Session: Motors, Drives & Lighting
LIGHTING 101: 10 Things to Remember
John L. Fetters, CEM, CLEP, CEA
EFFECTIVE LIGHTING SOLUTIONS, Columbus, OH
August 9, 2016
Rhode Island Convention Center • Providence, Rhode Island
LIGHTING 101: 10 Things to Remember
1. Lighting Terms
2. Incumbent Lamps
3. LED/SSL Sources
4. CRI Dilemma
5. Lighting Efficiency & Metrics
6. Electronic ballasts & LED drivers
7. Lighting Controls & Dimming
8. Retrofit & Re‐lighting 9. Lighting Maintenance
10.Lighting Surveys & Audits 2
Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #1: Lighting Terms
• Lighting has its own language
• Those working with lighting systems need to know what lighting terms mean
– AND what they don’t mean!
– Helps to filter out marketing BS!
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TEN THINGS to REMEMBER #1: Lighting Terms
• Average rated life (incumbent light sources only) – the point in time when 50% of large group of lamps have failed
• Ballast – an electrical device to start and control the current through a lamp
• Lamp – what lighting professionals call bulbs & tubes
• Lumen – total light from a source
• Luminaire – complete lighting fixtures with lamps, a connection to power & elements to position & protect lamps & distribute light (a.k.a. fixture)
• Visible light – that part of the spectrum from 380 nm (violet) to 770 nm (red)
• Footcandle (measures light level)
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TEN THINGS to REMEMBER #1: Lighting Terms
• Footcandle (FC) is measure of light level
• Measure in footcandles (FC)
• In USA (only)
lumens
FC = ________
square feet
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TEN THINGS to REMEMBER #1: Lighting Terms
• Absorption – all frequencies of white light are taken into a colored material, except the color of the material
– Which is reflected
• Color temperature – appearance of light source & measured in degrees K (warm or cool)
• Reflection – light that is redirected off a surface
– Can be specular (at certain angle) or diffuse (scattered randomly)
• Transmission – light that goes through a clear, transparent material (like window glass) or diffused through a translucent material
• White light – a blend of all colors of the spectrum
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TEN THINGS to REMEMBER #2: INCUMBENT LAMPS
• a.k.a. “traditional” light sources
• Everything except LED
• Why study them? Isn’t everything going LED/SSL?
– Need to know:
• What’s in lighting systems & how to identify them
– Lighting surveys & audits
• Characteristics
– Average rated life, color temp, CRI, etc.
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #2: INCUMBENT LAMPS
• Incumbent lamp families
– Incandescent
• Inefficient bulbs banned by U.S. legislation
– Several, more efficient halogen bulbs can still be used
– Fluorescent (incl CFL – compact fluorescent lamps)
• “Super” T8 systems good choice (most efficient)
• T5 & T5HO less efficient than “Super” T8
• CFLs quickly giving way to LED bulbs
– HID (High Intensity Discharge_
• Mercury Vapor (obsolete)
• Metal Halide (incl pulse‐start [PS] & ceramic metal halide [CMH]) (sort of white light)
• High‐pressure Sodium (HPS) (yelow/orange color)
• Low‐pressure Sodium (LPS) (NO color rendering)
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TEN THINGS to REMEMBER #3: LED/SSL SOURCES
• LED – Light‐emitting diode (refers to bulb to replace incandescent or CFL bulbs) OR to the light source in SSL units
• SSL – Solid‐State Lighting – fixtures that contain imbedded LEDs as a light source
• LED/SSL are much different than incumbent light sources
– Need to understand: Life, lumens, color
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TEN THINGS to REMEMBER #3: LED/SSL SOURCES
• LED/SSL Life
– Don’t fail suddenly like incumbent sources
– Life measured as a reduction in lumen output over time
– L70 is the point in time where the light level is 70% of the initial lumen output (typical 10,000 hrs or higher)
• “Delivered” lumens
– NOT source lumens like incumbent light sources
• Long term color consistency
– Binning, Cree “True White” system (dynamic feedback)
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TEN THINGS to REMEMBER #3: LED/SSL SOURCES
• “Delivered” lumens
– LED is true ‘point source’
– Can be coupled with optical‐grade plastic lens assemblies that result in
• Utilization Efficiency of SSL much higher than fixtures for incumbent sources
– LED’s will always be at a disadvantage to incumbent light sources when improperly compared
Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #3: LED/SSL SOURCES
• Saving energy with LEDs
•
LEDs can save significant power (kW) & energy (kWh)
•
Incumbent technologies may be more cost‐effective,
without saving as much energy
•
As LEDs & SSL products improve & prices come down,
market will shift toward SSL
• Incumbent technologies may be better now, but that will change
quickly in next 6 to 24 months
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #3: LED/SSL SOURCES
• Best Applications:
– LED bulbs
• Replacing incandescent/halogen lamps (esp floods & spots)
– Use EnergyStar or DLC listed for utility rebates
– Recessed cans (kit or new SSL fixture)
– Refrigerated case lighting (to replace fluorescent tubes)
– Exterior applications
• Parking lots – don’t forget controls!
