Day 3 Energy Audits of Lighting Systems


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Energy Audit in Building A Regional Training Workshop 1 - 5 June, 2010

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Day 3 Energy Audits of Lighting Systems

  1. 1. Energy audit of lighting systems RCREEE Energy Audit in Building Tunis, 1st – 5th June 2010 1Muhieddin Tawalbeh - National Energy Research Center
  2. 2. Overview1. Introduction2. Types of Lamps and Applications3. Street Lighting4. Energy Conservation Measures5. Assessment of Lighting Systems6. Case Studies 2
  3. 3. 1. Introduction Lighting uses more energy in a typical commercial office building than any other single... This segment is growing due to plug load, mostly computers All Others Heating Cooling LightingIt can vary from 25-50% for office buildings.It will be less for manufacturing, and more for warehouses or retail 3
  4. 4. Break-up of your lighting costover 15 years: Maintenance Energy Lamps 15 years Fixtures and Installation Energy is by far the largest cost in owning and operating a typical lighting system 4
  5. 5. All Other Lighting Heating Cooling Cooling Savings Lighting Savingslighting energy savings of 30% to 50% arecommon,and additional cooling savings are also oftenrealized 5
  6. 6. • A rule of thumb is 10-15% reduction in HVAC use with more efficient lighting systems*• For new construction applications, you may also have significantly smaller HVAC tonnage, reducing construction costs by tens of thousands of dollars• *actual HVAC energy savings are, of course, highly dependent upon the local climate and the design and operation of the given building 6
  7. 7. Basic Theory• Light: electromagnetic waves in space• Light is emitted through: a) Incandescence b) Electric discharge c) Electro luminescence d) Photoluminescence 7
  8. 8. There are two basic kinds oflight: Light that comes to our eyes directly from a light source (illuminance) ( such as fire, the sun, or a light bulb Light that is reflected off of something else before it reaches our eyes (luminance) • such as the walls of a room, the surfaces of grass and trees, or the earth’s atmosphere 8
  9. 9. To measure quantity oflight from a source The total light output of a source is measured in lumens. • Historically, a lumen was the amount of light from one candle which fell on one square foot of area, one foot away from the candle. Our historic “standard” candle produces 12.57 lumens A four foot fluorescent lamp produces about 3000 lumens Your standard 60 Watt light bulb (incandescent) produces about 900 lumensOne foot One lumen of light falls on a surface one foot square, which is held one foot away from the candle. 9
  10. 10. To measure the quantity oflight striking a surface We speak in terms of illuminance, measured in • Lumens per square foot, other wise known as footcandles (fc) • or, Lumens per square meter otherwise known as Lux (lx) These are the common measurements made by a light meter One foot-candle = 10.76 lux 10
  11. 11. Efficiency TerminologyEfficiency is a ratio of similar inputs tooutputs• Luminaire efficiency measures the ratio of the total lumens which exit from the luminaire to the total lumens emitted by the lamps within a luminaire• It is expressed as a percentageEfficacy is a ratio of input energy tooutput results• Like miles per gallon• We measure lamp efficacy in lumens per watt 11
  12. 12. Remember, Every LightingApplication has 3 Elements:The Source is all the hardware• This is what most people think of The as the lighting system, Surface• but just as important are…The Surface The• which is the room environment Sourc e and The Purpose (to read this) whatever you are looking atThe Purpose• The reason you need the light.• The activities or tasks that people are doing that require certain 12 visual conditions
  13. 13. The Color Rendering Index (CRI) CRI gages the relative ability of lamps to render a full range of subtle colors 100 = “perfect” Incandescent lamps are used as the 90-99 = superlative reference standard for very “warm” 80-89 = very good sources, and daylight for cooler sources. 70-79 = good • They are assigned an index of 100 (the 60-69 = fair highest) 50-59 = marginal Even though they don’t have “perfect” color <50 = poor rendering abilities themselves For example, incandescents are very poor at rendering blues • Other light sources are judged in comparison CRI has many limitations but, it’s the most useful, and widely used, color indication system we have 13
