This document provides an overview of energy auditing techniques for lighting systems in small commercial facilities. It discusses lighting concepts, common lighting system components, lamp types, and strategies for evaluating lighting efficiency opportunities. The goal is to help energy auditors understand lighting systems and identify areas for potential energy savings through lighting upgrades, controls, or retrofits. Key areas of focus include lighting power density, lamp efficacy and lifetime, appropriate applications of different lamp types, and control strategies.

1. Energy Auditing Techniques for
Small Commercial Facilities
2010
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Ryan Stroupe, Pacific Energy Center
Jim Kelsey P.E., kW Engineering
Richard Young, Food Service Technology Center
Lighting Systems

2. Learning Objectives
• Understand lighting concepts and terms
• Understand lamp efficiencies
• Know where find lamp/ballast wattages
• Understand lighting power density from T-24
• Understand appropriate applications for different sources
• Understand light quality concerns
• Understand lighting control strategies
• Understand O&M opportunities
• Understand energy saving calculations for lighting
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 3
Energy Auditor Role and Activities
• Survey and catalog lighting systems in a facility
• Recognize efficiency opportunities
• Distinguish over-illumination or under-illumination
• Asses other light quality issues
• Compare space to code compliant LPD
• Recommend lighting control strategies
• Use light meters and monitoring equipment
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 4

3. Why is Lighting Important?
• Represents 35% of electric energy in CA commercial buildings.
• For some facilities can be nearly 50% of electric energy use.
• Many DR strategies are related to lighting.
• Less of a focus for facility engineers and commissioning providers
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 5
Intention of Lighting Systems
• Illuminate spaces for specific tasks
• Illuminate surfaces or objects
www.nlm.nih.gov
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 6

4. Directional vs. Ambient Lighting
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 7
Lighting System Components
• Luminaire
– The complete lighting unit
• Lamp
– The light source; bulb
• Ballast
– Power regulator
• Reflector
– Component that directs/distributes
light
• Diffuser/Lens/Louver
– Shields eye from glare
– Evens out light distribution
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 8

5. Spectral Power Distribution
• Describes color distribution of light source across visible spectrum
• Vertical scale is power
• Horizontal scale is wavelength
Source: Philips Lighting
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 9
Inverse Square Law
• Resultant illuminance is inversely
I
proportional to the square of E=
distance from source to surface D2
• Double distance from source = ¼ E= Target Illuminance (fc)
illuminance I= Source Intensity (cd)
D= Distance from Source to Target
• Applies only to point sources
2H
H
100 fc 25 fc
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 10

6. Lighting Concepts
Term Units
• Luminous Flux Lumens
• Illuminance Foot-candle/Lux
• Power watts
• Efficacy lumens/watt
• Lighting Power Density watts/ft2
• Lamp Life hours
• Lumen Depreciation given as a % of initial lumens
• Correlated Color Temperature Kelvin degrees
• Color Rendering Index 0-100 scale (unit-less)
• Ballast Factor given as % of luminous output
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 11
Unit Sphere and Steradian
• One candle source
• One foot radius with
1’- 0” x 1’- 0” opening
• One meter radius with 1
meter x 1 meter opening
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 12

7. Luminous Flux
• Total amount of light emitted by
a source in all directions
• Measured in lumens
• Used to rate the output of lamps
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 13
Illuminance
• The density of light falling
on a surface
• Requires an area unit
• Measured in lumens per ft2
(footcandles)
• Also measured in lux
(lumens per meter2)
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 14

8. Efficacy
• A measure of lamp (and ballast) performance
• Describes system conversion efficiency of power to light
• Is light output over input power
• Units are lumens/watt
• Varies by lamp (and ballast) type
Light out
Power in
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 15
Lighting Power Density
• A measure of the power intensity of lighting systems
• Is lighting power over the area of a room or building
• Units are watts/square foot
• Energy code provides limits by space use or building type
Light power
Area
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 16

9. Lamp Life
• Total operating time that ½ of test set remains burning
• Tested under consistent temperatures and time/start
– 77F°
– 3 hrs/start for fluorescents
– 10 hrs/start for HID sources
– 12 hr/start data available from some manufacturers
– Number of starts adversely affect lamp life; longer runs than test
will allow lamps to outlast their rated life expectancy.
• Measured in hours
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 17
Lumen Depreciation
• Given as a percentage of initial lumens
• Factors include lamp aging and dirt accumulation
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 18

