Robin Green asked:
Dimmer switches can give a more relaxed feel to your home, and save you energy as well. But with the increasing prevalence of compact fluorescent lights or CFLs, many people are wondering 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 switch.
Let’s start by putting to rest some misconceptions people have over the relative energy use of fluorescent, incandescent, and halogen bulbs.
Many homeowners put in halogen bulbs, starting in the 1990’s, on the mistaken idea that these lights are more efficient than incandescent lights. In fact their energy efficiency is pretty much the same as that of incandescents. So don’t think you’re saving energy by using them.
CFLs, meanwhile, are very efficient - it takes about one fourth as much electricity to light up a CFL as to light up an incandescent or halogen lamp with the same light output. They also happen to last about eight times longer than incandescent lights.
So if you are using a dimmer primarily to save power, you might be better off just switching your incandescent or halogen lights to CFLs, and keeping the dimmer switch on full, or going back to a standard on-off switch. That will give you more light for less power.
If you want a more mellow lighting all the time, one way is to put in light bulbs that aren’t as bright. Whether you go down from, for example, a 100 watt incandescent to a 60 watt incandescent bulb, or down from a 100 watt incandescent bulb to an 18 watt CFL, you’ll still get less light and you’ll use less electricity. Of course, the CFL solution will save you much more electricity in the long run.
But chances are you want the best of both worlds: the low running cost and better durability of CFL bulbs, with the flexibility to dim them when you don’t need their full light.
You may have heard that you cannot put a regular CFL on a regular dimmer switch. In fact you can, but it is not recommended, because it can really reduce the life of the bulb. There is no increased risk of explosion or fire from installing a regular CFL on a standard dimmer switch - you’ll only increase the risk of shortened bulb life. And since the higher price of CFL bulbs is offset by the fact that they outlive incandescent bulbs by a ratio of 8 to 1, putting regular CFLs on a standard dimmer destroys that cost advantage.
If you choose to dim CFLs, you have two real options: buy a special dimmer switch that is compatible with CFLs, or buy dimmable CFLs that are designed to work with standard dimmers.
Both choices leave you with the energy-saving advantages of CFLs, as well as the ability to dim those CFLs. But for now at least, dimmable CFLs seem like the more affordable option, because fluorescent-compatible dimmer switches are prohibitively expensive, while the price difference between standard and dimmable compact fluorescents is miniscule.
Let’s consider the total cost for both options, for a fixture with three 60-watt light bulbs. Let’s assume you already have a standard dimmer switch and regular incandescent light bulbs. If you want to upgrade to CFLs, your choices are:
1. Installing three 13-watt standard CFLs at $3 a piece, and a $49 fluorescent dimmer switch. Total cost: $58.
2. Going for three 13-watt dimmable CFLs at $3.50 a piece, and use the existing dimmer. Total cost: $10.50!
As you can tell, using an existing dimmer switch is a more affordable alternative. Since both options use the same amount of energy, in terms of payback period the solution with dimmable compact fluorescent lights is definitely much shorter.
Even if you need to buy a dimmer switch because you don’t have one, it still makes sense to go with a standard switch and dimmable CFLs. You can get a standard dimmer switch for under $10. Even a fashionable one for $25 is more affordable than a fluorescent dimmer at $49. And with the cost gap between standard and dimmable CFLs so small, the only way a fluorescent dimmer switch will be cost competitive is if its price drops substantially, which it probably will over the coming years.
If your only motive for using a dimmer switch with CFLs is to save money, and you don’t already have a regular dimmer switch, I would suggest you stay with basic CFLs and forego the dimmer switch. Use the money you save on the dimmer switch to buy more CFLs for other areas of your house. Dimmer switches resulted in major savings for incandescent or halogen fixtures because the bulbs were so wasteful. For example, my rec room has six 50-watt bulbs on a dimmer switch. By using the dimmer at about half power, we use 150 watts instead of the full 300 watts. Assuming 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 CFLs, we’d save 81 kilowatt hours a year at their full strength. By turning them down to half, we’d only save an extra 13 kilowatt hours a year - that’s about $1.30 worth of electricity. Not really enough to make it worth considering this alternative.
Consumer response to dimmable CFLs has been less than overwhelmingly positive. There were certainly some teething issues with these lights - early burn-out, flashing light, and loud buzzing noises. These problems have been pretty much resolved in the more recent 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, until the market offers a wider range of choices for dimmable fluorescent lights. Who knows - in a year or two, fluorescent dimmer switches could be as cheap as standard dimmers.