  14. 14. Color TemperatureSome light sources seem “warm”. Theyare very rich in red light. However, they mimic the light created by a low temperature flame, like a candle. Hence, “warm” lights are called low color temperature sources.Some light sources seem “cool” or “cold”.They are very rich in blue light. However, they mimic the light created by an intensely hot, blue flame. Hence, “cool” lights are called high color temperature sources. 14
  15. 15. Common Color Temperatures CCT CRICandle light 1800K 100 CRIDaylight (Note that the color temperature of daylight changes throughout the day) • Sunrise, Sunset 3000K 100 CRI • Noon sun and sky 5500K 100 CRI • Cloudy day 7500K 100 CRI • North sky only (no sun) 10,000K 100 CRIIncandescent lamps • Edison era carbon filament 2400K 100 CRI • Modern tungsten filament 2800K 100 CRI • Tungsten halogen lamp 3100K 100 CRI • Theatrical halogen lamp 3200K 100 CRI • Photoflood lamp 3400K 100 CRI 15
  16. 16. Incandescent lamps give off light at In this slide, fluorescent light sources2700 Kelvin, which is very warm. at 4100 Kelvin (4100K) create a crisp, cool appearing space. Photo courtesy: IES 16
  17. 17. 2. Types of Lamps 17
  18. 18. Basic families of common commercial lamp types1.) Incandescent2.) Fluorescent3.) High Intensity Discharge4.) LED 18
  19. 19. The Incandescent LampElectricity flows through a coiled wire,called a filament. As it does, it heats thefilament , causing it to emit white light.The lamp is filled with an inert gas, usuallyargon, to prevent oxidation of the filament.The base can be one of many differenttypes and sizes. The most common is themedium base, also called the Edison base. 19
  20. 20. Incandescent Lamp ShapesThere are many incandescent lamp Note the most familiar “A” lampshapes, each serving a specificpurpose.The bulbs are typically made of anordinary hard glass which canbreak. Some lamps, like the PARlamp, are resistant to breaking aswell as to water and temperature.Special lamps, like rough servicelamps, are beefed up to survive in ahostile environment. Teflon coatedlamps will break but stay together 20like a soft boiled egg.
  21. 21. Color Characteristics & EfficacyStandard incandescent lighting is familiar to us all asthe typical residential “light bulb”• It has a “warm” orange glow Because it puts out most of its light in the orange and red parts of the spectrum It is very deficient in the blue and purple wavelengths• It is used as the reference standard (CRI=100) for other light sources at similar color temperatures (2500-3000K)• Incandescent Efficacy 10-20 lm/W• 21
  22. 22. A more efficient incandescent lampHalogen technology allows the filamentto run at a higher temperature thanregular incandescent lamps• This produces a “whiter” light• This is also more efficient, producing more visible light and less heat per watt of input 22
  23. 23. Fluorescent Lamps 23
  24. 24. What is a Fluorescent Lamp? ArcIn a fluorescent lamp, an electric currentpasses in an arc, like lightning, through aninert gas (argon or krypton).The arc emits radiation in the visible and UVultraviolet bands.The inside of the lamp’s glass tube is Visible Lampcoated with phosphorescent minerals wallwhich fluoresce (emit visible light) whenstruck by the UV light.The combination of minerals, or phosphors,determines the lamp’s color temperature Visibleand CRI. 24
  25. 25. Tube Size Matters T-12 = 1 1/2 inch diameter Because fluorescent lamps are virtually always tubes of some shape, the bulb style is called “T” T-10 = 1 1/4 inch diameter (like tubular, man!) followed by the lamp diameter in 1/8’s of an T-8 = 1 inch diameter inch. The diameter of the tube effects cost of production T-5 = 5/8 inch diameter (less material = less cost to manufacture and ship)The smaller diameter tubes also tend to have higher light outputper unit of surface area . Whereas the eye can look comfortablyat a bare T12 bulb, the light from a T5 can be more intense and 25glaring.