• Parking garages w/ bi‐level controls
– Long hrs‐of‐use applications
• Retrofit kits or SSL fixtures for fluorescent fixtures
• SSL fixtures to replace HID fixtures (watch temp ratings)
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TEN THINGS to REMEMBER #4: CRI Dilemma
• CRI – Color Rendering Index
– Appearance of colored objects when viewed under a light source compared to when viewed under standard
– Relative measure in % ‐
higher number, closer to standard & less shift
– Measure does not work well for LED products
R1
R2
R3
R5
R6
R7
R4
R8
R1 – R8 = Ra
75 85
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TEN THINGS to REMEMBER #4: CRI Dilemma
• Many LEDs do not do well with pastel colors, but often
do very well with bright or saturated colors
• Perception: People often think that LEDs with lower CRI
values make bright colors look more natural than other light
sources that have higher CRI
• Advice: Don’t automatically exclude lower CRI LEDs
• Many SSL products rated at 90+ CRI
• Forthcoming new measure: Color Quality Scale (CQS) (from
NIST) uses bright & pastel colors & may replace CRI
• Also, IESNA committee has written TM‐30‐15
• Difficult to use, may not be practical
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TEN THINGS to REMEMBER #4: CRI Dilemma
• Ra is red deficient
• R9 is saturated red color
• High R9 values in LED specifications is better approximation of how human visual system may interpret true colors
• California Title 24 now requires high values of R9 when lighting new residential & light commercial indoor applications with SSL
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TEN THINGS to REMEMBER #4: CRI Dilemma
“A Color Quality Scale (CQS) is being developed at
NIST* with input from the lighting industry and the
CIE (International Commission on Illumination) to
address the problems of the CIE Color Rendering
Index (CRI) for solid‐state light sources and to meet
the new needs of the lighting industry and
consumers for communicating color quality of
lighting products. The method for calculating the
CQS is based on modifications to the method used
for the CRI. Although simulations support the
appropriateness and usefulness of the proposed
CQS, vision experiments will be conducted to
improve and validate the CQS. It will then be
proposed as a new international standard.”
