Recessed lighting units

[nearlythere]

I have a new client who had a nice new 1hr plasterboard ceiling until an idiot of a spark came along and put a warehouse full of recessed light units in it. I recall seeing one time a FR guard or box that can be used to enclose the back of a light units. Anyone come across or have any knowledge of such a thing?

[Owain]

I have a new client who had a nice new 1hr plasterboard ceiling until an idiot of a spark came along and put a warehouse full of recessed light units in it. I recall seeing one time a FR guard or box that can be used to enclose the back of a light units. Anyone come across or have any knowledge of such a thing?

downlighter fire hood

http://www.screwfix.com/c/electrical-lighting/downlight-fire-hood/cat840954

http://www.tlc-direct.co.uk/Main_Index/Lighting_Menu_Index/Lighting_Downlights_Index/Fire_Cover_Downlight/index.html

Quality and approval certificates may vary but in general they're widely available.

[wee brian]

but check that the light fitting is compatible - it would be a shame if it overheated and caught fire

[Firescot]

I recently inspected a hotel that had these all over the place.

They were halogen recessed down lighters. An electrician recently inspected about 20% of them.

He found that they were connected to solenoids and were made in China.

Five of the solenoids, (which had plastic covers) were melted through due to overheating.

It is going to cost the Duty Holder a fortune to have them all inspected and/or replaced, as well as paying for fire covers on them in the areas where the ceiling is required for fire protection!

[kurnal]

There are two types of bulbs used, dichroic bulbs have a special reflector in the bulb that reflects the light downwards and allows the heat to rise upwards. These are generally unsuitable for use in ceilings in conjunction with hoods as most of the heat is projected upwards into the base of the fitting The beam is cooler but the back of the fitting has to withstand a great amount of heat.  The bulbholders that cannot safely use such a bulb are labelled with the IEC 605598 "No Cool Beam" symbol. For these fittings you need a bulb with a conventional aluminium reflector, that projects both light and heat forward. in the 240 volt range, GU10 bulbs generally reflect the heat downwards, GZ10 bulbs are dichroic and the fitting needs to be able to cope with the heat that these bulbs create.

[Mr. P]

Alot are also used in domestic dwellings and, when fitted in rooms above 1st floor ie bedrooms, they then get covered over by the insulation in the loft...

[Fishy]

In all likelihood the ceiling itself won't be 60 mins F/R - it'll contribute to the fire resistance of a floor.  For this reason the downlighters sometimes aren't as much of an issue as people think - see http://electrical.theiet.org/wiring-matters/14b/recessed-luminaires.cfm .  Also less of an issue with BS 476: Part 23 ceilings (i.e. protecting structural steelwork) than BS 476: Part 21 ceilings (fire separating).

If you do conclude that upgrading is required, then you can buy down-lighters that are inherently F/R and which don't therefore need hoods.  I don't think they're particularly expensive so replacement, rather than protection, might be the best option.

[wee brian]

use LEDs they are very efficient and dont get very hot