  26. 26. Main Shapes of Fluorescent Lamps The ends of standard T-8Full size lamps lamps: The black ended Linear with bases on each lamp with 1 pin is the F96T8 59-watt instant start end lamp; the others are 2 feet to 8 feet long standard rapid start T-8 lamps with medium bi-pin 4 to 215 watts bases.U-bent lamps Straight lamps bent Various T-8 U-bent lamps: into a “U” The industry standard, 6” leg spacing lamp is made Just a few types by all manufacturers - onlyCompact Fluorescent one company (Osram Sylvania) currently makesLamps (CFL) the narrow legged U- 4 to 32 watts lamps shown with it. Lots of shapes 26
  27. 27. Lamp Nomenclature 48” Here is General Electric’s product number for a standard, 32 watt, T-8 lamp with high CRI and 3500K color temperature: F for F32T8/SP35 Lamp color: SP means fluorescent special for a high CRI (70+) 35 refers toEither 3500KWatts ornominal T for tubularlength ininches The equivalent Philips product is F32T8/TL735 Lamp diameter The equivalent Osram Sylvania product is in 1/8’s of an inch FO32/735 Hint: the “O” means “Octron”, their name for T-8 27
  28. 28. Electronic BallastsElectronic ballasts employ analog or digital circuits whichrectify the AC power to DC current • then generate AC at very high frequency typically between 20 and 100 kHz. • Regulation of lamp current utilizes electronic circuits which offer superior lamp management Some electronic ballasts are “smart” and can sense incoming voltage and different lamp types. Inside an electronic ballast, there are smaller transformer windings and, various electronic devices. As a general rule, the simpler, the more reliable. Modern electronic ballasts are quite reliable. 28
  29. 29. Compact Fluorescent Lamps Photo courtesy: EPRI Compact fluorescent lamps represent the single greatest area of product innovation in recent lighting history 29
  30. 30. Induction lamps - A Type of CFL Operating principles • These are basically compact fluorescent lamps whose phosphors are energized by magnetic waves rather than an electric discharge Photo courtesy: Philips • Sometimes called “electrodeless” thus, there is no electrode to fail, or cause sparks Pros and Cons • Induction lamps last much longer than Photo courtesy: Osram ordinary lamps, 20,000 hours up toCurrent Products 100,000 hours!Phillips “QL” lamps, 55 • Lamps are relatively insensitive toand 85 watts temperatureGE “Genura” 23 watts • Lamps can be dimmed easilyOsram Sylvania, 100 and150 watts • Lamps are expensive • Shielding from radio waves needed 30 • Inductor may fail before lamp
  31. 31. High Intensity Discharge Lamps 31
  32. 32. What are High Intensity Discharge Lamps? High intensity discharge (HID) lamps are electric lamps in which light is created by the radiation from a very compact electric arc. The arc occurs in a vessel, or arc tube, that is designed specifically for operation at high pressure and high temperature. This is primarily what differentiates HID lamps from low pressure discharge lamps like fluorescent. The arc tube is filled with a noble gas and small bits of metal, whose vapor is energized by the arc and gives each lamp type its characteristic color. 32
  33. 33. Principal types of HID lampsMercury Vapor Mercury vapor lamps emit white light with exaggerated green and blue, tending to beHID lamps using mercury as themetal vapor. An older, less efficient deficient in red. Phosphor coating helpstechnology, rarely used indoors improve red performance.anymoreMetal Halide Metal halide lamps emit white light, theHID lamps using a number of different spectrum of which can vary depending onmetals, including mercury, indium, metals and arc tube type. Phosphorthallium sodium and others. Made in coating is sometimes used to improve redboth clear and phosphor coated lamps performance.High Pressure Sodium High pressure sodium lamps emitHID lamps employing sodium as the yellowish-white light which is generallymetal vapor. Made in clear and deficient in blue, green and red hues.diffuse coated lamps Certain HPS lamps can emit improved color. Diffuse coating does not alter color. 33