10. Light Source Chromaticity
• Refers to Correlated Color
Temperature (CCT)
• Measurement of coolness or
warmness of a light source
• Measured in degrees
Kelvin (º K)
• The higher the chromaticity,
the cooler the source appears
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 19
Color Rendering Index (CRI)
• Method of determining how well a light source
renders colors reflected by objects
• Used to compare color performance for light
sources of the same color temperature
• 0-100 point scale
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 20

11. Underwriters Laboratory
• Underwriters Laboratories Inc. (UL) is an independent, not-
for-profit product safety testing and certification organization.
• Look for the UL label to insure that the lighting products you
purchase are safe to install
• Testing includes
– Risk of fire
– Electric shock
– Injury to persons
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 21
Lamp Types
• Incandescent
• Halogen
• Fluorescent
• High Intensity Discharge
– Metal halide
– Mercury vapor
– High Pressure Sodium
– Low Pressure Sodium
• Induction lamps
• Light Emitting Diodes
• Neon
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 22

12. Incandescent Lamps
• Efficacy 6-24 l/w
• Kelvin temperature 2700K°
• Color Rendering Index 100
• Lamp life 750-2000 hours
• Lumen depreciation <20%
• Start to full brightness immediate
• Re-strike time immediate
• Dimming ability Yes
• Strengths
– First cost
–
–
Color rendering
Instant on
This lamp type is
– Very good lumen maintenance
– Ease of dimming a good candidate
– Not ambient temperature dependent
• Weaknesses for replacement!
– Low efficacy
– Short lamp life
– High lamp surface temperature
– Limited color
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 23
Incandescent Lamp Operation
• Resistive load; electricity passes
through a filament
• 90% of energy applied produces heat
• Light becomes redder with dimming
• Lamp life is reduced at higher
wattages
• Best applications:
– Where lamp/fixture may be damaged
– Extremely cold or hot environments
– Residential
Spectral power distribution
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 24

13. Halogen Lamps
• Efficacy 8-35 l/w
• Kelvin temperature 2900K°
• Color Rendering Index 100
• Lamp life 2000-6000 hours
• Lumen depreciation <5%
• Start to full brightness immediate
• Re-strike time immediate
• Dimming ability Yes
• Strengths
– Directional source
– First cost
– Color rendering
– Instant on
– Excellent lumen maintenance
– Ease of dimming
– Not ambient temperature dependent
• Weaknesses
– Low efficacy
– Relatively short lamp life
– High lamp surface temperature
– Limited color
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 25
Tungsten Halogen Cycle
Filament in quartz capsule surrounded by halogen gas and operates at higher temperature
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 26

14. Fluorescent Lamps
• Efficacy 60-100 l/w
• Kelvin temperature 2700-7500K°
• Color Rendering Index 50-98
• Lamp life 7500-30,000 hours
• Lumen depreciation 10-30%
• Start to full brightness 0-5 seconds
• Re-strike time immediate
• Dimming ability Yes, with proper ballast
• Strengths
– High efficacy
– Long lamp life
– Wide range of colors
– Very good lumen maintenance
– Cool lamp surface temperature
– Area source
• Weaknesses
– Sophisticated lamp/ballast combination
– Does not perform well in hot/cold environments
– Has warm-up time
– Older technologies hum and flicker
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 27
Fluorescent Lamp Operation
• Low pressure, gas discharge source
where light is produced by fluorescence
of phosphor coating when excited by
UV radiation from mercury arc.
• Ballast is required
• Comes in wide variety of shapes
• Light becomes bluer with dimming
• Best applications:
– Ambient lighting
– Where energy use is a concern
– Where lights on on for long periods
– Day lit environments
Spectral power distribution
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 28

15. Ballast Issues
• Component that regulates electricity to the lamp
– Provides required voltage for lamp start-up
– Limits current to lamp during operation
• Types
– Electromagnetic (magnetic)
• Steel or iron core
• 60hz output
• May hum
• Older ballasts (before 1973) may have PCBs
– Electronic
• More energy efficient (10-25% better than magnetic)
• Solid state components
• 20-40Khz output
• Reduced flicker
• Quiet operation
• Easier to install
• Lighter weight
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 29
Ballast Features
• Number of lamps powered (up to 4 lamps on one ballast)
• Start time
– Rapid start
– Instant start
– Programmed start
• Dimming capabilities
• Parallel wiring (will still work if one lamp fails in a two lamp fixture)
• Ballast Factor
– Relative luminous output of a lamp(s) operated on a ballast with
respect to the same lamp(s) driven on a reference ballast
– Used to describe ballasts that under- or over-drive lamps
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 30