*NIST – National Institute of Standards & Technology
www.nist.gov
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TEN THINGS to REMEMBER #5: Lighting Efficiency & Metrics
• LPW – Lumens per Watt is a measure of the efficiency of incumbent light sources
– Calculated by lamp companies &/or test labs
– Ex: Incandescent & halogen (15 ‐ 20 LPW)
– Ex: Fluorescent (65 ‐ 102 LPW)
• LPD – Lighting Power Density measured in lumens per watt is an indication of lighting efficiency
– Higher LPD values indicate inefficient systems
• Ex: Older fluorescent systems (2.0 – 6.0 w/SF)
– Lower LPD values indicate higher efficient systems
• Ex: “Super” T8 & SSL systems (0.5 – 0.7 w/SF)
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TEN THINGS to REMEMBER #5: Lighting Efficiency & Metrics
www.lightingwizards.com
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TEN THINGS to REMEMBER #5: Lighting Efficiency & Metrics
• Lighting Power Density (LPD) is lighting allowance for building lighting • Codes and standards (ASHRAE/IESNA 90.1)
• Measured in watts/SF; high efficiency = low LPD
• Good indicator of lighting efficiency & potential savings
• Screen for potential retrofit of re‐lighting projects by locating systems with high LPD
• Estimate savings by comparing state‐of‐the‐art designs
• Ex: Office lighting system that calculates to 2.3 w/SF can be upgraded to new or retrofit at 0.8 w/SF • Savings = 2.3 – 0.8 = 1.5 w/SF
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #5: Lighting Efficiency & Metrics
Calculating LPD:
Total watts of lighting system(s)
LPD =
Total SF covered by lighting system(s)
1,050 watts
LPD = = 2.0 w/SF
525 SF
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #6: Electronic Ballasts & LED Drivers
• Electronic ballasts (ELB)
– Electrical devices to start and operate fluorescent lamps
– Functions:
• 1. Provide correct voltage to start arc discharge
• 2. Provides impedance (AC resistance) to limit lamp current to design value (Ex: 265 ma for T8 lamps)
• 3. Provides energy to heat lamp cathodes
– Rapid‐start & Program‐start only
– Not just solid‐state replacement for magnetic components
– Different way to operate fluorescent lamps (high freq)
• 20 ‐ ~ 60 kHz
• Lamps operate more efficiently
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TEN THINGS to REMEMBER #6: Electronic Ballasts & LED Drivers
• Mistake: Failing to consider ballast factor (BF)
• Biggest mistake made in lamp & ballast upgrades is ignoring ballast factor
• IMPORTANT – BF determines light level & power input
• The higher the BF, the higher the light level & the higher the input power 23
Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #6: Electronic Ballasts & LED Drivers
•
•
•
•
BF values listed in ballast catalogs & ballast manufacturer’s websites (Ex: http://www.advance.philips.com/)
BF for electronic ballasts = 60 – 130%
Typical BF = 85 – 95% (Ex: GEB ~ 88%)
Use BF to calculate light level for new, re‐lighting, or retrofit projects
• Light output & power input is directly proportional to BF
• Select ballast based on light level required
• Use low BF models to lower light level (60 – 83%) • Use high BF for higher light level (100 – 130%)
• Often used when downsizing number of lamps in fixture
• Ballasts with BF up to 120% can be used without fear of overdriving lamps
– Overdriving lamps means exceeding rated current (Ex: T8 lamps rated at 265 ma)
• Can provide up to 30% more light
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TEN THINGS to REMEMBER #6: Electronic Ballasts & LED Drivers
• Transients: Areas with high transient activity
• High lightning activity areas • Now more prevalent due to increase in thunderstorms! (~ 16M/yr in USA)
• www.nssl.noaa.gov/education/svrwx101/thunder
storms
• Over 25 million lightning strikes hit USA each year (www.lightingsafety.noaa.gov)
• Large HP motors, such as elevator motors,
punch presses, extrusion molding machines or other large industrial machinery)
• Utility power sub‐station switching
– including breaker re‐closures
• Add separate Surge Protection Device (SPD) (a.k.a. TVSS) at lighting power distribution centers (breaker box)
• 3‐wire device + ground + LED indicators
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TEN THINGS to REMEMBER #6: Electronic Ballasts & LED Drivers
• LED drivers
– Not just a DC power supply
– Must be matched to LED arrays
– Power
• Universal input voltage (some mfg offer)
• Added cost – usually cheaper to specify dedicated voltage
– Power Quality issues
• Total Harmonic Distortion (THD)
– Acceptable: < 20% (similar spec to electronic ballasts
– Exceptionally Good: 10% (may cost more)
