When I purchased this portable air conditioner I did not realize it was only for window mounting. And it is made to be fitted into a window that opens by sliding up and down not side to side. You need a drill to drill holes into the window frame to mount it. I don't have a drill or proper window to mount it so Incan't use it. I turned it on for the night sitting on top of my dresser in front of an open window and it did cool my room down and the humming noise I find soothing.