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Transcript of Lighting Management
Management Done by: Zaid Atari
Mohammad Bahlawan < M In the past, lighting has been conceived by most managers under the myth of " More light is BETTER !!"
"No space can be over illuminated !!" Others have realized this wrong belief and thought of a solution to reduce expenses.
Like the case in the 1970s ! De-lamping Employees were left in the dark Today's retrofits aim not only to reduce energy expenses but also to improve lighting Efficiency and worker productivity. Why Lighting? It is easier to make lighting improvements than any other process upgrade.
provides many opportunities for cost-effective energy savings.
It attracts immediate employee attention and participation. Lighting usually accounts for 30-70% of the total energy cost in commercial and residential sectors and 5-25% in industrial facilities. Optimization of energy consumption, with no sacrifice in lighting quality. It is a combination of thoughtful design and selection of appropriate lamp, luminaire and control system selection, made in conjunction with informed choices of the illumination level required. What is Efficient Lighting Terminology Types of lighting Design & Management Since all buildings have lights, lighting retrofits are very common and generally offer an attractive return on investment.
lighting systems represents a significant percentage of electricity consumed in most countries. Lux/Foot candle: It is the most important measurement, represents how much light is actually reaching the workplace (lumen/m2), (FC/ft2) Lumen: represents the output of a lamp, describes how much light is being produced by a lamp. Watt: Represents the electrical input to the lighting system. Lighting requirements are specified in terms of lux/ foot candle not lumens or watt Efficacy: The amount of lumens produced per Watt from a lighting source. High efficacy mean: Providing more light with the same amount of power. Uniformity: Describes how evenly light spreads over an area.
Allows the occupants to perceive the environment continuously and without sudden breaks caused by lighting level drops.
can be expressed as: Highest illuminated area/ lowest The closer to "1" the more uniformity we have, This ratio varies depending on the task and place. Achieving high uniformity ratio is not the target Glare Caused by relatively bright objects in an occupant’s field of view and can result in visual discomfort. Visual Comfort Probability (VCP): VCP is a rating given to a fixture that indicates the percentage of people who are comfortable with the glare. For general spaces 70% is recommended HOW TO REDUCE GLARE:
Replacing fixtures with high VCP ones
Using indirect lighting
Reducing ambient light levels. Color rendering index (CRI) Coordinated Color Temperature (CCT) Color Values of CRI range from 0 to 100.
The higher the number, the easier it is to distinguish colors.
depends on the place CCT is measured in (Kelvins) and represents the color that an object would radiate at a certain temperature:
Red: CCT = 2000K
White: CCT = 5000K
Blue: CCT = 8000K What type of lamps shall I use ?! I need my system to be EFFICIENT !! CRI illumination CCI Glare Efficacy Uniformity Quality Lamps Incandescent Halogen Tungeston LED Low
Pressure Mercury Sodium Discharge Sodium Mercury Compact Fluorescent Linear Flourecent Cost Produces light by discharging an electric arc (similar to fluorfluorescent.escent)
Generates much more light, heat and pressure than Types:
Mercury Vapor Lamps
Metal Halide Lamps
High Pressure Sodium
Low Pressure Sodium Efficacy Light emitting diodes are semiconductor devices which emit light.
LEDs are an emerging technology and are often claimed to be very efficient
They can potentially have a very long life, (up to 50,000 hours).
offer reasonably high efficiencies (around 40 to 60 lm/W in a luminaire).
They are compact and tough. Lighting components Fixture ballast A unit consisting of the lamps, ballasts, reflectors, lenses or louvers and housing Role:
Connect the light source to the electricity supply
Protect the light source from mechanical damage
Control the distribution of light Efficiency Reflectors Coefficient of Utilization (CU) diffusers Percentage of lamp lumens produced that actually exit the fixture in the intended direction Percentage of lumens produced that actually reach the work plane. Includes fixture efficiency, mounting height, and reflectance of walls and ceilings. Prevent occupants from seeing uncomfortable direct beams of lights which hinders the occupant’s ability to view work surfaces and computer screens. Increase the VCP of a fixture Control gear for discharge lamps An efficient lighting system should provide the right Role:
Limit and stabilizes lamp current
Provide the correct condition for the ignition of the lamp Ballasts are either:
Electronic Electronic ballasts are superior to magnetic ballasts because they are: More energy efficient.
Less lamp flicker
Less ballast noise
Less waste heat. How Light is produced? Incandescence or thermo-luminescence: is the production of light from heat.
