Recessed lighting in a sealed space
Planeman
| Posted in Construction Techniques on
I am installing recessed “can lights”, the IC type in a cathedral cieling. The ceiling is framed out of 2 x 10’s, 16″ OC with 1/2″ OSB roofing above and 5/8 drywall below and stuffed with R30 fiberglass batts. Even though I am using IC rated fixtures, I am worried about overheating with 75 watt bulbs in such a confined space. All of the literature that came with the lights says you can pack insulation around them, but it always shows them in a normal attic setting where the heat has someplace to go, not an enclosed space. Any input based on your experience or suggestions for other lighting would be appreciated.
Experienced, but still dangerous!
Replies
I'm in the same boat with can lights being installed with Icynene insulation sprayed around them. I have the same fire hazard concerns.
Thanks for any imput on this.
Rupert
The IC units have a little thermal switch inside of the canister top, right above the lamp. It will disconnect the circuit if the temp becomes excessive.
In a perfect world you wouldn't use incandescent lamps. Flourescent lamps would provide the same lumens with less heat. Consider doing that if you still can.
Otherwise use the right lamp. Reflector type lamps with the correct or less wattage will keep you from fire. The lensing or bezel around the lamp generally has a pretty open construction so the air can circulate. Consider underlamping.
I too have cathedral ceilings with fib batts R38 are available for a 12 inch cavity (10 inch actual loft of the batts.) The insulation it is a special cathedral ceiling product available from the insulation supplier (not HD or any other big box store).
You are using 2x10's? So... the insulation is 8"? or are you using the styrofoam channel product to keep the roof board bottom side ventilated. It would be better to under-insulate rather than rot your OSB with no ventilation. You can still fir down the 2x10's to give yourself room to insulate and ventilate.
Just make certain you keep the ventilation area, above the insulation, open.
Thanks for the input. The insulation is 8" thick, so I am maintaining a ventilation space between the insulation and the OSB. I will try going with a lower wattage lamp just for safety. I understand about the overheat protection with the IC lights. Thanks again. Experienced, but still dangerous!
What's you climate like? Recessed lights in a cathedral ceiling (and many other ceilings for that matter) can contribute to ice dam problems.
Al Mollitor, Sharon, MA
Southern California, The only ice I have to worry about with comes with a cool drink!Experienced, but still dangerous!