Seth's Rant for September 9th, 2000

Stupid Light Bulb Tricks


I was just marveling at my newly installed garage door opener when I noticed that the light seemed kinda dim and orange. I opened up the case and found a 60 watt light bulb, which, while not the 100 watts the case is rated for, didn't explain the orange hue. Then I noticed that it was rated for 130 volts.

For those of you not up on the latest technological trends, standard household voltage in this country is between 110 and 120 volts. So, "Why," you might ask, "would someone rate a bulb at 130 volts?" Well, I'd ask, anyway.

It all started several years ago when GE decided that consumers were becoming energy conscious about their choice in light bulbs, but not so energy conscious that they'd shell out thirty bucks for a dim and flickering fluorescent bulb. Thus was born the "Miser Light" series. GE's brilliant (sorry) idea was to sell bulbs that were five watts less powerful than what you meant to buy. Want a 100 watt bulb? Buy a 95 instead!

Of course, legally, they had to tell you that you were paying more to get a less powerful and less bright bulb. Probably to the amazement of GE executives, the average consumer actually must have read the packaging because GE recently pulled the product. But, ingenious businessmen that they are, the folks at GE did not give up on selling less bulb for more money.

The current "energy saving" offering is a bulb that says it's 100 watts, but if you read the fine print it only achieves this output at 130 volts. Thus, in the reality of your 120 volt home, you only get a 92 watt bulb. What's worse, since the light is effectively dimmed, it glows slightly orange instead of white as a bulb would at it's rated voltage. But I guess GE figures you won't notice this until after you've paid for it.

The Light Bulb Guide

Given this confusion suddenly introduced into the important light bulb purchasing process, I've decided to write the definitive guide to light bulb purchasing. (Yes, I have better things to do, no I don't feel like doing them.)

The most obvious characteristic of a light bulb is wattage, and this is usually the only number consumers look at. A light bulb's wattage rating tells you how much power the bulb consumes, not how bright it is. Aside from helping you gauge efficiency, wattage also gives you an idea how much heat the bulb will produce and that is very important in deciding how powerful a bulb you can use.

Every light fixture has a maximum rating which, contrary to popular belief, is important. While putting a 100 watt bulb in a 60 watt socket won't cause the the light bulb police to come beating down your door, it will over heat the fixture. Over time, this will cause the wiring, lamp shade, cowling, and socket to deteriorate. Aside from the obvious danger of the shade or cowling catching fire, there's the more subtle problem of the socket and wire insulation crumbling and falling off. This problem ceases to be subtle when they short circuit and either electrocute you or start a fire.

Side Rant: I just had to have two light fixtures in my house replaced because the previous tenants had used 100 watt bulbs everywhere and burned out the wiring, causing minor shorts and power fluctuations that made my computers rather miffed.

Don't exceed the maximum wattage of the fixture!

This is a measure of how much light a bulb actually puts out. Don't worry about what the number means, just know that bigger is better. In particular, you want to buy the light that gives you the most lumens for your watts. Just remember the trick above: lumens and watts depend upon volts so watch out for bulbs rated at an alternate reality voltage.

Life Span
This is the average number of hours the bulb should burn. Once again, you are looking for the biggest number. This is usually the only place where your choice in brand matters: cheaper brands might not last as long as they claim. Then again, if they are really cheap, who cares?

If you really don't want to have to change your bulb again for a while, there are several "long life" types of bulbs out there. Some just plain last longer, while others use a "double filament" design. The "last longer" ones give you full performance for the life of the bulb, which is nice if your concern is not having to change it very often. The "double filament" kind have (surprise) two filaments inside. The first one is at the full rating of the bulb and won't last any longer than a normal bulb. The second one is dimmer and will come on the moment the first one breaks (assuming the shrapnel from the first one breaking doesn't take out the second one too). This type doesn't really last longer: the advantage is that when it goes, you still have some light to see by and you know that it's time to get a replacement. This is nice for security lights where you'd rather not be left completely in the dark.

