EFFICIENT LIGHTING
FROM LAMPS TO FIXTURES
Muji Mujahid & Chris Kreuter
FIVE ELEMENTS
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LAMPS
FIXTURES
CONTROL SYSTEMS
LIGHTING DESIGN
COST FACTOR
LAMP EFFICIENCY
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INCANDESCENT
HALOGEN
FLUORESCENT – COMPACT
FLUORESCENT – T8/T5
HIGH PRESSURE SODIUM
METAL HALIDE/CMH
LEDS
17 Lm/W
25-34 Lm/W
40-60 Lm/W
80-105 Lm/W
120-140 Lm/W
100-140 Lm/W
100-160 Lm/W
Lamp Efficiency – other factors
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Lm/W
Life
CRI Lumen Maint Cost $
Incandescent
17
1000
100
75-80
1-2
Halogen
24-35
2-3000
100
80-85
3-10
Fluorescent –Compact 40-70
10-15000 70-80
85
2-4
Fluorescent – T8/T5
90-105 20-35000 70-90
90
2-10
High Pressure Sodium 120-140 30-40000 60-70
80
15-30
Metal Halide
100-120 15,000
50-75
80
15-50
CMH
90-120 25-35000 80-90
90
18-40
LED
100-160 70000(L70) 80-95
90
15-25
FIXTURE EFFICIENCY
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DOWN LIGHTING
TROFFERS/LOUVERS
HIGH BAY
OUTDOOR FLOOD
LINEAR
LED FIXTURES
CONTROL SYSTEMS
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MOTION DETECTORS
PHOTOCELL – DAYLIGHT HARVESTING
DIMMING
EFFICIENCY INCLUDING BALLAST AND DRIVERS
TOTAL SYSTEM CONTROL
“A” LAMP REPLACEMENT
• 60 Watt – LED 12. 5 Watts 25,000 hrs 80 CRI
(82 Lm/Watt)
• 100 Watts – LED 22 Watts 25000 hrs 80 CRI
(85.8 Lm/Watt)
T8 FLUORESCENT TO LED
• 54-60 Watts to 20 Watts – 50,000 hrs, 60 %
• 40 Watts to 15 Watts – 50,000 hrs, 60 %
Under Cabinet Lighting - LED
Outdoor Flood Lighting - LED
Outdoor Flood Lighting - LED
LAMPS FOR LANDSCAPING
• 20 Watts Spot – Halogen to LED – 3 Watts
• 36 Watts Spot – Halogen to LED – 6 Watts
• 50 Watts Spot – Halogen to LED – 9 Watts
COST FACTORS
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UPPER END LIGHTING FIXTURES
MEDIUM RANGE
LOWER END
IMPACT OF COST ON NEW INSTALLATIONS
NEW TECHNOLOGIES
• OLED
• LASER DIODES
Organic light-emitting diode
Construction of a Luminaire
200 lumens-per-watt prototype LED lamp is the world’s
most efficient
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Progress in the LED lighting industry can best be measured in two separate metrics: pricing and efficiency. Pricing gets
most of the attention, but so many factors affect it — from the cost of materials to various subsidies — that it is primarily
interesting as an overall trend. Efficiency, which is measured in terms of lumens-per-watt, is a better way to look at
progress. It too depends on multiple factors (including the price of more expensive components) but the industry’s steady
increase in lumens-per-watt (lpw) is a less adulterated indicator of advances in technology and design.
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In keeping with these advances, today Philips announced that they have created the world’s most efficient warm white
LED lamp. The prototype operates at 200 lumens-per-watt, a number that is more than double what is found in typical
household LED products. The “warm white” part might seem like a minor detail, but it’s actually rather important. The
majority of people prefer their indoor lighting to be at warm white, usually 2700K, so gaining efficiency at this color
temperature matters. Raising the color temperature is an easy way to increase efficiency (less color shift is necessary), so
hitting 200 lpw with a 5000K lamp would be less of an accomplishment.
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In the release Philips noted that the new TLED (tube-style light) does not compromise on light quality and that this is going
to be a product for the real world. These are lighting industry code words for a CRI of above 80, color temperature of
around 2700-3000K, and a respectable light pattern. At this point, this is likely more reflective of their goals than it is the
current prototype.
III-nitride LEDs vs. laser diodes (LDs)
Power Conversion Efficiency
1
LED more LD more
efficient efficient
0.8
air
Silicone
l~450 nm
LED
n-GaN
MQWs
p-GaN
Ag mirror/contact
0.6
Lumileds LED
0.4
LD
Osram LD
Valley of droop
contact
p-GaN
p-AlGaN clad
MQWs core
n-AlGaN clad
0.2
0
0
5
10
15
20
25
30
GaN substrate
contact
Input Power Density (kW/cm2)
J. J Wierer, Jr., D. S. Sizov, and J. Y. Tsao, “Comparison between blue lasers and lightemitting diodes for future solid-state lighting,” to be published in Lasers and
Photonics Reviews (2013).
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After threshold LDs are not affected by efficiency droop.
LDs are more efficient at higher input power densities.
Color rendering of a laser white source
A. Neumann, J. J. Wierer, Jr., W. Davis, Y. Ohno, S. R. J. Brueck, and J.Y. Tsao, Optics Express,
19, A982, 2011.
• Only slight preferences when comparing LD and
traditional sources.
• LD white is a good color rendering source. Why?
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High Luminous efficacies of radiation
FWHM=50nm
FWHM=100nm
FWHM=10nm
FWHM=2nm
• Spiky sources give highest luminous efficacies of radiation (lm/W)
• Red/yellow power varied to give CCT=3800, Ra=85
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LD has improved directionality
LED
laser diode
G-LEDs
Useful
flux
Source
area
NoWasted
wasted
flux!
flux
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q
B-LEDs
R-LEDs
LD white examples
2005 Nichia
2012 BMW
Fiber light
headlight
2011 Sandia/UNM
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