How do I improve the feng shui/ energy of this room?

My boyfriend has a work room that he uses for his school related stuff. Its on the side of the house. When in this room, I feel totally drained of energy and I feel depressed, which I find weird. He claims to feel the same way. I think it has a lot to do with the lay out and interior decoration of the room.

The walls are painted light blue. It has a fan. One window to see outside. It has one couch in the middle by the window. It has a TV cabinet (but no TV yet). It has a large table in the middle of the room. Tile floors, but a large carpet over it. A computer desk with a computer on it. One light stand. hmmmm….. what else… oh, and horrible grandma curtains.

The worst part is the fact that his parents smoke in a florida room that is next to this work room, and the smell permeates to his room, and makes it difficult to breath.

How do I help him improve this rooms feng shui, and thus improving his and I’s work energy while in there?