Air tight Can Lights from below ceiling
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| Posted in Energy, Heating & Insulation on
I just installed 6″ IC23W Air-Loc Juno brand can light housings in our addition. I did not install a box in the attic around each can light to make it air tight, just blew fiberglass insulation over them. I plan on using LED lights/trims. Any suggestions on what type of trim to use to make them as air tight as possible? Would it be safe to add some foam between the drywall and the housing? Since I did not build a box around the housing I do not see why that would be a problem, plus the LED’s do not get that warm.
Replies
Those are incandescent rated cans so the next person to live in the house may rip out the LED trims and put incandescent bulbs in them. For that reason, I would not use foam as most of the foams are quite flammable.
You could use fire-block foam - not flammable until much higher temps. Or RTV silicone caulk.
Dow now makes a foam intended as an airtight drywall gasket- the day before the drywallers show up, you have to lay beads of it around all rough openings in the exterior walls, plus the top and bottom plates and all corner studs. It's a bit of a PITA, but no worse than other airtight drywall approaches. Might be more expensive. It's a urethane but it cures by drying out, not by incorporating moisture like other urethane foams, which is why you have to be a day ahead of the drywallers. The nice part is that it's VERY compressible- a 1/2" bead will easily compress to nearly zero, but will also spring back.
When I did my house, I used some wafer thin (less than 1/2") LEDs from Lithonia ( https://www.homedepot.com/p/Lithonia-Lighting-WF6-Ultra-Thin-Wafer-6-in-White-Dimmable-Integrated-LED-Recessed-Kit-WF6-LED-30K-MW-M6/301313819 ). They're air-tight, dimmable, IC & wet location rated, 1020 lumens, 36,000 hr. rating. 3000K, but I think there's a new version that has adjustable CCT. The 1/2" thickness means you can even install them in the drywall under a joist- they're held in place by spring loaded arms.
BUT, they don't have a seal between the drywall ceiling and the flange of the pancake, which is where the drywall gasket comes in- you just lay a 1/4" bead around the ceiling side of the flange (a day ahead of installation) and that gives you a gasketed joint.
After about 6 months, I'm pretty satisfied. I get some minor pop-corning sometimes, but I used cheap (Feit) dimmers from Costco, so that may be the cause.