16. Fluorescent Lamp Types
• T (Tubular)
• U-shape
• Circline
• Flat
• 2D
• Compact
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 31
Fluorescent Lamp Nomenclature
F32T8/835/HO
• F32T8 •HO
–HO High output
– Fluorescent
–RS Rapid start
– 32 input power in watts
–ES Energy saving
– Tubular lamp type
–CW Cool white
– 8 1/8” inches in diameter or 1”
–WW Warm white
• 835 –SS Super Saver
– 80-89 CRI –ECO Ecologic
– 3500 Kelvin Temp –D Daylight
Note: Lamp coding may vary by manufacturer
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 32

17. T-12 Fluorescents
• About 60 l/w with magnetic ballasts
• Changing to T-8s with electronic ballasts is a 20-40%
improvement in efficacy
• Larger T-12 lamp prevents light from exiting fixture
• Still accounts for nearly 50% of all fluorescents in US
This lamp type is
a good candidate
for replacement!
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 33
High Efficiency, 3rd Gen. or Super T-8s
• Excellent efficacy up to 95 l/w at mean life
• Good lumen maintenance 93% at 12,000 hrs
• Long lamp life in excess of 18,000 hours
• CRI 80 or better
This new fluorescent lamp
type is the only T-8 linear
fluorescent that qualifies
for PG&E’s Deemed
Incentive Program
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 34

18. Identifying Magnetic Ballasts
• Use the flicker checker
• Much easier than opening fixture
• Under electronic ballasts
– Looks like shades of gray
– rotating in one direction
• Under magnetic ballasts
– Has color
– Rotating in both directions
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 35
T-5 Fluorescents
• Excellent efficacy up to 90 l/w at mean life
• Good lumen maintenance 95%
• Long lamp life in excess of 20,000 hours
• CRI 80 or better
• Notes:
– Thinner lamp allows light fixture to be more efficient
– With reflector provides high light output
(encroaches on HID market)
– Metric length and lamp holder size makes retrofits difficult
– Variety of colors available (3000-4000K)
– This fluorescent lamp type qualifies for PG&E Incentive
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 36

19. Cold Cathode Fluorescent
• Operate at a much higher voltage and lower
current than conventional fluorescent lamps.
• The higher voltage overcomes the need to heat
the tube while the lower arc current greatly
extends the life of the discharge electrodes.
• Cold cathode lamps are typically ten to 30
percent more efficient than a comparable hot
cathode fluorescent lamp.
• Cold cathode lights have a life expectancy
more than twice that of typical compact
fluorescent lamps and do not suffer accelerated
degradation with variations in supply voltage.
• This fluorescent lamp type qualifies for PG&E
Incentives* for incandescent replacement
(fluorescent must be 2 to 8 watts).
*Check PGE.com for updates and incentive details
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 37
Compact Fluorescent Lamps
• Efficacy 28-84 l/w
• Kelvin temperature 2700-5000K°
• Color Rendering Index 82-86
• Lamp life 10,000-20,000 hours
• Lumen depreciation <30%
• Start to full brightness 0-5 minutes
• Re-strike time immediate
• Dimming ability Yes, with proper ballast
• Notes:
– May come with integrated ballast
– Ballast must be ventilated; Do not enclose lamp
– This lamp type qualifies for the PG&E incentives
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 38

20. Compact Fluorescent Lamps
• Strengths
– High efficacy
– Compact size
– Long lamp life
– Good CRI
– Wide range of colors
– Good lumen maintenance
– Cool lamp surface temperature
– High frequency operation
• Weaknesses
– Higher first cost (over incandescent)
– Position sensitive
– Does not perform well in hot/cold environments
– Has warm-up time
– Expensive to dim
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 39
Compact Fluorescent Lamp (CFL) Shapes
Source: IESNA ED-150 Instructor Guide, 1995
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 40

