Serge Auckland wrote:

"Eeyore" wrote
Serge Auckland wrote:

Quite apart from the problems of disposing of old CFLs, I question the
whole principle of Low Energy lighting. If you have a conventional bulb,
much
of the energy output is in the form of heat, which will help heat the room,

and consequently will reduce the need for other heating, central or
otherwise.

That's sort of fine if you want extra heat. Often as not you don't.

If the central heating is on, then you are, by definition, needing extra
heat. The heat output from lighting will mean that the room thermostat (or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod all to warm
a room.

I suggest you compare sitting in front of a 1kw bar electric fire to switching
on ten 100w light bulbs to see how true that is.

Graham

"Eeyore" wrote in message
...


Serge Auckland wrote:

"Eeyore" wrote
Serge Auckland wrote:

Quite apart from the problems of disposing of old CFLs, I question the
whole principle of Low Energy lighting. If you have a conventional
bulb,
much
of the energy output is in the form of heat, which will help heat the
room,

and consequently will reduce the need for other heating, central or
otherwise.

That's sort of fine if you want extra heat. Often as not you don't.

If the central heating is on, then you are, by definition, needing extra
heat. The heat output from lighting will mean that the room thermostat
(or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod all to
warm
a room.

I suggest you compare sitting in front of a 1kw bar electric fire to
switching
on ten 100w light bulbs to see how true that is.

Look at all the energy that is wasted producing light! :-)

"Richard Crowley" wrote in message
...

"Eeyore" wrote in message
...


Serge Auckland wrote:

"Eeyore" wrote
Serge Auckland wrote:

Quite apart from the problems of disposing of old CFLs, I question
the
whole principle of Low Energy lighting. If you have a conventional
bulb,
much
of the energy output is in the form of heat, which will help heat the
room,

and consequently will reduce the need for other heating, central or
otherwise.

That's sort of fine if you want extra heat. Often as not you don't.

If the central heating is on, then you are, by definition, needing extra
heat. The heat output from lighting will mean that the room thermostat
(or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod all
to warm
a room.

I suggest you compare sitting in front of a 1kw bar electric fire to
switching
on ten 100w light bulbs to see how true that is.

Look at all the energy that is wasted producing light! :-)


What happens to all the 'waste' heat produced in vacuum "filled" bulbs that
used to be, if not still are, produced for garden use ? It can't be radiated
into the atmosphere, as the envelope is substantially cold to the touch.
Does the fact that it must be hanging around in the vicinity of the
filament, modify the power consumption of the lamp compared to its light
output ? Does this make it a low(er) energy lamp? Why does the heat from the
anode of a power tube readily radiate across the vacuum, but the heat from
the filament of a vacuum light bulb seems not to? d;~}

Arfa

Arfa Daily wrote:

"Richard Crowley" wrote in message
...

"Eeyore" wrote in message
...


Serge Auckland wrote:

"Eeyore" wrote
Serge Auckland wrote:

Quite apart from the problems of disposing of old CFLs, I question
the
whole principle of Low Energy lighting. If you have a conventional
bulb,
much
of the energy output is in the form of heat, which will help heat the
room,

and consequently will reduce the need for other heating, central or
otherwise.

That's sort of fine if you want extra heat. Often as not you don't.

If the central heating is on, then you are, by definition, needing extra
heat. The heat output from lighting will mean that the room thermostat
(or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod all
to warm
a room.

I suggest you compare sitting in front of a 1kw bar electric fire to
switching
on ten 100w light bulbs to see how true that is.

Look at all the energy that is wasted producing light! :-)


What happens to all the 'waste' heat produced in vacuum "filled" bulbs that
used to be, if not still are, produced for garden use ?

What vacuum ?


It can't be radiated
into the atmosphere, as the envelope is substantially cold to the touch.
Does the fact that it must be hanging around in the vicinity of the
filament, modify the power consumption of the lamp compared to its light
output ? Does this make it a low(er) energy lamp? Why does the heat from the
anode of a power tube readily radiate across the vacuum, but the heat from
the filament of a vacuum light bulb seems not to? d;~}

Both do. It's called infra red radiation.

There's also conduction too.

Graham

"Eeyore" wrote in message
...


Arfa Daily wrote:

"Richard Crowley" wrote in message
...

"Eeyore" wrote in message
...


Serge Auckland wrote:

"Eeyore" wrote
Serge Auckland wrote:

Quite apart from the problems of disposing of old CFLs, I question
the
whole principle of Low Energy lighting. If you have a conventional
bulb,
much
of the energy output is in the form of heat, which will help heat
the
room,

and consequently will reduce the need for other heating, central
or
otherwise.

