Downlighter city...

[rlc]

Morning all,

My task has been to connect something like 40 downlighers in various rooms throughout a new build - during lunch the boss informed me that he is getting a number of plasterboard boxes made to sit over the cans of the downlighters for the following reasons:

1. to prevent vapour entering the loft space and rotting the timbers

2. so the loft insulation can be laid over them.

now I'm no scientist, but there seems a couple of issues to me:

1. vapour ? - is this not just hot air

2. More importantly the thermal issue to consider - natural dissipation of the heat via the metal can is going to be considerably reduced and net effect will probably mean TTF of the lamps will be significantly reduced. The can of these lights is no totally sealed though they maintain 30 &60 min fire protection - there are a number of smalll'ish "10mm" holes in the top of the can. The downlighters are:

http://www.screwfix.com/search.do;j...FFY?_dyncharset=UTF-8&fh_search=25727&x=0&y=0

I was of the understanding that it is acceptable to cut-back?

Is there a regulation that clarifys the installation of downlighters and issues regarding coverings etc.

Is he right in his approach/solution?

Having seen this evolve I now agree downlighters aren't the way forward...

Thanks

 

[stem]

The installation will depend upon the design of the lights. Different manufacturers state different requirements, for example how far away insulation must be etc., To be honest though I've never installed any with the intumescent material and metal can.

The manufacturer is responsible for providing a safe product. What do the manufacturers instructions say?

 

[rlc]

from memory not a lot but I will check at the w/e to be 100% sure. From over hearing the discussion it came across that it was a _new_ regulation that the insulation in the loft space was continuous & needed to run over the top of the lights and therefore these "safety" boxes were required. Seemed to me that cut-back was not acceptable to them,

Is cut-back OK in your eyes?

 

[Adam_151]

I must admit to not having looked at the guidence to part L that closely, but from what I gather, installing 'holey' insulation wouldn't comply

I cannot really see any issues with the plasterboard boxes, as long as the guy who knocks these up is careful to check with the downlight instructions what the min clearances are (and adds a tad on to be on the safe side)

However a better solution would be to install different types of light fixture, and indeed you might find part L gets you on this anyway on the two many TH lamps and not enough CFL point (though I suppose you could be installing those new CFL downlights)

 

[DESL]

It's all a bit accademic at present as what will happen when filament lamps are phased out, which may be sooner than we think.

Any request I get to fit the dreaded downlighters I strongly recomend cfl versions especially as I see d/lighters as a very inefficient means of lighting but the customers think they look pretty!!

 

[dingbat]

I avoid fitting fire-hazards whenever possible.

The plasterboard box idea is a widely accepted method of reducing the multiple regulation-breaching effects of using downlighters.