The equivalent Osram Sylvania product is
in 1/8’s of
an inch FO32/735 Hint: the “O” means
“Octron”, their name for T-8
27

28. Electronic Ballasts
Electronic ballasts employ analog or digital circuits which
rectify the AC power to DC current
• then generate AC at very high frequency
typically between 20 and 100 kHz.
• Regulation of lamp current utilizes electronic circuits
which offer superior lamp management
Some electronic ballasts are “smart” and can sense
incoming voltage and different lamp types.
Inside an electronic ballast, there are
smaller transformer windings and,
various electronic devices. As a
general rule, the simpler, the more
reliable. Modern electronic ballasts are
quite reliable.
28

29. Compact Fluorescent Lamps
Photo courtesy: EPRI
Compact fluorescent lamps represent the single greatest
area of product innovation in recent lighting history
29

30. Induction lamps - A Type of CFL
Operating principles
• These are basically compact fluorescent
lamps whose phosphors are energized by
magnetic waves rather than an electric
discharge
Photo courtesy: Philips
• Sometimes called “electrodeless”
thus, there is no electrode to fail, or
cause sparks
Pros and Cons
• Induction lamps last much longer than
Photo courtesy: Osram
ordinary lamps, 20,000 hours up to
Current Products 100,000 hours!
Phillips “QL” lamps, 55 • Lamps are relatively insensitive to
and 85 watts temperature
GE “Genura” 23 watts • Lamps can be dimmed easily
Osram Sylvania, 100 and
150 watts • Lamps are expensive
• Shielding from radio waves needed 30
• Inductor may fail before lamp

31. High Intensity
Discharge
Lamps
31

32. What are High Intensity Discharge Lamps?
High intensity discharge (HID) lamps are electric
lamps in which light is created by the radiation from
a very compact electric arc.
The arc occurs in a vessel, or arc tube, that is
designed specifically for operation at high pressure
and high temperature.
This is primarily what differentiates HID lamps from
low pressure discharge lamps like fluorescent.
The arc tube is filled with a noble gas and small bits
of metal, whose vapor is energized by the arc and
gives each lamp type its characteristic color.
32

33. Principal types of HID lamps
Mercury Vapor Mercury vapor lamps emit white light with
exaggerated green and blue, tending to be
HID lamps using mercury as the
metal vapor. An older, less efficient deficient in red. Phosphor coating helps
technology, rarely used indoors improve red performance.
anymore
Metal Halide Metal halide lamps emit white light, the
HID lamps using a number of different spectrum of which can vary depending on
metals, including mercury, indium, metals and arc tube type. Phosphor
thallium sodium and others. Made in coating is sometimes used to improve red
both clear and phosphor coated lamps performance.
High Pressure Sodium High pressure sodium lamps emit
HID lamps employing sodium as the yellowish-white light which is generally
metal vapor. Made in clear and deficient in blue, green and red hues.
diffuse coated lamps Certain HPS lamps can emit improved
color. Diffuse coating does not alter
color.
33

34. Metal Halide (MH) Lamps Similar to MV with the
addition of some iodides of
metals like Thallium, Indium,
and Sodium
Long starting and restarting
Special
times
long arc Produce high levels of UV
MH lamps radiation
used in Color shifting can occur
Efficacy range is 75-125
scientific lumen/watt
and
photographi
c process Standard mogul
equipment based high wattage
MH lamps
Photo courtesy: EPRI
Bent arc tube, horizontal
Standard medium based
Compact high CRI, MH lamps burning position high
low wattage lamps
output mogul based lamps
VERY GOOD ENERGY EFFICIENCY LIGHTS
34

35. High Pressure Sodium (HPS) Lamps
Currently HPS lamps are the
most popular lamp for lighting
streets, factories, and other
heavy duty lighting where
color discrimination is not
considered important.
Watts range from 35 to 1000.
• Sodium lamps use no phosphors and emit no UV radiation
• Sod. atoms emit visible light, mostly in the longer wavelength
• PA cylinder transmits 90% of visible light created inside it
• Performance is very sensitive to gas pres. inside the arc tube.
• Quality of light may significantly reduce their effective efficacy 35

