A long lasting luminaire is a combination of the right LED and an incredible heat sink design
By Kartiki Negi
Monday, July 21, 2014: Much has been said about the benefits of LEDs in terms of efficiency and efficacy. Similarly, there should be more awareness about LED luminaires, which will be most efficient and have a longer life if the right kind of LEDs are fixed into the right fixtures and components.
This was emphasised by Greenstar, a group company of Toshiba Lighting & Technology Corporation, Japan, at a seminar ‘Little Known Facts About LED Lighting’, organised with an aim to create awareness among the LED consumers about advantages of LED lighting and how can it contributes in reducing light pollution.
Several eminent speakers from Greenstar such as Chuk Chakravarty, CTO, Katsuhiro Shinosawa San, CEO, Sarosij Sengupta, director, India technology and operations centre, and Rajat Behal, VP, sales and marketing spoke about the latest LED technology. Among the others were Amrith Prabhu, country manager Philips Lumileds and Murili Devrajalu, senior manager-green initiatives Infosys.
Speaking at the seminar, Sarosij Sengupta said, “Buyers must understand that the life of the luminaire is linked to more than just the LEDs life, which is 60,000 hours.” He explained that the luminaire’s life depends on three aspects—life of the LEDs, the power supply/electronic driver and the operating environment. Even if one of these fails, the whole luminaire will fail.
Environment conditioning for LEDs
Sarosij Sengupta pointed out that the operating environment of the LED and luminaire is the most important factor influencing performance, since lights perform differently in different environments. Therefore, the luminaire should be made to match the application of a product. “A long lasting luminaire is a combination of the right LED with a 60,000-hour life and an incredible heat sink design, as heat is the biggest enemy of an LED light,” said Sengupta.
Choosing the right luminaire
Sengupta pointed out that choosing the right luminaire will lower the total lifetime cost of the lighting installation. “For a good LED light, one should look for total luminous flux, luminous intensity distribution, B-U-G rating, electrical power characteristics, luminous efficacy and colour characteristics (CRI, CCT, etc),” he said.
The seminar concluded that buyers needed to check the following factors in any LED luminaire, in order to ensure it lasts for a long time:
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Adequate illumination, that is, lumens
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High uniformity as there should be no dark patches
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No light should be wasted, so zero uplight
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Quality of light, which includes colour rendering index (CRI), correlated colour temperature (CCT), etc
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Maximum efficacy in terms of light per energy unit
Importance of tests
In a country like India, LED lights are exposed to different environmental conditions such as high and low temperatures, voltage fluctuations, water and dust pollution, vibration, surges, spikes and thermal shock. An LED luminaire should be protected from all these factors and, hence, should be put through several tests before being launched in the market, said Sengupta. Some of the prominent tests include in-situ temperature measurement tests, which measure the LED source temperature within the LED luminaire or lamp. Another test is the TM-21-11, which is a method of taking LM-80 data and making reasonably accurate lifetime projections of the LED product. The high accelerating light test exposes the LED to temperatures of 300ºC to 400ºC. If the product passes this test successfully, then it can easily withstand the normal temperature fluctuations.
Users should also be aware of the standards that LED luminaires need to comply with. They must ask for the following protection while buying an LED light:
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Optical performance as per the LM79 standard
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Minimum 3G vibration resistance
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IP66—water and dust ingress protection, etc.