I don't know if hanging sheets ect up helps keep energy costs down but a friend of mine when she lived in a mobile home they cut off the kitchen that way & you could feel the difference between the kitchen & living room. we did that last year on a northern window, because of the north winds being so awful & having a window a/c unit that was sealed in. Otherwise no one would/could sit there w/out a chill
we still need to get the plastic up on the big window. The joys of an older "fixer upper" & a single income, updating takes a while. Unless we win the lottery or something
Cercis - now if you could get that thru my dh's head to clean that vent tube out!