21. High Intensity Discharge Sources
• Used to light surfaces some distance from source
• Applications
– Street lights
– Exterior lighting of buildings
– Warehouse lighting
– High-bay retail
• Types
– Mercury Vapor
– Metal Halide
– High Pressure Sodium
– Low Pressure Sodium
• Alternatives
– Induction lamps
– T-5 Fluorescent
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 41
Mercury Vapor
• Efficacy 30-65 l/w
• Kelvin temperature 5600-7000K
• Color Rendering Index 15-40
• Lamp life 10,000-16,000 hours
• Lumen depreciation 30-50%
• Start to full brightness 3-5 minutes
• Re-strike time 5 minutes
• Dimming ability yes, with special ballast
• Strengths
– Long lamp life
• Weaknesses This lamp type is
– Only incandescents are more inefficient
– Poor color rendering a good candidate
– Poor lumen maintenance
– Long strike time and re-strike time for replacement!
– New outdoor installations are illegal under some state laws.
– Mercury lamp ballasts are noisy
– Lamps are quite voltage sensitive
– A special dimming ballast is required to dim mercury lamps.
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 42

22. Metal Halide Lamps
• Efficacy 50-110 l/w
• Kelvin temperature 3000-6000K
• Color Rendering Index 65-92
• Lamp life 6000-20,000 hours
• Lumen depreciation 10-30%
• Start to full brightness 2-10 minutes
• Re-strike time 3-20 minutes
• Dimming ability with difficulty
• Strengths
– High efficacy
– Long lamp life
– Good lumen maintenance
– Good color rendering for HID source
• Weaknesses
– Has warm-up time
– Long re-strike time
– Color shifts with age
– Lamp position sensitivity
– Expensive to dim
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 43
Metal Halides Features
• Pulse Start
– Probe start provides brief, high-power pulse for lamp start up
– Up to 50% improvement in efficacy
– Reduced strike and re-strike time
– High lumen maintenance
– Improved color stability
– Longer lamp life
– This lamp type qualifies for the PG&E incentives
• Bi-level control
– Switch lamps to lower energy-saving level
– Continuous dimming is more difficult due to flicker, color shift & lamp shutdown
– Can be controlled based on occupancy
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 44

23. High Pressure Sodium Lamps
• Efficacy 50-120 l/w
• Kelvin temperature 2100-2200
• Color Rendering Index 21-65
• Lamp life 16,000-24,000 hours
• Lumen depreciation 10-20%
• Start to full brightness 4-6 minutes
• Re-strike time 1 minute
• Dimming ability with difficulty
• This lamp type qualifies for the PG&E incentives
• Strengths
– High efficacy
– Long lamp life
– Good lumen maintenance
– Universal burning position
• Weaknesses
– Has warm-up time
– Re-strike time
– Poor CRI
– Expensive to dim
– Color shifts with age
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 45
Induction Lamps
• Efficacy 60-80 l/w
• Kelvin temperature 3000K-4100K
• Color Rendering Index 80
• Lamp life 100,000 hours
• Lumen depreciation 20-25%
• Start to full brightness Some warm up
• Re-strike time immediate
• Dimming ability No
• This lamp type qualifies for the PG&E incentives
• Strengths
– Extremely long lamp life
– Tolerates varied temperatures
– On/off cycling does not affect lamp life
– No color shift over lamp life
• Weaknesses
– Not as efficient as high-efficiency fluorescents
– Have yet to collect enough long-term performance data
– Lumen depreciation is significant
– Unable to dim
– Immediate strike and re-strike
– High first cost
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 46

24. Light Emitting Diodes
• Efficacy 20-60 l/w*
• Kelvin temperature 3000K-4500K
• Color Rendering Index 20-70
• Lamp life 50,000-100,000 hours
• Lumen depreciation 10-30%?
• Start to full brightness immediate
• Re-strike time immediate
• Dimming ability Yes
• This lamp type qualifies for PG&E incentives
• Applications
– Exit signs
– Traffic lights
– Signage
– Safety lights (theaters)
– Replace Neon
* test data in labs is much higher (130 l/w)
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 47
Light Emitting Diodes (LEDs)
• Strengths
– Adequate light at low wattage for some applications
– LED exit signs require 2-25% of the wattage of
incandescent exit signs
– LED exit signs require 25-50% of the wattage of
CFL exit signs
– Rugged
– Extremely long lamp life; some claims of up to 25 year life
– 1/3 the life cycle cost of incandescents over a ten year life
• Weaknesses
– Low efficacy ( 20-60 L/W)
– White LEDs have lower efficacy than colored LEDS Not
appropriate for all applications
– Have yet to collect enough long-term performance data
– Currently-manufactured LEDs are rated for operating
temperatures of 25 degrees C; at lower temperatures they
produce more light and at higher temperatures, less.
– Signs should be changed when light levels drop below
accepted standards
– Require DC power
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 48

