I know there are different size cans- 3, 4,5. Any advice as to what I should consider for the size? Is it more aesthetics than anything? I am assuming smaller cans will allow for less heat loss.
Are costs all comparable?
Can sizes range from 2" to 6". The costs increase when the size decreases for a number of reasons.
1. The smaller cans could contain a low voltage power supply.
2. The smaller cans could utilize MR16 reflector bulbs which cost more.
Cans today could be rated as Air-tite and for direct contract with insulation which helps minimize heat loss/ gain.
There is more info on the link below
Here is a link that might be useful: LED recessed lighting