  34. 34. Metal Halide (MH) Lamps Similar to MV with the addition of some iodides of metals like Thallium, Indium, and Sodium Long starting and restartingSpecial timeslong arc Produce high levels of UVMH lamps radiationused in Color shifting can occur Efficacy range is 75-125scientific lumen/wattandphotographic process Standard mogulequipment based high wattage MH lamps Photo courtesy: EPRI Bent arc tube, horizontalStandard medium based Compact high CRI, MH lamps burning position highlow wattage lamps output mogul based lamps VERY GOOD ENERGY EFFICIENCY LIGHTS 34
  35. 35. High Pressure Sodium (HPS) LampsCurrently HPS lamps are themost popular lamp for lightingstreets, factories, and otherheavy duty lighting wherecolor discrimination is notconsidered important.Watts range from 35 to 1000. • Sodium lamps use no phosphors and emit no UV radiation • Sod. atoms emit visible light, mostly in the longer wavelength • PA cylinder transmits 90% of visible light created inside it • Performance is very sensitive to gas pres. inside the arc tube. • Quality of light may significantly reduce their effective efficacy 35
  36. 36. Mercury Vapor •Similar to fluo. lamps but •Makes the most sense where have lower efficacy(30-65) relamping access is difficult. •long life, low initial cost, and •They emit more UV radiation than color stability fluorescent•Mercury is pressurized 30-60psi creates more V. light POOR CHOICE FOR ENERGY EFFICIENCY 36
  37. 37. Electronic Ballasts and DimmingElectronic ballasts are beginning tobecome common in the 39,70 and 100watt sizes for standard lamps Some specialty HID lamps work only with electronic ballastsHID lamps can be dimmed to save energy Just like incandescent lamps, dimmed HID lamps are not as efficacious as lamps run at full power. Also, HID lamps experience a color shift when dimming that is generally not appealing But dimming can save considerable energy when daylight is available or other reasons exist to dim 37
  38. 38. HID Lamps and ColorLamp Family Color temperature CRIStandard clear metal halide (175-400w) 4300 65Standard coated metal halide (175-400w) 3700 703K Coated metal halide (175-400w) 3000 70Standard clear metal halide (1000 w) 3400 65Standard coated metal halide (1000w) 3400 70Standard clear metal halide (50-150w) 3200 65Standard coated metal halide (50-150w) 3200 70“Warm” ceramic metal halide (39-150w) 2900 85“Warm” ceramic metal halide (39-150w) 4100 85Compact source iodide (CSI) 4300 85HMI (film/theater lamp) 5500 92Clear mercury vapor 4700 33Coated mercury vapor 4100 50High pressure sodium 2100 21Deluxe high pressure sodium 2200 65White sodium 2600 85 38
  39. 39. LED Lamps• Newest type of energy efficient lamp• Two types: • red-blue-green array • phosphor-coated blue lamp• Emit visible light in a very narrow spectrum and can produce “white light”• Used in exit signs, traffic signals, and the technology is rapidly progressing• Significant energy savings: 82 – 93%• Longest lamp life: 40,000 – 100,000 hours 39
  40. 40. Comparing lamps Lum / Watt ColorType of Lamp Rendering Typical Application Life (Hours) Range Avg. IndexIncandescent 8-18 14 Excellent Homes, restaurants, 1000 general lighting, emergency lightingFluorescent Lamps 46-60 46- 50 Good w.r.t. Offices, shops, hospitals, w.r.t. 5000 coating homesCompact 40-70 40- 60 Very good Hotels, shops, homes, 8000-10000 8000-fluorescent lamps offices(CFL)High pressure 44-57 44- 50 Fair General lighting in 5000mercury (HPMV) factories, garages, car parking, flood lightingHalogen lamps 18-24 18- 20 Excellent Display, flood lighting, 2000-4000 2000- stadium exhibition grounds, construction areasHigh pressure 67- 67- 90 Fair General lighting in 6000-12000 6000-sodium (HPSV) SON 121 factories, ware houses, street lightingLow pressure 101- 101- 150 Poor Roadways, tunnels, canals, 6000-12000 6000-sodium (LPSV) SOX 175 street lighting 40