36. Mercury Vapor
•Similar to fluo. lamps but •Makes the most sense where
have lower efficacy(30-65) relamping access is difficult.
•long life, low initial cost, and •They emit more UV radiation than
color stability fluorescent
•Mercury is pressurized 30-60
psi creates more V. light
POOR CHOICE FOR ENERGY EFFICIENCY
36

37. Electronic Ballasts and Dimming
Electronic ballasts are beginning to
become common in the 39,70 and 100
watt sizes for standard lamps
Some specialty HID lamps work only with
electronic ballasts
HID lamps can be dimmed to save energy
Just like incandescent lamps, dimmed HID lamps
are not as efficacious as lamps run at full power.
Also, HID lamps experience a color shift when
dimming that is generally not appealing
But dimming can save considerable energy when
daylight is available or other reasons exist to dim 37

38. HID Lamps and Color
Lamp Family Color temperature CRI
Standard clear metal halide (175-400w) 4300 65
Standard coated metal halide (175-400w) 3700 70
3K Coated metal halide (175-400w) 3000 70
Standard clear metal halide (1000 w) 3400 65
Standard coated metal halide (1000w) 3400 70
Standard clear metal halide (50-150w) 3200 65
Standard coated metal halide (50-150w) 3200 70
“Warm” ceramic metal halide (39-150w) 2900 85
“Warm” ceramic metal halide (39-150w) 4100 85
Compact source iodide (CSI) 4300 85
HMI (film/theater lamp) 5500 92
Clear mercury vapor 4700 33
Coated mercury vapor 4100 50
High pressure sodium 2100 21
Deluxe high pressure sodium 2200 65
White sodium 2600 85
38

39. LED Lamps
• Newest type of energy efficient lamp
• Two types:
• red-blue-green array
• phosphor-coated blue lamp
• Emit visible light in a very narrow spectrum and
can produce “white light”
• Used in exit signs, traffic signals, and the
technology is rapidly progressing
• Significant energy savings: 82 – 93%
• Longest lamp life: 40,000 – 100,000 hours
39

40. Comparing lamps
Lum / Watt Color
Type of Lamp Rendering Typical Application Life (Hours)
Range Avg.
Index
Incandescent 8-18 14 Excellent Homes, restaurants, 1000
general lighting,
emergency lighting
Fluorescent Lamps 46-60
46- 50 Good w.r.t. Offices, shops, hospitals,
w.r.t. 5000
coating homes
Compact 40-70
40- 60 Very good Hotels, shops, homes, 8000-10000
8000-
fluorescent lamps offices
(CFL)
High pressure 44-57
44- 50 Fair General lighting in 5000
mercury (HPMV) factories, garages, car
parking, flood lighting
Halogen lamps 18-24
18- 20 Excellent Display, flood lighting, 2000-4000
2000-
stadium exhibition grounds,
construction areas
High pressure 67-
67- 90 Fair General lighting in 6000-12000
6000-
sodium (HPSV) SON 121 factories, ware houses,
street lighting
Low pressure 101-
101- 150 Poor Roadways, tunnels, canals, 6000-12000
6000-
sodium (LPSV) SOX 175 street lighting 40

41. Designing with Light
Recommended light levels for different tasks (BEE India, 2005)
Illuminance level (lux) Examples of Area of Activity
General Lighting for 20 Minimum service illuminance in exterior circulating
rooms and areas areas, outdoor stores , stockyards
used either
50 Exterior walkways & platforms.
infrequently
and/or casual or 70 Boiler house.
simple visual tasks 100 Transformer yards, furnace rooms etc.
150 Circulation areas in industry, stores and stock rooms.
200 Minimum service illuminance on the task
300 Medium bench & machine work, general process in
chemical and food industries, casual reading and
filing activities.
General lighting for 450 Hangers, inspection, drawing offices, fine bench and
interiors machine assembly, colour work, critical drawing
tasks.
1500 Very fine bench and machine work, instrument &
small precision mechanism assembly; electronic
components, gauging & inspection of small intricate
parts (may be partly provided by local task lighting)
Additional localized 3000 Minutely detailed and precise work, e.g. Very small
lighting for visually parts of instruments, watch making, engraving. 41
exacting tasks

