This is the first installment in an on-going series that will address all of your LED lighting concerns. Today’s experts are Joel and Tim.
How is the price of LED bulbs going to change over the next few years?
Tim: Pricing is largely influenced, or outright set, by the chip’s manufacturer. Different types of chips will also reveal differences in prices because, as with most products, the higher a chip’s quality, the more expensive it will be. However, as LED technology continues to improve, prices will probably come down.
Joel: Actually, the pricing may not come down, but the best chips are doubling in light output every 12-18 months, so the compensation is increased light output.
What are the technical challenges faced by the R&D; department when trying to design a replacement bulb?
Tim: There are two basic challenges faced by researchers and designers of LED lights – heat dissipation and Color Rendering Index (CRI) rating. The former is normally solved with a heat sink of some kind while the latter is achieved with a phosphorous coating that adjusts the light’s color temperature by making it “warmer,” i.e. closer to sunlight or traditional incandescent light.
Any interesting new bulbs in development?
Joel: Not really. Standard bulbs – like A-19, MR-16, PARs, fluorescents, etc. – are what we are set on replacing, and we have models designed to do just this already in production.
According to my research, LEDs aren’t very expensive. What makes the bulbs so expensive?
Tim: What LED did you research? The old 2-pin 5mm? Super-flux? SMD? High Power?
Joel: The best chips on the market – Cree, Luxeon, Nichia – are not inexpensive. In fact, it is by and large the price of the chip that sets the price of the fixture, be it cheap or expensive. We deal largely with professionals who stake a lot of money on the quality of our product, so it wouldn’t make sense for us to sell fixtures that use cheaper, far less reliable chips.
Why is the warranty so short when they are designed to last much longer?
Joel: This is a common question as well as a logical one. It is true that LEDs (the Cree XRE type that we use in our best bulbs) can easily last 80,000 hours in a perfect environment. What we are afraid of is the lamps being used in what I will call, for lack of a better term, an abusive environment. In other words, it protects manufacturers like us from wholesale replacement situations where a large quantity of bulbs has failed prematurely due to improper ventilation and installation.
How does LED dimming work?
Joel: It’s important to keep in mind that the LED is a computer chip. As such, it cannot be dimmed by varying the amperage (in a series type situation). What we do instead is keep the amperage constant and vary the voltage. It is certainly at first blush more complicated than standard dimming, but it is quite possible and practicable.
How are today’s LEDs that are used in light fixtures different from classic LEDs used as indicators?
Tim: LED’s in light fixtures for the most part are using High Power chips specifically designed to be used in lighting fixtures and bulbs in place of things like incandescence and fluorescence. Indicator lights use older, low-brightness LED technology that has been around for decades.
What is on the horizon in terms of advancement of brightness?
Tim: The best chips we use are rated at about 60-70 lumens/Watt. The problem facing this figure, as I indicated earlier, is heat dissipation and CRI rating. There are indeed much brighter chips in existence, but many are difficult to put in a fixture or are downright impossible to at this stage of the technology’s development, and their CRI ratings are poor. We keep abreast of all aspects of the LED world, so you can rest assured that the LED lights we sell, though they may not be the brightest possible, are the best possible.
*Joel Slavis is the president of LED*Waves.
*Tim Seeto is one of LED*Waves’ premier LED experts.
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