I heard that GU10 230v lamps throw the heat forwards and other types,
including LV, throw the heat backwards. The forward throwing type is
better for fire safety in ceilings.

Building inspectors are getting shirty about downlighters in ceilings,
wanting fireproof boxes around them. If a lamp throws heat forwards
then the fire aspect should not be an issue.

Does anyone know what lamps are more safe than others in this respect?

wrote in message
ups.com...
I heard that GU10 230v lamps throw the heat forwards and other types,
including LV, throw the heat backwards. The forward throwing type is
better for fire safety in ceilings.

Building inspectors are getting shirty about downlighters in ceilings,
wanting fireproof boxes around them. If a lamp throws heat forwards
then the fire aspect should not be an issue.

Does anyone know what lamps are more safe than others in this respect?

I imagine that the LED downlighters which are a
direct replacement for GU10s would be the
coolest option, but you need more of them to get
the same amount of light.

http://www.electriclightcompany.co.u...Lamps_154.html

Al

On Wed, 02 Feb 2005 02:49:37 -0800, timegoesb wrote:

I heard that GU10 230v lamps throw the heat forwards and other types,
including LV, throw the heat backwards. The forward throwing type is
better for fire safety in ceilings.

Building inspectors are getting shirty about downlighters in ceilings,
wanting fireproof boxes around them. If a lamp throws heat forwards
then the fire aspect should not be an issue.

Does anyone know what lamps are more safe than others in this respect?

Anything with a dichroic (selective) reflector attempts to throw visible
light forward whilst letting infrared pass though it and out the back.

One property of dichroic reflectors is they appear "colourful" if you look
at them, with little patches of colour depending on how you look at them.

I've mostly seen dichroic used on LV halogen (where the reflector is part
of the bulb assembly)

Timbo

In article . com,
writes:
I heard that GU10 230v lamps throw the heat forwards and other types,
including LV, throw the heat backwards. The forward throwing type is
better for fire safety in ceilings.

Building inspectors are getting shirty about downlighters in ceilings,
wanting fireproof boxes around them. If a lamp throws heat forwards
then the fire aspect should not be an issue.

The reason for the fireproof box is not the lamp itself, but
due to you punching a hole through a fire barrier (the ceiling).
Of course, mounting a cheap crappy incendiary device in the hole
is not the brightest of ideas either, but secondary to the main
issue.

Does anyone know what lamps are more safe than others in this respect?

None. There are some more expensive commercial recessed fittings
with integral fire barrier.

--
Andrew Gabriel

On 2 Feb 2005 02:49:37 -0800, wrote:

larva lamps from the 60's, by the way the word is kewl
bob

In article ,
(Andrew Gabriel) writes:
Does anyone know what lamps are more safe than others in this respect?

None. There are some more expensive commercial recessed fittings
with integral fire barrier.

A further comment: This is from the building regs perspective.

If you are talking from the perspective of the lamp starting a
fire, then a fully aluminised reflector rather than a dichroic
reflector lamp would be better, but they've become very hard
to find nowadays.

--
Andrew Gabriel

wrote:

I heard that GU10 230v lamps throw the heat forwards and other types,
including LV, throw the heat backwards. The forward throwing type is
better for fire safety in ceilings.

There are several issues here...

there is the issue of how much heat is generated by the fitting/bulb.
This tends to be more of a problem with reducing the life of the bulb
and transformer rather than being a direct fire risk IIUC.

(You are correct that the bulbs with aluminium reflectors tend to
project more IR forward. The dichroic ones will let more reach the
fitting (hence the fitting has to be designed to be able to take it).
You can get dichroic bulbs in both 240V and 12V).

Building inspectors are getting shirty about downlighters in ceilings,
wanting fireproof boxes around them. If a lamp throws heat forwards
then the fire aspect should not be an issue.

The more significant fire issue in many cases, is that fitting down
lighters requires a large(ish) hole be cut in the ceiling. This in many
cases breaching a fire resistant layer (i.e. the skim/plasterboard)
between habitable rooms. In these cases an intumescent hood can be
fitted to restore the integrity of the fire block.

Does anyone know what lamps are more safe than others in this respect?

Hard to choose on safety grounds... with a downlighter of any sort you
need enough space behind it. Given that the bezel of a non dichroic bulb
may get hotter, and hence be more of a touch hazard (if the ceiling is
low enough), I would lean toward the dichroic bulb. On aesthetic grounds
the dichroic bulb wins on several counts.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

wrote
| I heard that GU10 230v lamps throw the heat forwards and other types,
| including LV, throw the heat backwards. The forward throwing type is
| better for fire safety in ceilings.
| Building inspectors are getting shirty about downlighters in ceilings,
| wanting fireproof boxes around them. If a lamp throws heat forwards
| then the fire aspect should not be an issue.

The issue is not so much the heat generated by the lamp. A fireproof box is
going to concentrate that heat in a particular area, rather than letting it
dissipate through the void. The problem is the fact that the ceiling is
being pierced allowing the spread of smoke and fire from the room below into
the ceiling void. The plasterboard ceiling is an important part of
maintaining the fire integrity of the whole floor structure. These fire
domes also have to be used for ceiling speakers, which do not generate any
heat.

The use of ceramic flowerpots, while useful for keeping loft insulation away
from the luminaire, does not preserve the fire integrity of the ceiling.

Owain

Andrew Gabriel wrote:

If you are talking from the perspective of the lamp starting a
fire, then a fully aluminised reflector rather than a dichroic
reflector lamp would be better,

Yup agreed. I would have thought the prospect of the lamp itself being
responsible for a fire is limited, since although they get hot, they
don't typically get _that_ hot... (250 deg C tops as a guess, which is
going to be below the flash point of most building materials).