Incandescent versus Fluorescent

If you actually spend some time reading the labels in the light bulb isle, you'll quickly realize that nearly all the incandescent bulbs are the same. You may also notice that they suck down about 3 times as many watts per lumen as fluorescents and only last a tiny fraction as many hours. So is it worth it to spend the extra bucks and get a compact fluorescent? That depends. The performance of compact fluorescent bulbs has improved dramatically in recent years but there are still some issues to consider:
Fluorescent bulbs flicker. Even "non-flicker" bulbs flicker a little. The problem is that your household electricity turns on and off one hundred and twenty times per second (twice per cycle, sixty cycles per second in the US). This isn't noticeable with an incandescent bulb because the filament is glowing white hot and it takes more than 1/120th of a second for it to cool down noticeably. But a fluorescent bulb, being so much more efficient and cooler than its counterpart, dims significantly as the current alternates.

The question is, do you notice? Personally, I can see the flicker from even "non-flicker" bulbs and it gives me a headache if I'm trying to read. Some people don't notice the flicker even from regular fluorescents. In any event, every bulb brand is different so if you are sensitive to flickering, just assume they all will. This doesn't mean you can't use fluorescents, however. The trick is to mix types. Since flickering bothers me, I pair a fluorescent with an incandescent whenever possible. The incandescent provides enough background glow that I don't notice the flickering. You can save power by using a low power incandescent paired with a bright fluorescent as noted later.

Fluorescent bulbs often give off a bluish or greenish light which makes colors seem unnatural. This can be particularly annoying if you are trying to eat dinner and all your food is green. Some bulbs provide better color than others and a few brands sell "natural hue" bulbs that are supposed to give you the same light quality as an incandescent (for a price). Once again, my solution is to simply mix types: a dim incandescent fills in the orange end of the spectrum while a bright fluorescent provides the bulk of the light.

Time Variation
Some fluorescents take up to two minutes to reach their full brightness. Others come on bright, but their color varies over time. Reading the package carefully before you buy may help, but mostly it's just a matter of experimenting to see which bulbs perform the way you like.

The big advantage to using a compact fluorescent in place of an incandescent is that you get a lot more light for a lot less power. This means that you can stick a much brighter light into a socket without exceeding the socket's wattage rating. Most fluorescent packaging will say something like "100 watt equivalent". Ignore that and look for the fine print that says how much power the bulb actually uses. That's the number you need to keep in mind when deciding how big a bulb you can fit into a socket.

For example, my bathroom inexplicably has only one light socket that is only rated for 60 watts. That makes for a pretty dim room. But by putting in a "100 watt equivalent" fluorescent that really only uses 40 watts of power, I'm under the limit and I get a bright bathroom.

As I mentioned above, it's often useful in a multi-bulb fixture to mix bulb types. The important thing is to make sure that none of the bulbs' actual power consumption exceeds the rated limit of the socket. This is pretty easy since I don't know of any compact fluorescents which use more than 40 watts. Better still, it only takes one dim incandescent (40 or 60 watts) to eliminate color and flicker problems. Thus the 120 watt max light fixture above my head is putting out 160 watts "equivalent" of light with a 60 watt incandescent and a 40 watt compact fluorescent: lots of light, no flicker, good color, using 38.5% less power and generating about 38.5% less heat.

Compact fluorescent bulbs cost more up front, but how much more varies by store and brand. Where I live I can pay anywhere from $8 to $30 for bulbs that have the same ratings. In that case, the $30 bulb actually performs worse because it takes two minutes to "warm-up" to full brightness. Thus it pays to shop around.

Ultimately, using some fluorescents will save you money. In the summer, they'll actually save you money twice: they use less electricity AND they generate less heat for your A/C to remove.

Who cares?

That's probably more than you ever wanted to know about choosing a light bulb, but your eyes (and your electric bill) will thank you.

This rant solely reflects the opinion of the author, probably while he was half asleep, drunk, or otherwise incapacitated. It does not necessarily reflect the actual opinion of DEI, it's associates, or possibly the author in a more conscious state. Hate mail will be prosecuted. Constructive criticism may be posted or ignored. Have a nice day.

Seth B. Noble - Rant - sbnoble - July 30, 2000