Δαφνη Ευτυχια Αρθουρος

In the summertime, we have AC in our living room, but the living room doesn't have a closeable door so I got one of those spring tension rods and put it in the doorframe and took a lightweight blanket and safety pinned it to the rod (you could just use a curtain or even just a sheet, anything will help keep heat in one room and cold in the other.) I just close the curtain and it works to keep the cool in the room in the summer. We also don't have a guest bedroom, so when we have overnight guests they have to sleep on the sofa, it also provides a bit of privacy for them.
Spring tension rods work great for hanging a sheet or blanket (has to be sort of light weight since they don't support alot of weight) in a doorway.