25. Light Emitting Diode (LED) - Operation
Hard Plastic
Phosphor coating (optional)
Semi-Conductor
Anvil
Base Pins
• Produce light by electroluminescence
• Solid state light source
• Semiconductor chip Image license: GNU Free Documentation License.
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 49
LED - SPD Curve
• Continuous
curve
• Blue weighted
• Varies for color
LEDs
PG&E Pacific Energy Center 2007
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 50

26. Lamp Comparison Matrix
Source Efficacy Lamp Life Color Voltage Temperature
Lamp Family LLD CRI Dimmable2
Type (lm/W) (rated hours) Temp.1 Sensitive2 Sensitive2
Incandescent Point 15 1,000 95% W 100 Y Y N
Halogen
Point 20 3,000 100% W 100 Y Y N
Incandescent
Fluorescent Linear 95 25,000 95% WMC 86 Y N Y
Compact
Area 70 12,000 86% WMC 86 S N Y
Fluorescent
Pulse Start
Point 100 20,000 85% WM 70 S N N
Metal Halide
Ceramic
Point 90 20,000 85% WM 92 S N N
Metal Halide
High Pressure
Point 110 24,000 90% W 21 N N N
Sodium
Induction
Area 80 100,000 75% WM 80 N N N
Lamps
White LEDs Projection 40 50,000 70% MC 75 Y N Y
1 - W (Warm), M (Mid-range), C (Cool) Note: Values are representative of lamp family performance
2 - Y (Yes), S (Special Cases), N (No)
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 51
Mean Lamp/Ballast System Efficacy
Halogen PAR38
Incandescent A19
Halogen IR PAR38
White LED
CFL PL13 2-pin - Mag
CFL 15W Screw-in
CFL 26W Double - GEB
Lamp (and Ballast) Type
CFL 42W Triple - GEB
MH 400W - Mag
MH 100W - Elec, pulse
MH 400W - Mag, pulse
CMH 400W - Mag, pulse
MH 400W - Elec, pulse
CMH 400W - Elec, pulse
T12 - Mag
Biaxial - GEB, prog
T5HO - GEB, prog
Basic T8 - GEB, ins
Super T8 - EE, prog
T5 - EE, ins
Super T8 - EE, ins
0 20 40 60 80 100
Efficacy [mean lm/W]
*GEB: Generic Electronic Ballast, EE: Extra Efficient Ballast, ins: instant start, prog: programmed start, pulse: pulse start
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 52

27. Daylighting
• Efficacy 80-250 l/w
• Kelvin temperature 5,400-10,000K
• Color Rendering Index 100 (best source)
• Lamp life Infinite, but daily cycle
• Lumen depreciation None
• Notes:
– Savings dependant on reducing electric lighting load
– Associated with increased productivity, reduced sick days…
– Some heat introduced with daylight
– Indirect light is ideal (less glare and heat)
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 53
Recommended Illuminance Levels
These are recommendations not code requirements
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 54

28. De-Lamping Opportunities
• Efficient lighting systems often provide more light
– New lamps and ballasts may provide higher lumen output
– Ballast may have high ballast factor
– Reflectors may be added
– Fixtures may be cleaner
• Older buildings designed for higher illuminance
• Many spaces over-illuminated for appropriate task
• Task/low ambient lighting strategies
• Scotopic lighting provides better visual acuity and higher perceived
brightness
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 55
Lighting Controls
• Objectives
– In all cases reduce the hours of operation of lighting equipment
– In some cases reduce the power draw of lighting equipment
• Types
– Manual switches
– Schedule controls/Sweeps
– Timers
– Occupancy sensors
– Manual dimmers
– Daylight controls/Photosensors
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 56

29. Scheduled Controller/Sweep
• Controlled through building
automation system (BAS)
• Ideal for spaces with regular use
• Best option is manual ON,
controlled OFF
• Applications
– Open office space
– Schools
– Retail spaces
– Manufacturing
• This control equipment qualifies for
the PG&E Incentive
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 57
Data from Timer Controls
Retail Example Retail Store Stockrooms
Men's Ware Visual Lingerie Shoes
200
180
160
140
120
100
80
60
40
20
0
Fri Sat Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat Sun
0:00 0:00 0:00 0:00 0:00 0:00 0:00 0:00 0:00 0:00 0:00 0:00 0:00 0:00 0:00 0:00 0:00
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 58