That's sort of fine if you want extra heat. Often as not you don't.

If the central heating is on, then you are, by definition, needing
extra
heat. The heat output from lighting will mean that the room
thermostat
(or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod
all
to warm
a room.

I suggest you compare sitting in front of a 1kw bar electric fire to
switching
on ten 100w light bulbs to see how true that is.

Look at all the energy that is wasted producing light! :-)


What happens to all the 'waste' heat produced in vacuum "filled" bulbs
that
used to be, if not still are, produced for garden use ?

What vacuum ?


It can't be radiated
into the atmosphere, as the envelope is substantially cold to the touch.
Does the fact that it must be hanging around in the vicinity of the
filament, modify the power consumption of the lamp compared to its light
output ? Does this make it a low(er) energy lamp? Why does the heat from
the
anode of a power tube readily radiate across the vacuum, but the heat
from
the filament of a vacuum light bulb seems not to? d;~}

Both do. It's called infra red radiation.

There's also conduction too.

Graham


Agreed that *should* be the case, but the fact is that the envelope of a
vacuum light bulb remains substantially cold in use, whilst a 6L6's envelope
will take the skin off your fingertips after a few minutes use ...

Arfa

"Half a Brain Daily"


Agreed that *should* be the case, but the fact is that the envelope of a
vacuum light bulb remains substantially cold in use,


** Only true if the bulb is made from a special grade of quartz glass with
very low IR absorption.

Eg: " Infrasil ".


whilst a 6L6's envelope will take the skin off your fingertips after a few
minutes use ...


** Made with IR absorbing glass, as are nearly all light bulbs.

Some low powered lamps and most "pilot " bulbs are vacuum lamps and they get
damn hot.



....... Phil

"Phil Allison" wrote in message
...

"Half a Brain Daily"


Agreed that *should* be the case, but the fact is that the envelope of a
vacuum light bulb remains substantially cold in use,


** Only true if the bulb is made from a special grade of quartz glass with
very low IR absorption.

Eg: " Infrasil ".


whilst a 6L6's envelope will take the skin off your fingertips after a
few minutes use ...


** Made with IR absorbing glass, as are nearly all light bulbs.

Some low powered lamps and most "pilot " bulbs are vacuum lamps and they
get damn hot.



...... Phil



Ok, I'll buy that.

Arfa

Arfa Daily wrote:

"Eeyore" wrote
Arfa Daily wrote:

Why does the heat from the anode of a power tube readily radiate across the
vacuum, but the heat from the filament of a vacuum light bulb seems not
to? d;~}

Both do. It's called infra red radiation.

There's also conduction too.


Agreed that *should* be the case, but the fact is that the envelope of a
vacuum light bulb remains substantially cold in use, whilst a 6L6's envelope
will take the skin off your fingertips after a few minutes use ...

What lighbulbs have *vacuums* in the bulb ? It's normally filled with a
non-reactive gas mixture.

Graham

"Eeyore" wrote in message
...


Arfa Daily wrote:

"Eeyore" wrote
Arfa Daily wrote:

Why does the heat from the anode of a power tube readily radiate
across the
vacuum, but the heat from the filament of a vacuum light bulb seems
not
to? d;~}

Both do. It's called infra red radiation.

There's also conduction too.


Agreed that *should* be the case, but the fact is that the envelope of a
vacuum light bulb remains substantially cold in use, whilst a 6L6's
envelope
will take the skin off your fingertips after a few minutes use ...

What lighbulbs have *vacuums* in the bulb ? It's normally filled with a
non-reactive gas mixture.

Graham


Maplins do a candle bulb that's vacuum filled. Also, see info on vacuum
bulbs at

http://members.misty.com/don/bulb1.html

Arfa

On Wed, 27 Jun 2007 02:19:52 GMT, the renowned Eeyore
wrote:



Arfa Daily wrote:

"Eeyore" wrote
Arfa Daily wrote:

Why does the heat from the anode of a power tube readily radiate across the
vacuum, but the heat from the filament of a vacuum light bulb seems not
to? d;~}

Both do. It's called infra red radiation.

There's also conduction too.


Agreed that *should* be the case, but the fact is that the envelope of a
vacuum light bulb remains substantially cold in use, whilst a 6L6's envelope
will take the skin off your fingertips after a few minutes use ...

What lighbulbs have *vacuums* in the bulb ? It's normally filled with a
non-reactive gas mixture.

