Lighting TechnologiesApplications Energy Consumption MAE 406 / 589 John Rees, PE, CEM Eric Soderberg, PE, CEM September 13, 2010
The 3 Pillars of Energy Efficient Lighting Visual Task Visual Task WATTS LUMENS F O O T C A N D L E S Meet target light levels Efficiently produce and deliver light Automatically control lighting operation Most Important Slide in Today’s Seminar! 3
Lighting Fundamentals - Illumination • Light Output. • Measured at the lamp surface. • Measured in lumens. • Illuminance or Light Level. • Measured at the working surface. • Measured in foot-candles. • Luminance or Brightness. • Measured at an angle to the working surface. • Measured in footlamberts.
Targeted Illumination Levels • Targeted illumination level is determined by: • Tasks being performed (detail, contrast, size). • Ages of the occupants. • Importance of speed and accuracy.
Quality of Illumination • Quality of illumination may affect worker productivity. • Quality is affected by: • Glare. Too bright. • Uniformity of illumination. • Color rendition. Ability to see colors properly. • Scale is 0 to 100 (100 is best) • Color Temperature. Warm to Cool. • Measured in degrees kelvin. 3000 is warm (yellowish); 5000 is cool or “daylight”.
Color Rendering Index(CRI) A relative scale indicating how perceived colors illuminated by the light source match actual colors. The higher the number the less color distortion from the reference source. 85 -100 CRI = Excellent color rendition 75 - 85 CRI = Very Good color rendition 65 - 75 CRI = Good color rendition 55 - 65 CRI = Fair color rendition 0 – 55 CRI = Poor color rendition
Color Temperature (K˚) • A measure of the “warmth” or “coolness” of a light source. • ≤ 3200K = “warm” or red side of spectrum • ≥ 4000K = “cool” or blue side of spectrum • 3500K = “neutral” • 5000K = “Daylight”
Color Temperature Scale North Sky - 8500K Daylight Fluo - 6500K Cool White - 4100K Halogen – 3100K Warm White - 3000K Incandescent – 2700K HPS - 2100K 10
Color Rendition cool source is used enhancing blues and greens warm light source is used, enhancing reds and oranges neutral light source is used Color rendering, expressed as a rating on the Color Rendering Index (CRI), from 0-100, describes how a light source makes the color of an object appear to human eyes and how well subtle variations in color shades are revealed. The higher the CRI rating, the better its color rendering ability.
Efficiency • Lighting efficiency is expressed as lumens output/wattage input. • Ranges from 4 to 150 lumens/watt. • Show overhead.
Lamp Lumen Depreciation • As lamps age, they lose a certain amount of output. • Old T12 fluoresecents can lose up to 30% of output over their life. • New T8 fluorescents maintain up to 95% of original lumens. • This depreciation must be accounted for when installing new lighting system.
Luminaires • Luminaire = Lighting fixture • Lamps • Lamp sockets • Ballasts • Reflective material • Lenses, refractors, louvers • Housing • Directs the light using reflecting and shielding surfaces.
Luminaires (cont’d) • Luminaire Efficiency • Percentage of lamp lumens produced that actually exits the fixture. • Types of luminaires • Direct (general illumination). • Indirect (light reflected off the ceiling/walls; “wall washers”). • Spot/Accent lighting. • Task Lighting. • Outdoor/Flood Lights.
Types of Lighting • Incandescents/Halogens. • Fluorescents. • High Intensity Discharge (HID). • Inductive. • Light Emitting Diode.
Incandescent Lamps • One of the oldest electric lighting technologies. • Light is produced by passing a current through a tungsten filament. • Least efficient – (4 to 24 lumens/watt). • Lamp life ~ 1,000 hours.
Incandescent Lamps (cont’d) • High CRI (100) – Warm Color (2700K) • Halogen 2900K to 3200K) • Inexpensive • Excellent beam control • Easily dimmed – no ballast needed • Immediate off and on • No temperature concerns – can be used outdoors • 100, 75, 60 and 40 watt lamps will be going away per 2007 law beginning 2012
Tugnsten-Halogen Lamps • A type of incandescent lamp. • Encloses the tungsten filament in a quartz capsule filled with halogen gas. • Halogen gas combines with the vaporized tungsten and redeposits it on the filament. • More efficient. • Lasts longer (up to 6,000 hrs.)