  41. 41. Designing with Light Recommended light levels for different tasks (BEE India, 2005) Illuminance level (lux) Examples of Area of ActivityGeneral Lighting for 20 Minimum service illuminance in exterior circulatingrooms and areas areas, outdoor stores , stockyardsused either 50 Exterior walkways & platforms.infrequentlyand/or casual or 70 Boiler house.simple visual tasks 100 Transformer yards, furnace rooms etc. 150 Circulation areas in industry, stores and stock rooms. 200 Minimum service illuminance on the task 300 Medium bench & machine work, general process in chemical and food industries, casual reading and filing activities.General lighting for 450 Hangers, inspection, drawing offices, fine bench andinteriors machine assembly, colour work, critical drawing tasks. 1500 Very fine bench and machine work, instrument & small precision mechanism assembly; electronic components, gauging & inspection of small intricate parts (may be partly provided by local task lighting)Additional localized 3000 Minutely detailed and precise work, e.g. Very smalllighting for visually parts of instruments, watch making, engraving. 41exacting tasks
  42. 42. Daylight 42
  43. 43. DaylightingThe practice of usingwindows, skylights, and otherforms of fenestration to Photo courtesy: Jeff Andersonbring light into the interiorsof buildingsAnd, the use of automaticphoto-controls to turn offunnecessary electric lighting Photo courtesy: Jeff Anderson 43
  44. 44. Benefits of Daylighting Positive human response Excellent light quality • Flicker-free, scotopically rich, full spectrum light source Positive energy impacts • More illumination than electrical lighting systems per cooling load Lessens pressure on cooling load • Savings coincide with summer energy peaks5% -70% lighting load reductions• But only with functioning photo controls 44
  45. 45. Skylighting canprovide excellentuniformillumination insingle storybuildings 45 Photo courtesy: Lisa Heschong
  46. 46. Balanced daylight from skylights and windows in a classroom Note luminaires run parallel to windows, and are turned off! Photo courtesy: Kalpana KuttahiahPhoto courtesy: Kalpana Kuttahiah 46
  47. 47. Light ( Lumens )Luminous Efficacy = Heat (Watt ) Higher efficacy = less cooling loads for same light Daylight outside has higher efficacy than all electric light sources Daylight inside of high performance glass has even higher efficacy • High performance glass = glazing filters out more heat (low SHGC) than light (high visible transmittance) 47
  48. 48. Luminous Efficacy Indoor Daylight with of Light Sources “High Performance” Glazing 140 120 100 Outdoor Outdoor Outdoor Lumens/Watt 80 60 40 20 0 Clear Sky HPS Sunlight Overcast Incand EE Mag Electronic Metal Halide Sky 48
  49. 49. 3. Street LightingThe operation of street lightingconsumes a significant amount ofenergy, particularly when considereda community, regional, Provincial orcountry level. It consumes 2-5% ofthe total country’s electricityconsumption 49
  50. 50. Original Lamp New Lamp Type Energy saving per Effect on Ra Effect on Effect on Notes Type lamp replaced light levels lamp life (including control gear savings) 250W mercury 150W high-pressure %37 - + +vapour sodium. 250W mercury 150W metal halide %37 + + -vapour 400W mercury 250W high pressure %35 - + +vapour sodium 400W mercury 250W metal halide %36 + - - If reductionvapour in light levels is acceptable.50W mercury 26W compact %50 + No change +vapour fluorescent lamp (triphosphor(80W mercury 42W triphosphor %48 + No change +vapour fluorescent lamp50W high 35W metal halide %28 + - - Ifpressure sodium reduction in light levels is acceptabl70W high 70W metal halide No change + + - Key benefits e.pressure sodium are improvemen t in colour Lamp Replacement rendering 50 ability and light levels.
