Technology writer Clive Thompson says:
“The only reason we don’t notice how absolutely interwoven our thinking processes have become with older technologies – pencils, paper, electric light, penicillin, fire – is that they’re so old, we’ve ceased to notice their effects.”
How does this relate to lighting technology?
LEDs are commonly known to be energy efficient. But LEDs also have several other major benefits: they create no radiant heat, have a very long operating life, provide many color choices, and are ideal for use in a wide range of applications. Many people are trying to adopt LED lighting and incorporate it into their building designs. The problem is, most people are so used to conventional lighting setups that they try to use retrofit LED lights in the exact same way. Here are some ideas on how to correctly use LED lights, but first here is some background information.
LED lighting technology works very differently from that of conventional lighting, and trying to mesh the two technologies is not efficient or practical. In order to maximize the power of LED lighting technology, we need to understand and think about lighting in a whole new way. Let’s compare conventional lighting methods (incandescent, halogen, and fluorescent lighting) with LED lighting.
Problems in Conventional Lighting
Conventional lighting methods have poorer lighting efficiency. Power consumption for conventional lights is high (low lumens delivered per Watt). In comparison, LEDs have high lighting efficiency and low power consumption (high lumens delivered per Watt). LEDs can save as much as 85% of the electricity used by similar incandescent bulbs and 50% of the electricity used by similar fluorescent lights.
Conventional lighting methods have poorer light delivery. Light produced by conventional lights is projected in all directions, and much of it is delivered where it is not needed. In order to deliver sufficient lighting using conventional light fixtures, it might be necessary to install a large number of light fixtures or redirect some of the produced light using reflectors. In comparison, LEDs produce light that is focused, directional, and delivered primarily where it is needed.
Conventional lighting methods generate a large amount of heat. The large amount of radiant heat created by conventional lights is generally undesirable as it leads to reduced lighting efficiency and low product lifespan. Not only is radiant heat produced by conventional lighting wasted, but it can also lead to higher utility and building HVAC costs. In comparison, LEDs do not produce radiant heat (though they do need to get rid of conductive heat). Unlike conventional lights, standard LED lights typically do not produce any UV rays or infra-red heat.
Conventional light fixtures are large in size compared with LED fixtures. Professional installation of conventional lighting fixtures may require adding weight supports and extra conduits to house the wiring. The smaller size of LEDs provides flexibility with installation.
Conventional lighting methods have much lower operating lifetimes than LEDs. If an LED fixture is well designed, its L70 life span can usually be estimated to be around 60,000 hours. This is much greater than the life span of incandescent, fluorescent, or HID lamps. A typical 60W incandescent bulb only lasts around 1,500 hours of operation, and a typical 14W fluorescent bulb lasts around 8,000 hours. Sunlite products are designed to last over 60,000 hours; they have excellent heat dissipation and are made with glass lenses that do not degrade or turn yellow over time.
Conventional lighting methods typically run on AC current, but LED lights run on DC current in most applications. AC current is widely used for most applications because it is much easier (and cheaper) to step up and down in voltage than DC. However, DC current is safe and simpler to use to power most electronics, which tend to require DC to operate. Running on DC current can sometimes be considered a benefit of LED lights. For instance, “green technologies” such as wind turbines, solar panels, and fuel cells generate DC power, and may be used to power LED lights directly, without the energy losses associated with transferring AC to DC. This may be the future of all LED lighting.
Many people are interested in LED lighting for these reasons, but they still think of applying LED lights in the same way that they think of conventional lighting.
Companies and individuals often try to find retrofit solutions to be able to utilize the many benefits of LEDs, and many light manufacturers design retrofit LED products to replace light bulbs or halogen tubes. Unfortunately, this is the wrong way to use LED lights; replacing conventional lights with retrofit LEDs has several problems and is inefficient for several reasons.
Problems with Retrofit LED Lights
The weakest component in LED lighting is usually the power supply. Most LEDs run on DC current supplied by a driver. While LEDs themselves usually last for many years (or even decades), [Spider_Video_Player id=”1″]LED drivers generally have a warranty of five years. Most retrofit LED kits have a driver built into the fixture, and when the electrical components of the driver inevitably fail, the entire fixture has to be replaced (even though the driver is the only bad component).
Although they are much more efficient than conventional lights, LEDs are still only about 40% efficient (60% of power supplied is turned into heat instead of light). Heat is bad for all electronic components and leads to reduced efficiency and product lifespan. In a retrofit LED, the heat generated by the built-in driver adds to that produced by the LED. This compounds the heat issue and leads to reduced operating life and lower lighting efficiency.
Retrofit LEDs are much more expensive than traditional bulbs and also have higher fabrication costs than other LEDs. Additional retrofit LED fabrication costs are primarily due to the extra materials needed to make the metal heat sink. Retrofit LEDs in older fixtures also generally require larger diameter wire. In contrast, Sunlite’s low-voltage LEDs use 18AWG wire.
Dimming retrofit LEDs is usually done using a TRIAC dimmer. Unfortunately, retrofit LEDs often have dimming problems. When retrofit LEDs are dimmed, low voltages may not provide enough load for the LED driver and can cause the LED light to flicker.
Correct Use of LED’s
The correct way to use LED lights is to design them to minimize fabrication costs while maximizing their lifetime, brightness, lighting efficiency, and energy savings. Sunlite Science & Technology has patented an Application Specific (AS) LED design that addresses the heat buildup and driver problems associated with retrofit LEDs.
- Sunlite’s LED packages are mounted directly to an extruded aluminum housing. This housing acts as the most efficient heat sink possible for the LED.
- Sunlite’s power supplies are mounted remotely so that they can be easily changed. This is much more efficient than replacing an entire fixture or bulb when a power supply goes bad, and brings huge savings of time, money, and frustration.
- Sunlite uses domed glass lenses instead of plastic lenses to cover and protect its LEDs. Plastic LED coverings tend to turn yellow and cause light discoloration. They also prohibit heat dissipation and eventually degrade, crack, and fail. Glass lenses are optimal for heat dissipation and product longevity.
- Sunlite’s AS-LED design has only a tiny, 0.0001mm insulating layer (that acts as an adhesive) between the chip and aluminum housing heat sink. Most other LED module designs have several >0.1mm insulating layers (between the chips and discrete LED packages, between the packages and PCB board, and between the PCB board and fixture). These layers act as barriers and trap heat.
- Sunlite’s products are generally small, compact, lightweight, and easy to install, leading to maximum flexibility and usefulness for a wide range of applications.