Re: Slightly OT. Heat and a Bench Light ...

In message <Wu4ck.249528$1B6.13899@xxxxxxxxxxxxx>, Arfa Daily <arfa.daily@xxxxxxxxxxxx> writes

"Jeff Liebermann" <jeffl@xxxxxxxxxx> wrote in message
news:tbf0745m65iugupkjtnnasnbe2vf777j6q@xxxxxxxxxx
On Sun, 6 Jul 2008 02:08:27 +0100, "Arfa Daily"
<arfa.daily@xxxxxxxxxxxx> wrote:

Potential fire hazard, or am
I just being paranoid ? Does this need bringing to someone's attention ?

You might have a point, however I find it odd that you're using a 75
or 100 watt incandescent bulb in a desk lamp.

You're mis-understanding me, I think. I'm not using a 75 or 100 watt bulb.
I'm using a 60 watt bulb, as specified for the lamp, and always have done.
Up until now, they have always been the 'standard' tennis ball sized type.
The smaller ones that I have been buying lately, are still rated at 60
watts, but in my opinion, put out the *heat* of a standard-sized 100 watt
bulb.

Arfa

I haven't been following the thread, so apologies if this explanation has been offered earlier.

I'm guessing, but I reckon that smaller sized bulb may be hotter because:
(a) The filament may be physically smaller (squeezed in more, and coiled up tighter). Some parts of the filament may be obstructing the path of the light from other parts. Similarly, the path for radiated heat may be being obstructed. As a result, the filament may be less efficient (less light output, but more heat).
(a) The glass bulb is closer to the hot filament.
(b) The glass bulb has quite a lot less surface area available to dissipate the heat.

What do you think?
--
Ian
.

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