LED Bulb Buying Considerations

Due to their many advantages over traditional incandescent and fluorescent bulbs, LED lights are poised to transform all forms of lighting. Selecting and purchasing LED lights requires buyers to learn new terminology and consider the factors they do not have to think about when buying traditional types of lighting. This short article provides some basic background and buying considerations for first-time buyers of LED replacement lights.

As most people probably already know, LED stands for Light Emitting Diode. LEDs are actually semiconductors (just like computer chips) that produce light more efficiently than traditional light sources. When electricity passes through them, they emit energy in the form of light. These semiconductors are doped or injected with chemicals that determine their light color. LEDs convert most of the energy that passes through them into light, unlike incandescent light bulbs that produce light as a by-product of heating. For this reason, LEDs can be up to 90% more efficient than traditional filament bulbs.

LEDs have been widely used as displays and indicator lights for almost 40 years. Recently, however, engineers have figured out how to mass produce and mass produce bright white LEDs that can be used for general purpose lighting. The high brightness and point source characteristics of LEDs have made them the number one choice for automobile stoplights and taillights, where visibility and reliability are essential.

So what do you need to know when buying LED bulbs? The following list provides some basic guidelines:

1. While the initial cost per bulb is still high, the total lifetime cost of an LED bulb is actually lower than that of equivalent incandescent bulbs and CFLs. Considering energy costs, as well as the time and resources required to replace incandescent and CFL bulbs, an 80,000-hour LED bulb has a much lower cost of life.

2. LEDs are diverse, and since unfortunate buyers are likely to find it the hard way, many types are useless for general lighting applications. The best LED chips emit light with a color rendering index (CRI) of 85%. The CRI, by the way, is a quantitative measure of the ability of a light source to faithfully reproduce the colors of various objects compared to an ideal or natural light source. LED bulbs that use high quality led shop lights will last much longer than the novelty bulbs that many sell and 60% longer than many competing bulbs that use inferior LEDs.

3. Contrary to what you can read in some places, LEDs generate heat, and this heat is actually the biggest problem manufacturers face when developing LED lighting applications. Manufacturers can now produce individual LED chips that are as bright as a 100-watt incandescent bulb, but these LEDs are practically useless for general lighting because installing them in a device creates ventilation problems that have not yet been resolved. The LEDs installed in devices and bulbs need to be properly vented, and the better the chip, the harder it will be to properly cool it down. There are many LED bulbs on the market that don't take this into account and use cheap chips so they don't have to ventilate them, or they don't ventilate their chips properly, significantly reducing their lifespan. While the typical LED bulb hardly heats up to the touch, if the chip is not well ventilated it may fail prematurely.

4. While LED bulbs last much longer than conventional bulbs, take a close look at the manufacturer's claims about the life of the bulbs. The lifespan of an LED bulb should be its "half life". LED bulbs don't burn out; rather, they gradually fade away. When a vendor says that an LED bulb will last 80,000 hours, it means that at that point, the chips will have reached 50% efficiency, and the bulb should be replaced. So the bulb can last 100,000 hours or more, but its efficiency will have greatly degraded at that point. Using this 100,000-hour life as a selling point is therefore misleading. While LEDs don't last forever, they will last 50-75 times longer than a comparable incandescent and 6-8 times longer than a CFL.