42. Daylight
42

43. Daylighting
The practice of using
windows, skylights, and other
forms of fenestration to Photo courtesy: Jeff Anderson
bring light into the interiors
of buildings
And, the use of automatic
photo-controls to turn off
unnecessary electric lighting
Photo courtesy: Jeff Anderson
43

44. Benefits of Daylighting
Positive human response
Excellent light quality
• Flicker-free, scotopically rich, full spectrum light
source
Positive energy impacts
• More illumination than electrical lighting
systems per cooling load
Lessens pressure on cooling load
• Savings coincide with summer energy peaks
5% -70% lighting load reductions
• But only with functioning photo controls 44

45. Skylighting can
provide excellent
uniform
illumination in
single story
buildings
45
Photo courtesy: Lisa Heschong

46. Balanced daylight from skylights and
windows in a
classroom
Note luminaires run parallel to windows,
and are turned off!
Photo courtesy: Kalpana Kuttahiah
Photo courtesy: Kalpana Kuttahiah
46

47. Light ( Lumens )
Luminous Efficacy =
Heat (Watt )
Higher efficacy = less cooling loads for same light
Daylight outside has higher efficacy than all electric
light sources
Daylight inside of high performance glass has even
higher efficacy
• High performance glass = glazing filters out more heat (low
SHGC) than light (high visible transmittance)
47

48. Luminous Efficacy
Indoor Daylight with
of Light Sources “High Performance”
Glazing
140
120
100
Outdoor
Outdoor
Outdoor
Lumens/Watt
80
60
40
20
0
Clear Sky
HPS
Sunlight
Overcast
Incand
EE Mag
Electronic
Metal Halide
Sky
48

49. 3. Street Lighting
The operation of street lighting
consumes a significant amount of
energy, particularly when considered
a community, regional, Provincial or
country level. It consumes 2-5% of
the total country’s electricity
consumption
49

50. Original Lamp New Lamp Type Energy saving per Effect on Ra Effect on Effect on Notes
Type lamp replaced light levels lamp life
(including control
gear savings)
250W mercury 150W high-pressure %37 - + +
vapour sodium.
250W mercury 150W metal halide %37 + + -
vapour
400W mercury 250W high pressure %35 - + +
vapour sodium
400W mercury 250W metal halide %36 + - - If reduction
vapour in light
levels is
acceptable.
50W mercury 26W compact %50 + No change +
vapour fluorescent lamp
(triphosphor(
80W mercury 42W triphosphor %48 + No change +
vapour fluorescent lamp
50W high 35W metal halide %28 + - - If
pressure sodium reduction
in light
levels is
acceptabl
70W high 70W metal halide No change + + - Key benefits
e.
pressure sodium are
improvemen
t in colour
Lamp Replacement rendering
50
ability and
light levels.

51. Illumination can be dimmed according to traffic density or the time of night.
- Less energy consumed.
- Lamp life is increased.
Dimming and part-night lighting is controlled by timetables.
Detection of defective ballast components causing energy wastage.
51

52. Intelligent Street Lighting
52

53. (30)
(1)
53

54. 54

55. Voltage Regulators
55

56. Electronic Ballasts
56

57. Astronomical Switch
57

58. Lamp Control Unit
58

59. Expected Results
Electricity saving: It is expected
to save around 30-40% which
results in annual cost savings of
about JD 1.8 million
Emission Reduction: it is
estimated to reduce CO2
emission by 63000 ton annually.
Awareness increase
Fuel Import: The project will lead
to a reduction in fuel imports by
22000 T.O.E annually.
59

60. 60

61. Savings measures
Replacing inefficient lamps: More efficient lamps allow you to save
energy while maintaining or improving light levels. If you decide to replace
your lamps you will often need to change the control gear as well.
Reducing the number of lamps operating: Reduce lamp numbers and
maintain lighting levels by using more efficient lamp types.
Reducing operating hours: Use daylight sensors or time clocks to ensure
that lamps only operate when required.
Replacing inefficient switching equipment: Replace outdated cadmium
sulphide light photo sensors with electronic sensors.
Changing type of energy used: Consider use of solar energy. This can be
an attractive option in some specialist applications.
Improving maintenance practices: Lamps fail at fairly predictable
intervals, so planned, mass-replacement of lamps is a good option and
can be less expensive than spot replacement. Lenses should be kept free
from dirt to ensure that light output is not reduced.
Improving data management: Energy management and other asset
management tasks will be simplified if records of lamp and luminaire
types are kept up to date. Commercial software is available to assist in
data management. It's also important to know how much you are paying
to run your street lights, and how the energy costs are calculated.
61