  51. 51. Illumination can be dimmed according to traffic density or the time of night.- Less energy consumed.- Lamp life is increased.Dimming and part-night lighting is controlled by timetables.Detection of defective ballast components causing energy wastage. 51
  52. 52. Intelligent Street Lighting 52
  53. 53. (30) (1) 53
  54. 54. 54
  55. 55. Voltage Regulators 55
  56. 56. Electronic Ballasts 56
  57. 57. Astronomical Switch 57
  58. 58. Lamp Control Unit 58
  59. 59. Expected ResultsElectricity saving: It is expectedto save around 30-40% whichresults in annual cost savings ofabout JD 1.8 millionEmission Reduction: it isestimated to reduce CO2emission by 63000 ton annually.Awareness increaseFuel Import: The project will leadto a reduction in fuel imports by22000 T.O.E annually. 59
  60. 60. 60
  61. 61. Savings measuresReplacing inefficient lamps: More efficient lamps allow you to saveenergy while maintaining or improving light levels. If you decide to replaceyour lamps you will often need to change the control gear as well.Reducing the number of lamps operating: Reduce lamp numbers andmaintain lighting levels by using more efficient lamp types.Reducing operating hours: Use daylight sensors or time clocks to ensurethat lamps only operate when required.Replacing inefficient switching equipment: Replace outdated cadmiumsulphide light photo sensors with electronic sensors.Changing type of energy used: Consider use of solar energy. This can bean attractive option in some specialist applications.Improving maintenance practices: Lamps fail at fairly predictableintervals, so planned, mass-replacement of lamps is a good option andcan be less expensive than spot replacement. Lenses should be kept freefrom dirt to ensure that light output is not reduced.Improving data management: Energy management and other assetmanagement tasks will be simplified if records of lamp and luminairetypes are kept up to date. Commercial software is available to assist indata management. Its also important to know how much you are payingto run your street lights, and how the energy costs are calculated. 61
  62. 62. Energy Conservation Measures •Reduce General lighting •Reduce/Control Unnecessary lighting •Use High Efficiency Lighting Equipment •Maintenance •Daylighting •Lighting Retrofits 62
  63. 63. …how do we know how much lightwe actually have?…or how much light we are goingto get? • we will talk about measuring existing lighting conditions, • and calculating average lighting conditions and how and why these two might differ… 63
  64. 64. we measure lightIlluminance Meters are relatively inexpensive at from $50 to$500.• They measure incident illumination on a small integrating sphere, and report in footcandles or lux• Nice features for a good meter include: Illumination meters, also called a protective cover and/or case light meters or footcandle meters, are the most two or more sensitivity scales common a hold button to freeze a reading a remote measurement head that allows you to take readings at a distance from your body 64
  65. 65. Reduce General Lighting• Measure Light levels to minimum required.• Reduce artificial Lighting• Use task Lighting• Lower the Mounting Height of lamps• Clean lamps and luminaries regularly• Clean walls, Ceilings and other reflecting surfaces• Disconnect ballast were lights have been eliminated• Set up group re- lamping program 65
  66. 66. Reduce/Control or Unnecessary Lighting•Turn off lights when they are not in use•Review light switches to allow more localized control of lighting•Rewire light switches to allow more than one level of lighting•Use occupancy sensors in areas not permanently occupied 66
  67. 67. LightingControls 67
  68. 68. Why Control Lights?To save energy• by turning them off, or dimming them down when there is sufficient daylight when no one is aroundTo tailor light levels to specific needs• accommodate changing uses in the same space• let each worker optimize their spaceTo create different moods in the samespace• especially for hotels, restaurants, and function rooms 68
  69. 69. How Lighting Controls Save EnergySince electrical energy consumption is measured inkilowatt hours, there are two ways to save energy: Reducing power, Energy = Watts x Time or reducing hours 69
  70. 70. Lighting Control StrategiesManual Controls Automatic Controls• Simple switching • Timers• Bi-level switching • Occupancy Sensors• Dimming Passive Infrared Ultra sonic • Photo- sensor Controls Open loop vs. Closed loop Switching vs. Dimming Adaptation Compensation • Demand Management 70
  71. 71. Fluorescent Switching MythsMyth #1: “Fluorescent Lamps last longerif they are left on.”• It’s true that the burning hours of lamps are reduced with switching, but not necessarily the calendar life of the lamps.• Furthermore, the electricity savings quickly compensate for increased lamp replacement costs The economic break-even point is typically between 5 and 15 minutes depending upon electricity rates and lamp replacement costs. The same applies to HID lamps, but the break-even point is around one hour between switching. 71
