LED Lighting Facts
Consumer education will be very important for LED Bulbs to be successful in the American marketplace. Bulb manufacturers are using standard light bulb bases (E26 and E12), but just because an LED bulb fits into the socket does not mean it will function properly.
- Heat Dissipation Issues
- Forget about WATTS Incandescent bulbs were sold in wattage and that's what consumers have come to expect. Two things have happened in the marketplace. First, in a rush to achieve equivalent lumens for 60 watt bulbs the LED watts have trended upwards, and the more watts the more thermal dissipation issues you are going to have. 60 watts is generally defined as 850 lumens for A-19 style bulbs. LED bulbs at this rating produce lots of heat. A 7-watt LED bulb which puts out 600-640 lumens is roughly equivalent to a 50 watt bulb (when is the last time you saw a 50 watt incandescent bulb?), but the thermal signature of a 7-watt LED bulb is considerably cooler than that "60" watt equivalent putting out 850 lumens. To the naked eye, when you are putting 600 lumen bulbs into a vanity fixture with 3 to 5 bulbs, it's virtually impossible to tell much difference and your bulb lifetime is going to be greater and your electrical costs will be lower. Remember, less heat, longer life time! Second, discount bulb manufacturers are putting Watt equivalency ratings on their bulbs which are outright misrepresentations based on standard lumen measurements on incandescent bulbs. The obsession with wattage equivalency to incandescent bulbs does a disservice to American consumers, getting the exact equivalency to incandescent bulbs results in sub-optimal LED bulbs. The FTC has tried to address this with the mandatory label from above, but retailers still focus on the incandescent equivalency. Always look for the Lighting Facts label and don't assume that a bulb that doesn't have an exact incandescent equivalency rating is not going to work for you. These comparisons are really apples to oranges comparisons. With LED bulbs consumers are going to eventually find a lot more selection in light output (lumens) than incandescent bulbs.
- Bulb Color Temperature LEDs have been around for decades, digital clocks, calculators, VCRs, DVDs and many consumer electronics use LEDs for a variety function. One of the challenges in the development of LED light bulbs has been developing LEDs that produce a natural white light. 80% of the incandescent bulbs sold in the United States have a color temperature of "warm white" which is closer to the light output of a candle, which has an orangish hue to it. This is an accident of history, the first mass produced bulbs were essentially electric candles not producing optimal light. As time went on manufacturers of incandescent bulbs solved this problem and were able to produce natural white bulbs. But guess what, if a defect persists long enough in a product, it becomes a feature - consumers find "warm white" soothing. Thus consumers have come to expect that orange like glow from their bulbs. This represents another challenge for LED manufacturers - many suppliers are unable to supply "warm white" color temperatures. For way more information that you ever wanted to know about color temperature see Correlated Color Temperature. CCT is measured in Kelvin, but the terms most consumers are use to seeing are "Warm White", "Soft White" and "Cool White". This also presents a labeling dilemma for retailers - consumers really want "warm white", which is a challenge for LED bulbs to produce, thus the temptation is to take these somewhat imprecise meanings and bend the rules on the labeling. The following table shows the generally accepted CCTs for the most common bulbs color temperatures based on what labeling consumers have seen on incandescent bulbs.
- Warm White - 2700K to 2900K
- Soft White - 3000K to 3500K
- Cool White - 4000K to 4200K
The thermal signature of a LED bulb is very different than incandescent bulbs. An incandescent bulb becomes hot to the touch throughout the entire bulb. Likewise, high temperatures have a much less significant impact on bulb lifetime. LED bulbs are very different. Generally the illuminated surface is cool to the touch, but all the heat is generated behind the LED components. Hence the "franken" bulbs that are so prominent, the reason for these strange shapes is the heat sink designs to handle heat dissipation. Unlike incandescent bulbs, higher temperatures for an LED bulb have a significant impact on bulb lifetime. Another key difference is that LED bulbs need proper airflow for heat dissipation. Current LED bulbs that are put into sealed ceiling fixtures will fail rapidly as thermal overload will quickly destroy the LEDs or the control chips. To help educate consumers Grimaldi® branded bulbs will include additional information in the FTC mandatory labeling which will identify the proper lighting fixtures that have been tested by our lab.
We are working with suppliers on different technologies and heat dissipation techniques. Our testing shows fairly good heat dissipation results with latest ceramic heat sinks. Moreover, we are actively encouraging suppliers to put in a thermal overload safety chip which will automatically dim the bulb to reduce heat rather than fail. Consumers might find such thermal overload safety options annoying, but if your bulb is dimming, it is preventing itself from self-destructing and telling you "I don't like this fixture" while protecting your investment in the bulb. Another options we are actively encouraging suppliers to consider in our premium bulbs are small piezo electrical fans to aid in heat dissipation. The bottom line is that effective heat dissipation is critical to achieving the lifetime ratings for LED bulbs. Until new technologies come online consumers need to be careful about where they deploy LED bulbs. Deploying an LED bulb in the wrong type of fixture will fail faster than an incandescent bulb. Consumers need to pay attention to these restrictions and retailers need to make the information clearly available on the product packaging.