To add to what has been written, IC rated cans can be found at most retail stores, including the Home Depot and Lowes big box stores. The 3″ size may mean you need to purchase over the Web to get a proper selection based on your cosmetic needs (baffles, angled, light type, etc.). IC-rated cans are superior because the lost heat will be somewhat retained due to the surrounding insulation.

There are also high-efficiency IC cans, called AIR-TITE, which are a great purchase. An IC-rated can loses an unbelievable of heat, and the AIR-TITE prevents a large part of this heat transfer (keeping the heat in your home).

The use of CF bulbs will reduce the heat output of the bulb, gaining energy efficiency during the summer (beyond the other advantages). However, CF bulbs are hard to find for 3″ sizes. You could consider Energy Star rated cans, which have a special type of CF bulb. This raises the cost.

There are some LED options available, including in 3″ sizes, but this is a developing technology. Unless there are showrooms in your area, you would be taking chances on the light quality and luminance/warmth type.

Halo (a Cooper brand) makes some recessed lighting housings that can be installed within insulation. On the source page below check out the descriptions on the boxier looking housings.

The second link is the where to purchase page that will help you find an authorized distributor.

Hope this helps and good luck with the remodel!

You need to find cans that are IC Rated cans.If Home Depot doesn’t have any try calling a electrial supply house.