Can I put a window air conditioner in without screwing it in?
Well, duct taping it in to get a seal would work, but you don’t want to leave it just wedged in there, not safe. i would screw it in to be safe, the duct tape seals well against draft, but it’s a lot more work to scrub the gummy adhesive off, than to putty 4 small holes, pre-drill the holes with a slightly smaller drill bit to prevent the window sash splitting, i would use 1 1/4 inch flat headed course thread phillips (x -head) screws, just long enough to really hold, too short to come out the back of the sash, and small shank, so small hole to fill.
