May 25, 12
The following are excerpts from actual reviews on 1000Bulbs.com. What do they have in common? They’re all from reviews of 130 volt light bulbs.
“…even though the watt ratings are the same…the new ones aren’t as bright as the old ones.”
“The low output also makes the the color of the light very yellow…”
“…for 300 watts I thought it would be brighter.”
These customers, and several others, have a fundamental misunderstanding of 130 volt light bulbs. That’s not their fault, however; it’s ours. So let me try to clear up this issue once and for all.
As discussed briefly in an earlier article, the short, technical version goes like this: 130 volt Halogen and incandescent light bulbs are manufactured with a thick filament designed to withstand a theoretical 130 volts. I say “theoretical” because almost all homes in the US operate on only 110-120 volts. The thicker filament in a 130 volt bulb, when operated on typical 110-120 line voltage, provides less resistance to the electrical current flowing through the filament. As a result, the bulb burns cooler, uses less energy (watts), and lasts longer; however, as a trade-off, the bulb is also slightly dimmer and has a lower (more yellow) color temperature.
Understanding Voltage, Amps & Watts: “Hose Theory”
To understand this phenomenon, an analogy is useful. Think of a garden hose. When you turn on the tap to just a trickle, water flows freely through the hose without resistance. As you turn the tap more, you force a larger volume of water through the hose, which is met by a small amount of resistance from the hose. Now turn the tap to its highest setting. Instead of trickling from the end of the hose, water now sprays across your lawn and into the leather interior of your neighbor’s new convertible.
Because the hose is relatively small, it provides a lot of resistance to the more voluminous water flow, which causes pressure to build inside the hose. The increased pressure in the hose propels the water several feet instead of flowing with the mere trickle you saw when you had the tap at a lower setting. To take this concept further, imagine you continued to increase the volume of water flowing through the hose by attaching it to a fire hydrant (assuming such a thing was possible). At that point, the water pressure would become so intense it would weaken the hose, eventually causing it to rupture.
Maybe that’s a dramatic example, but the thin tungsten filament of a light bulb is not unlike a water hose. In the case of electricity, however, the volume of water is electrical current and the water pressure is voltage. With a 60 watt light bulb, for example, you are forcing 0.5 amp of electrical current (the “water”) through the filament (the “hose”) with 120 volts of pressure. The current meets the resistance of the filament, causing the filament to become hot and glow. Over time, just as with the water hose, this stress will cause the filament to break, making the bulb “burn out.”
130 Volt Bulbs Save Energy & Last Longer
To prolong the life of the bulb, you could lower the volume (amps) or the pressure (voltage). This is the approach taken by old rheostat dimmers.
Voltage Decrease & Bulb Efficiency
However, you could also use a bulb with a thicker filament (a bigger hose), that places less resistance on the current so that it flows more easily. This method, as stated before, is the approach taken by the 130 volt bulb. Because the current moving through the thicker filament meets less resistance, it requires less energy to produce light. The more freely moving current also does not make the filament as hot so that the color temperature of the light is also lower.
As the table to the right shows (from Jack L. Lindsey’s Applied Illumination Engineering), the trade-off is a very good one, too. A very small decrease in voltage and lumens leads to a huge increase in life and a considerable decrease in energy usage (watts). Lowering the voltage only 8%, for example, leads to a 300% increase in life and nearly 15% decrease in energy usage with only a 25% loss in light output!
Now back to the original question: Why buy 130 volt light bulbs? The answer is simple. Buy 130 volt bulbs when you want to save energy, change your bulbs less often, and don’t mind slightly lower light output and warmer color temperature.
Jan 27, 12
The third and final part in a series about life hours and how you can use this spec to inform your purchase and maximize the life of your bulbs.
If you’re a lighting nerd like most of us at 1000Bulbs.com, you’ve likely heard of the 110-year-old Centennial Bulb in Livermore, California. If (more likely) you’re not a lighting nerd, here’s the brief rundown: The Centennial Bulb was installed in a firehouse over 110 years ago and still hasn’t burned out. It’s not known exactly how it has lasted so long, but there are a few good clues: One, it has only rarely been moved; two, it has been switched off only a handful of times, and three, it is operated at very low power.
The two previous articles in this series explained how manufacturers determine life hours and how life hours and warranties are two different things. This third and final article in the series explains how you can make your light bulbs last longer. We can’t guarantee they’ll last 110 years (in fact, we can almost guarantee they won’t), but by following a few tips you can easily double or triple the life of your bulb. One caveat, however, because not all light bulbs use the same technology, these tips do not apply to all bulbs.
Don’t move it! Light bulbs get hot. Really hot. And when metal (which makes up a bulb’s filament) gets hot, it gets brittle. The more you handle a bulb with a brittle filament, the more vibration you subject it to, making the filament much more likely to snap. This doesn’t apply only to handling the bulb; it also applies to placement. Any bulb installed in a place that moves also moves. The swish of a ceiling fan or the slam of a refrigerator door, while barely heard by you, is a light bulb’s death knell. It’s for this reason that you may have seen special bulbs with reinforced filaments marketed as “ceiling fan bulbs” and “appliance bulbs.” As you might have picked up, this rule only applies to bulbs with filaments, like incandescent and halogen bulbs.