  72. 72. Fluorescent Switching Myths Myth #2: “Leaving Fluorescent Lamps on saves more energy than turning them off.” When first turned on, the inrush current is 10 to 40 times higher than the normal operating current But the inrush lasts only 10 milliseconds!Current 1 second of the lamps being off saves as much energy as is consumed during inrush 10 msec Time 72
  73. 73. Manual DimmingIt is easy to dim incandescent lamps• Just add a rheostat to reduce the power to socketTo dim a fluorescent lamp a special dimming ballastis required• Dimming electronic ballasts are coming down in price, but they are still more expensive than regular electronic ballasts• Fluorescent lamps need to be operated at full power initially before they can be successfully dimmed• The reduction in power is not as great as the reduction in light output, therefore efficiency declines somewhat with dimming 73
  74. 74. TimersTiming controls vary from extremely simple tovery sophisticated• The simplest, mechanical twist timer allows user to chose an extra ten minutes to two hours of light• Automatic schedulers can be under individual or centralized control• Programmable and astronomical clocks are more expensive, but can predict sunrise and sunset throughout a year, accounting for daylight savings times, vacations, shift changes, leap year, etc. 74
  75. 75. Time Control: Using a Central System Energy Management Systems (EMS) have been used commonly to control HVAC systems for large buildings • EMS can also be used to control lights from a central or remote location Two features are essential to success: • A warning that the lights are about to go out • Local overrides that allow people to keep the lights on, or choose levels different from defaults 75
  76. 76. Automatic Time Control: Unpredictable SchedulesWhat do you do whenpeople come and go attheir own schedule?Motion Sensors!Originally developed bythe security industry, Photo courtesy: EPRIthey now commonly Ceiling mounted Wall mountedcontrol lights 76
  77. 77. Motion Sensors - Basic TypesPassive Infrared Sensors Ultrasonic Sensors• A sensor receives infrared light • The sensor emits a very high pitched (heat) from multiple directions, sound, and then listens for changing and registers changes in the echoes pattern just like a little bat• People and animals are warm, • Motion creates waves of different and move around a lot, so they frequency due to the Doppler effect are generally easy to spot • HOWEVER: the sensor may also• HOWEVER: the sensor must be detect motion of non living objects able to “see” the motion There is also a Dual Mode sensor which is designed to use the best of both types, and it usually costs twice as much, too. 77
  78. 78. Motion Sensor SavingsEnergy savings are highly dependantupon the occupancy patterns of therooms they controlTips:• In bathrooms, leave some of the lights always on so that there is never total blackness• Conference rooms are excellent candidates because they are used intermittently and no one “owns” the space, taking responsibility for the lights 78
  79. 79. Photo sensor ControlsThere are several ways to use photo sensorcontrols to save energy:• Switch exterior lights on at sunset and off at sunrise.• Switch or dim lights during the day in areas where there is adequate daylight.• Dim lights at night in lobbies and transitional areas where people’s eyes are adapted to the darkness outside. 79
  80. 80. Photo sensor DevicesA photocell is an electronic element which turns light energy into electric energy. A photoswitch uses a photocell to operate an on-off switch. Photo switches are commonly used to control outdoor lighting. A photosensor uses a photocell to generate a continuous signal which can be interpreted by a controller to change lighting levels by switching or dimming. 80
  81. 81. DaylightingPhoto sensors can be used with any combination of:• simple switching or multi-level switching --any lamp type• step (or two level) ballasts --fluorescent or HID• continuous dimming ballasts --fluorescentThere are two main photo control strategies:• Closed Loop - the sensor integrates the contribution of both daylight and electric light inside the space• Open loop - the sensor measures daylight only, either inside or outside the space 81
  82. 82. Use High- Efficiency Lighting Equipment (Retrofit or New)∗Use higher- efficiency, lower wattage lamps in existing fixtures∗Convert to more efficient light sources (Fluorescent, MH, SV)∗Use high efficiency or electronic ballast instead of standard ballast∗Use high efficiency luminaires, such as mirrored reflectors or thermally controlled fixtures∗Eliminate inefficient lamps from company stocks 82
