Alright, so it’s done. Jeff did a great job at the Green Health Live interview.
Here’s the link to the blog on The GHL site. Marc did a good job of writing an overview of how LED’s work using the images that we gave him for the show. Check it out.
http://thestream.tv/blog/?p=379
Here’s the link to the video.
http://www.thestream.tv/watch.php?v=560
I don’t quite agree with Jeff’s fashion choice (I mean who wears cyan dress shirts, really?) but that didn’t deter from his knowledge of the product. There was another 45 minutes of Q&A afterwards with some interesting questions, but unfortunately, that didn’t get aired.
The best question that someone wrote in was “So what happens when the bulbs explode?!” The look on Jeff’s face was classic. It was a cross between “Is that a real question?” and “Uhh….is anybody screening these submissions?”
The answer to that, is that LED lights DON’T explode. They are solid state electronics (kind of like a USB drive), meaning it’s just a chip. The newer bulbs casings are made mostly from aluminum (rather than polycarbonate, a stiff plastic) which are used as a heatsink to dissipate the heat produced from the high intensity LED chips. Compact fluorescents are glass tubes that have an argon gas (or sometimes krypton gas) and a little bit of mercury inside. The old style and office fluorescents had a separate block of electronics called a ballast that’s meant to “jumpstart” the lighting process. The compact fluorescents have a mini-ballast inside the base of the bulb to do this. I haven’t heard of these lights exploding either, but I have heard stories of these burning out, especially when you turn the lights on and off rapidly. Apparently doing that will greatly decrease the life of a CFL. Luckily, LEDs don’t have this problem. And of course you definitely don’t want to be in the vicinity of a broken CFL or fluorescent due to the small mercury issue. (Just kidding, it’s not a small issue…click here for the cleanup instructions.)
Incandescents and halogens are both glass “globes” that contain a metal filament that heats up to an extreme temperature, which creates light. The bulb contains no gas, but actually contains a vacuum, so the filament is less prone to oxidation from the air (and thus burning out more quickly). As you can imagine, this high heat is transferred to the thin glass bulb and dissapated through the air. Halogens are a bit more efficient that incandescents (more light for the same wattage) but they both get hot enough to burn you (and start various curtain/paper/fabric fires) if you touch them.
I remember back in my younger years, we had one of lamps with a lampshade. Nothing special, just the typical run-of-the-mill table lamps. I had one of those mist bottles, the kind you use for Windex, but it was filled with water for ironing clothes. In my infinite wisdom, I knew that such a fine mist would evaporate quickly from warm surfaces, so I thought it would be fun to see the water turn quickly into steam by spraying it on a hot light bulb. Bad idea. I was (and still am) a little scientist and thought I knew what I was doing, it seemed so simple in my head. In the same way that glass cracks when heated up and dunked in water, the light bulb did the same. Except being under pressure and being so thin, instead of cracking, it EXPLODED. Bulb shards everywhere. Luckily the lampshade was still on, which shielded me from flying slivers of broken glass to the face, or you’d be probably be calling me Patches right now. What happens is that the glass on the outside contracts due to the cooler temperature, while the glass on the inside of the bulb doesn’t. This non-uniform stretching causes stress in the glass, and ultimately rupture.
I can’t believe I actually made it to my age in one piece when I think about all the dumb things I did as a kid. Retrospectively of course. At the time, it was pure genius…
