This month's lightbulb wars going on over at Re-Nest got me thinking about whether or not dimmer switches save energy. In the past, the electricity from the unused energy was converted to heat at the switch, but is that still the case?
I have to admit, this post might resolve an ongoing turn-off-the-lights/why-can't-I-leave-them-on-dimmed debate that has been ongoing in my household because dimmer switches DO indeed save electricity. If you have the newer dimmer switches, they now include a "Triac Switch" which cuts the flow of energy to the light. It causes a constant flicker which the human eye cannot register, cutting down on the actual electricity used to power the light. The best news is that if you use the dimmer switch at about 50% you will save money on your electric bill in the long run!
If you don't have dimmer switches currently and are looking to install them, you can find an easy seven step install how-to here.
Image: Micki Howl
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The flicker is definitely noticeable if you use compact fluorescent bulbs. I think you need to either buy special CFL dimmer bulbs or go with regular bulbs - which aren't particularly efficient.
Dimming Incandescent also extends the lamp life of your "bulbs", which means changing them less often. However you don't get any added lamp life by dimming Compact Fluorescent or LED.
I'd heavily dispute that the "human eye can't register".
I absolutely hate our dimmer switch and would happily replace it with a normal switch that doesn't make these awful energy efficient CCFL bulbs (dimmer compatible model) flicker. My partner can't see it, but it gives me a splitting headache and means we have to use lamps all the time.
If I didn't rent I'd replace the switches with normal ones.
Less light from the same lamp means it uses less energy, unless you covered it with blanket or something (which is not bright :)). If you have the right equipment you can dim almost any light source. That includes fluorescent lights and LEDs. If you have trouble with lights flickering when dimmed, replace the bulbs or the dimmer with different type. The cheap stuff often doesn't cut it.