Fluorescent Lamps • Most common commercial lighting technology. • High Efficicacy: up to 100 lumens/watt. • Improvements made in the last 15 years. • T12: 1.5 inch in diameter. • T8: 1 inch in diameter. • ~30% more efficient than T12. • T5: 5/8 inch in diameter. • ~40% more efficient than T12.
Fluorescent Lamps (cont’d) • Configurations • Linear (8 ft., 4 ft., 2 ft., 1 ft.) • Ubend (fit in a 2 ft. x 2 ft. fixture). • Circular (rare, obsolete). • Fixtures can be 4, 3, 2, or 1 lamp per fixture. • Output Categories • Standard Output (430 mA). • High Output (800 mA). • Very High Output (1,500 mA).
Schematic of Fluorescent Lamp Phosphor crystals Mercury atom Electron Electrode
Compact Fluorescent Lamps (CFLs) • Fluorescent lamp that is small in size (~2 in. diameter, 3 to 5 in. in length). • Developed as replacement for incandescent lamps. • Two Main Types • Ballast-integrated. • Ballast non-integrated (allows only lamp to be replaced).
Compact Fluorescent • Excellent color available – comparable to incandescent • Many choices (sizes, shapes, wattages, output, etc.) • Wide Range of CRI and Color Temperatures • Energy Efficient (3.5 to 4 times incandescent) • Long Life (generally 10,000 hours – • lasts 12 times longer than standard 750 hour incandescent lamps) • Less expensive dimming now available (0-10v dimming to 5%) • Available for outdoor use with amalgam technology
Use ¼ the power of an incandescent for an equivalent amount of light. (an 18-watt CFL is equivalent to a 75-watt incandescent.) 10,000 hour life. (10x an incandescent). Saves about $30 over the life of the CFL. Compact Fluorescent Lamps (cont’d)
Ballasts • Auxiliary component that performs 3 functions: • Provides higher starting voltage. • Provides operating voltage. • Limits operating current. • Old type ballasts were electromagnetic. • New ballasts are electronic. • Lighter, less noisy, no lamp flicker, dimming capability).
Ballast Factor • DEFINITION: The fraction of rated lamp lumens produced by a specific lamp-ballast combination • APPLICATIONS: High Ballast Factor Increases output • (1.00-1.30) AND energy consumption • Typical Ballast Factor Comparable light output in • (0.85-0.95) one-to-one replacement • Low Ballast Factor Decreases light output • (0.47-0.83) AND energy consumption • For optimal efficiency lamps and ballasts must be properly matched. • Maximize energy savings by selecting electronic ballasts with ballast factor that provides target illuminance.
Ballast Circuit Types • Instant Start Ballast – starts lamp instantly with higher starting voltage. Efficient but may shorten lamp life. • Rapid Start – delay of about 0.5 seconds to start; supplies starting current to heat the filament prior to starting and continues during operation. Uses 2 to 4 watts more than an instant start ballast. • Programmed Rapid Start - delay of about 0.5 seconds to start; starting current heats the filament prior to starting, then cuts off during operation.
High Intensity Discharge (HID) Lamps • produces light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina (ceramic) arc tube filled with special gases.
High Intensity Discharge Lamps (cont’d) • Arc tube can be filled by various types of gases and metal salts. • HID lamps are used in industrial high bay applications, gymnasiums, outdoor lighting, parking decks, street lights. • Efficient (up to 150 lumens/watt). • Long Life (up to 25,000 hours). • Drawback – take up to 15 minutes to come up to full light after power outage.
High Intensity Discharge Lamps (cont’d) • Types of HIDs • Mercury Vapor (obsolete) • Sodium Vapor • High pressure • Low pressure • Metal Halide • Arc tube contains argon, mercury, and metal halides. • Gives better color temperature and CRI.
Metal Halide Lamps • Most common HID in use today. • Recent Improvements. • Allow higher pressure & temperature. • Better efficiency, better CRI and better lumen maintenance. • Pulse Start vs. older Probe Start • Ceramic vs. older Quartz arc tube.
Light Emitting Diodes (LED) • Latest Lighting Technology. • Invented in 1962. • In the past, used as indicator lights, automotive lights, and traffic lights; now being introduced for indoor and outdoor lighting. • LED is a semiconductor technology. • Electroluminescence. Electrons recombine with holes in the semiconductor, releasing photons.
