Heat sinks for LED downlighters?

Proposal is to insert LED downlighters into the kitchen ceiling (replacing old central lights). The attic is immediately above the ceiling with a good thickness of rockwool (c250mm).
LEDs are semiconductor devices, so are heat sinks required to control temperature rise?
ISTM that plasterboard is an unlikely heatsink. Also I'm uncertain about fire hoods are the answer. ISTM that a method of generating a flow of air is needed.
TIA for any suggestions.
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Is the attic floored with the rockwool on top ? If so, there will be spaces between the ceiling, the floorboards and the joists that will allow cooling air to rise through the lamp fittings. Make sure the fittings are of the type that allows air to rise through them. That's how I did my kitchen some years ago. I changed the original 33 watt flouro lamps with 12 watt LEDs last year, and no problems so far.
If however your rockwool is laid between the joists, just cut 10-12cm dia holes in it immediately above the lampholders.
Jim Hawkins
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Jim Hawkins wrote:

You might want to think a little more about the safety and legal consequences of breaching a fire barrier in this way.
Chris
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Thanks for raising the issue, Chris. Does this type of downlighter cause a significant breach of a fire barrier ?
Jim Hawkins
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On Wednesday, February 12, 2014 3:10:33 PM UTC, Jim Hawkins wrote:

Thanks for the replies

The bungalow roof is above the kitchen ceiling ie: plasterboard (12mm)(held up by joists) c.250mm of rockwool laid on the plasterboard big unusable void tiled conventional roof.
What my problem seems to boil down to is, how can the required cooling air flow be engineered whilst retaining an intact fire barrier (ie the ceiling)?
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On Wednesday, February 12, 2014 4:22:42 PM UTC, uncle snipped-for-privacy@hotmail.co.uk wrote:

I don't *think* there is any requirement to protect your roof from a fire in the kitchen (BICBW). If there was a bedroom above the kitchen, it would be rather different.
In other words, I don't think you need to retain an intact fire barrier.
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wrote:

Mine have an intumeniscent(sp) seal.
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wrote:

Well, I've heard it called some names !
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On Wed, 12 Feb 2014 21:07:23 -0000, "Jim Hawkins"

Intumescent (GIYF)

You must be thinking of something else. Try this link:
<http://en.wikipedia.org/wiki/Intumescent>
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On Thu, 13 Feb 2014 04:28:48 +0000, Johny B Good

Mine had to have intumescent 'hoods' to get through building regs approval. However they were all halogen bulbs then.
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Normally the temperature ranges for devices are quoted somewhere, so I'd be guided by those really. Brian
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