Dimmer switches can give a more relaxed feel to your home, and save you energy as well. But with the increasing prevalence of compact fluorescent lights or CFLs, many people are wondering 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 switch.
Let’s start by putting to rest some misconceptions people have over the relative energy use of fluorescent, incandescent, and halogen bulbs.
Many homeowners put in halogen bulbs, starting in the 1990’s, on the mistaken idea that these lights are more efficient than incandescent lights. In fact their energy efficiency is pretty much the same as that of incandescents. So don’t think you’re saving energy by using them.
CFLs, meanwhile, are very efficient - it takes about one fourth as much electricity to light up a CFL as to light up an incandescent or halogen lamp with the same light output. They also happen to last about eight times longer than incandescent lights.
So if you are using a dimmer primarily to save power, you might be better off just switching your incandescent or halogen lights to CFLs, and keeping the dimmer switch on full, or going back to a standard on-off switch. That will give you more light for less power.
If you want a more mellow lighting all the time, one way is to put in light bulbs that aren’t as bright. Whether you go down from, for example, a 100 watt incandescent to a 60 watt incandescent bulb, or down from a 100 watt incandescent bulb to an 18 watt CFL, you’ll still get less light and you’ll use less electricity. Of course, the CFL solution will save you much more electricity in the long run.
But chances are you want the best of both worlds: the low running cost and better durability of CFL bulbs, with the flexibility to dim them when you don’t need their full light.
You may have heard that you cannot put a regular CFL on a regular dimmer switch. In fact you can, but it is not recommended, because it can really reduce the life of the bulb. There is no increased risk of explosion or fire from installing a regular CFL on a standard dimmer switch - you’ll only increase the risk of shortened bulb life. And since the higher price of CFL bulbs is offset by the fact that they outlive incandescent bulbs by a ratio of 8 to 1, putting regular CFLs on a standard dimmer destroys that cost advantage.
If you choose to dim CFLs, you have two real options: buy a special dimmer switch that is compatible with CFLs, or buy dimmable CFLs that are designed to work with standard dimmers.
Both choices leave you with the energy-saving advantages of CFLs, as well as the ability to dim those CFLs. But for now at least, dimmable CFLs seem like the more affordable option, because fluorescent-compatible dimmer switches are prohibitively expensive, while the price difference between standard and dimmable compact fluorescents is miniscule.
Let’s consider the total cost for both options, for a fixture with three 60-watt light bulbs. Let’s assume you already have a standard dimmer switch and regular incandescent light bulbs. If you want to upgrade to CFLs, your choices are:
1. Installing three 13-watt standard CFLs at $3 a piece, and a $49 fluorescent dimmer switch. Total cost: $58.
2. Going for three 13-watt dimmable CFLs at $3.50 a piece, and use the existing dimmer. Total cost: $10.50!
As you can tell, using an existing dimmer switch is a more affordable alternative. Since both options use the same amount of energy, in terms of payback period the solution with dimmable compact fluorescent lights is definitely much shorter.
Even if you need to buy a dimmer switch because you don’t have one, it still makes sense to go with a standard switch and dimmable CFLs. You can get a standard dimmer switch for under $10. Even a fashionable one for $25 is more affordable than a fluorescent dimmer at $49. And with the cost gap between standard and dimmable CFLs so small, the only way a fluorescent dimmer switch will be cost competitive is if its price drops substantially, which it probably will over the coming years.
If your only motive for using a dimmer switch with CFLs is to save money, and you don’t already have a regular dimmer switch, I would suggest you stay with basic CFLs and forego the dimmer switch. Use the money you save on the dimmer switch to buy more CFLs for other areas of your house. Dimmer switches resulted in major savings for incandescent or halogen fixtures because the bulbs were so wasteful. For example, my rec room has six 50-watt bulbs on a dimmer switch. By using the dimmer at about half power, we use 150 watts instead of the full 300 watts. Assuming 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 CFLs, we’d save 81 kilowatt hours a year at their full strength. By turning them down to half, we’d only save an extra 13 kilowatt hours a year - that’s about $1.30 worth of electricity. Not really enough to make it worth considering this alternative.
Consumer response to dimmable CFLs has been less than overwhelmingly positive. There were certainly some teething issues with these lights - early burn-out, flashing light, and loud buzzing noises. These problems have been pretty much resolved in the more recent 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, until the market offers a wider range of choices for dimmable fluorescent lights. Who knows - in a year or two, fluorescent dimmer switches could be as cheap as standard dimmers.
