For bedrooms and specially dens, put an exhaust fan on the ceiling or wall farthest from the window. It will suck-in the cold air outside and keep the air inside the room fresh and cool. This can even save you electricity bills by not using your air conditioner during cool months.
The bedroom is your private space, among all rooms in your home, your bedroom's look and atmosphere should be the most relaxing and reflective of your personal taste and style.