Graham

Many high voltage/low power bulbs are vacuum, IIRC. Don Klipstein says
break-even is 6-10W/cm of filament.

http://members.misty.com/don/bulb1.html


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

"Arfa Daily" wrote in message


Agreed that *should* be the case, but the fact is that
the envelope of a vacuum light bulb remains substantially
cold in use,

Maybe a really low-wattage bulb. But at 50 watts and up, you won't
comfortably unscrew a hot bulb with your bare fingers.

whilst a 6L6's envelope will take the skin
off your fingertips after a few minutes use ...
Arfa

"Eeyore" wrote in message
...


Serge Auckland wrote:

"Eeyore" wrote
Serge Auckland wrote:

Quite apart from the problems of disposing of old CFLs, I question the
whole principle of Low Energy lighting. If you have a conventional
bulb,
much
of the energy output is in the form of heat, which will help heat the
room,

and consequently will reduce the need for other heating, central or
otherwise.

That's sort of fine if you want extra heat. Often as not you don't.

If the central heating is on, then you are, by definition, needing extra
heat. The heat output from lighting will mean that the room thermostat
(or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod all to
warm
a room.

I suggest you compare sitting in front of a 1kw bar electric fire to
switching
on ten 100w light bulbs to see how true that is.

Graham

I'm not so sure about that. Go to downtown Vegas and walk under the entrance
awnings of some of the 'legacy' casinos that still have incandescent
lighting rather than LEDs, and then tell me that it doesn't feel like having
an electric fire a few feet over your head ...

Arfa

Eeyore wrote:

If the central heating is on, then you are, by definition, needing extra
heat. The heat output from lighting will mean that the room thermostat (or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod all to warm
a room.

Wrong.

dizzy wrote:

Eeyore wrote:

If the central heating is on, then you are, by definition, needing extra
heat. The heat output from lighting will mean that the room thermostat (or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod all to warm
a room.

Wrong.

Not wrong.

Graham

"Eeysore ASD retarded MORON"
dizzy wrote:


The heat from most lamps hangs around at ceiling level. It does sod all
to warm
a room.

Wrong.

Not wrong.


** Its a whole lot worse that just wrong.

It is massively asinine, autistic ****wit think.

The only kind the Graham Stevenson menace ever does.




........ Phil

Eeyore wrote:

dizzy wrote:

Eeyore wrote:

If the central heating is on, then you are, by definition, needing extra
heat. The heat output from lighting will mean that the room thermostat (or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod all to warm
a room.

Wrong.

Not wrong.

Graham


Then you've never been in a TV studio, Donkey.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"Michael A. Terrell" wrote in message
...
Eeyore wrote:
If the central heating is on, then you are, by definition, needing
extra
heat. The heat output from lighting will mean that the room
thermostat (or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod
all to warm
a room.

Wrong.

Not wrong.

Then you've never been in a TV studio

Hey you're both partly right. As it generates heat, it will add *something*
to the room temperature. But if the fitting is at ceiling height, and since
hot air rises, it is not an efficient way to warm the part of the room that
humans inhabit. And if you don't have ceiling insulation, it will do even
less.
It's normally considered far better to place electric radiant heaters at
floor level, and relatively close to humans.

Of course the radiant heat from studio lamps is far greater than normal
domestic bulbs, but I wouldn't want to be paying for the electricity they
use either.
Even bathroom heat lamps are mirror backed to project the heat downwards,
and they are a pretty inefficient heating method regardless. Fortunately
they are only designed to be used for short periods.

MrT.

"Mr.T" MrT@home wrote in
u:

It's normally considered far better to place electric radiant heaters at
floor level, and relatively close to humans.


It is, and it's not wise. It places stresses on the body, strong enough to
make it ill. I remember getting into the strong localised heat one winter.
I ended up shivering if I moved away to another room, even if moving out of
the direct radiance. Going outside felt terrible. I had headaches and flu-
like symptoms. It was one of the more stupid experiments I ever tried.

It's far better to live with a well-spread heat source that doesn't cause
strong changes. That way the body can maintain thermal equilibrium and stay
safe, the immune system strengthens, and going outside is an easy extension
of internal activity. It makes it easier to get used to wider extremes.

If I have to use a radiant heater, I point it at distant furnishings at low
level but not at me. Most times I now rely on convection and low-grade
radiation from electrical devices, relying on their waste heat and on good
home insulation but also good ventilation. In short, anything that produces
heat but no strong thermal gradients. I've found it the most healthy way to
get heating done. A single strong lamp in the centre of the ceiling fits
into that well enough.

