Passive cooling

Got a window that lets the hot sun in during the summer? Plant annual vines to shade it. It's still early enough in most parts to plant morning glories, black-eyed Susan vines, cup and saucer vines or a double duty vine like (edible) scarlet runner bean. You'll need to offer some support - a light wood or metal system of some kind, but that needn't be expensive if you make your own or creatively use old grills, stakes, etc. Plant the vine so that it will shade the window during the hottest part of the day and take into consideration the angle of the sunshine later in the year.