My bedroom is upstairs in the attic and much of the interior walls/ceiling are the underside of the roof.
I believe there is a couple inches of hard foam between the drywall and the sheathing/roofing. The walls/ceiling of the room can get quite warm in the summer as the sun beats down on the dark asphalt tiles outside.
I'm trying to size an AC for the room, but see that most ACs suggest a square footage rule of thumb. I presume this square footage assumes a more typical mix of interior/exterior walls.
Is it worth considering my situation differently than just buying the AC that matches my room's square footage?