Electrical Discharge: is the production of light from the passage of electricity through a gas or vapor.
Phosphorescence & Fluorescence : the processes of converting the invisible ultra-violet energy emitted normally from an electrical discharge, into visible light Quality & Watt
CCT Quantity Dimensions Case Study Optimization People Lighting Design
Driving Factors Workplace Task Money Basic steps to improve lighting efficiency First: Identify qualitative and quantitative requirements Second: Improve light source efficiency (frequent occupancy) Third: Optimize lighting controls (infrequent occupancy) Maintaining system performance New Technologies Residential Industrial Lighting system controls A control system must include:
Input devices (switches, occupancy sensors, timers & photocells).
Control processes (from simple wiring network to a computer based control system).
Controlled fixtures (turning them ON and OFF). Switches Occupancy Sensors Timers Photocells Daylight They vary from simple switches used to turn the lights on/off to dimmer switches. They are based on Passive infrared (PIR) detectors.
They monitor the presence of people in a place and switch lights ON/OFF accordingly. Time switches can turn lamps on and off at given times.
Also used in street lighting, by changing the time to switch lights throughout the year so that the lamps are switched at dawn and dusk. The simplest to use, they switch on at one illuminance value and switch off at another.
commonly used to turn exterior lights on at dusk and off at dawn. Systems Exist to Serve their Users A lighting system should acknowledge human variability and capability as a design parameter. Considerations for an efficient lighting system:
Proper distances from light sources.
Proper use of colors.
Avoid unwanted excessive glare. Inefficient lighting system not only affect the occupants health but also can sharply affect worker productivity A lighting process design begins with an understanding of the user’s task in overall system performance Task Lighting The act of reducing ambient light levels while maintaining or increasing the light levels on a particular task. Efficient Non-Uniform Lighting Design Considerations:
Occupancy Area and distances
Effect on HVAC HVAC Lighting is an expensive way for Heating Efficient Lighting system Less heat dissipated Reduced air-conditioning cost (Summer) Increased heating cost (Winter) Since most offices use air-conditioning for more months per year than heating, efficient lighting can significantly reduce cost. It's All About SAVINGS Lighting systems lose performance over time
Factors affecting this degradation of performance:
Lamp lumen Depreciation (LLD)
Fixture Dirt Depreciation (FDD)
Room Surface Dirt Depreciation (RSDD)
These factors can be minimized by cleaning surfaces and minimizing dust Group Re-lamping Advantages:
Group relamping at one time can be more efficient than re-lamping one at a time.
Bulk purchasing may also yield savings.
Reduced time and labor cost.
Reduced disposal costs
Re-lamping interval is either determined by facility manager evaluation or from recording and documenting lamps replacement Examples of proven technologies: Miniaturizing of electronic ballasts Ballasts Ballasts with universal voltages Advantages:
Smaller, thinner and lighter.Less material, easier handling and installation.
Fit into the new low profile fixtures. Those ballasts with universal voltages feature will automatically use any line voltage applied (between 120-277 V). T2 lamps The sub- miniature 0.25″ diameter lamps Side tabs instead of end points.
Available in standard fluorescent colors
CRI in the mid 80s
LLD of 0.95
Lamp efficacy ratings in the mid 60s.
Low profile fixtures used for task and under-counter lighting.
Used in lighting showcase and decorative lighting. T5 lamps High output T5 Provide higher lumen output than standard T5.
Available in the three standard fluorescent color temperatures.
CRI greater than 80.
They peak in their lumen rating at 35°C.
Generate from 1.5 to 2 times the light output of the standard T5
They are approximately 10-15% less efficient than standard T5 lamps Induction lighting Characteristics:
provide white light with a minimum color shift.
CRI and LDD similar to fluorescent lamps.
have no electrodes to wear out as other lamps.
Long life is the primary advantage of these systems
High maintenance labor cost
Good payback period.
They come ON relatively quickly.
short re-strike time Lets investigate our meeting room lighting efficiency Using Dialux software Three different cases were examined:
1. Current case
3. Under-illuminated Current Under-Illumination Over- Illuminated They can improve fixture efficiency, Light intensity and distribution.
They redirect the light downward the fixture.
They perform better when there are less lamps in the fixture.
The most energy efficient light Relative amounts of daylight and artificial light are regulated by sensors and a control system.
Daylight harvesting employs photo-sensors and electronic dimming ballasts
Some building Management systems (BMS) accomplished this control by using a depreciation algorithm to adjust the output of the electronic ballasts instead of relying on photo-sensors. Thank You High Pressure