Leave it on! This may sound contradictory to common sense, but it’s not. Every time you flip a switch, you are blasting your light bulb with power. That poor little filament is forced to go from room temperature to 5000° F in a fraction of a second! You do that too many times, and the filament will literally crack under the pressure. This also goes for ballasted bulbs like linear fluorescents, CFLs, and HID lamps. In the case of an instant start fluorescent ballast, you’re hitting the fluorescent tube cathodes with 600 volts every time you flip the switch. After so many power cycles, the lamp will fail. Keep in mind, however, that while this trick will prolong the life of your bulb, it could also increase your electricity usage.
Operate it at low power. This may be the real secret to the Centennial Bulb’s longevity. Less power means less heat, which translates to less stress on a bulb filament. If you live in the United States, your house is operating on ~110V, so if you buy a bulb rated for 130V, you’ll be hitting the bulb with 15% less power than it is designed to handle (130V – 15% = 110.5V). You can stretch this principle even further with a dimmer switch. When you dim a bulb, you are lowering the voltage delivered to the bulb filament, putting it under less stress. This also applies to fluorescent technology, but in a slightly different way: Unlike an instant start ballast, a programmed start ballast supplies a much lower starting voltage and heat to the lamp. If you switch to this type of ballast, you could extend the life of your fluorescent bulbs by over 30%.
Finally, remember that the aim of extending bulb life, in most cases, is to save money. Is it really worth it to make that incandescent bulb last forever by dimming it and leaving it on for longer periods? In many cases, it’s better to switch to a more efficient CFL or LED. But if you’re a die-hard incandescent fan, or want to recreate your own Centennial Bulb, these tips will come in handy.
Jan 20, 12
Part 2 in a series about life hours and how you can use this spec to inform your purchase and maximize the life of your bulbs.
In the previous article, we discussed how manufacturers determine life hours differently for incandescents, fluorescents, HID lamps, and LEDs. Switching to something less technical, this article will give you information that is much more practical, namely, how to choose the right light bulb for your application.
Life hour ratings are often confused with warranties, but unlike a warranty, a life hour rating is not a guarantee of the life of the bulb. If your light bulb is rated for 1,500 hours and has a warranty of one year, you’ll be hard pressed to get the manufacturer to reimburse you the cost of the bulb after one year and a day, even if you only used the bulb 1,499 hours. Likewise, the manufacturer would be likely to reimburse you if your bulb failed one day short of a year but you used the bulb 1,501 hours. (On a side note, if you set a stopwatch every time you screw in a light bulb, you need to find a new hobby.)
So when you go to buy a light bulb, should you just ignore the life hour rating and look for the longest warranty? That depends on your application. If you’re a homeowner looking to get your full return on some expensive new LED bulbs, you’d be wise to look for an ironclad warranty. But if you’re outfitting an auditorium with 50 foot ceilings, you’d be better off selecting bulbs with the longest life hours. Why? A warranty isn’t much consolation when you still have to climb 50 feet to change a bulb.
Several major lighting manufacturers don’t even offer warranties, and if they do, they tend to make the warranty documentation difficult to find and contingent on more variables than most people care to read. Sylvania’s Quick60+ Warranty, for example is a system warranty, meaning it only applies if you are using both Sylvania lamps AND ballasts in your application. If you’re using Advance ballasts with your Sylvania lamps, then sorry, you’re out of luck!
The other two of the “big three,” GE and Philips also tend to be stingy with their warranties. However, a lack of a warranty doesn’t mean a low-quality bulb. In fact, if you’re into the big brands, just the opposite could be argued. You’ll remember from the last article in this series that life hours represent roughly the amount of time it took one half of a test batch of bulbs to burn out. The other half hadn’t yet burned out. Think about your application, how often you’re going to use the bulb, and how likely you are to hold on to your receipt. You might find yourself less concerned with warranties than you thought.
In the next and final installment of this series, we’ll tackle the fine art of making your bulbs last longer, sometimes longer than either warranty or life hours. A hint: It’s not really an art at all.
Jan 16, 12
Part 1 in a series about life hours and how you can use this spec to inform your purchase and maximize the life of your bulbs.
The term “life hours” sounds simple but is one of the most misunderstood of all lighting terms. A life hour rating isn’t a warranty or guarantee of a light bulb’s life, so the life hour rating you see on a bulb’s packaging isn’t necessarily how long the bulb will last in your fixture.
A manufacturer’s projection of life hours has to take into account many variants including the calibration of manufacturing equipment, temperature fluctuations, and material quality, to name just a few. By using a big enough test sample, manufacturers hope to account for any manufacturing inconsistencies, making their rating as accurate as possible.
Manufacturers determine life hours for filament lamps, fluorescent tubes, HID lamps, and LED bulbs all in slightly different ways. Here’s the rundown:
Filament Lamps (Incandescent and Halogen)
- Manufacturers test a group of sample lamps by burning them continuously.
- The point at which 50% of the lamps fail is the life hour rating.
Fluorescent Lamps (Linear, U-Bend, Plug-In)
- Manufacturers test a group of sample lamps by burning them for 3-hour intervals.
- The point at which 50% of the lamps fail is the life hour rating.
HID Lamps (Metal Halide, HPS, Mercury Vapor)
- Manufacturers test a group of sample lamps by burning them for 10-hour intervals.
- The point at which the lamps meet 40% of their original lumen output is the life hour rating.
- Manufacturers test a group of sample lamps by burning them continuously. Like HID lamps, LEDs aren’t allowed to burn out.
- The point at which the lamps meet 70% of their original lumen output is the life hour rating.
In the next part of this series, we’ll show how you can use this information to inform your light bulb purchase.