Simon wrote:
I don't like to be pickey about this, but there should be less heat, not
more. If the bulbs are rated at the same wattage (ie. energy input) and
a greater proportion of that energy is emitted as visible light
(ie. they are brighter), then it follows that a smaller proportion must
be emitted as heat.
I checked with one of the lighting experts at GE's R&D Center a few months
ago when this thread was last active. He said that normal incandescent bulbs
were so inefficient and that halogen incandescents were not really any more
efficient. For all intents and purposes, the heat given off by halogen and
regular incandescents was the same for a given wattage.
The context of the question I posed to Vic was 40W regular incandescents vs
55W halogen incandescents (or something like that). For the purpose of
calculating heat output the two are the same (per watt). As I recall, the
reason why halogens work is that the halogen gas keeps the tungsten from
"flaking off" (there's a real scientific term for you :-) the filament, thus
you can run the same filament at higher wattages (or whatever - I'm a
software jock, not an EE). That's why they're brighter, not because so much
more light is given off at a given wattage.
So, for Roland's example, unless his new-fangled halogen light bulbs are
higher wattage than his old ones, he shouldn't notice any increase in
brightness. If he's running a higher wattage halogen, it will be brighter,
but then his plastic lenses may melt...
Anyone for itty bitty flourescent lights? :-)
--
Skip Montanaro (montanaro@ausable.crd.ge.com)
Now working for Automatrix. Details at 11.
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