LED for INDOOR LIGHTING APPLICATION 1 What is LED LED : Light Emitting Diode LEDs are tiny devices made from semi conductor materials that convert electrical energy into visible and near UV wave lengths and of course some heat when they are assembled in a package and connected to electrical circuit. These semi conductor materials are basically crystals,comprised of mixture of below given elements. - Gallium phospide [GaP] - Galliun Indium nitride [GaInN] 2
What is LED The diode is formed by bringing together two slightly different semi conductor materials which are called layers. Electrodes are placed on each end of this assembly When a forward voltage is applied to this structure electrons move from one layer, that is, from negative to positive and due to the recombination photon is emerged. Ideally the excess energy from each electron s transition results in the spontaneous emission of Photon 3 Why LED Over the years many improvements have been achieved with these tiny diodes in following parameters. - colour range - lumen output - colour stability - life span,etc.. With these credentials in hand the LEDs have started encroaching, nay, dominating every field of lighting. Being smaller in size.., LEDs have become easy and handy for us.., the lighting designers, to utilize its potential in each and every application. 4
Life Time & Lumen Maintenance Light Source Comparisons 110% 100% Lumen Output (%) 90% 80% 70% 60% 100 W Incandescent 5mm LED 42W CFL 50 W Tungsten Halide 400 W Metal Halide 25 W T8 Fluorescent Cree XLamp 50% 40% 0 10 20 30 40 50 60 70 80 90 100 Operating Time (k hrs) LEDs lead any known light source in lifetime and lumen maintenan ce (>50,000 hours at 70% lumen maintenance) LEDs inherently fail gracefully no burn out, catastrophic failure Up to 100,000 hours (>11 years continuous life) can be projected 5 Low power vs Power LEDs There are two varieties of LEDs in use. 1. Low power LED 2. Power LEDs Low power LEDs Used in applications like indicator lights, mobile phones, TVs, etc Power LEDs Lighting Due to customer demands low power LEDs are also used in lighting applications 6
Low power vs Power LEDs Low power LEDs produces less light out put and correspondingly the heat produced is less per LED. High power LEDs on the other hand produces more heat, but, the lumen output per watt is more. It also attaches a challenge on thermal management which if rightly addressed to.. ensures very high stability in the out put and in life This day we have LEDs from manufacturers like CREE which gives an out put of >125 lumens/watt 7 Lighting Class Phosphor: Stable White Point CREE leads the industry in providing white point stability data for Xlamp LEDs Under the stable specified operating conditions, the color temperature of the LED should be stable ( COLOR Test Stability data provided in next slide. This is a Solid State Lighting Industry (SSL) Standard Test ) 0.46 2500K 0.45 CCy 0.44 0.43 0.42 0.41 0.40 0.39 0.38 0.37 0.36 0.35 0.34 0.33 5000K 1000 hrs 4000K 500 hrs 3000K BBL Low Quality LEDs may drift in any direction in terms of COLOR Temperature. ( As indicated by the Red Arrows ) 0.32 0.33 0.34 0.35 0.36 0.37 0.38 0.39 0.40 0.41 0.42 0.43 0.44 0.45 0.46 0.47 0.48 0.49 0.50 CCx Starting Point Hour ZERO XLamp White LEDs will maintain white point stability even under the harshest of operating conditions! 8
0.46 0.45 0.44 3000K 2500K 0.43 0.42 4000K 0.41 0.40 500 hrs BBL CCy 0.39 5000K 0.38 0.37 0.36 0.35 1000 hrs 0.34 0.33 0.32 0.33 0.34 0.35 0.36 0.37 0.38 0.39 0.40 0.41 0.42 0.43 0.44 0.45 0.46 0.47 0.48 0.49 0.50 CCx Starting Point Hour ZERO 8A Lighting Class Phosphor: Stable White Point After 5000 Hrs. of accelerated testing (If = 700mA, Ta = 85C), the Color drift remains within 4 Step Macadam 0.010 If = 700mA 0.008 0.006 0.004 0.002 v' 0.000-0.010-0.008-0.006-0.004-0.002 0.000 0.002 0.004 0.006 0.008 0.010-0.002-0.004-0.006-0.008-0.010 u' 9 1008 hours 3145 hours 4507 hours 5087 hours 4-step Macadam 7-step Macadam
Low power vs Power LEDs LIGHTING -CLASS LEDs High Output (cool/warm) >107/80 lm @ 350 ma (min) High Efficacy (cool/warm) >97/73 LPW Stable Color Point > 40K hrs per IESNA LM -80 Long Lifetime > 40K hrs per IESNA LM -80 Isolated Thermal Path Designed for Lighting apps High Color Rendering Index > 75 Available in a range of CCT 2700K -7000K ANSI Binning Per ANSI 78.377A 10 Applications Lighting Indoor Outdoor Parks Others Office Retail stores Streets Shops Theatres Malls Architectural Fuel stns 11
Office Lighting As has been seen in the previous slides, we have graduated from using the incandescent lamps to fluorescent lighting to LED lighting Right from the spot lights used for the corridors, lift lobby, etc to the 2x18s,4x14s,4x24s,4x54s used in variety of working areas such as cabins, conference rooms, pantries, toilets which belong to the family of conventional fluorescent luminaires, LEDs are coolly finding their way in.. with a promise to offer reduction in power bill and reduction in heat contributing to a Greener Globe. 12 Office lighting A case study Recently we have completed a project of office lighting for our own office the details of which are as given below. Project : Future group office, Mumbai Area : ~ 200000 sq.ft Luminaires : Combination of LED and fluorescent Power consumption achieved : < 0.5 W per sq.ft [LEED spec : 0.8W/sq.ft] Diffuser used : Krome diffuser made of very special bio degradable material which offers 30% more lighting as compared to acrylic diffusers Fixtures : Designed by us and manufactured in our own factories 13
Office lighting A case study Some of the LED luminaires used in our Office Lighting project 14 Retail store / Mall Lighting Potential exists to replace the metal halide and fluorescent luminaires which are very commonly used in all the retail stores with LED fixtures We have already offered track mounted LED fixtures to one of our customers M/s. Bharathi Wall mart using 8 nos.3w LEDs Also presented LED solutions for spot lamps and down lights to one of our prestigious clients for their speciality stores Handful of projects from our existing customers including Spencer Plaza for replacing existing power guzzlers with LED luminaires 15
Challenges Ahead Yes.. we are slated to contribute to a Greener Globe through continuous learning from our customers and from our own successes and non-successes Our R&D is on a continuous vehicle of efforts with thirst to develop newer and better products for the customers We are focusing on the fixture designs to offer optimum solutions Thermal management : Special thrust is given in the design and manufacture of heat sinks, as we have customer requirement mixed with a combination of special fixtures and the standard ones 16 THANK YOU 1