LED FAQ's - everything you need to know about LED's for commercial use.
Although LED's have been about for a while most people do not know what an LED is or what makes it different from other lighting options. We are regularly asked questions about LED's so we have put together a short list of FAQ's that we get everyday to help you understand why LED's are the way of the future.
LED is the common abbreviation for a light-emitting diode. Each individual LED consists of a semiconductor diode that emits light when a voltage is applied to it. The electronics industry has used LED technology for several decades as indicator lights for various electronic devices. In more recent years, LED technology has progressed to the point where it is viable for general lighting applications.
Where have LED's been used in the lighting industry?
LED's are commonly used in aesthetic, effect, or specialty lighting applications, including architectural highlighting. Most traffic lights and exit signs, for example, now use red, green or blue LED's.
How do you evaluate LED products?
Lumen output is only part of the story and can be misleading. To fully evaluate an LED product one needs to review the overall system efficiency, optical control, thermal management of the LED's, and know at what point in time the fixture will reach 30 percent lumen depreciation. Products with good optical efficiency and thermal management will be able to deliver more lumens, on average, than traditional HID products.
Can I use LED lights in outdoor or wet environments?
LED360 will always work with your location and conditions to choose the correct luminaire for your application. Most LED's can be placed in outdoor locations provided they are not directly exposed to water. They will often be rated for damp locations so can be recessed in soffits or in outdoor lighting fixtures. Some LED's will be specifically rated for wet locations.
Do LED lights emit IR or UV light?
Unlike incandescent or fluorescent light sources, LED lights generally do not emit IR (infrared) or UV (ultraviolet) spectrums, which means they are not harmful to your skin, health, products or materials.
How are LED lights able to outperform HID?
Super-bright white LED lights have the advantage of minimal lumen depreciation, better optical efficiency and high lumens per watt. LED lights also have a vastly longer life span than traditional lamp sources. The luminaire must be designed to leverage these inherent advantages of LED lights. A Total Systems Approach is needed for an LED light to bring all these features together.
LED luminaires also have an environmental advantage in that they contain no Mercury, are NZAS compliant, last longer and produce less waste. In fact, 20 to 25% (by weight) of the product is made using post-consumer recycled materials (aluminium castings and extrusions). Furthermore, 70% (by weight) of LED fixtures are readily recyclable. The remaining LED circuit boards, drivers, wires and connectors are all non-hazardous, mercury-free, and NZAS compliant.
If an LED light has lower initial lumen output than a traditional HID light, how can LED lights claim to deliver lumens more efficiently than HID?
When you average delivered lumens over the course of 60,000 hours, you'll see that a LED light outperforms a 400-watt MH lamp operated in a horizontal position (60,000 hours is used for this comparison to show three full life cycles of the HID).
The MH's lumen depreciation, as well as optical and ballast losses, quickly reduce output of the HID system. Note that there are three relamps over 60,000 hours.
Conversely, LED lighting has significantly better lumen maintenance and a more efficient driver. Also note that the LED fixture typically doesn't need relamping from zero to 60,000 hours.
Result: On average LED lights deliver 74% higher lumens than HID over 60,000 hours.
Do I have to replace LED diodes?
An LED does not burn out like a standard lamp, so individual diodes do not need to be replaced. Instead, the diodes gradually produce lower output levels over a very long period of time. If one LED fails, it does not produce a complete fixture outage.
How does ambient temperature affect the efficiency of LED lights?
LED fixtures must be designed with junction temperature thermal management as a key component and use the correct LEDs. These products will then be robust enough to operate in most ambient temperature applications. Unlike fluorescent sources, cold temperatures do not impact the performance of LED lights.
Why is the life span of an LED light measured as lumen depreciation?
The life span of an LED light is vastly longer than that of incandescent, fluorescent or HID lamp sources, generally lasting 50,000 hours or longer. Although the LED light never really burns out, product life span is measured by lumen depreciation.
The Illuminating Engineering Society's (IES) current standard for calculating the life of an LED light as the point at which the LED light reaches 30% lumen depreciation.
Remember, a 100,000-hour rating is not equivalent to lamp life rating. A LED lights life is rated where it has reached 30% lumen depreciation. At 100,000 hours an LED would still be operating, but at a decreased lumen output.
How long is 50,000 hours?
Based on how long a fixture is illuminated per day, here's what 50,000 works out to: