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

In message <Wu4ck.249528$1B6.13899@[EMAIL PROTECTED]
>, Arfa Daily 
<arfa.daily@[EMAIL PROTECTED]
> writes
>
>"Jeff Liebermann" <jeffl@[EMAIL PROTECTED]
> wrote in message
>news:tbf0745m65iugupkjtnnasnbe2vf777j6q@[EMAIL PROTECTED]
>> On Sun, 6 Jul 2008 02:08:27 +0100, "Arfa Daily"
>> <arfa.daily@[EMAIL PROTECTED]
> 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