As we mentioned before, there are many factors which caused led high bay ’s lumens depreciation. Then how could we do to effectively decrease lumens depreciation? This article mainly introduce that the chip of LED fixtures is extremely sensitive to temperature. Now, all what we should do is to adopt various measures to control temperature in order to efficiently increase the lifetime of LED fixtures and lumens depreciation.
1. LED Cold Light Source
LED gives out light mainly depending on the transition of electron between energy bands which is totally different from tradition incandescent that shines by solid heat source. Its spectrum is single without infrared. Therefore, LED is named as cold light source. In fact, LED chip is only able to transfer 10% electric energy into luminous energy and the left 90% into thermal energy. Besides, the thermal energy only can emit by transmission. Therefore, the design of heat dissipation is quite important for LED working normally.
2. LED Working Temperature
The chip of LED fixtures is extremely sensitive to temperature, which is the same with other semiconductor. Therefore, the lifetime of LED is related to temperature. In theory, when the temperature is 25℃, the lifetime is 100,000 hours. With the increase of temperature, the lifetime correspondingly shortens. When temperature increases every 10℃, lifetime reduces one half. If the temperature reaches 95℃, lifetime is only left 780 hours. The working temperature of many LED in inferior quality is more than 95℃, that is to say, its lifetime is less than 780 hours.
3. Heat Dissipation
After experiment and test, expert suggest that the temperature of LED High Bay should be controlled under 55℃. If the weather temperature is 35℃, in order to make the temperature below 55℃, on the condition of natural convection, every 1W needs 100cm2 heat dissipation area in shell, besides, the heat resistance between chip and heat sink should be less than 10k/w.
4. Use copper bracket replace steel bracket
The majority of LED fixtures in the market are applied to steel bracket to save manufacturing cost, whose lifetime is only about 1/4 of copper bracket. Therefore, it’s suggested to use copper bracket.