"Mr.T" wrote:

Even bathroom heat lamps are mirror backed to project the heat downwards,
and they are a pretty inefficient heating method regardless. Fortunately
they are only designed to be used for short periods.

I have one of those. It's quite nice in the winter.

Graham

"Mr.T" wrote:

"Michael A. Terrell" wrote in message

Then you've never been in a TV studio

Hey you're both partly right. As it generates heat, it will add *something*
to the room temperature. But if the fitting is at ceiling height, and since
hot air rises, it is not an efficient way to warm the part of the room that
humans inhabit. And if you don't have ceiling insulation, it will do even
less.



Military TV station in Alaska in the early '70s: Halogen studio
lights at the ceiling, and less than half in use at any one time. In the
winter I would open the back door to the studio to allow the sub zero
air into the studio to keep it below 80 degrees. In the summer, the
talking heads did the news in a dress uniform shirt and jacket, and
their underwear, because there was no air conditioning.


It's normally considered far better to place electric radiant heaters at
floor level, and relatively close to humans.

Of course the radiant heat from studio lamps is far greater than normal
domestic bulbs, but I wouldn't want to be paying for the electricity they
use either.


Newer studio cameras need less light than the older models. That
reduces studio operating costs, and mantainenece costs, as well.


Even bathroom heat lamps are mirror backed to project the heat downwards,
and they are a pretty inefficient heating method regardless. Fortunately
they are only designed to be used for short periods.


Its stupid NOT to have a reflector on any ceiling mounted lamp. When
it comes to studio lighting, there are different types of fixtues to
choose from. The choice depends on the lighting pattern that is
required. Also, small studio spotlights are used with brass Gobos to
project patterens on the studio walls. The last custom one I made was a
Shamrock, for an Irish preacher, who was visiting WACX TV.

http://www.sfxdesigninc.com/v2/ for examples of stock Gobos.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"Michael A. Terrell" wrote in message
...
Military TV station in Alaska in the early '70s: Halogen studio
lights at the ceiling, and less than half in use at any one time. In the
winter I would open the back door to the studio to allow the sub zero
air into the studio to keep it below 80 degrees. In the summer, the
talking heads did the news in a dress uniform shirt and jacket, and
their underwear, because there was no air conditioning.

Its stupid NOT to have a reflector on any ceiling mounted lamp. When
it comes to studio lighting, there are different types of fixtues to
choose from. The choice depends on the lighting pattern that is
required. Also, small studio spotlights are used with brass Gobos to
project patterens on the studio walls. The last custom one I made was a
Shamrock, for an Irish preacher, who was visiting WACX TV.

http://www.sfxdesigninc.com/v2/ for examples of stock Gobos.


And the relevence to the current discussion is ..... ????????

MrT.

"Michael A. Terrell" wrote:

Eeyore wrote:
dizzy wrote:
Eeyore wrote:

If the central heating is on, then you are, by definition, needing extra
heat. The heat output from lighting will mean that the room thermostat (or
radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod all to warm
a room.

Wrong.

Not wrong.


Then you've never been in a TV studio, Donkey.

It's a hell of a lot hotter up where the lamps are.

Besides, TV spotlights are hardly a valid comparison with ordinary domestic lighting.

Graham

Eeyore wrote in
:



dizzy wrote:

Eeyore wrote:

If the central heating is on, then you are, by definition, needing
extra heat. The heat output from lighting will mean that the room
thermostat (or radiator valves) will turn off that bit sooner.

Not really.

The heat from most lamps hangs around at ceiling level. It does sod
all to warm a room.

Wrong.

Not wrong.

Graham



Yes it is. Most of the heat is radiant. Just because the intensity falls
off fourfold per unit distance doesn't mean the energy vanishes. Even if
you consider the ceiling covering nearly half of the volume through which
heat tries to radiate through, the shallow angle of incidence means that
most of that reflects to join the rest to warm the walls and anything else
it can reach. The small amount of heat above the lamp is from convection,
and keeping the bulb clean will help to let the heat radiate more
efficiently and usefully.

Cieling heat isn't useless in heating a room anyway. While I think it IS a
bit daft, I remember a house I visited a few times as a kid, it had a low
temperature heater in the entire ceiling of one room. It was very low-grade
heat, but it still warned the room. I felt it on my face when I looked up
at it. Less so while sitting, but not much, because the area was so large.
Similarly, a lightbulb radiating across a ceiling adds heat usefully to the
whole room. More in fact (proportionally), because more of it is radiated
than conducted away above.