This video from green homes america provides a good overview of the air leakage issue with recessed lights and shows an actual top hat installation.
Insulation around recessed ceiling lights.
How to insulate around can lights.
The recessed lights in my house are accessible from the attic but there s no insulation around them because it says on the fixtures that they need to vent the heat generated by incandescent bulbs.
If i replace those bulbs with leds will that reduce the heat enough so i can insulate around the existing lighting cans.
The letters ic stand.