Originally Posted by
Jim Robinson
I saw somewhere a good article on making an insulation box out of 2" styrofoam to place on top of a Non-IC light can. It would stop air infiltration, but still allow 3" of air space around the light fixture. Does anyone have a web link to something like that? I've been Googling for a while, and I can't seem to find it.
That won't work as the insulation needs to be kept 3" back from the recessed light fixture ... with the top above the light fixture left open so the heat from the recessed light can escape.
You now have a huge hole in your insulated ceiling, and those recessed housings are also not 'air tight' type housings.
That (making a box with drywall) was the first thing people did when those codes came into effect, but as soon as we started doing that, we realized the tops has to be open, so we started putting screen on top to keep the insulation out and still allow the heat to ventilate up, but soon realized that the screen just allowed the blown in insulation to pile up on the screen, making the net effect for ventilating out the heat from the recessed light a big fat -0-.
The first insulated ceiling lights were TC type, with a thermo couple which would turn the lights off when they over heated, of course, though, people did not like their recessed lights turning off, then coming back on later (big Duh! here), so IC lights came out which effectively used derated wattages to reduce the heat build up in the recessed fixture to make them safe for installation in insulated ceilings.
Then, around 1996-97 or so one recessed light manufacturer started promoting their recessed lights and that they were 'air tight type', which, of course, made all (at least most) inspectors aware of 'Oh, yeah, that's been in the energy codes since way back when they came out in 1983 (Florida Energy Code anyway), so 'non-air tight type' recessed lights were no longer allowed, which made all of the other manufacturers jump and start making 'air tight type' recessed lights real quick like.
But, getting back to the box made of insulation ... all that will do is trap heat into the light and raise the possibility of fire to a higher level.