62. Energy Conservation Measures
•Reduce General lighting
•Reduce/Control Unnecessary lighting
•Use High Efficiency Lighting Equipment
•Maintenance
•Daylighting
•Lighting Retrofits
62

63. …how do we know how much light
we actually have?
…or how much light we are going
to get?
• we will talk about measuring
existing lighting conditions,
• and calculating average lighting
conditions
and how and why these two
might differ…
63

64. we measure light
Illuminance Meters are relatively inexpensive at from $50 to
$500.
• They measure incident illumination on a small integrating sphere,
and report in footcandles or lux
• Nice features for a good meter include: Illumination meters, also called
a protective cover and/or case light meters or footcandle
meters, are the most
two or more sensitivity scales common
a hold button to freeze a reading
a remote measurement head that allows you to
take readings at a distance from your body
64

65. Reduce General Lighting
• Measure Light levels to minimum required.
• Reduce artificial Lighting
• Use task Lighting
• Lower the Mounting Height of lamps
• Clean lamps and luminaries regularly
• Clean walls, Ceilings and other reflecting surfaces
• Disconnect ballast were lights have been eliminated
• Set up group re- lamping program
65

66. Reduce/Control or
Unnecessary Lighting
•Turn off lights when they are not in use
•Review light switches to allow more localized
control of lighting
•Rewire light switches to allow more than one
level of lighting
•Use occupancy sensors in areas not
permanently occupied
66

67. Lighting
Controls
67

68. Why Control Lights?
To save energy
• by turning them off, or dimming them down
when there is sufficient daylight
when no one is around
To tailor light levels to specific needs
• accommodate changing uses in the same space
• let each worker optimize their space
To create different moods in the same
space
• especially for hotels, restaurants, and function
rooms
68

69. How Lighting Controls Save Energy
Since electrical energy consumption is measured in
kilowatt hours, there are two ways to save energy:
Reducing
power,
Energy = Watts x Time
or reducing
hours
69

70. Lighting Control Strategies
Manual Controls Automatic Controls
• Simple switching • Timers
• Bi-level switching • Occupancy Sensors
• Dimming Passive Infrared
Ultra sonic
• Photo- sensor Controls
Open loop vs. Closed loop
Switching vs. Dimming
Adaptation Compensation
• Demand Management
70

71. Fluorescent Switching Myths
Myth #1: “Fluorescent Lamps last longer
if they are left on.”
• It’s true that the burning hours of lamps are
reduced with switching, but not necessarily the
calendar life of the lamps.
• Furthermore, the electricity savings quickly
compensate for increased lamp replacement costs
The economic break-even point is typically between
5 and 15 minutes depending upon electricity rates
and lamp replacement costs.
The same applies to HID lamps, but the break-even
point is around one hour between switching.
71

72. Fluorescent Switching Myths
Myth #2: “Leaving Fluorescent Lamps
on saves more energy than turning
them off.”
When first turned on, the inrush current is 10 to
40 times higher than the normal operating current
But the inrush lasts only 10 milliseconds!
Current
1 second of the lamps being off saves as much
energy as is consumed during inrush
10 msec
Time
72

73. Manual Dimming
It is easy to dim incandescent lamps
• Just add a rheostat to reduce the power to socket
To dim a fluorescent lamp a special dimming ballast
is required
• Dimming electronic ballasts are coming down in price, but
they are still more expensive than regular electronic ballasts
• Fluorescent lamps need to be operated at full power
initially before they can be successfully dimmed
• The reduction in power is not as great as the reduction in
light output, therefore efficiency declines somewhat with
dimming
73

74. Timers
Timing controls vary from extremely simple to
very sophisticated
• The simplest, mechanical twist timer allows user to
chose an extra ten minutes to two hours of light
• Automatic schedulers can be under individual or
centralized control
• Programmable and astronomical clocks are more
expensive, but can predict sunrise and sunset
throughout a year, accounting for daylight savings
times, vacations, shift changes, leap year, etc.
74