• Power Factor (PF)
– Specify HPF >/= 90% – When PF not mentioned in specification, assume “normal” PF < 90%
– “Actual” may be as low as 40% (usually in cheaper products)
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TEN THINGS to REMEMBER #7: Lighting Controls & Dimming
• Lighting controls
– To reduce hours‐of‐use (hours on)
• Reduce kWh by switching
– To reduce power (kW)
• Reduce kW & kWh by dimming
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #7: Lighting Controls & Dimming
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #7: Lighting Controls & Dimming
• PIR technology occupancy sensors – Does not emit anything (“passive”)
– Reacts to body heat
– Sense occupancy by detecting difference in body heat & background
• Fan patterns created by lens
– Sensors need to “see” area to control
• Movement across field of view easier to detect than to/from
• Ceiling mounting most effective
– Sensors use low‐voltage to operate relays (“power packs”) that control lighting system power
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #7: Lighting Controls & Dimming
R
T
• Ultrasonic occupancy sensors
–
–
–
–
–
Volumetric detectors
Transmit sounds above range of human hearing
Senses shift in frequency of reflected waves
360 degree coverage
Most sensitive to small movement close to detector (10‐20 ft)
• Sensitivity reduced at edges of controlled area (40‐50 ft)
• Add sensors to get better coverage
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #7: Lighting Controls & Dimming
• Dual‐technology occupancy sensors
• 2 technologies ‐ usually PIR & Ultrasonic
• Either technology turns on lights
• Both technologies must sense to turn off lights
• Only one technology needed to keep lights on
• Prevents “false offs”
• Vacancy Sensor
–
–
Like occupancy sensor operated in “manual on” “auto‐off” mode
Saves more energy than occupancy sensors
• Situations where only brief occupancy & don’t need lights on
–
Required by California Title 24 & 90.1 ‐
2013
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TEN THINGS to REMEMBER #7: Lighting Controls & Dimming
• Photocells
• Respond to ambient light
• Inexpensive dusk‐to‐dawn controls
•
•
Cadmium‐sulfide (CdS) cell (not recommended)
Change sensitivity over time
•
Erodes savings
• “Electronic” photocell (recommended)
•
•
Solid‐state silicon sensor
6 year warranty
• Delay feature prevents rapid cycling during cloudy days or lightning
• Aim North in northern hemisphere
•
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To get view of reflected light from Northern sky
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TEN THINGS to REMEMBER #7: Lighting Controls & Dimming
• Daylight harvesting (DLH) is energy management strategy that uses electronic lighting control to automatically adjust the output of electric lighting based on the amount of daylight entering a space
• Control must meet visual & comfort needs of occupants as daylight varies over the day & by season
• Not easily done
• Problems can occur when occupants are disturbed by low light levels or sudden changes in light level
• Use fade control to slow response
• System control elements
• Electronic dimming ballasts
• Photo‐sensors (w/integrated fade control)
• Low‐voltage control
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TEN THINGS to REMEMBER #7: Lighting Controls & Dimming
• How do DLH systems perform?
• Wisconsin Energy Center monitored 20 DLH projects
• Most projects fell short of expectations
• Median system saving 23% (including impacts on HVAC)
• About half not meeting expectations
• 4 of 20 spaces studied had NO savings
• Are DLH systems cost‐effective?
• With LPD (Lighting Power Density) of SSL systems at 0.5 ‐
0.7 w/SF, low savings
• Hard to justify added cost
• Long payback
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #7: Lighting Controls & Dimming
Percent Light Perceived
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• Dimming:
• Square law of dimming
• Response of human visual system not linear
• Light measured varies as the square of perceived light
• Perceived light varies as square root of measured light
• Most dimming occurs at low end (< 10%) Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #7: Lighting Controls & Dimming
• LED lamps & dimming
• Light output proportional to power • Some LED lamps require ELV dimmers (Electronic Low‐Voltage)
• Dimming extends LED life (LEDs run cooler)
• Many compatibility issues
• Investigate for your applications
• Check websites of LED bulb mfg &/or dimmer mfg
• Inrush current sets max number of lamps/dimmer
• Not wattage rating of dimmer!
