There are two oposite factors that effect the lifetime of incandescent lamps. Allmost all modern dimmers use a solid state switch to 'clip' the sinusoidal wave back creating a sharp change of voltage at the point where it is cut. This rapid change of voltage induces a rapid change of current and magnetic field causing the filament to act like a tiny electrical motor and twists it much more violently than during a normal smooth transition. The more expensive the dimmer the better the choke which smooths out these spikes. The lower temperatures reduce chemical reactions inside the bulb, which lengthens the lifespan.
I cannot understand why so many people are talking about swapping to flourescent lamps from incandescents as lighting only makes up an average of 3% of the energy used in a typical home. Flourescent lamps contain mercury so must be disposed of as hazardus waste, but not many people know this so they end up in land fills. They also use a lot of energy during the start up process and only settle down to low power consumption after many seconds, during which time they do not output very much light so are not very good in hallways where the light may only be used for a minute or so. What I want to see is the cost of high effeicency LED clusters come down in price so that the extremely long lifetime can offset manufacturing energy with much better energy to light efficiencies and little hazardus waste.
On an industrial scale, power companies charge more for bad power factor users. If you are running large inductive loads then the power company has to build hugely expensive, high power capacitors to bring the current & voltage back into phase to protect the generators. So the VA is costly in the big picture.
I'm thinking similar orders of magnetude: Why are we debating lowering standby power from 2 to 1 watt per device when most of us drive vehicles that use 100,000 to 200,000 watts at below 30% efficiency! The gas boiler in my house uses about 30,000 watts at about 60%efficiency. Until we spend our money on addressing these high power / low efficiency machines we are, I agree, just "pissing in the wind" turbine.
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There are two oposite factors that effect the lifetime of incandescent lamps. Allmost all modern dimmers use a solid state switch to 'clip' the sinusoidal wave back creating a sharp change of voltage at the point where it is cut. This rapid change of voltage induces a rapid change of current and magnetic field causing the filament to act like a tiny electrical motor and twists it much more violently than during a normal smooth transition. The more expensive the dimmer the better the choke which smooths out these spikes. The lower temperatures reduce chemical reactions inside the bulb, which lengthens the lifespan.
I cannot understand why so many people are talking about swapping to flourescent lamps from incandescents as lighting only makes up an average of 3% of the energy used in a typical home. Flourescent lamps contain mercury so must be disposed of as hazardus waste, but not many people know this so they end up in land fills. They also use a lot of energy during the start up process and only settle down to low power consumption after many seconds, during which time they do not output very much light so are not very good in hallways where the light may only be used for a minute or so. What I want to see is the cost of high effeicency LED clusters come down in price so that the extremely long lifetime can offset manufacturing energy with much better energy to light efficiencies and little hazardus waste.
On an industrial scale, power companies charge more for bad power factor users. If you are running large inductive loads then the power company has to build hugely expensive, high power capacitors to bring the current & voltage back into phase to protect the generators. So the VA is costly in the big picture.
I'm thinking similar orders of magnetude: Why are we debating lowering standby power from 2 to 1 watt per device when most of us drive vehicles that use 100,000 to 200,000 watts at below 30% efficiency! The gas boiler in my house uses about 30,000 watts at about 60%efficiency. Until we spend our money on addressing these high power / low efficiency machines we are, I agree, just "pissing in the wind" turbine.