LED stands for Light Emitting Diode. The diode comes in the form of a computer chip on a circuit board. The properties of the diode cause it to generate light when an electric current passes through it. Depending on the chip and materials used, different colors in the color spectrum can be created. Prior to the technological revolution of the 90s and the rapid advancement of the microchip, the LED was used only in small-scale applications such as indicator lights.
The same advancements that spurred the computer to reach dizzying levels of efficiency have also done the same for the LED. Just as computers have become faster and cheaper, LED lights have become brighter, smaller, less expensive, and more sophisticated.
LEDs are solid state technology. That means there is no glass bulb, no pressurized gases, no mercury and no burning filament. With the traditional bulb, 90% of its energy is transmitted as heat while light is a mere by-product of electrifying the metal coil inside the bulb.
From the indicator light on your VCR to the light fixture above your head, LEDs have come a long way in becoming the go-to solution for building and home illumination.
Q: Are E26 and E27 light bulb bases interchangeable?
Yes. The E26 is the standard 120 Volt American base. The E27 is the European variant and is rated at 220 Volts. E26 is 26 mm and the E27 is 27 mm diameter. However, an E26 bulb can fit in E27 base and an E27 bulb can fit in E26 base without problem. The sockets / bulbs are interchangeable except for the voltage rating. Therefore, LED E26 bulbs that are universal line-voltage can be used in both E26 and E27 sockets.
Q: Why are LED lights so expensive?
Even considering the energy savings and replacement costs, LED lights come with a fair amount of sticker shock. Part of this is because they're so new; more research and development is being poured into this field than any other lighting technology. As our understanding of this technology increases prices will continue to fall. For example, early LEDs were mounted on a sapphire substrate. Today's LED chip designers are experimenting with various silicon substances to replace expensive sapphire while not compromising performance.
Still, it is unlikely that LED lights will ever break the price point of standard incandescent lights since more work goes into the components. Light-emitting diodes are not based simply on fire or a heated filament in a glass like older technology; each lamp is the product of soldering together a number of parts - a heat sink, driver, circuit board and LED chips engineered for specific lighting applications. Think of an LED light fixture as an appliance rather than a disposable object.
LED Waves happens to build products exclusively with high-quality, name brand LEDs. These chips reflect more years of research in the field, and the fact that companies like Cree and Nichia have lasted so long amid other fly-by-night LED operations speaks to the dependability of these finished products. If an LED bulb promises 5 years of useful life, shouldn't its chip manufacturer have been in business at least that long?
Q: What are IP ratings (i.e IP65, IP67, etc.?)
A two-digit number established by the International Electro Technical Commission, is used to provide an Ingress Protection rating to a piece of electronic equipment or to an enclosure for electronic equipment. The first digit indicates protection against ingress of solid objects. The second digit indicates protection against ingress of liquids.
Q: What are the advantages of using LEDs over traditional lighting?
The LED lights of today match or surpass the performance of all incumbent lighting technologies. LEDs operate on significantly less energy than incandescent lights, which are wildly inefficient. They also last longer (average 10 years of normal use) and are more durable because they are solid state, shock-proof, and can be housed safely in plastic instead of glass. LED wall washers and spotlights are DMX controllable to create color and light intensity effects which cannot be achieved with other technologies.
At roughly half the efficiency, a CFL almost stacks up against an LED bulb yet still comes up short in terms of reliability. Fluorescent lights rely on chemical reactions with gases (including the neurotoxin mercury) contained within a fragile bulb. These reactions are adversely affected by upside-down installations. Furthermore, the ballast of a CFL is not designed to handle rapid on-off cycles - all of which explain why so many people are disappointed by these bulbs.
The bottom line is that LEDs are easier and safer to use than all previous lighting technologies. And LEDs will save you money by consuming less power, requiring fewer replacements, and generating much less heat, which in turn combine to result in lower cooling costs.
Q: How do I compare my current lighting with LED lighting so I can make intelligent decisions?
In the past, we have generally referred to the brightness of a bulb in terms of its wattage, or the amount of power that the bulb uses (or energy it consumes). Because of the disparity between incandescent and LED technologies, we have to change our language a bit in order to account for progress. When referring to brightness, we now find ourselves comparing lumens (see Q: What is a lumen?).
However, when comparing LEDs with incandescents, it gets a little trickier because the typical incandescent projects light in 360 degrees – at the ceiling, within the fixture, everywhere - not just where you need it. Because LED lights are directional, they focus all the light they generate exactly where you want it, and nowhere that you don't.
Another consideration is color temperature. In the past, this has been very difficult to control because you basically got whatever color your particular bulb produced. Typically this was a Warm White (about 3000K) if you had an incandescent bulb, and a Cool White (around 5000K) if you had a fluorescent bulb. Because the LED is an intelligent, solid-state technology, we are able to produce LEDs that not only produce Warm White and Cool White, but are able to produce up to 16 million different colors, each a different temperature.
Q: With all the buzz around compact fluorescent bulbs, should I skip this step towards efficient lighting altogether and move directly to a LED bulb?
Compact fluorescents are great bulbs but they lack all the advantages of LEDs; namely size and environmentally friendliness because they contain mercury, do not last as long, and they degrade with rapid on-off cycles and temperature fluctuations.
Q: What is lumen?
A: Lumen is a unit that measures luminous flux, or the total amount of visible light emitted by a source. If a light source emits one candela (approximately one candle's worth) of luminous intensity into one steradian (a solid angle - picture light waves emitting from a source in a cone shape), the total luminous flux emitted into that steradian is one lumen. The lumen can be thought of casually as a measure of the total amount of visible light emitted. For example, a standard 100 Watt incandescent bulb emits about 1500 lumen.
Q: What is Lux?
A: Lux is lumen per square meter. The difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread. 1000 lumens, concentrated into an area of one square meter, lights up that square meter with an illuminance of 1000 lux. The same 1000 lumens, spread out over ten square meters, produces a dimmer illuminance of only 100 lux.
Eason Wang