On Wed, 16 Sep 2009 15:24:10 +0100, Jerry wrote:

"pete" wrote in message
...

[ re Tungsten Filament bulbs and how they contribute to the
heating of a room ]

:
: The problem with the heat from TF bulbs is that it's mostly at
ceiling
: height, since that's where most bulbs hang from. What people
need
: is heat at body (whether seated or standing) height, to keep
them warm.

Not sure what you're trying to get at there (you might have even
been agreeing with me?), if the TF bulb helps to increase the air
temperature at ceiling level above that of the lower level then
more heat (quite possibly at a lower temperature) will remain
were it *is needed* for longer - all heat rises eventually, even
heat given off by under floor heating eventually ends up at
ceiling level if there is no other exit or means of heat exchange
such as cold surfaces or ambient air temperature IYSWIM.

Well, if you have a 100W TF light suspended from the ceiling, the heat
from that bulb will rise to the top of the room. The occupants won't get
any direct benefit from that 100Watts. Not unless they're exceptionally
tall - in which case their heads will get a little warmer.
As you say, you may get some small improveent from that heat adding to
the temperature gradient in the room, but it won't be anything like the
100Watts the bulb is putting out. You'd be far better off putting in a
CFL (or 6) and installing a small fan to move the warm air off the ceiling
if only temporarily, so that it can usefully warm the room's occupants.