Light Emitting Diodes (cont’d) • Lower energy consumption. • Longer lifetime (50,000 to 100,000 hrs). • Smaller size. • Faster switching. • Greater durability and reliability. • Cycling. • Dimming.
LED Applications Successfully used today for many markets • Signs & Traffic signals (most common) • Displays (change colors for attention) • Exit Signs (most common) • Indicators and Flashlights • Under Counter & Coves • Accent • Parking Garage & Outdoor • Downlights • Food Freezers
LED vs. HPS 41
Comparison: LED to Ceramic Metal Halide Cree LED Lighting LRP38 – Total Wattage = 36W Ceramic Metal Halide – Total Wattage ~ 158 to 237W 42
Induction Lights • Light source in which the power required to generate light is transferred from the outside of the lamp envelope by means of electromagnetic fields. • Type of fluorescent lamp – uses radio waves rather than arc to excite phosphor coating on lamp to glow • Long lifespan due to the lack of electrodes - between 65,000 and 100,000 hours depending on the lamp model; • High energy conversion efficiency of between 62 and 90 Lumens/Watt [higher wattage lamps are more energy efficient]; • High power factor due to the low loss of the high frequency electronic ballasts which are typically between 95% and 98% efficient; • Minimal Lumen depreciation (declining light output with age) compared to other lamp types as filament evaporation and depletion is absent; • “Instant-on” and hot re-strike, unlike most conventional lamps used in commercial/industrial lighting applications (such as Mercury-Vapor lamp, Sodium Vapor Lamp and Metal Halide Lamp); • Environmentally friendly as induction lamps use less energy, and use less mercury per hour of operation than conventional lighting due to their long lifespan.
Induction Lighting Type of fluorescent lamp – uses radio waves rather than arc to excite phosphor coating on lamp to glow Advantages: • QL and Icetron: 60,000 to 100,000 hours – if used 12 hours each day will last 20 years! • Good for hard to maintain locations Disadvantages: • Large light source – difficult to control beam of light making it inefficient for delivered and task lumens • Expensive - $200+ adder to HID • No industry standards for Induction
Induction Applications • Applications where maintenance is expensive and/or difficult • 24 hour a day.7 days a week applications • Bridges • Low Bay Industrial • Select Outdoor Lighting Applications • Long burning hour applications
Exit Signs • Old incandescent exit signs used (2) 20-watt incandescent lamps. • At $0.08/kWh, energy cost for 1 sign = $28/yr. • CFL exit signs use 10 to 12 watts • Energy cost for 1 sign = $7 to $8.50/yr. • LED exit signs use 3 to 4 watts • energy cost for 1 sign = $3 to $4/yr. • Photoluminescent sign uses 0 watts, but may have (slightly) radioactive material. • New technology claims completely non-toxic and recyclable.
Outdoor Lighting • Older technology for outdoor lighting • High pressure sodium • Metal Halide • Newer technology • Compact fluorescents • LEDs • Solar street lights (economical when electric lines don’t need to be run in a new installation).
Hazardous Waste Disposal Hazardous Waste Lamps will now be regulated under the Federal Universal Waste Rule which was first developed to regulate the disposal of other widely generated wastes that contain toxic materials, such as batteries and pesticides State Rule supersedes Federal Rule Under current federal law, mercury-containing lamps (fluorescent, HID) may be hazardous waste The rule applies only to lamps that fail the TCLP (Toxicity Characteristic Leaching Procedure) test which is used to determine if a waste is hazardous.
Mercury Content of Lamps TYPICAL MERCURY CONTENT OF VARIOUS LAMPS 250 watt Metal Halide lamp 38 mg 250 watt High Pressure Sodium lamp 15 mg Pre 1988 T12 Fluorescent 45 mg Post 1988 T12 Fluorescent 12 mg Typical T8 Fluorescent Tube 4-5 mg Typical Compact Fluorescent (CFL) 4-5 mg 4-5 mg is less mercury than a coal fired power plant will emit while producing the additional energy to power an equivalent incandescent lamp. Lamps containing mercury that fail the TCLP test must be recycled! EPA encourages responsible disposal practices to limit the release of mercury into the environment. EPA encourages lamp recycling