Dimmer switches can give a more pleasant feel to a room, and save you money at the same time. But with the rising prevalence of compact fluorescent lights or CFLs, many people are asking themselves what options they have for using a dimmer with these lights - or whether it saves more electricity to use a regular CFL, or to use incandescent or halogen bulbs on a dimmer.
We should start by clarifying some misconceptions people have over the relative efficiency of incandescent, halogen, and fluorescent light bulbs.
Many homeowners put in halogen lights, beginning in the 1980's, on the mistaken assumption that these lamps are more efficient than incandescent bulbs. In fact their energy efficiency is pretty much exactly the same as that of incandescents. So don't kid yourself that you're cutting your costs by using halogen lights.
CFLs, on the other hand, are very efficient - it takes about one fourth as much electricity to run a compact fluorescent as to light up an incandescent or halogen lamp of the same luminosity. They also happen to last around eight times as long as incandescent lights.
So if you are using a dimmer switch mainly to save energy, you might increase your savings by just changing your incandescent or halogen lights to CFLs, and keeping the dimmer switch on full power, or going back to a standard on-off switch. You'll wind up with more light for less energy.
If you want to give your room a more relaxed feel all the time, one solution is to put in bulbs with a lower light output. Whether you go down from, for instance, a 100 watt incandescent bulb to a 60 watt incandescent bulb, or down from a 100 watt incandescent to an 18 watt CFL, you'll still have less light and you'll use less energy. Of course, the CFL solution will save you more electricity in the long run.
But chances are you want it both ways: the low running cost and longer life of CFL bulbs, with the ability to dim them when their full light is too bright.
You might have heard that you can't put a regular compact fluorescent light on an ordinary dimmer switch. In fact you can, but I don't recommend it, because it substantially shortens the remaining bulb life. You won't be adding to the risk of explosion or fire from installing a regular CFL on a standard dimmer switch - you'll only shorten the bulb life. And because the higher cost of CFLs is offset in part by the fact that they outlive incandescent bulbs by a factor of 8 to 1, putting regular CFLs on a standard dimmer destroys that cost advantage.
If you want to dim compact fluorescent lights, you have two viable options: buy a dimmer switch that is compatible with fluorescent lights, or buy so called dimmable CFLs that are compatible with standard dimmer switches.
Both choices will yield the energy-saving benefits of compact fluorescent lights, along with the ability to dim those lights. But for the time being, dimmable CFLs would appear to be the more affordable option, because fluorescent-compatible dimmer switches are very expensive, while the price difference between standard and dimmable compact fluorescents is just pennies.
Let's consider the total cost for both options, for a lamp with three 60-watt light bulbs. Let's grant that you already have a regular dimmer switch and regular incandescent light bulbs. For an upgrade to compact fluorescents, your choices are:
1. Putting in three 13-watt regular CFLs at $3 a piece, and a $49 fluorescent-compatible dimmer switch. Total cost: $58.
2. Going for three 13-watt dimmable CFLs at $3.50 a piece, and use the preexisting dimmer switch. Total cost: $10.50!
As you can tell, using an existing dimmer switch is a much more affordable choice. Since both solutions use the same amount of energy, in terms of payback period the second solution with dimmable CFLs is definitely much shorter.
Even if you need to get a dimmer switch because you don't have one, it is still better to buy a standard switch and dimmable CFLs. You can purchase a standard dimmer switch for under $10. Even a fashionable one costing $25 is cheaper than a fluorescent dimmer switch at $49. And with the cost gap between standard and dimmable CFLs so narrow, the only way a fluorescent dimmer switch can become cost competitive is if the price on it drops substantially, which it probably will over the next few years.
If your only objective for using a dimmer switch with CFLs is to save electricity, and you don't already have a standard dimmer switch, I'd suggest you stick with standard CFLs for now and forego the dimmer switch, and use the money you save on the dimmer switch to purchase more compact fluorescent lights for other rooms in your house. Dimmer switches added up to big savings for incandescent or halogen fixtures because the bulbs were so wasteful. For example, my rec room has six 50-watt halogen bulbs on a dimmer. By using the dimmer at about the 50% setting, we use 150 watts instead of the full 300 watts. Given an hour on each day, that would save 150 x 365 watts, or 55 kilowatt hours a year.
But if we were to switch those halogen bulbs to 13-watt dimmable compact fluorescent bulbs, we'd reduce consumption by 81 kilowatt hours a year at their full strength. By turning them down to half, we'd only cut our use by an extra 13 kilowatt hours a year - that's about $1.30 worth of energy. Not really enough to make it worth seriously considering this alternative.
Consumer response to dimmable compact fluorescents has been mixed. There were certainly some early quality issues with these lights - early burn-out, flashing light, and annoying buzzing noises. These problems have been largely worked out in the newer dimmable compact fluorescents. But if there isn't a strong motivation for you to dim your CFLs, I would recommend sticking with standard compact fluorescents for a year or so, until the market offers a wider range of choices for dimmable fluorescent lights. You never know - in that timeframe, fluorescent dimmer switches may drop in price as well.
ไม่มีความคิดเห็น:
แสดงความคิดเห็น