75. Time Control: Using a Central System
Energy Management Systems (EMS) have
been used commonly to control HVAC
systems for large buildings
• EMS can also be used to control lights from
a central or remote location
Two features are essential to
success:
• A warning that the lights are about to go out
• Local overrides that allow people to keep the
lights on, or choose levels different from
defaults
75

76. Automatic Time Control:
Unpredictable Schedules
What do you do when
people come and go at
their own schedule?
Motion Sensors!
Originally developed by
the security industry, Photo courtesy: EPRI
they now commonly Ceiling mounted Wall mounted
control lights
76

77. Motion Sensors - Basic Types
Passive Infrared Sensors Ultrasonic Sensors
• A sensor receives infrared light • The sensor emits a very high pitched
(heat) from multiple directions, sound, and then listens for changing
and registers changes in the echoes
pattern just like a little bat
• People and animals are warm, • Motion creates waves of different
and move around a lot, so they frequency due to the Doppler effect
are generally easy to spot • HOWEVER: the sensor may also
• HOWEVER: the sensor must be detect motion of non living objects
able to “see” the motion
There is also a Dual Mode sensor which is designed to use the best of both types,
and it usually costs twice as much, too.
77

78. Motion Sensor Savings
Energy savings are highly dependant
upon the occupancy patterns of the
rooms they control
Tips:
• In bathrooms, leave some of the lights always on so that
there is never total blackness
• Conference rooms are excellent candidates because they
are used intermittently and no one “owns” the space,
taking responsibility for the lights
78

79. Photo sensor Controls
There are several ways to use photo sensor
controls to save energy:
• Switch exterior lights on at sunset and off at sunrise.
• Switch or dim lights during the day in areas where
there is adequate daylight.
• Dim lights at night in lobbies and transitional areas
where people’s eyes are adapted to the darkness
outside.
79

80. Photo sensor Devices
A photocell is an electronic element which
turns light energy into electric energy.
A photoswitch uses a photocell to operate
an on-off switch. Photo switches are
commonly used to control outdoor
lighting.
A photosensor uses a photocell to generate
a continuous signal which can be
interpreted by a controller to change
lighting levels by switching or dimming.
80

81. Daylighting
Photo sensors can be used with any combination of:
• simple switching or multi-level switching --any lamp type
• step (or two level) ballasts --fluorescent or HID
• continuous dimming ballasts --fluorescent
There are two main photo control strategies:
• Closed Loop - the sensor integrates the contribution of
both daylight and electric light inside the space
• Open loop - the sensor measures daylight only, either
inside or outside the space
81

82. Use High- Efficiency Lighting
Equipment (Retrofit or New)
∗Use higher- efficiency, lower wattage lamps in existing fixtures
∗Convert to more efficient light sources (Fluorescent, MH, SV)
∗Use high efficiency or electronic ballast instead of standard ballast
∗Use high efficiency luminaires, such as mirrored reflectors or
thermally controlled fixtures
∗Eliminate inefficient lamps from company stocks
82

83. Reduction of Lighting Feeder Voltage
• Can save
energy
• Provided drop
in light output
is acceptable
83

84. Assessment of Lighting Systems
Designing with Light
• Better lighting: increased productivity
• Two main questions for designer:
• Choose correct lighting level
• Choose quality of light (color rendering)
84

85. Assessment of Lighting Systems
Recommended light levels for different tasks (BEE India, 2005)
Illuminance Examples of Area of Activity
level (lux)
General Lighting for 20 Minimum service illuminance in exterior circulating
rooms and areas used areas, outdoor stores , stockyards
either infrequently
50 Exterior walkways & platforms.
and/or casual or simple
visual tasks 70 Boiler house.
100 Transformer yards, furnace rooms etc.
150 Circulation areas in industry, stores and stock rooms.
200 Minimum service illuminance on the task
300 Medium bench & machine work, general process in
chemical and food industries, casual reading and filing
activities.
General lighting for 450 Hangers, inspection, drawing offices, fine bench and
interiors machine assembly, colour work, critical drawing tasks.
1500 Very fine bench and machine work, instrument & small
precision mechanism assembly; electronic components,
gauging & inspection of small intricate parts (may be
partly provided by local task lighting)
Additional localized 3000 Minutely detailed and precise work, e.g. Very small
lighting for visually parts of instruments, watch making, engraving. 85
exacting tasks