Having said that, if your transformer melts and goes low resistance that
might do it ;-)

but they've become very hard
to find nowadays.

I though that most GU10s were typically ali, and GZ10s the dichroic
versions?

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article ,
John Rumm writes:
Andrew Gabriel wrote:

If you are talking from the perspective of the lamp starting a
fire, then a fully aluminised reflector rather than a dichroic
reflector lamp would be better,

Yup agreed. I would have thought the prospect of the lamp itself being
responsible for a fire is limited, since although they get hot, they
don't typically get _that_ hot... (250 deg C tops as a guess, which is
going to be below the flash point of most building materials).

Having said that, if your transformer melts and goes low resistance that
might do it ;-)

There have been cases. Two I know of were both due to bad
lampholder connections -- in one case the lampholder started
a fire and in the other case it shorted out and the transformer
then started the fire.

but they've become very hard
to find nowadays.

I though that most GU10s were typically ali, and GZ10s the dichroic
versions?

Yes, you're right (although I can never remember which way round
they are without looking it up). I was thinking of the 12V lamps,
where fully aluminised reflectors used to be available, but have
vanished now.

--
Andrew Gabriel

wrote:
I heard that GU10 230v lamps throw the heat forwards and other types,
including LV, throw the heat backwards. The forward throwing type is
better for fire safety in ceilings.

Building inspectors are getting shirty about downlighters in
ceilings,
wanting fireproof boxes around them. If a lamp throws heat forwards
then the fire aspect should not be an issue.

Does anyone know what lamps are more safe than others in this
respect?

No-ones really answered the question, least not the way I read it... my
answer is CFLs. You could also say LEDs, but theyre not a serious
contender practically.


NT

wrote:


No-ones really answered the question, least not the way I read it... my
answer is CFLs. You could also say LEDs, but theyre not a serious
contender practically.

I think the asnwer is there is not much to choose between them. It is
the cutting of the hole that posses more risk than the choice of lamp.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Owain" wrote in message
...
wrote
| I heard that GU10 230v lamps throw the heat forwards and other types,
| including LV, throw the heat backwards. The forward throwing type is
| better for fire safety in ceilings.
| Building inspectors are getting shirty about downlighters in ceilings,
| wanting fireproof boxes around them. If a lamp throws heat forwards
| then the fire aspect should not be an issue.

The issue is not so much the heat generated by the lamp. A fireproof box
is
going to concentrate that heat in a particular area, rather than letting
it
dissipate through the void. The problem is the fact that the ceiling is
being pierced allowing the spread of smoke and fire from the room below
into
the ceiling void. The plasterboard ceiling is an important part of
maintaining the fire integrity of the whole floor structure. These fire
domes also have to be used for ceiling speakers, which do not generate any
heat.

The use of ceramic flowerpots, while useful for keeping loft insulation
away
from the luminaire, does not preserve the fire integrity of the ceiling.

An upturned ceramic pot with notch out of the rim for the cable and sealed
with silicon to the plasterboard with preserve fire integrity.



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"Doctor Evil" wrote in message
...

"Owain" wrote in message
...
wrote
| I heard that GU10 230v lamps throw the heat forwards and other types,
| including LV, throw the heat backwards. The forward throwing type is
| better for fire safety in ceilings.
| Building inspectors are getting shirty about downlighters in ceilings,
| wanting fireproof boxes around them. If a lamp throws heat forwards
| then the fire aspect should not be an issue.

The issue is not so much the heat generated by the lamp. A fireproof box
is
going to concentrate that heat in a particular area, rather than letting
it
dissipate through the void. The problem is the fact that the ceiling is
being pierced allowing the spread of smoke and fire from the room below
into
the ceiling void. The plasterboard ceiling is an important part of
maintaining the fire integrity of the whole floor structure. These fire
domes also have to be used for ceiling speakers, which do not generate
any
heat.

The use of ceramic flowerpots, while useful for keeping loft insulation
away
from the luminaire, does not preserve the fire integrity of the ceiling.

An upturned ceramic pot with notch out of the rim for the cable and sealed
with silicon to the plasterboard with preserve fire integrity.

You'll have to get the silicon VERY hot to melt it enough to make it nice
and sticky ;-)

and to remain on topic, I recenly tried out the little 7W GU10-compatible
fluorescents to replace 5xmains 50W downlighters in the kitchen.

VERY disappointing - the halogens are back in and the mini fluorescents are
doing a great job in my study.

Regards,
Simon.

In article ,
"Simon Stroud" writes:

and to remain on topic, I recenly tried out the little 7W GU10-compatible
fluorescents to replace 5xmains 50W downlighters in the kitchen.

VERY disappointing - the halogens are back in and the mini fluorescents are
doing a great job in my study.

Multiply 7W by 4 to get equivalent, and in this case knock a bit
off due to reflector losses and comparison with 12V rather than
240V lamps, and you're probably looking at 20-25W equivalent, so
it's not surprising it fell short of 50W lamps.

--
Andrew Gabriel

"Al Reynolds" wrote in message
...
wrote in message
ups.com...
I heard that GU10 230v lamps throw the heat forwards and other types,
including LV, throw the heat backwards. The forward throwing type is
better for fire safety in ceilings.

Building inspectors are getting shirty about downlighters in ceilings,
wanting fireproof boxes around them. If a lamp throws heat forwards
then the fire aspect should not be an issue.

Does anyone know what lamps are more safe than others in this respect?

I imagine that the LED downlighters which are a
direct replacement for GU10s would be the
coolest option, but you need more of them to get
the same amount of light.


http://www.electriclightcompany.co.u...mpany_LED_GU10
_Lamps_154.html

Al

Has anyone ever used these? Any reports? Light? Type of light? etc?



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