put your vent in a piece of plywood, and paint the whole thing black. put the piece of plywood over the window, black side out. leave the blinds (or put some blinds) between the window and the plywood. use tape (duct or aluminum) to seal up any light leaks.

from the inside the room will appear empty. don't forget a carbon scurbber if you are going to exhaust this way. you might be better off pulling in fresh air and exhausting somewhere else.


-shake