86. Assessment of Lighting Systems
Methodology for Efficiency Study
• Step 1: Make inventory of lighting system
elements and transformers
Table: Device rating, population and use profile
Lighting Rating in Use / Shifts as
Plant
S. No. Device & Watts Lamp Numbers I / II / III shifts /
Location
Ballast Type & Ballast Day
86

87. Assessment of Lighting Systems
Methodology for Efficiency Study
• Step 2: Measure and document the Lux levels
• Step 3: Measure and document the voltage and
power consumption at input points
• Step 4: Compare the measured Lux values with
standard values as reference
• Step 5: Analyze the failure rates of lamps,
ballasts and the actual life expectancy levels
87

88. Assessment of Lighting Systems
Methodology for Efficiency Study
Step-6 : identify improvement options, for example:
• Maximum sunlight use options through
transparent roof sheets
• Replacements of lamps and ballasts to more
energy efficient types
• Selecting interior colors for light reflection
• Modifying layout as per needs
• Providing individual / group controls for
lighting
• Use Task Lighting 88

89. Example
A hospital had 415 (2x40) watt fluorescent fixtures,
which operate 24 hours/day, year around. The lamps
and ballasts were replaced with (2x36) watt and
electronic ballasts.
Assume:
Power consumption for magnetic ballast equals 15 watt
and electronic ballast 5 watt.
36 watt lamp saves 10% of energy
Electronic Ballast price =$15
36 Lamp price = $1.5
Utility price =0.07 $/kWh
Calculate:
Reduction in Demand KW
Energy Saving; kWh and cost saving
Payback Period
Ignore labor cost
89

90. Demand Reduction = 415 x (2x(40+15)- (2x36+5))/1000
= 13.7 kW
Energy Saving = 13.7 x 8760
= 120012 kWh
Energy Cost Saving = 120012 x 0.07 $/kWh
= $ 8400
Electronic Ballasts Cost = 415 x $ 15
= $ 6225
New Lamps Cost = 415 x 2 x $ 1.5
= $ 1245
Total Retrofit Cost = $ 7470
Simple Payback = 0.9 years
90

91. Case Study 2
Saudi Arabia
Investment Saving Payback
(Rial) (Rial) (Year)
987,000 176,250 5.6
91

92. Case Study 1
Street Lighting in
Irbid City
No. of Invest. Exist. Expected Saving Pay % of
Lamps Needed Consum Consum Back Savin
JD p. p. JD year g
GWh GWh
2080 374,40 10.4 6.2 139,68 2.68 40%
0 0 2
92

93. Case Studies- EE Measures
Distribution of lighting Numbers, Movinpic (Deadsea)
Number of lighting Lamps
CFL's
Floodlights & 27%
Others
2%
Flourescent lamps
5%
Incandescent
17% Halogen
49%
93

94. Case Studies- EE Measures
Savings-Lighting: Movinpick (Deadsea)
Annual
Annual Cost Investment Pay Back
Energy
Item saving
saving Required Period
(JD) (JD) (Year)
(kWh)
Replacement of
Conventional Ballast by
79182 4988 6651 1.3
Electronic Ballast for
fluorescent lamps
Replacement of 35 watt
by 20 watt Halogen 47786 3011 1091 0.4
Lamps
Replacement of 25 watt
incandescent lamps by 7 watt 177245 11167 4093 0.37
Compact Fluorescent lamps
Total 304213 19166 11835 0.62
94

95. Case Studies- EE Measures
Savings-Lighting: Four Seasons
Annual Annual
Investment Pay Back
Energy Cost
Required Period
Item saving saving
(JD) (Year)
(kWh) (JD)
Replacing of halogen
lamps 149,796 9,437 1387 0.1
Replacing of Incandescent
293,054 18,462 5845.5 0.31
lamps
Use of occupancy
98,550 6,200 Nil immediately
sensors at Ball Rooms
Total 541,400 34,099 7232.5 0.3
95

96. Thank You
96