lighting 101: 10 things to remember - energy exchange · lighting 101: 10 things to remember...

Rhode Island Convention Center • Providence, Rhode Island

LIGHTING 101: 10 Things to Remember

Session: Motors, Drives & Lighting

John L. Fetters, CEM, CLEP, CEAEFFECTIVE LIGHTING SOLUTIONS, Columbus, OH

August 9, 2016

Energy Exchange: Federal Sustainability for the Next Decade

1. Lighting Terms2. Incumbent Lamps3. LED/SSL Sources4. CRI Dilemma5. Lighting Efficiency & Metrics6. Electronic ballasts & LED drivers7. Lighting Controls & Dimming8. Retrofit & Re‐lighting 9. Lighting Maintenance10.Lighting Surveys & Audits

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LIGHTING 101: 10 Things to Remember


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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• 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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Energy Exchange: Federal Sustainability for the Next Decade5

• Footcandle (FC) is measure of light level

• Measure in footcandles (FC)• In USA (only)

lumensFC =

square feet

________



• 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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• 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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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 #2: INCUMBENT LAMPS


• 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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• “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



• 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



• 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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• 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

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R1 R2 R3 R4

R1 – R8 = Ra

R5 R6 R7 R8

75 85

TEN THINGS to REMEMBER #4: CRI Dilemma


• Many LEDs do not do well with pastel colors, but oftendo 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 lightsources 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



• 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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“A Color Quality Scale (CQS) is being developed atNIST* with input from the lighting industry and theCIE (International Commission on Illumination) toaddress the problems of the CIE Color RenderingIndex (CRI) for solid‐state light sources and to meetthe new needs of the lighting industry andconsumers for communicating color quality oflighting products. The method for calculating theCQS is based on modifications to the method usedfor the CRI. Although simulations support theappropriateness and usefulness of the proposedCQS, vision experiments will be conducted toimprove and validate the CQS. It will then beproposed as a new international standard.”

www.nist.gov

*NIST – National Institute of Standards

& Technology



• 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



• 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



Calculating LPD:

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Total watts of lighting system(s)

LPD =

Total SF covered by lighting system(s)

1,050 watts

LPD = = 2.0 w/SF

525 SF



• 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



• 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



• 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/thunderstorms

• 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



• 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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• 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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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



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



• 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



• 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• To get view of reflected light from

Northern sky



• 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



• 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



Percent Light Perceived

• 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%)



• 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



• 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


www.lighting.philips.com

• 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



http://www.lighting.philips.com/

• 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

– 0 – 10V; Philips Mark 10 leading edge dimming; step/ bi‐level

• 5 year warranty• Quick installation; 1 person ~ 5 min• DLC Listed

Philips EvoKit LED Retrofit

Gen 3: Includes SimpleSet TechnologyAllows setting max lumen level prior toinstallation using smartphone‐based App



• 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*

* Low lighting level must meet NFPA Life Safety Code 101 1 FC min

http://lamarlighting.com



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 #9: Lighting Maintenance


• 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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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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TEN THINGS to REMEMBER #10: Lighting Surveys & Audits


TEN THINGS to REMEMBER: Summary

1. Lighting Terms2. Incumbent Lamps3. LED/SSL Sources4. CRI Dilemma5. Lighting Efficiency & Metrics6. Electronic ballasts & LED drivers7. Lighting Controls & Dimming8. Retrofit & Re‐lighting 9. Lighting Maintenance10.Lighting Surveys & Audits


QUESTIONS?

After the presentation:email: [email protected]

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Lighting 101: TEN THINGS to REMEMBER

lighting 101: 10 things to remember - energy exchange · lighting 101: 10 things to remember...

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