30. Time Clocks
• Allows lights to run in a
space for a limited time
• Essentially a timed switch
• Simple controller
• Inexpensive
• Types:
– Mechanical
– Electronic
• Applications:
– Stock/Storage rooms
– Laundry rooms
– Service areas
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 59
Occupancy Sensors
• Ideal for spaces with irregular use
and unoccupied at least ½ operating
hours
• Sensors located in spaces
• May be tied to BAS
• Two main sensor types
– Infrared
– Ultrasonic
• Applications
– Rest rooms
– Stock rooms
– Conference rooms
– Garages
• This control equipment qualifies for
PG&E Incentive
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 60

31. Passive InfraRed Sensor Attributes
http://www.wattstopper.com/pdf/Sensor_Broch_Final.pdf
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 61
Ultrasonic Sensor Attributes
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 62

32. Data from Occupancy Controls
Garage Example
8
7
6
5
4
3
2
1
0
9/20 9/22 9/24 9/26 9/28 9/30 10/2 10/4
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 63
Interior Daylight Controls
• Ideal for interior spaces
with a daylight factor >2%
• Sensors located in spaces
• May be tied to BAS
• Two main strategies
– Photocells
– Photosensors
• Applications
– Single-story buildings
– Perimeter office spaces
– Schools
– Big-box retail
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 64

33. Data from Daylighting Controls
Grocery Store Example
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 65
Exterior Lighting Controls
• Sensor typically located
above fixture
• Photocells switch lights
off when there is adequate
daylight
• This control equipment
qualifies for the PG&E
Incentive
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 66

34. Summary of Lighting Opportunities
• Change out inefficient lighting
– Replace incandescent lamps
– Replace halogens used as ambient sources
– Replace T-12 fluorescents
– Replace magnetically ballasted fluorescents
– Replace mercury vapor lamps
– Used LED for exit signs and signage
• De-lamp in over-illuminated spaces or service areas
• Add lighting controls
– Sweeps
– Timers
– Occupancy sensors
– Daylighting/photosensor controls
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 67
Lighting Operations & Maintenance
• Re-lamp whole building on a regular schedule
• Replace flickering, dim and burned-out lamps
• Clean diffusers, lenses and lamps
• Trim bushes and trees away from outdoor lighting
• Verify controls
– Check scheduled off times for sweeps
– Tune/commission occupancy sensors
– Tune/commission photosensors for daylight controls
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 68

35. Other Lighting Issues
• Consider light system performance
– Consider luminaire efficiency not just lamp efficacy
– Remember distance from source impact light levels
– Spacing of luminaires is a factor
– Lighter wall and ceiling colors are advantageous
• Consider scotopic sources
• High efficiency systems reduce cooling loads
• Glare is a concern especially with computers
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 69
Lighting Tools and Resources
• Flicker checker
• Illuminance meter
• Lighting loggers
• Occupancy loggers
• Luminance meter
• Measuring tape/Disto
• Circuit tracer
• Recommended illuminance level table
• Lighting fixture wattage tables
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 70

36. Key Points to Remember
• Relative lighting efficacies
• Where to find light system wattages
• How to calculate Lighting Power Density
• How to use meters and test equipment
• Appropriate control strategies for different situations
• Lighting O&M opportunities
• Where to find lighting incentive information
• How to calculate energy savings potential
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 71
References and Resources
• Advanced Lighting Guidelines: 2003 Edition
– http://www.newbuildings.org/lighting.htm
• Lighting Fundamentals Handbook
– Free through EPRI http://my.epri.com/
• Table of Standard Fixture Wattages
www.entergy-texas.com/content/Energy_Efficiency/documents/Small_CommercialWattageTable_020504.xls
www.entergy- texas.com/content/Energy_Efficiency/documents/Small_CommercialWattageTable_020504.xls
• Occupancy Sensor Design and Application Guide
http://www.wattstopper.com/getdoc/419/OSappsNewDesignFinal.pdf
• California Energy Code, Title 24
http://www.energy.ca.gov/title24/
• PG&E Lighting Incentives
http://www.pge.com/mybusiness/energysavingsrebates/rebatesincentives/ref/lighting/
http://www.pge.com/mybusiness/energysavingsrebates/rebatesincentives/ref/lighting/
2009 Energy Auditing Techniques for Small and Medium Commercial Facilities 72