technical NOTES

(Project Pridr) #1

Compared to traditional lighting solutions, LEDs are more efficient source of light
and consume typically 50 to 60% less energy than metal halides, high-pressure
sodium, incandescent, and mercury vapour fixtures.


This significant reduction in energy costs could result in substantial cost savings
where energy costs are particularly high.


By virtue of their solid-state design, LEDs are a more durable lighting solution and
reliable, long-life performance for a decade or more, with some manufacturers
now offering a 3 to 5 year full-performance warranty. The extended life and reliability
of LEDs saves by significantly reducing annual maintenance expenses.


LED are energy efficiency, maintenance savings, and overall lower cost of ownership.
LED technology is already proven to be the most cost-effective alternative to
conventional lighting systems. With a more durable design and advanced features
for convenience and extended performance, LED lighting can deliver significant
savings, high ROI.


17.1 Lighting Systems Characteristics



  • Lumen: Lumen is the SI units for luminous flux, which is the quantity of light
    emitted by a source or the quantity of light received by a surface. Typical values
    of luminous flux emitted by some common sources of light are given below
    Luminous fluxes emitted by common light sources are as under (for reference)

  • Lux: Lux is the SI unit for illuminance, which is a measure of the direct illumination
    on a surface area of one square meter. One lux is one lumen/m2.
    LED lighting has superior power factor in the range of 0.93 to 0.99 over the
    fluorescent lighting of 0.59 to 0.69. The magnetic ballast used in the fluorescent
    lighting is the main culprit that contributes to the low power factor of fluorescent
    lighting system. From the measurement, it can be shown that the input power
    rating of LED lighting uses only about 45% of fluorescent lighting system.


It is important to note that the ballast used in the fluorescent lighting system
has further contributed for about 6W for total wattage used in the fluorescent
lighting system.


17. LED Fixtures v/s Conventional Lighting Fixtures


Lamp Lamp Wattage Lumens
Fluorescent lamp 15 watt 810
Fluorescent lamp 36 watt 2200
LED 18 watt 1800

Criteria LED Fluorescent
Power Factor (PF) 0.99 0.69
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