from Peg in Mosinee, WI:
#837
A few years ago, dimmer switches on lights were suggested to save energy. They all seem to buzz and get very warm when on less than full brightness. So do they really save energy when it seems the heat generated is just moved from the incandescent bulbs to the switch?
Lowering the wattage saves energy, but ENERGY STAR qualified CFLs save the most!
As a general rule any time you lower wattage, you lower power consumption. Dimmers do reduce the total amount of energy being used, even with the heat that is dissipated at the switch, and have the added bonus of extending the total life of an incandescent lamp which can save you money on bulb replacement costs.
The symptoms you describe are typical of using a cheap dimmer, overloading the dimmer, or using too many dimmers in a single box. It is essential to make sure that the dimmer is rated for the load that you want to control. Dimmers that are rated properly will perform much better and should not hum or buzz, but may feel warm (not hot) to the touch due to heat sinking that is built in to direct heat away from the wires. The buzzing is typically due to the incandescent filament vibrating from being essentially turned on and off 120 times each second (which is what the dimmer does to get a dimmed light level) and is typically most noticeable when dimmed about 50%. Incandescent lamps with reinforced filaments may help resolve this problem (often advertised as “long life” or “rough service”). For more information, you can check out manufacturer websites; most will have info on these issues.
However, if your major concern is lowering your energy bill, I would try switching to ENERGY STAR qualified CFLs (compact fluorescent light bulbs), they provide almost the same quality and quantity of light, at a fraction of the power consumption.
Published Wednesday, July 14, 2010