Thermal for sure. I use these in a doorway of a room within a room made of unframed, taped together walls and ceiling of insulating wallboard. It is inside an unventilated garage in hot sunny CA! It is unbearable to be in that garage. BUT, we put a little room a/c inside and the room is frigid in minutes and stays cool even right up by the curtains. PLUS they are sharp, pretty and full of ambiance. the cat, serendipitously looks JUST like the beloved cat of the man for whom the room was built. It houses a sofa and all of his books! The gothic window and books were a perfect image. The prices was reasonable and I am just delighted with the product. Well made, strong, pretty, functional. I will buy other images of these sometime for other rooms.