Exactly as promised
April 3, 2011
This housing looks to be nominally airtight, with tight-fitting seams. There is a gasket around the circular opening for the light that makes a good seal with the sheetrock. I use new construction fittings on remodels, and this housing can be installed from the attic if there is clearance above the ceiling. The center of the hole can be as little as 3.5 inches from a joist (3.25 inches with a bit of modification to the extending arms that span the joists). Installed, it is a bit higher than a 2x6, so plywood laid across joists to facilitate access might accidentally rest on one of these fixtures.
Pros:Airtight, IC rated, can be installed fairly close to a joist.
Cons:Some modification required to get the center of the hole to 3.25 inches from a joist.