• Compatibility Standard
“Phase‐Cut Dimming for Solid‐State Lighting –Basic Compatibility”
NEMA SSL 7A‐2015 Free download from: www.nema.org
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TEN THINGS to REMEMBER #8: Retrofit & Re‐lighting
• Retrofit – reuse old fixture (ok if old fixture quality fixture)
– Limited change potential
– Requires good lighting retrofit company to be effective
• Re‐lighting – removing old fixtures and installing new fixtures
– One‐for‐one OR
– Different layout with fewer fixtures
– Typically done by electrical contractors
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TEN THINGS to REMEMBER #8: Retrofit & Re‐lighting
• Philips “InstantFit” 4‐ft LED T8 Lamps (all rated at 50,000 hrs)
No rewiring; fixture retains original UL & CSA compliance
“Std” 12‐w used w/ELB w/BF=0.88 14.5‐w, 1500‐1650L, 103‐114 LPW
“Std” 12‐w used w/ELB w/BF=0.78 12.5‐w, 1300‐1450L, 104‐116 LPW
“Std” 12‐w used w/ELB w/BF=1.18 18.5‐w, 1700‐2000L, 92‐108 LPW “HO” 16.5‐w used w/ELB w/BF=0.88 19‐w, 2000‐2150L, 105‐113 LPW
“HO” 16.5‐w used w/ELB w/BF=0.78 17.5‐w, 1800‐1950L, 103‐111 LPW
“HO” 16.5‐w used w/ELB w/BF=1.18 25.5‐w, 2700‐2900L, 106‐114 LPW
2‐ft, 3‐ft & 6U‐tube models also
120‐277v, 347v universal voltage input
Instant on; no mercury; CRI=82
Optimized for instant‐start ballasts; compatible with some program(med)‐start ballasts
– Some models DLC qualified
– 5 yr warranty
–
–
–
–
–
–
–
–
–
–
–
www.lighting.philips.com
Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #8: Retrofit & Re‐lighting
• Led retrofit kits
• For 2x4 (or 2x2) recessed troffers
– Minimum depth 3”
• 3,600 – 4,200 Lumens; 31 – 39 watts
– 108 – 117 LPW
• L70 = 70,000 hrs
• 3500K or 4000K; CRI = 85
• Dimmable
Philips EvoKit LED Retrofit
– 0 – 10V; Philips Mark 10 leading Gen 3: Includes SimpleSet Technology
edge dimming; step/ bi‐level
Allows setting max lumen level prior to
installation using smartphone‐based App
• 5 year warranty
• Quick installation; 1 person ~ 5 min
• DLC Listed
http://www.lighting.philips.com/
Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #8: Retrofit & Re‐lighting
• Re‐Lighting
• “Smart” fixtures: SSL solution
– Motion controlled fixtures
• Integral ultrasonic sensor
– Provide safe & dependable light while controlling energy
• UL listed
– Uses bi‐level step dimming electronic ballast
– Used in corridor and stairwell lighting*
http://lamarlighting.com
* Low lighting level must meet NFPA Life Safety Code 101 1 FC min
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TEN THINGS to REMEMBER #9: Lighting Maintenance
Unlike all other building energy‐using systems, doing maintenance on lighting systems does NOT save energy
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TEN THINGS to REMEMBER #9: Lighting Maintenance
• Regular maintenance must be performed to keep lighting systems performing as designed
• Recommend replacing lamps at regular intervals (group re‐lamping) or as they burn out (spot re‐
lamping)
– Most organizations that use group re‐lamping, do spot re‐
lamping to replace burnouts between group re‐lampings
• Clean light reflecting surfaces
• Fixtures
• Room surfaces
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TEN THINGS to REMEMBER #10: Lighting Surveys & Audits
• Surveys
– Simple gathering of information on existing lighting systems
• Minimum amount of data
– Checking existing conditions
– Looking for potential of simple lighting improvements
– Estimating fixture watts, hours‐of‐use, square footage of area(s), etc.
– Recording impressions and notes.
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER #10: Lighting Surveys & Audits
• Audits
– Detailed, systematic evaluation of existing conditions & lighting system performance
– Lots of data collected & analysis of several retrofit/re‐
lighting options
– Measurements made with audit tools
• Light meter, ballast checker, distance meter, data logger, etc.
– Usually done by consultants for a fee
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Energy Exchange: Federal Sustainability for the Next Decade
TEN THINGS to REMEMBER: Summary
1. Lighting Terms
2. Incumbent Lamps
3. LED/SSL Sources
4. CRI Dilemma
5. Lighting Efficiency & Metrics
6. Electronic ballasts & LED drivers
7. Lighting Controls & Dimming
8. Retrofit & Re‐lighting 9. Lighting Maintenance
10.Lighting Surveys & Audits 45
Energy Exchange: Federal Sustainability for the Next Decade
Lighting 101: TEN THINGS to REMEMBER
QUESTIONS?
After the presentation:
email: johnlfetters@mac.com
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Energy Exchange: Federal Sustainability for the Next Decade