"Richard Blackwood" wrote in message ...
Once again the hot weather has reminded me of just how much I dislike it!
Last night I noticed the amount of heat given of by my ordinary bedside
lamp - IIRC something like 80% of the energy in light bulbs is heat not
light. It made me wonder whether different bulbs would produce less heat?

Argos do a pack of 3 15 Watt BC Energy Saving Fluorescent Bulbs for £6.99

http://www.argos.co.uk/webapp/wcs/st...y?storeId=1000
1&langId=-1&catalogId=2501&productId=104088

These seem to have an ordinary 'bayonet' type fixing. Would these emit less
heat as well as being more efficient?

Can anyone shed some light on the subject?


All a bulbs power input becomes heat: about 98% of it becomes heat
directly, the rest becomes light, which turns to heat less than a
microsecond later as its absorbed. The power input always equals the
heat output.

CFLs are the solution, but dont be caught out by the one issue: the
stated equivalent powers are unrealistic, as they are comparisons with
a different type of bulb than everyone expects. The real efficiency
improvement is about 3.5x - 4x, so to replace a 60w bulb you need a
15-17 watts.

If you trust the box's equivalency claims, its dimmer and doesnt look
right.


NT