Recessed Lighting / heat loss
New homeowner. I have 10 6″ prescolite IC non-airtight cans atop my 2nd floor going to my attic and 11 of the same IC non-airtight cans in cathedral ceilings going to the roof. They are square housings.
I have explored all the options. The attic is covered with I believe r-30 batts and about 12″ of blown-in cellulose on top of that. They put additional bats all around the fixtures like a moat but not on top of them — not sure why, since they are IC rated.
Access to the attic is very bad. Most of the fixtures abut joists and digging around the cellulose to build air-tight boxes is my last resort since I’d have to do a lot of custom cuts etc.
Commercial electric makes a gasketed led retrofit which they claim/certified airtight. I assume that will greatly cut down on air-flow to the attic? If I install those and add some insulation directly over the cans in the attic, is that a good solution for cutting air passage and bolstering insulation in those areas?
If I use those retrofits in the cathedral areas, since the retrofits are IC rated too, can I stuff some fiberglass into the old IC housings themselves before installing the retrokit or is that a no-no?
Lastly, I know there are a lot of factors at play here, but can anyone help ballpark for me annual heat loss costs per can in a situation like this? I’ve seen $5-30 per can per year. I’m in New England so winters are cold.