  83. 83. Reduction of Lighting Feeder Voltage• Can save energy• Provided drop in light output is acceptable 83
  84. 84. Assessment of Lighting SystemsDesigning with Light• Better lighting: increased productivity• Two main questions for designer: • Choose correct lighting level • Choose quality of light (color rendering) 84
  85. 85. Assessment of Lighting Systems Recommended light levels for different tasks (BEE India, 2005) Illuminance Examples of Area of Activity level (lux)General Lighting for 20 Minimum service illuminance in exterior circulatingrooms and areas used areas, outdoor stores , stockyardseither infrequently 50 Exterior walkways & platforms.and/or casual or simplevisual tasks 70 Boiler house. 100 Transformer yards, furnace rooms etc. 150 Circulation areas in industry, stores and stock rooms. 200 Minimum service illuminance on the task 300 Medium bench & machine work, general process in chemical and food industries, casual reading and filing activities.General lighting for 450 Hangers, inspection, drawing offices, fine bench andinteriors machine assembly, colour work, critical drawing tasks. 1500 Very fine bench and machine work, instrument & small precision mechanism assembly; electronic components, gauging & inspection of small intricate parts (may be partly provided by local task lighting)Additional localized 3000 Minutely detailed and precise work, e.g. Very smalllighting for visually parts of instruments, watch making, engraving. 85exacting tasks
  86. 86. Assessment of Lighting Systems Methodology for Efficiency Study • Step 1: Make inventory of lighting system elements and transformers Table: Device rating, population and use profile Lighting Rating in Use / Shifts as Plant S. No. Device & Watts Lamp Numbers I / II / III shifts / Location Ballast Type & Ballast Day 86
  87. 87. Assessment of Lighting Systems Methodology for Efficiency Study • Step 2: Measure and document the Lux levels • Step 3: Measure and document the voltage and power consumption at input points • Step 4: Compare the measured Lux values with standard values as reference • Step 5: Analyze the failure rates of lamps, ballasts and the actual life expectancy levels 87
  88. 88. Assessment of Lighting Systems Methodology for Efficiency Study Step-6 : identify improvement options, for example: • Maximum sunlight use options through transparent roof sheets • Replacements of lamps and ballasts to more energy efficient types • Selecting interior colors for light reflection • Modifying layout as per needs • Providing individual / group controls for lighting • Use Task Lighting 88
  89. 89. ExampleA hospital had 415 (2x40) watt fluorescent fixtures,which operate 24 hours/day, year around. The lampsand ballasts were replaced with (2x36) watt andelectronic ballasts.Assume: Power consumption for magnetic ballast equals 15 watt and electronic ballast 5 watt. 36 watt lamp saves 10% of energy Electronic Ballast price =$15 36 Lamp price = $1.5 Utility price =0.07 $/kWhCalculate: Reduction in Demand KW Energy Saving; kWh and cost saving Payback PeriodIgnore labor cost 89
  90. 90. Demand Reduction = 415 x (2x(40+15)- (2x36+5))/1000 = 13.7 kWEnergy Saving = 13.7 x 8760 = 120012 kWhEnergy Cost Saving = 120012 x 0.07 $/kWh = $ 8400Electronic Ballasts Cost = 415 x $ 15 = $ 6225New Lamps Cost = 415 x 2 x $ 1.5 = $ 1245Total Retrofit Cost = $ 7470Simple Payback = 0.9 years 90
  91. 91. Case Study 2 Saudi ArabiaInvestment Saving Payback (Rial) (Rial) (Year) 987,000 176,250 5.6 91
  92. 92. Case Study 1 Street Lighting in Irbid CityNo. of Invest. Exist. Expected Saving Pay % ofLamps Needed Consum Consum Back Savin JD p. p. JD year g GWh GWh2080 374,40 10.4 6.2 139,68 2.68 40% 0 0 2 92
  93. 93. Case Studies- EE Measures Distribution of lighting Numbers, Movinpic (Deadsea) Number of lighting Lamps CFLs Floodlights & 27% Others 2% Flourescent lamps 5% Incandescent 17% Halogen 49% 93
  94. 94. Case Studies- EE MeasuresSavings-Lighting: Movinpick (Deadsea) Annual Annual Cost Investment Pay Back Energy Item saving saving Required Period (JD) (JD) (Year) (kWh)Replacement ofConventional Ballast by 79182 4988 6651 1.3Electronic Ballast forfluorescent lampsReplacement of 35 wattby 20 watt Halogen 47786 3011 1091 0.4LampsReplacement of 25 wattincandescent lamps by 7 watt 177245 11167 4093 0.37Compact Fluorescent lampsTotal 304213 19166 11835 0.62 94
  95. 95. Case Studies- EE Measures Savings-Lighting: Four Seasons Annual Annual Investment Pay Back Energy Cost Required Period Item saving saving (JD) (Year) (kWh) (JD)Replacing of halogenlamps 149,796 9,437 1387 0.1Replacing of Incandescent 293,054 18,462 5845.5 0.31lampsUse of occupancy 98,550 6,200 Nil immediatelysensors at Ball RoomsTotal 541,400 34,099 7232.5 0.3 95
  96. 96. Thank You 96